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aquaJournal of Ichthyology and Aquatic

BiologyVol. 5 (1), November 2001

AquapressISSN

0945-9871

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Chem Yi-yu, Institute of Hydrobiology, Academia Sinica,Wuhan Hubei, P. R. China

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aqua is an international journal which publishes originalscientific articles in the fields of systematics, taxonomy,bio geography, ethology, ecology, and general biology offishes, amphibians, aquatic invertebrates, and plants.Papers on freshwater, brackish, and marine organismswill be considered. aqua is fully refereed and aims atpublishing manuscripts within 2-4 months of acceptance.With the pub li cation of aqua we are pursuing a new con-cept: In view of the importance of colour patterns inspecies identi fication and animal ethology, authors areencouraged to submit colour illustrations as well asdescriptions of coloration. It is our aim to provide the international scientific community with an efficientlypublished series meeting high scientific and technicalstandards.

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ISSN 0945-9871Publisher: Aquapress, Redazione aqua, I-27010 Miradolo Terme (Pavia), ItalyPrinter: Grafiche Dessi s.r.l., ItalyTypesetting: Rossella Bulla© 2001 aqua, Journal of Ichthyology and Aquatic Biology

aqua - Journal of Ichthyology and Aquatic Biology

aqua vol. 5 no. 1 - 20011

aqua, Journal of Ichthyology and Aquatic Biology

Food Resource and Habitat Sharing by the Three Western South AtlanticSurgeonfishes (Teleostei: Acanthuridae: Acanthurus) off Paraíba Coast,

North-eastern Brazil

Thelma L. P. Dias1, Ierecê L. Rosa2 & Bertran M. Feitoza3

Universidade Federal da Paraíba, CCEN, Departamento de Sistemática e Ecologia, Campus I, João Pessoa, Paraíba, Brasil, 58059-900.

E-mails: 1) [email protected]; 2) [email protected]; 3) [email protected]

Accepted: 28.09. 2001

KeywordsDiet, feeding behaviour, reef fishes, Acanthurus,

western South Atlantic, North-eastern Brazil, naturalreefs, shipwrecks.

AbstractDiet and feeding behaviour of the three western

South Atlantic acanthurids (Acanthurus bahianus, A.chirurgus, and A. coeruleus) were analysed, based onstomach contents analysis and underwater observ -ations. Data were obtained at three natural reefs andtwo shipwrecks along the coast of Paraíba State, NEBrazil. The results of Schoener’s Index suggest thatdietary overlap was not significant between speciespairs; however, some degree of microhabitat segrega-tion was observed. Juveniles of A. bahianus and A.chirurgus formed feeding aggregations, whereas juve-niles of A. coeruleus foraged solitarily. Adults of thethree studied species formed intra- or interspecificfeeding groups. Following behaviour was observedbetween acanthurids and Halichoeres spp., Pseu du -peneus maculatus, and Sparisoma spp.

ZusammenfassungNahrung und Fressverhalten wurden anhand von

Mageninhalt-Analysen und Unterwasserbeobach t -ung en an drei Acanthuriden (Acanthurus bahianus, A.chirurgus und A. coeruleus) aus dem westlichenSüdatlantik untersucht. Die Daten wurden an dreinatürlichen Riffen sowie an zwei Schiffwracks gesam-melt, entlang der Küste vom State Paraíbo, NO-Brasilien. Die Ergebnis e, auf Schöners Index ausgew-ertet, zeigen an dass Nahr ungsüberschneidung unterArtpaaren nicht von Bedeutung war; jedoch es wurdeein gewisser Grad von Mikro-Habitatunterteilungbeobachtet. Jung tiere von A. bahianus and A. chirur-gus bildeten Fütterungsgruppen, währ end junge A.coeruleus als Ein zelgänger fraßen. Adulte Exemplareder untersuchten Arten bildeten intra- oder interspez-ifische Fressgruppen. Nachfolgeverhalten wurde unterAcanthuriden und Halichoeres-Arten, Pseudo peneusmaculatus und Sparisoma-Arten beobachtet.

Résumé

Le régime et le comportement alimentaires ont étéanalysés chez trois acanthurides de l’Atlantique du Sud-Ouest (Acanthurus bahianus, A. chirurgus and A.coeruleus), grâce á l’examen du contenu stomacal etd’observations en plongée. Les données ont été recueil-lies sur trois récifs naturels et deux épaves le long de lacôte de l’état de Paraiba, nord-est du Brésil. Les résul-tats de l’index de Schoener suggèrent que le chevau -chement des régimes alimentaires entre paires d’espè -ces n’est pas significatif; toutefois, un certain degré deségrégation par microhabitat a pu être observé. Lesjeunes de A. bahianus et de A. chirurgus fourragent encom mun, cependant que les jeunes de A. coeruleuss’alimentent solitairement. Les adultes des trois espècasobservées forment des groupes d’alimentation intra- etinterspécifiques. Un comportement d’accompagnementa été noté entre les acanthurides et Halichoeres spp.,Pseudopeneus maculatus and Sparisoma spp.

SommarioSulla base del contenuto intestinale e di osserva zioni

subacquee, vengono analizzate la dieta e le abitudini ali-mentari di tre specie di pesci chirurgo dell’Atlanticosudoccidentale (Acanthurus bahianus, A. chirurgus, e A.coeruleus). I dati sono stati raccolti nei pressi di tre bar-riere naturali e di due relitti sommersi, lungo la costadello Stato di Paraiba, nel Brasile nord-orientale. Il cal-colo dell’indice di Schoener mostra che non c’è una sig-nificativa sovrapposizione alimentare tra le specie. Sonostati tuttavia osservati fenomeni di segregazione dimicrohabitat. Durante la ricerca del cibo, gli individui gio-vani di A. bahianus e A. chirurgus si uniscono in grup pi,mentre quelli di A. coeruleus hanno abitudini so li tarie. Gliadulti di tutte e tre le specie formano invece gruppi intra-e interspecifici. Sono state inoltre osservate associazionialimentari con alcune specie dei generi Ha lichoeres eSparisoma e con Pseudupeneus maculatus.

IntroductionAmong reef fishes, surgeonfishes constitute a vis -

ually important group in tropical reefs (Alevizon, 1994)and represent, among herbivore fishes, an ecologic -ally and evolutionarily important component of tropical

aqua vol. 5 no. 1 - 2001 2

Food Resource and Habitat Sharing by the Three Western South Atlantic Surgeonfishes (Teleostei: Acanthuridae: Acanthurus)

reef communities (Randall, 1965). Together withparrotfishes they constitute the largest and mostmobile group of herbivore reef fishes which contributeto the transport of large amounts of inorganic nitro-gen, thus having an important role in the nutrientregeneration and cycling (Duarte & Acero, 1988).

In Brazil, surgeonfishes are visually striking reeffishes and are subject to commercial exploitation atvarious localities, chiefly as juveniles for the aquariumtrade, and more rarely as adults for human consump-tion. Despite this, they remain virtually unstudied inBrazil, except for the work by Ferreira et al. (1998) onseasonal grazing rates and food processing inAcanthurus bahianus.

This paper compares the feeding habits, diet, andfeeding behaviour of the three species of surgeonfishesfound in the western South Atlantic - Acanthuruscoeruleus Bloch & Schneider, 1801, A. chirurgus(Bloch, 1787), and A. bahianus Castelnau, 1855. Thethree species were chosen for the following reasons:they are all diurnal (Randall, 1967) and exhibit similarfeeding strategies that could lead to competition notonly for food but also for space (Duarte & Acero, 1988).Additionally, acanthurids constitute the most abundantfish family at the reefs of Paraíba State (Rocha et al.,1998), thus baseline data on these taxa could be usedfor monitoring the reefs in the study area.

Materials And MethodsStudy sites:

The study was carried out along the coast of ParaíbaState, NE Brazil (Fig. 1), at three natural reefs (Poço,Picãozinho, and Areia Vermelha) and two shipwrecks(Queimado and Alice) (Fig. 1, Table I), which wereconsidered as artificial reefs following the terminology

adopted by Potts & Hulbert (1994).Collections and stomach contents analyses:

Collections were made monthly from April 1998 toNovember 1999 (except June, July, and August, rainymonths with low visibility). A total of 209 specimenswere captured with spear gun or dip net (juveniles< 6 cm), and placed in ice to interrupt the digestiveprocess by thermal shock, following Aguiar &Filomeno (1995). Collections and observations at thenatural reefs were made through snorkelling, and atthe artificial reefs through SCUBA dives. All speci-mens were measured (standard length - SL and totallength - TL, in mm) and weighed (g) prior to analysis.Total length of examined specimens ranged from 38to 192 (A. bahianus), 32 to 229 (A. chirurgus) and 54to 262 (A. coeruleus). Stomachs were preserved in4% formalin. Field observations were made to char-acterise each studied locality (Table I). Voucher speci -mens were deposited in the fish collection at the Uni-versidade Federal da Paraíba, Brazil (UFPB).

Food items were weighed, and identified based onliterature (Joly, 1967; Littler et al., 1989) and with theaid of specialists. Scientific names for algae followWynne (1998). Stomach contents were analysedusing the Frequency of Occurrence and Gravimetricmethods, both as revised by Hyslop (1980) andMarrero (1994).

The results of the two analyses were combined intothe Index of Relative Importance (IRI of Pinkas et al.(1971), modified by Pérez-España & Abitia-Cárdenas(1996). In our study, intersections (abundance value%) were replaced by weight (%) as follows:

IRI = %P X %F100

where F = frequency of occurrence (expressed aspercentage %) and P = weight (%) of the item.

The Shannon-Wiener diversity index (H’) was usedto assess dietary diversity and evenness for eachspecies (Ludwig & Reynolds, 1988). Wet weight wasused as a proxy for volume. The overlap among dietsof surgeonfishes was determined using Schoener’s(1986) index (D), as follows:

D = 1-0.5 ∑ | Pxi - Pyi |

where Pxi is proportional weight of alimentary com -ponent i in the species X, and Pyi is proportionalweight of alimentary component i in the species Y.This overlap index varies from 0, when the twospecies use totally different resources, to 1, when theyuse the same food categories in the same propor-tions. According to Keast (1978), an overlap equal toor above 0.6 is considered significant.Feeding Behaviour:

Feeding behaviour was recorded at the five studysites through ad libitum observations, following Lehner(1979), totalling nine hours of observations per species.Fig. 1. Map of Paraíba State coast showing study sites.

Behaviours were recorded on an underwater slate, andfeeding strategies were photo graphed. Special atten-tion was given to foraging behaviour, feeding aggrega-tions, and use of space during feeding.

ResultsFood items consumed by A. bahianus, A. chirurgus,

and A. coeruleus, as well as IRI results, are given inTable II. Of the 27 species of algae identified, 12 wereconsumed by the three species, but there were differ-ences in the amount consumed by each. There werealso differences in the number of species and theamount of algae consumed per locality. Regarding thenumber of items consumed, A. coeruleus had the mostdiversified diet, utilising 34 items, whereas A. chirurgusconsumed 22 items and A. bahianus 18. According toIRI, the most important alga ingested at the natural reefsby A. chirurgus, A. bahianus, and A. coeruleus was thebrown alga Hypnea musciformis. However, overall themost important item ingested by A. chirurgus was theorganic material presumed to be present in the ingestedsediment (Fig. 2).

At the shipwrecks, A. chirurgus and A. bahianus mos -

tly consumed Osmundaria obtusiloba and A. coeruleusmainly utilised H. musciformis. Contents of sedimentwas also an important component of the diet of A. bahi-anus and A. chirurgus at the shipwrecks (Fig. 3).

In terms of dietary diversity, A. coeruleus attainedthe greatest diversity, both at natural and artificialreefs (natural reefs, H’ = 2.03; shipwrecks, H’ = 1.77).At natural reefs, A. bahianus had a lower dietary diver-sity (H’ = 1.19) than A. chirurgus (H’ = 1.48), the oppo-site occurring at the shipwrecks, where A. bahianushad a greater dietary diversity (H’ = 1.33) than A. chirurgus (H’ = 1.05). At the natural reefs, A. coeruleus showed the greatest dietary evenness (E = 0 .67) followed by A. chirurgus (E = 0.52) and A. bahianus (E = 0.48). A. bahianus had the greatestdietary evenness at shipwrecks (E = 0.82), followedby A. coeruleus (E = 0.60) and A. chirurgus (E = 0.51).

Although the three species consumed large num-bers of common items (mainly algae), both at naturalreefs and shipwrecks, according to Schoner's Indexdietary overlap was not significant within any speciespairs (D<0.6) (Table III). However, between A. coeruleus and A. chirurgus Schoener’s Index value

aqua vol. 5 no. 1 - 20013

Thelma L. P. Dias, Ierecê L. Rosa & Bertran M. Feitoza

Locality Depth Number of Characteristics(m) specimens

Poço reef 0.5-2.5 AB = 04ACH = 30

S 07°01' ACO = 18 W 34°48'

Picãozinho 0.3-4.5 AB = 15reef ACH = 24

ACO = 16S 07°07'W 34°48'

Areia 0.5-2.5 AB = 15Vermelha ACH = 19reef ACO = 09

S 07°01'W 34°49'

Queimado 9-18 AB = 11wreck ACH = 05

ACO = 09S 07°05'W 34°44'

Alice 7-12 AB = 05wreck ACH = 14

ACO = 13S 07°03'W 34°43'

Exposed portion during low tide covered by Caulerpa racemosa. Internal pools withmarked growth of Gracilaria cervicornis, Caulerpa racemosa, and Halimeda opuntia.Dictyota spp. and Dictyopteris spp. were also found. Upper portions of the pools facingthe continent with marked growth of Caulerpa racemosa and Halimeda opuntia. Por-tions closer to the bottom with Gracilaria cervicornis, Sargassum sp., and Lobophoravariegata. In areas with sandy bottoms the main algae were Penicillus capitatus andUdotea flabellum. In sheltered areas and in crevices the most abundant alga was Gelid-ium sp. Main coral species: Siderastrea stellata, Montastrea cavernosa, and Milleporaalcicornis. Bottom: chiefly calcareous rubble (Halimeda and fragments of gastropodshells). Use of the area: small-scale fishing and tourism.

Internal pools with marked growth of Sargassum sp., Halimeda opuntia, and Dicty-opteris spp. Pools connected to the sea with a predominance of Halimeda opuntia, Dic-tyopteris spp., and Dictyota spp. Reef front mainly with Caulerpa racemosa and Hal-imeda opuntia. Main coral species: Siderastrea stellata, Mussimilia hartii, M. hispida,and Millepora alcicornis. Bottom: calcareous rubble (Halimeda) in the internal pools andfine-grained sediment in open and deeper areas. Use of the area: small-scale fisheryand intense tourism.

Pools facing the continent with abundance of Hypnea musciformis, and also Acanth -ophora spicifera, Padina sp., and Sargassum sp. Pools connected to the sea mainly withGracilaria cervicornis and Ochtodes secundiramea. Main coral species: Siderastreastellata, Millepora alcicornis, and Montastrea cavernosa. Bottom: sandy (fragments ofgastropod shells and of Foraminifera). Use of the area: intense tourism and small-scaleand recreational fisheries.

Bottom formed by pebbles covered by Osmundaria obtusiloba, Bryothamnion tri-quetrum, and Lobophora variegata. Wrecks covered by Bryopsis pennata. Presence ofdrifting Caulerpa racemosa, C. mexicana, C. cupressoides, C. prolifera, Dictyota spp.,Dictyopteris spp., and Hypnea musciformis. Use of the areas: small-scale fishery,tourism (SCUBA diving), and spearfishing.

Table I. Characteristics of the study sites, and number of specimens captured per locality. AB = Acanthurus bahianus;ACH = Acanthurus chirurgus,and ACO = Acanthurus coeruleus.

was near to significant (D = 0.59), suggesting somedegree of dietary overlap.

A. bahianus usually exploited algae located on thelateral walls of the natural reefs, only occasionallyfeeding near the substrate, in areas where the bottomwas covered by algae (Fig. 4).

At the artificial reefs, where algal growth was mostlylimited to the small rocks surrounding the wrecks, A.bahianus (as well as A. chirurgus and A. coeruleus) wasseen feeding either on the algae attached to the rocks(Fig. 5), or, more rarely, on drifting algae. A. chirurgussearched for food both in the water column (up to about10 cm below the surface) and on the bottom (Fig. 6, a-b), and was also seen consuming drifting algae.

A. coeruleus fed mostly on the apical portions of thealgae located on the upper portions of the lateral walls

of the reef. On one occasion one specimen was seenfeeding on the bottom, where one specimen of A.chirurgus was also found. The A. chirurgus reactedaggressively to the presence of the intruder, andchased it away. We also occasionally observed sol -itary juvenile specimens of A. coeruleus foraging withA. bahianus and A. chirurgus (Fig. 7).

A. bahianus formed feeding aggregations both at thenatural reefs and shipwrecks; however, at the naturalreefs juveniles and adults seemed to be spatially seg-regated, with the former occupying the shallowerpools, and the latter utilising the deeper pools or thereef front. Occasionally adults were seen in the shallow pools, but they did not form aggregations.

In all aggregations of juveniles of A. bahianus, aswell as those of young A. chirurgus, or in mixed aggre-

aqua vol. 5 no. 1 - 2001 4


Species A. bahianus A. chirurgus A. coeruleus

NR SW NR SW NR SW

Division RhodophytaAcanthophora spicifera 0.321 0.004 0.268Botryocladia occidentalis 0.004 0.032 <0.001Bryothamnion seaforthii <0.001 0.081 0.004 0.198Bryothamnion triquetrum 0.017 0.006 14.210Ceramium sp. <0.001 0.010Corallinaceae <0.001 <0.001 0.012 0.117Cryptonemia crenulata <0.001 0.010 0.031Gelidiella sp. 0.005Gelidium sp. 0.003 0.695Gracilaria caudata 0.049 <0.001 0.027Gracilaria cervicornis 1.309 1.351 3.756Gracilaria sp. 1.149 8.544 0.093 4.490 0.197 1.007Hypnea musciformis 37.866 5.075 0.123 10.112 15.424Osmundaria obtusiloba 14.825 5.411 <0.001 8.588Unidentified Rhodophyta 0.217 0.005 0.012 0.037 0.439

Division PhaeophytaDictyota sp. 0.063 <0.001 0.057 1.015 0.560Dictyopteris sp. 0.009 0.021 3.436Lobophora variegata 0.003 0.015 0.126Spatoglossum schoederi 0.024

Division ChlorophytaBryopsis pennata <0.001 <0.001Caulerpa cupressoides 0.312Caulerpa mexicana 0.072 0.026Caulerpa prolifera 0.158Caulerpa racemosa 0.667 0.342 5.067Caulerpa sertularioides <0.001Udotea flabellum <0.001Unidentified Chlorophyta <0.001 <0.001 0.003

Diatoms <0.001Phylum Porifera <0.001Phylum Cnidaria

Class Hydrozoa <0.001 <0.001 0.004 0.005Phylum Mollusca

Class Gastropoda 0.065 <0.001Phylum Arthropoda

Class Crustacea (fragment) <0.001 Silt 0.062 <0.001Unidentified Vegetable Organic Matter 0.383 3.123 0.028 0.578 0.155 1.477Sediment 0.654 8.905 18.508 36.356 0.023

Total Number of Items Ingested 15 6 20 9 27 22

Table II. Food items consumed by A. bahianus, A. chirurgus, and A. coeruleus at natural reefs (NR) and shipwrecks (SW),as expressed by the IRI.

chirurgus, A. bahianus, Spar isoma axillare (Scar idae)Halichoeres brasiliensis, and H. maculipinna (Labri-dae).

No solitary juveniles of A. bahianus were seen, andgroups of juveniles were mostly found in depths ofless than 1 m. On the other hand, adult specimens ofA. bahianus were seen either solitary or in schools,usually in areas deeper than 1 m. At the shipwrecks,A. bahianus was frequently seen feeding in conspec -ific schools and also forming feeding aggregationswith A. chirurgus, S. axillare, H. brasiliensis, H. mac-ulipinna, H. bivittatus, and Pseudupeneus maculatus(Mullidae). On various occasions, while specimens of

gations of young of both species, we observed at leastone specimen of parrotfish (Sparisoma radians or S.axillare) (Fig. 8) feeding with the surgeonfishes. AtPicãozinho reef, on one occasion we sighted a rela-tively large school (approximately 100 specimens) ofyoung A. bahianus (average size about 50 mm TL).The individuals grazed repeatedly, but not in a syn-chronous way, as they swam over areas occupied bythe damselfish Stegastes fuscus (Pomacentr idae).The damselfishes attacked the passing school, whichin turn avoided the attack by temporarily splitting upand then moving away from the territory. We alsosighted heterospecific feeding groups formed by A.

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Fig. 2. IRI values of Acanthurus bahianus (a),A. chirurgus (b), and A. coeruleus (c) at natural reefs.

Fig. 3. IRI values of Acanthurus bahianus (a),A. chirurgus (b), and A. coeruleus (c) at shipwrecks.

P. maculatus probed the substrate with their barbels,A. bahianus and A. chirurgus fed on the turned-overmaterial. During this feeding interaction, P. maculatusexhibited a red coloration resembling that of the sub-strate, and after cessation of the behaviour it resumedits usual whitish background coloration with longitud -inal black spots. Both juveniles and adults of A. chirur-gus formed feeding aggregations at the natural reefs,as well as mixed schools with Abudefduf saxatilis(Pomacentridae), S. axillare, and Halichoeres spp.

Young specimens of A. chirurgus fed on algaelocated on the top of the reef, whereas adults wereusually found in depths greater than 1 m. Specimenslarger than 20 cm TL were solitary whenever found indepths of less than 1 m (Fig. 9). At the shipwrecks,individuals of A. chirurgus larger than 6 cm TL formedmixed schools with A. bahianus, whereas smallerindividuals formed only conspecific schools.

Contrary to the pattern observed in A. bahianus and

aqua vol. 5 no. 1 - 2001 6


Fig. 4. Juvenile Acanthurus bahianus swimming over analgae-covered bottom at Areia Vermelha reef, Paraíba,Brazil. Note the presence of one specimen of parrotfish(Sparisoma axillare). Photo by B. M. Feitoza.

Fig. 5. Adult Acanthurus bahianus feeding on algaeattached to the rocks at Queimado wreck, Paraíba,Brazil. Photo by B. M. Feitoza.

Fig. 7. Solitary juvenile Acanthurus coeruleus foragingwith juvenile A. bahianus and A. chirurgus at Picãozinhoreef, Paraíba, Brazil. Photo by B. M. Feitoza.

Fig. 6. (a) Foraging group of Acanthurus chirurgus feeding on substrate at Picãozinho reef, Paraíba, Brazil; (b) Solitaryadult of Acanthurus chirurgus feeding on hard substrate at Picãozinho reef, Paraíba, Brazil. Photos by B. M. Feitoza.

a b

A. chirurgus, juveniles of A. coeruleus were not seenforming feeding aggregations, either at the naturalreefs or at the shipwrecks. The few juveniles sightedwere solitary and occupied shallow and isolatedpools, generally in areas close to crevices wherethese individuals could take refuge (Fig. 10). Interest-ingly, many individuals larger than 100 mm TL seenat the shipwrecks retained the juvenile-phase colourpattern (completely yellow or blue body with yellowtail). At both natural and artificial reefs, adults of A.coeruleus formed large schools (with about 30 indiv -iduals) which were commonly seen feeding on thenatural reef walls, or around the wrecks. Schools were

generally monospecific, however mixed schools of A.coeruleus, A. chirurgus, and A. bahianus were alsooccasionally observed.

Our data indicate that red algae predominated in thediet of the basically herbivorous A. coeruleus, andalso constituted an important component of the diet ofA. bahianus and A. chirurgus. According to Duarte &Acero (1988), the last-named two species are consid-ered to be omnivores that supplement a herbivorousdiet with detritus and the microfauna associated withthe benthos, and in captivity can even become carni-vores. It is known that herbivorous fishes have a highrate of food ingestion but a low assimilation rate (Ogden

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Fig. 10. Solitary juvenile of Acanthurus coeruleus neara crevice at Picãozinho reef, Paraíba, Brazil. Photo by B. M. Feitoza.

Fig. 9. Solitary adult of Acanthurus chirurgus in a shallow pool at Picãozinho reef, Paraíba, Brazil.Photo by B. M. Feitoza.

Fig. 8. Mixed foraging group of juvenile Acanthurus bahianus and A. chirurgus feeding on Dictyopteris sp. in the upperportions of the Picãozinho reef, Paraíba, Brazil. Note one juvenile specimen of parrotfish on lefthand side. Photo by B. M. Feitoza.

& Lobel, 1978). This could lead some species, as in thecase of A. bahianus and A. chirurgus, to seek alterna-tive food sources such as sediment, which, as pointedout by Duarte & Acero (1988), may contain a rich inter-stitial community.

Previous work on the feeding habits of acanthurids (egRandall, 1967; Clavijo, 1974; Duarte & Acero, 1988)noted a greater dietary similarity between A. bahianusand A. chirurgus than between either species and A.coeruleus. This similarity was associated by Clavijo(1974) with a relatively greater similarity in the morpho -logy of their branchial arches and pharyngeal teeth, andin the stomach wall. Randall (1967), Clavijo (1974),Duarte & Acero (1988), and Bölhke & Chaplin (1993)remarked that A. bahianus and A. chirurgus have athicker-walled stomach, adapted to the consumption offine sedimentary particles, organic debris, and filament -ous algae, whereas A. coeruleus possesses a thin-walled stomach and seems to be best adapted to pro-cessing filamentous algae and harder plants. Based onthese observations, Duarte & Acero (1988) hypothe-sised that A. chirurgus and A. bahianus (but not A.coeruleus) shared a common niche, and indicated that,as the food items eaten by A. chirurgus, A. bahianus, andA. coeruleus were close to one another, the threespecies would compete not only for food but also forspace.

In our study, despite the observed similarities in termsof feeding habits and of food items consumed by thethree acanthurids, the overall feeding niche overlapwas low and not significant (D < 0.6), and this could beseen as an indication of low competition. However, theobserved lack of dietary overlap could be a conse-quence of Schoener’s index placing a strongeremphas is on the proportional weight of the items thanon their occurrence in the diet, and does not necessar-ily provide evidence for food resource segregation. Fur-thermore, as mentioned by Clavijo (1974), it is probablethat A. bahianus, A. chirurgus, and A. coeruleus main-tain their identities as different species because of sub-tle differences in other aspects of their biology.

Regarding space utilisation, a possible segregationwas observed in the distinct food-search patterns of thethree species. In the case of A. bahianus and A. chirurgus, although they ingested relatively largeamounts of sedimentary material, few individuals of theformer species were seen feeding directly on the sub-strate, suggesting that in A. bahianus sedimentarymaterial was obtained mainly from the ingested algae

rather than from the reef bottom where A. chirurgus for-aged. In the case of A. coeruleus and A. chirurgus, theformer species searched for food on the upper portionsof the lateral walls of the reefs, and did not utilisesedimentary material, differing in this respect from A.chirurgus and also from A. bahianus.

The values of Schoener’s Index were generally lowerat the natural reefs, possibly because of their greaterstructural complexity and shallower location, whichresulted in greater availability of algae. Parameterssuch as luminosity and site topography were probablythe main reasons for the observed differences in algaeabundance between coastal reefs and shipwrecks. Theapparently lower abundance of green algae on the arti-ficial reefs possibly results from their deeper location,and consequent lower light penetration.

In terms of feeding categories (sensu Jones, 1968),A. bahianus and A. chirurgus are considered to be"grazers" that ingest inorganic material with the algae,and A. coeruleus is considered to be a "browser" thatingests food with little or no inorganic material (Randall,1967; Clavijo, 1974). Randall (1965, 1967) suggestedthat the large amounts of inorganic material ingested byadults of A. bahianus and A. chirurgus are used forgrinding the ingested algae into finer particles. How-ever, in our study the grinding role of the sediment wasnot so apparent in A. chirurgus, as the algal piecesfound in its stomach and intestine did not visually differfrom one another in terms of size and consistency.Regarding the number of items consumed, A.coeruleus exhibited the most diversified diet, not show-ing a marked preference for any particular food item,which resulted in the relatively high evenness valuesobtained both at the natural reefs and at the ship-wrecks. However A. bahianus was responsible for thehighest evenness values obtained in this study, eventhough its dietary diversity was relatively low in com-parison to that of A. coeruleus.

In the three species studied, there seemed to be arelationship between resource availability and con-sumption which could be interpreted as an indication oflow selectivity on the part of the acanthurids. However,similar to what has been observed by Clavijo (1974),some visibly abundant algae such as Halimeda opun-tia, Udotea flabellum, Penicillus capitatus, Padina gym-nospora, and Sargassum sp. were not consumed, orwere ingested in extremely low amounts, perhaps sug-gesting an avoidance on the part of the surgeonfishes.According to Hay (1991), the resistance to herbivoryexhibited by many species of Halimeda can be attrib-uted to both morphological (calcification) and chemicaldefences. The same author also suggested that thedefences developed by Halimeda may be responsiblefor its abundance in most of the shallow reef habitats,characterised by intense herbivory by grazers. In fact,various studies (eg Norris & Fenical, 1982; Lewis et al.1987; Paul, 1987) indicate that, in response to herb -ivory, many species of algae develop different methods

aqua vol. 5 no. 1 - 2001 8


Schoener Index Value

Species pair Natural Reefs Shipwrecks

A. bahianus - A. chirurgus 0.46 0.39A. bahianus - A. coeruleus 0.40 0.52A. coeruleus - A. chirurgus 0.24 0.59

Table III. Dietary overlap in Acanthurus bahianus,A. chirurgus, and A. coeruleus.

of resistance, by means of considerable morphologicalvariations and production of poisonous metabolites,such that many of the relatively abundant algae acces-sible to herbivores contain biologically active sub-stances.

On the other hand, Paul (1987) mentioned that themain natural products of Udotea and Halimeda may notbe effective against grazers. Furthermore, as pointed outby Norris & Fenical (1982), in some cases spec ialisedherbivores have seemingly co-evolved with their foodsource and acquired tolerance of chemical deterrents,and even use them in their own defences against preda-tors. Additionally, it is worth nothing that one of the algaeconsumed by the species studied, particularly by A.coeruleus at the natural reefs, was Caulerpa racemosa,an abundant alga at the sites studied. In much the sameway, Randall (1967) and Earle (1972), studying A. bahi-anus, A. coeruleus, and A. chirurgus in the VirginIslands, recorded Sargassum spp., Halimeda spp., andUdotea sp. in their diets, but, as the amounts ingested bythe species are not given in those two studies, a directcomparison with our data is not possible. Although noexperiment was conducted to test the toxicity of C. race-mosa, the family Caulerpaceae, to which that speciesbelongs, is known to include species capable of produc-ing secondary metabolites, such as caulerpina, whichcan act as ichthyotoxins (Paul & Fenical, 1986).

In tropical waters, the family Acanthuridae is char -acterised by forming mono- or heterospecific “foraginggroups" (Ogden & Lobel, 1978). These groups prob ablyfunction as a protection against predators and toincrease efficiency during feeding, especially in areaswhere territorial fishes control part of the availableresources for feeding (Robertson et. al., 1976; Alevizon,1994).

Foraging groups or feeding aggregations were fre-quently observed for the studied species of Acanth urus.Contrary to the results obtained by Lawson et al. (1999)in Barbados, where no schools of juvenile A. bahianuswere seen, in our study large groups of juv eniles of thatspecies were sighted at the natural reefs, especially inshallow pools. Interspecific groups formed by juvenilesof A. bahianus and A. chirurgus were seen frequentlyaccompanied by parrotfishes (Sparisoma axillare and S.radians) mostly in areas occupied by damselfishes (Ste-gastes variabilis and S. fuscus). Perhaps, as observedby Lawson et. al. (1999), school size can be related tothe density of territorial fishes, supporting the hypothesisthat the large schools of acanthurids seen in our studypermit exploitation of the high quality food found insidethe territories of the damselfishes. Risk (1998) showedthat recruits of A. bahianus preferred places with con-specifics and avoided places where Stegastes leucos-tictus occurred. Robertson et. al. (1976) suggested thatthe presence of parrotfish can reduce the impact ofaggressive attacks on the part of territorial fishes.

Juveniles of A. coeruleus, on the other hand, weremostly solitary (even while searching for food), a

pattern also observed by Clavijo (1974) and Bell &Kramer (2000), although on a few occasions juvenileindividuals were seen feeding with other acanthurids orparrotfishes, perhaps seizing upon the temporary pro-tection offered by the group.

The following behaviour observed among A. bahianus,A. chirurgus, and the goatfish Pseudupeneus macula-tus (Mullidae) has also been recorded by Earle (1972).According to Strand (1988), invertebrates which burrowin the sand are flushed out by the foraging activity ofstingrays, goatfishes, and other sand-flat foragers, andspecies in or under algal coverings are displaced by thegrazing of herbivores. Small generalised pred ators (thefollowers) are able to capitalise upon this displacementor uncovering of prey items. In the case where Acan-thurus chirurgus and A. bahianus foraged in a mixedgroup composed of Halichoeres spp., Pseudup eneusmaculatus, and Sparisoma axillare, we observed thatwhile the Acanthurus species fed on the materialflushed by Pseudupeneus maculatus, the goatfish andHalichoeres species preyed upon organisms displacedby the foraging activities of the Acanthurus species andSparisoma axillare, possibly resulting in benefits to boththe surgeonfishes and the other followers.

In general, A. coeruleus can be considered a morespecialised feeder, ingesting almost exclusively algae,and generally foraging on the upper portions of reefwalls. A. bahianus and A. chirurgus are more “general-ist” species which obtain additional food items throughthe ingestion of sedimentary material. Some degree offood resource and microhabitat partitioning was foundduring this study, but this does not provide an argu-ment for competition among the three studied acan-thurids. As pointed out by Sala & Ballesteros (1997),experimental studies are needed to ascertain whetheror not the observed patterns are a result of competitionbetween species.

AcknowledgementsWe are grateful to Amélia Kanagawa and George

Miranda for help in algae identification, Ismar Just forproviding SCUBA gear, Cristina Buitron for help infield activities, Marileide Miranda and João Feitoza forlogistical support, and CNPq (Conselho Nacional deDesenvolvimento Científico e Tecnológico) for financ -ial support.

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alimentares de Orthopristis ruber (CUVIER, 1830),(Osteichthyes - Haemulidae) na Lagoa da Con-ceição, SC, Brasil. Biotemas 8 (2): 41-49.

Alevison, W. S., 1994. Caribbean Reef Ecology.Pisces Books, Houston. 115 pp.

Bell, T. & D. L. Kramer, 2000. Territoriality and habitatuse by juvenile blue tangs, Acanthurus coeruleus.Environmental Biology of Fishes 58: 401-409.

Böhlke, J. E. & C. C. G. Chaplin,1993. Fishes of the

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Bahamas and Adjacent Tropical Waters (2nd edition).University of Texas Press, Austin. 771 pp.

Clavijo, I. E., 1974. A contribution to the Feeding Habitsof Three Species of Acanthuridae (Pisces) from theWest Indies. Master’s Thesis, Florida Atlantic Univer-sity, Boca Ratón, U.S.A. 44 pp.

Duarte C. S. A. & A. Acero P.,1988. Hábitos alimenta-res de los peces del género Acanthurus (Perciformes:Acanthuridae) en la región de Santa Marta (CaribeColombiano). Revista de Biologia Tropical 36 (2B):399-405.

Earle, S. A., 1972. The influence of herbivores on themarine plants of Great Lameshur Bay, with an annot -ated list of plants. In: Collette, B. B. & S. A. Earle,(eds.), Results of the Tektite Program: ecology of coralreef fishes. Natural History Museum, LosAngeles County, Science Bulletin 14: 17-44.

Ferreira, C. E. L., Peret, A. C. & R. Coutinho, 1998.Seasonal grazing rates and food processing by trop -ical herbivorous fishes. Journal of Fish Biology 53(Supplement A): 222-235.

Hay, M. E., 1991. Fish-Seaweed interactions on coralreefs: effects of herbivorous fishes and adaptations oftheir prey. 96-119. In: Sale, P.F. (ed.). The Ecology ofFishes on Coral Reefs. Academic Press, Inc., 754 pp.

Hyslop. E. J., 1980. Stomach contents analysis - areview of methods and their application. Journal ofFish Biology 17: 411-429.

Joly, A .B., 1967. Gêneros de Algas Marinhas daCosta Atlântica Latino-Americana. Editora da Univer-sidade de São Paulo, São Paulo. 461 pp.

Jones, R. S., 1968. Ecological relationships in Hawai-ian and Johnston Island Acanthuridae (surgeon-fishes). Micronesica 4: 309-361.

Keast, A., 1978. Trophic and spatial interrelationshipsin the fish species of an Ontario temperate lake.Environmental Biology of Fishes 3: 7-31.

Lawson, G. L., Kramer, D. L. & W. Hunte., 1999. Size-related habitat use and schooling behavior in twospecies of surgeonfish (Acanthurus bahianus and A.coeruleus) on a fringing reef in Barbados, WestIndies. Environmental Biology of Fishes 54: 19-33.

Lehner, P. N., 1979. Handbook of Ethological Methods.Garland STPM Press, New York. 403 pp.

Lewis, S. M., Norris, J. N. & R. B. Searles, 1987. Theregulation of morphological plasticity in tropical reefalgae by herbivory. Ecology 68 (3): 636-641.

Littler, D. S., Littler, M. M., Bucher, K. E., & J. N. Nor-ris, 1989. Marine Plants of the Caribbean: a fieldguide from Florida to Brazil. Smithsonian InstitutionPress, Washington. 263 pp.

Ludwig, J. A. & J. F. Reynolds, 1988. Statistical eco -logy. John Wiley and Sons, Inc., New York. 337 pp.

Marrero, C., 1994. Métodos para Cuantificar Con-tenidos Estomacales en Peces. Talleres Gráficos deLiberil, Caracas, Venezuela. 37 pp.

Norris, J. N. & W. Fenical, 1982. Chemical defense intropical marine algae. 417-431. In: Rützler, K. & I.G.

Macintyre (eds.), The Atlantic Barrier Reef Ecosystemat Carrie Bow Cay, Belize. 1. Structure and Communi-ties. Smithsonian Contributions to the Marine Sci-ences 12, 539 pp

Ogden, J. C. & P. S. Lobel, 1978. The role of herbivor -ous fishes and urchins in coral reef communities.Environmental Biology of Fishes 3: 49-63.

Paul, V. J. 1987. Feeding deterrent effects of algal nat-ural products. Bulletin of Marine Science 41 (2): 514-522.

Paul, V. J. & W. Fenical, 1986. Chemical defense intropical green algae, order Caulerpales. MarineEcology Progress Series 34: 157-169.

Pérez-España, H. & L. A. Abitia-Cárdenas, 1996.Description of the digestive tract and feeding habits ofthe King angelfish and the Cortes angelfish. Journalof Fish Biology 48: 807-817.

Pinkas, L., Oliphant, M. S., & I. L. K. Iverson, 1971.Food habits of albacore, bluefin tuna and bonito inCalifornia waters. Fishery Bulletin 152: 1-105.

Potts, T. A. & A. W. Hulbert, 1994. Structural influencesof artificial and natural habitats on fish aggregations inOnslow Bay, North Carolina. Bulletin of Marine Sci-ence 55 (2): 609-622.

Randall, J. E., 1965. Grazing effects on sea grasses byherbivorous reef fishes in the West Indies. Ecology 46(3): 255-260.

Randall, J. E., 1967. Food habits of reef fishes of theWest Indies. Studies in Tropical Oceanography 5:665-847.

Risk, A., 1998. The effects of interactions with reefsresidents on the settlement and subsequent persist ence of ocean surgeonfish, Acanthurus bahianus.

Environmental Biology of Fishes 51: 377-389.Robertson, D. R., Sweatman, H. P. A., Fletcher, E. A.,

& M. G. Cleland, 1976. Schooling as a mechanism forcircumventing the territoriality of competitors. Ecology57 (6): 1208-1220.

Rocha, L. A., Rosa, I. L. & R. S. Rosa, 1998. Peixesrecifais da costa da Paraíba, Brasil. Revista Brasileirade Zoologia 15 (2): 553-566.

Sala, E. & E. Ballesteros, 1997. Partitioning of foodand space resources by three fish of the genus Diplo-dus (Sparidae) in a Mediterranean rocky infra littoralecosystem. Marine Ecology Progress Series 152:273-283.

Schoener, T. S., 1986. The Anolis lizards of Bimini:resource partitioning in a complex fauna. Ecology 49:704-725.

Strand, S., 1988. Following behavior: interspecific for-aging associations among Gulf of California reeffishes. Copeia 1988: 351-357.

Wynne, M. T., 1998. A checklist of benthic marine algaeof the tropical and subtropical Western Atlantic (firstrevision). Nova Hedwigia, J. Cramer, Stuttgart. 155 pp.

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aqua vol. 5 no. 1 - 200111

KeywordsMorphology, habitat, species associations, scaled

sculpin, Archaulus, Kuril Islands, Aleutian Islands

AbstractThe scaled sculpin Archaulus biseriatus Gilbert &

Burke, 1912 is reported from three new North Pacificrecords from off the northern Kuril Islands, Russia,and the central Aleutian Islands, Alaska, north ofSeguam Island. This species was previously knownfrom the type series from the Aleutian Islands, PetrelBank in the southern Bering Sea, and a recent reportand redescription of a single specimen from the cen-tral Kuril Archipelago off Simushir Island (Yabe andSoma, 2000). Additional records from the northernKuril Islands and the eastern Aleutian Islands north ofSeguam Island are also reported. Notes on themorphology, habitat, and species associations ofArchaulus are presented, and photographs of speci-mens are provided.

ZusammenfassungDie Beschuppte Groppe Archaulus biseriatus Gilbert

& Burke, 1912, wird anhand von drei neuen Fundortenvor den nördlichen Kurilen (Russia), sowie an den zen-tralen Aleutian Inseln (Alaska) nördlich der InselSeguam beschrieben. Bisher war diese Art nur von dergattungsbeschreibenden Serie von den AleutianInseln, der Petrel Bank im südlichen Beringmeer undeinem neueren Bericht mit einer Neubeschreibungeines einzelnen Exemplars vom Zentral-KurilenArchipel, vor der Insel Simushir (Yabe und Soma, 2000)bekannt. Weitere Funde vor den nördlichen Kurilen andden östlichen Aleutian Inseln (nördlich der InselSeguam) werden ebenfalls erwähnt. Bemerkungen zurMorphologie, Habitat and Artenzusammensetzung vonArchaulus werden gemacht, im Zusammenhang mitentsprechenden Fotografien von Exemplaren.

RésuméLe Chabot de mer à écailles Achaulus biseriatus

Gilbert & Burke, 1912 est signalé de trois nouvelles

stations du Pacifique nord au large des Iles Kourilesseptentrionales (Russie) et des Iles Aléoutiennes cen-trales (Alaska), au nord de l’Ile de Seguam. L’espècen’était jusqu’à présent connue que par la série-typeprovenant de la partie sud de la Mer de Behring (lebanc des Petrels dans le Iles Aléoutiennes), et larécente description complémentaire d’un seul spéci-men de la partie centrale de l’Archipel des Kouriles aularge de l’Ile Simushir (Yabe & Soma, 2000). D’autrelocalités du nord des Iles Kouriles et de l’est des IlesAléoutiennes, au dessus de l’Ile Seguam, sont aussisignalées. Des notes sur la morphologie, l’habitat etles espèces associées à Achaulus, ainsi que des pho-tographies de spécimens, sont produites.

SommarioIl cottide Archaulus biseriatus Gilbert & Burke, 1912

è stato rinvenuto in tre nuove località del Nord Paci-fico, e precisamente al largo delle Isole Kurili (Russia)e a nord dell’Isola di Seguam, nelle Isole Aleutinecentrali (Alaska). La specie era precedentementenota solo per gli esemplari-tipo raccolti nel PetrelBank, Isole Aleutine, Mare di Bering meridionale e daun unico esemplare raccolto e ridescritto nell’IsoleKurili centrali, al largo dell’Isola Simushir (Yabe andSoma, 2000). Pertanto, a questi si aggiungono i nuoviritrovamenti nelle Isole Kurili settentrionali e nelleIsole Aleutine orientali a nord di Seguam. Inoltre ven-gono qui presentate note sulla morfologia, l’habitat ele associazioni di Archaulus con altre specie. I datisono corredati da fotografie degli esemplari raccolti.

IntroductionThe scaled sculpin Archaulus biseriatus Gilbert &

Burke, 1912, was described from ten specimens(holotype and nine paratypes) collected in 1906 fromPetrel Bank (Fig. 1), in the southern Bering Sea offSemisopochnoi Island in the Aleutian Archipelago,52°11’ N, 179°49’ E, 52°12’ N, 179°52’ E, and 52°11’N, 179°57’ W (Gilbert and Burke, 1912). Later authors(Taranets, 1937; Wilimovsky, 1954, 1964; Quast andHall, 1972; Fedorov, 1973), taking into account the


Additional records of scaled sculpin Archaulus biseriatus Gilbert & Burke,1912 (Teleostei: Cottidae) from the North Pacific

Alexei M. Orlov1, Alexei M. Tokranov2, and Andrei V. Vinnikov3

1) Russian Federal Research Institute of Fisheries and Oceanography, VNIRO, V, Krasnoselskaya 17, 107140, Moscow, Russia; e-mail: [email protected]

2) Kamchatka Institute of Ecology and Nature Management, KIENM, Partizanskaya, 6, 683000, Petropavlovsk-Kamchatsky, Russia; e-mail: [email protected]

3) Kamchatka Research Institute of Fisheries and Oceanography, KamchatNIRO, Naberezhnaya, 18, 683602, Petropavlovsk-Kamchatsky, Russia; e-mail [email protected]

Accepted 12.11.2001

aqua vol. 5 no. 1 - 2001 12

Additional records of scaled sculpin Archaulus biseriatus Gilbert & Burke, 1912 from the North Pacific

data of Gilbert and Burke (1912), included thisspecies in lists of fishes inhabiting the Bering Sea andwaters off the Aleutian Islands. Notes on the occur-rence of scaled sculpin off the Kuril Islands haverecently been published (Borets, 1997, 2000; Fedorov,2000; Sheiko and Fedorov, 2000), although all havebeen based only on field samples and field identifica-tions. No specimens documenting these records havebeen deposited in fish collections. Since the originaldescription, only a single additional specimen hasbeen collected, from the central Kuril Archipelago offSimushir Island (Yabe and Soma, 2000). Here wereport upon three additional specimens collected fromoff the northern Kuril Islands, Russia, and the easternAleutian Islands, Alaska, during bottom trawl opera-tions. We also present observations on the morphol-ogy, habitat, and species associations of Archaulusbiseriataus and provide photographs of new speci-mens.

MethodsMeristics and morphometrics follow Yabe and Soma

(2000). Standard length (SL) is used throughout. Dataon the type material used for the original descriptionof the species and on the additional specimen weretaken from Yabe and Soma (2000). Data on localitiesand depths of all known collections of scaled sculpinwere taken from Gilbert and Burke (1912) and Yabeand Soma (2000). Sex of specimens was determinedvisually according to the presence or absence of aurogenital papilla.

Archaulus biseriatus Gilbert and Burke,1912Scaled sculpin (Figs. 2 & 3, Table I)

Archaulus biseriatus Gilbert and Burke, 1912: 36(original description; type locality, Petrel Bank,Bering Sea, depth 78.6 to 98.8 m); Eschmeyer et al.,1998: 234 (validity); Yabe and Soma, 2000: 159(redescription; record, Central Kuril Archipelago, offSimushir Island, depth 123 m).

New material examinedOne adult female, 159 mm and 0.09 kg, (Figs. 2, 3)

was collected on 3 October 2000 over an underwaterplateau southeast of Shiashkotan Island, NorthernKuril Islands, by A. M. Orlov and O. Yu. Nemchinov.The specimen was collected in a bottom trawl (5-7 mvertical opening, about 25 m horizontal opening) at 48°14.0’ N, 154°35.1’ E (Fig. 4) at 138-140 m depth(Japanese trawler Tomi Maru No. 82, haul No. 160).The currently uncatalogued specimen (VNIRO, uc) isdeposited in the fish collection of the Russian FederalResearch Institute of Fisheries and Oceanography(VNIRO), Moscow, Russia.

Two adult males, one (Fig. 3) 150 mm and 0.11 kg,(urogenital papilla 12 mm (8.0 % SL)) was collectedon 26 May 2001 by A. V. Vinnikov and A.I. Varkentin inthe same area as the previous specimen, using thesame trawl type. The specimen was collected at 48°16.5’ N, 154°32.0’ E (Fig. 4) at 100-117 m depth

Fig. 1. Map of locations of new and previous records of scaled sculpin Archaulus biseriatus in the North Pacific Ocean:1 - off the northern Kuril and Aleutian Islands (our data); 2 - off the central Kuril Islands (Yabe and Soma, 2000); 3 - in thesouthern Bering Sea off the Aleutian Islands (Gilbert and Burke, 1912). Picture of scaled sculpin adapted from Gilbertand Burke (1912).

aqua vol. 5 no. 1 - 200113

Alexei M. Orlov, Alexei M. Tokranov, and Andrei V. Vinnikov

(Japanese trawler Tomi Maru No. 53, haul No. 125).The currently uncatalogued specimen (KIE, uc) isdeposited in the fish collection of the Kamchatka Insti-tute of Ecology and Nature Management (KIENM),Petropavlovsk-Kamchatsky, Russia.

A second adult male (Fig. 2) 122.8 mm and 0.08 kg,(urogenital papilla 13.5 mm (11.0 % SL)), was collectedon 4 June 2000 by J. W. Orr north of Seguam Island inthe eastern Aleutian Islands. The specimen was caughtin a small bottom typing net attached to a bottom trawlat 52°03.5’ N, 172°33.1’ W (Fig. 1) at 145 m depth (F/VDominator, haul No. 72) and is deposited in the Univer-sity of Washington Fish Collection (UW, uc).

MorphologyMorphological characters of our specimens of

scaled sculpin agree well with the description of thetype material (Gilbert and Burke, 1912; Yabe andSoma, 2000) and the additional specimen

redescribed by Yabe and Soma (2000), with minorexceptions (Table I).

The female was our largest specimen (159 mm) andhad a slightly deeper head (18.0 % of SL) than thecomparative material (holotype, paratypes, and Yabeand Soma’s (2000) specimen (19.6-21.7 % SL)). Inaddition, its predorsal distance and length of the firstdorsal fin base were slightly shorter when comparedwith the type material and Yabe and Soma’s (2000)specimen (21.4 vs. 24.4-28.3 and 15.6 vs. 16.1-20.6%, respectively). However, the caudal peduncle of ourfemale was slightly longer than in the type material(13.8 vs. 11.2-13.3 %).

Our smaller Kuril Islands specimen (150 mm) showsgreater variability in morphological characters whencompared with the type material and Yabe and Soma’s(2000) specimen. Proportionally, it has a slightlysmaller depth at first dorsal fin origin, length, depth,width, and postorbital length of head, pre-anal length,

Fig. 2. Specimens of scaled sculpin Archaulus biseriatus caught: (a) off the northern Kuril Islands, 159 mm SL (VNIRO,uc) - fresh; (b) off the Aleutian Islands, 122.8 mm SL (UW, uc) - fresh.

b

a

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length of orbit, and length of upper jaw. At the sametime, its body depth at anal fin origin, lengths of seconddorsal and anal fin bases, depth of caudal peduncle,interorbital width, and length of mandible were some-what greater. The differences between these two spec-imens and the comparative material reported here areprobably related to significantly greater length (150 and159 mm vs. 80.9-129.2 mm in comparative material)and possibly to some distortion of both Kuril specimensafter fixation and preservation in formalin.

The Aleutians male was proportionally smaller thanthe comparative material in several body measure-ments: body depth at first dorsal fin origin, head lengthand depth, snout length, predorsal length, prepelviclength, pre-anal length, and length of second dorsalfin base.

Differences in morphometrics were also foundbetween males and females, and probably representevidence of sexual dimorphism in the species. Thefemale’s body width at first dorsal fin origin (16.3 vs.16.8-19.0 % in the male), body width at anal fin origin(10.4 vs. 10.7-12.7 %), and length of first dorsal finbase (15.6 vs. 16.1-18.2 %) were slightly less than therespective measurements in males. Conversely, thefemale had a somewhat longer prepelvic length (30.2vs. 25.5-29.9 %), pre-anal length (46.9 vs. 40.1-46.1%), length of caudal peduncle (13.8 vs. 11.4-13.2 %),pectoral fin length (32.1 vs. 28.6-31.0 %), and pelvicfin length (16.3 vs. 14.7-15.5 %) than males.

Both Kuril Islands specimens considered here werecaught quite a distance away from previous capturelocations, on an underwater plateau with specific envi-

Locality 1 Southern 2 Southern 3 Central 4a Northern 4b Northern 5 EasternBering Bering Kuril Kuril Kuril Aleutian

Sea Sea Islands Islands Islands Islands

Number of specimens 1 7 1 1 1 1Sex 0 0 0 Y 0 0Standard length (SL) in mm 129.2 80.9-85.4 121.0 159.0 150.0 122.8

Morphometrics, all % SL Mean Range

Body depth at 1st dorsal fin origin 25.4 26.4 25.7-28.6 27.3 26.2 24.0 23.8Body depth at anal fin origin 24.3 24.6 23.6-25.5 26.1 25.7 26.7 25.0Body width at 1st dorsal fin origin 17.0 18.3 17.1-19.3 19.0 16.3 17.3 16.8Body width at anal fin origin 10.9 11.3 10.1-12.6 12.7 10.4 10.7 11.4Head length 28.0 29.4 28.6-31.0 27.8 26.2 24.0 23.8Head depth 19.8 20.4 19.6-21.7 20.2 18.0 18.7 17.4Head width 17.0 17.6 16.6-18.0 17.6 16.7 15.3 16.8Predorsal length 24.8 27.4 25.8-28.3 24.4 21.4 24.0 19.8Prepelvic length 29.9 29.0 27.4-30.8 28.4 30.2 28.7 25.5Pre-anal length 46.1 47.2 46.0-48.9 44.1 46.9 43.3 40.1Length of first dorsal fin base 17.6 19.0 16.6-20.6 16.1 15.6 18.0 18.2Length of second dorsal fin base 50.9 49.8 48.5-50.9 54.2 52.8 55.3 47.8Length of anal fin base 45.6 44.7 43.4-46.2 45.8 45.1 48.0 44.4Length of pectoral fin base 13.0 12.8 11.6-15.0 12.5 12.7 13.3 11.7Length of caudal peduncle 11.8 12.3 11.2-13.3 11.4 13.8 12.0 13.2Depth of caudal peduncle 6.6 6.1 5.6- 6.9 7.0 6.9 7.3 6.4Snout length 9.4 8.6 7.7- 9.5 10.2 7.7 8.0 5.8Length of orbit 7.8 8.9 8.4- 9.4 7.9 7.9 6.7 6.9Interorbital width 4.3 2.9 2.5- 3.4 3.7 4.2 4.7 4.0Length of upper jaw 9.1 9.5 9.0- 9.9 9.5 8.8 8.0 8.2Length of mandible 8.8 9.1 8.8- 9.5 9.0 9.0 10.0 10.0Postorbital length of head 13.4 13.5 12.8-13.8 12.5 12.6 12.0 12.1Pectoral fin length 31.0 32.2 29.9-34.5 28.6 32.1 28.7 30.8Pelvic fin length 14.7 15.1 12.5-18.7 14.8 16.3 15.3 15.5

MeristicsFirst dorsal fin spines 9 9* 9-10 8 9 9 9Second dorsal fin rays 28 28* 28-29 29 29 29 28Pectoral fin rays 16 17* 17 17 16 16 16Pelvic fin rays I, 3 I, 3* I, 3 I, 3 I, 3 I, 3 I, 3Anal fin rays 23 22* 22-23 24 24 25 23Lateral line scales 46 47* 45-47 48 47 49 49Abdominal vertebrae 11 na na 11 na na naCaudal vertebrae 33 na na 35 na na na

Table I. Meristics and morphometrics of scaled sculpin Archaulus biseriatus specimens collected in the North Pacific. 1 Holotype USNM 74365; 2 Paratypes USNM 70879, 74503, 74504; 3 HUMZ 165817; 4a Uncatalogued specimen VNIRO,4b Uncatalogued specimen KIENM; 5 Uncatalogued specimen UW. na = not available, * = mode.

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ronmental conditions (existence of mesoscale meand -ers, eddies, and rings; bottom relief, water tempera-ture, and salinity different to those of neighbouringareas). These morphological differences may repre-sent the maximal range of variability in the species.

Catch composition and vertical distribution ofspecies

The specimens of A. biseriatus reported here werecaptured during commercial bottom trawl operationstargeting Atka mackerel Pleurogrammus monoptery-gius (haul No. 125) and during research bottom trawlsurveys (hauls 160 and 72) (Table II). Other fishestaken in these bottom trawls were typical of thespecies composition found off the northern KurilIslands at these depths (Orlov, 1998a). Species com-position differed considerably between hauls: of 33 fishspecies found in these catches, only 3 were commonto all hauls. Atka mackerel represented the bulk of one(haul no. 125) Kuril Islands catch (96.4 % by numberand 98.6 % by weight), while the other catch (haul no.

160) consisted mainly of darkfin sculpin Malacocottuszonurus (52.6 and 33.5 % respectively), longfin Irishlord Hemilepidotus zapus (28.3 and 11.7 % respect -ively) and spectacled sculpin Triglops scepticus (14.5and 7.8 % respectively). The Aleutian catch (haul no.72) contained primarily Pacific cod Gadus macro-cephalus (37.0% by number and 66.1 % by weight),with Pacific halibut Hippoglossus stenolepis (2.4 and12.6 % respectively), northern rockfish Sebastes poly-spinis (33.9 and 9.1 % respectively), and white-blotched skate Bathyraja maculata (2.4 and 8.3 %respectively) making up additional significant compon -ents. Invertebrates caught in the Kuril Islands haulswere species typically found on hard bottoms and wererepresented by sponges (Porifera), barnacles (Bal-anidae), brittle stars (Opiuroidea), sea urchins(Strongylocentrotus spp.), sea cucumbers (Cucumariacf. japonica), and also by bentho-pelagic red squidBerryteuthis magister. Invertebrates captured with theAleutian Archaulus were also species typically foundon hard bottoms. Sponges, sea urchins, brittle stars,

Fig. 3. Specimens of scaled sculpin Archaulus biseriatus caught off the northern Kuril Islands: (a) 159 mm SL (VNIRO,uc) - preserved in formalin; (b) 150 mm SL (KIE, uc) - preserved in formalin.

b

a

aqua vol. 5 no. 1 - 2001 16


barnacles, bryozoans, ascidians, primnoid corals, andsnails were the components of that haul.

The depth range of scaled sculpin in the northwesternPacific Ocean is 10-200 m based on all records, includ-ing those not represented by vouchered specimens(Borets, 1997, 2000; Fedorov, 2000; Sheiko andFedorov, 2000). Fedorov (2000) noted that this speciesinhabits shallower waters in depths of 10 to 70 m,although Sheiko and Fedorov (2000) noted depths of10 to 100 m. The type material was caught off the PetrelBank in the Bering Sea at a depth of 78.3 to 98.3 m(average 88.3 m) (Gilbert and Burke, 1912). Therecently reported specimen off Simushir Island (centralKuril Archipelago) was caught at a depth of 123 m(Yabe and Soma, 2000). Our specimen from theSeguam Pass was collected from 145 m depth, andrepresents the deepest vouchered record of thespecies and a considerable extension of its geographicrange. The average depth of all known records ofscaled sculpin in the North Pacific Ocean is 116.9 m.

There are several hypotheses that may explain recentrecords of scaled sculpin in the North Pacific. Scaledsculpin appears to have a continuous distribution along

the Aleutian ridge, through the eastern Aleutian andCommander Islands, to the northern Kuril Islands. Theabsence of recorded specimens from 1906 until 1999may be associated with the fact that the inshore fishfauna of the region has been poorly studied. Severalscaled sculpins were recently reported caught off theKuril Islands (Borets, 1997, 2000; Fedorov 2000;Sheiko and Fedorov, 2000), but no vouchered speci-mens were retained to verify these collections.

Pelagic young of scaled sculpin may be transportedfrom the Aleutian Islands to the Kuril Islands by currents.Although no early life history data on Archaulus bis -eriatus are available, many sculpins (Cottidae) havepelagic larvae and juveniles (Matarese et al., 1989).Several typical species of the northeastern Pacificichthyofauna that had not been previously reported inthe area, such as rex sole Glyptocephalus zachirus,dusky rockfish Sebastes ciliatus, and northern rockfishSebastes polyspinis, among others, have recently beentaken off southeastern Kamchatka, the CommanderIslands, and the northern Kuril Islands (Orlov, 1998b;Sheiko and Tranbenkova, 1998, Tokranov and Vinnik- ov 2000).

Table II. Species composition of catches (expressed as percentages of total catch, 1 in numbers, 2 by weight) contain-ing scaled sculpin Archaulus biseriatus, from the Pacific waters off the northern Kuril Islands (Hauls 125 and 160) andeastern Aleutian Islands (Haul 72).

Taxon Haul 125 Haul 160 Haul 721 2 1 2 1 2

Scaled sculpin Archaulus biseriatus < 0.1 < 0.1 0.1 < 0.1 < 0.1 < 0.1Blackline snipe eel Avocettina infans - - - - 0.8 < 0.1Whiteblotched skate Bathyraja maculata < 0.1 0.2 0.4 6.2 2.4 8.3Aleutian skate B. aleutica - - 0.1 3.2 - -Nutcracker prickleback Bryozoichthys lysimus - - 0.3 0.1 - -Snailfish Careproctus cf. cyclocephalus - - 0.1 0.4 - -Pacific viperfish Chauliodus macouni - - - 3.1 < 0.1Fedorov’s lumpsucker Eumicrotremus fedorovi < 0.1 < 0.1 0.2 < 0.1 - -Pacific spiny lumpsucker E. orbis - - - - 8.7 -Pacific cod Gadus macrocephalus - - 0.1 2.5 37.0 66.1Armorhead sculpin Gymnacanthus galeatus - - 0.2 0.3 - -Yellow Irish lord Hemilepidotus jordani < 0.1 0.1 - - 3.9 2.0Longfin Irish lord H. zapus 2.8 0.8 28.3 11.7 0.8 < 0.1Bigmouth sculpin Hemitripterus bolini - - - - 0.8 1.4Rock greenling Hexagrammos lagocephalus < 0.1 < 0.1 - - - -Pacific halibut Hippogolossus stenolepis - - 0.5 28.6 2.4 12.6Fourhorn poacher Hypsagonus quadricornis - - 0.2 < 0.1 - -Spatulate sculpin Icelus spatula - - 0.4 < 0.1 - -Sawback poacher Leptagonus frenatus 0.4 < 0.1 0.2 < 0.1 - -Cubed snailfish Liparis tesselatus (?) - - 0.1 < 0.1 - -Whitebar eelpout Lycodes albolineatus - - 0.1 0.5 - -Darkfin sculpin Malacocottus zonurus 0.1 0.1 52.6 33.5 - -Atka mackerel Pleurogrammus monopterygius 96.4 98.6 0.3 0.3 - -Simushir snailfish Polypera simushirae < 0.1 0.1 0.1 1.3 - -Pacific ocean perch Sebastes alutus 0.1 < 0.1 - - 2.4 0.4Northern rockfish S. polyspinis - - - - 33.9 9.1Walleye pollock Theragra chalcogramma< 0.1 0.1 0.6 3.2 - -Spectacled sculpin Triglops scepticus - - 14.5 7.8 - -Sponge sculpin Thyriscus anoplus - - 0.4 < 0.1 - -Prowfish Zaprora silena - - 0.1 0.2 - -Snailfish unidentified Careproctus sp. - - 0.1 < 0.1 - -Lanternfishes unidentified Myctophidae gen. sp. - - - - 3.1 < 0.1Scaleless dragonfishes Melanostomiidae gen. sp. - - - - 0.8 < 0.1

Conversely, we speculate that fish found at PetrelBank in the Bering Sea by Gilbert and Burke (1912),and our Aleutians specimen, may have originatedfrom the Kuril Islands, because they comprisedsmaller specimens of 80.9-129.2 mm, while largerindividuals of 150-159 mm were caught by us off thenorthern Kuril Islands. Similar examples are wellknown. The longfin Irish lord Hemilepidotus zapuswas also originally described from the Bering Sea offthe Aleutian Islands (Gilbert and Burke, 1912) andwas thought to occur only in the vicinity of the Aleut-ian Islands, where only small or immature fish withlengths up to 155 mm have been caught (Peden,1978; Orr, pers. comm.). A recent study showed thatlongfin Irish lord is one of the most abundant sculpins,

inhabiting an underwater plateau southeast of Shi-ashkotan Island, and represented there mainly bymature individuals with lengths up to 260 mm(Tokranov and Orlov, 2001a). The blacktip snailfishCareproctus zachirus was also described from off theAleutian Islands (Kido, 1985) and there were only sev-eral additional records in that area later (Orr, pers.comm.). Recent studies of the northern Kuril Islandsichthyofauna have shown that this species is rathercommon in this area. In particular, blacktip snailfishare most frequently captured at the underwaterplateau off Shiashkotan Island (Tokranov and Orlov,2001b). These examples suggest that pelagic youngof scaled sculpin spawned off the Kuril Island may betransported to the Aleutian Islands.

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Fig. 4. Map of locations of new records of scaled sculpin Archaulus biseriatus off the northern Kuril Islands: 1= in 2000,2 = in 2001 (thin lines and numbers are isobaths).

aqua vol. 5 no. 1 - 2001 18


Acknowledgements The authors deeply appreciate the contribution made

by their colleague Dr James Wilder Orr (research zool-ogist for the National Marine Fisheries Service, NationalOceanic and Atmospheric Administration, Alaska Fish-eries Science Center, Resource Assessment and Con-servation Engineering Division, 7600 Sand Point WayNE, Seattle, WA 98115-0070), who provided processedmorphological data, data on distribution and speciesassociation for the Aleutian Islands specimen, and aphotograph of it; and who offered comments andremarks on the manuscript and helped with the revisionof an early draft. We also would also like to thank ourcolleagues A.I. Varkentin (Kamchatka Research Insti-tute of Fisheries and Oceanography, KamchatNIRO,Petropavlovsk-Kamchatsky, Russia) and O. Yu. Nemchi-nov (Sakhalin Research Institute of Fisheries andOceanography, SakhNIRO, Yuzhno-Sakhalinsk, Russia)for their assistance in collecting specimens.

ReferencesBorets, L. A., 1997. Bottom ichthyocenes of the Russ-

ian Far East seas shelf: composition, structure, func-tioning elements and commercial importance.TINRO-Centre: Vladivostok. 217 pp. (In Russian).

Borets, L. A., 2000. Annotated list of fishes of the FarEast seas. TINRO-Centre: Vladivostok. 192 pp. (InRussian).

Eschmeyer, W. N., Ferraris, C. J. Jr., Hoang, M. D.,& D. J. Long, 1998. Species of Fishes. Catalog offishes. California Academy of Science: San Fran-cisco. : 25-1820.

Fedorov, V. V., 1973: List of fishes of the Bering Sea.Izvestiya TINRO 87: 42-71. (In Russian).

Fedorov, V. V., 2000. Species composition, distrib utionand habitation depths of the Northern Kuril Islandsfish and fish-like species. Commercial and biologicalstudies of fishes in the Pacific waters of the KurilIslands and adjacent areas of the Okhotsk andBering Seas in 1992-1998. VNIRO: Moscow. : 7-41.(In Russian).

Gilbert, C. H. & C. V. Burke, 1912. Fishes from BeringSea and Kamchatka. Bulletin of the Bureau of Fish-eries, 30: 31-96.

Kido, K., 1985. New and rare species of the genusCareproctus (Liparididae) from the Bering Sea.Japanese Journal of Ichthyology 32 (1): 6-17.

Matarese, A. C., Kendall, A. W. Jr., Blood, D. M. & B.M. Vinter, 1989. Laboratory guide to early life historystages of Northeast Pacific fishes. U.S. Departmentof Commerce, NOAA Technical Report NMFS 80:1-652.

Peden, A. E., 1978. A systematic revision of thehemilepidotine fishes (Cottidae). Syesis, 11: 11-49.

Quast, J. C. & E. L. Hall, 1972. List of fishes of Alaskaand adjacent waters with the guide to some of theirliterature. U.S. Department of Commerce, NOAATechnical Report NMFS SSRF 658: 1-47.

Orlov, A. M., 1998a. Demersal ichthyofauna of Pacificwaters off the northern Kuril Islands and southeast-ern Kamchatka. Biologiya Morya 24 (3): 146-160 (InRussian).

Orlov, A. M., 1998b. Eastern Pacific elements in theichthyofauna of Pacific continental slope off thenorthern Kuril Islands and southeastern Kamchatka.Actual Problems of Fish Taxonomy. Abs. Int. Conf.,St. Petersburg, November 17-19, 1998. ZoologicalInstitute: St. Petersburg : 44-45 (In Russian).

Sheiko, B. A. & A. G. Tranbenkova, 1998. New forRussian fauna and rare marine fishes from Kam-chatka, Kuril and Commander Islands. Actual Prob-lems of Fish Taxonomy. Abs. Int. Conf., St. Peters-burg, November 17-19, 1998. Zoological Institute: St.Petersburg : 62-63 (In Russian).

Sheiko, B. A. & V. V. Fedorov, 2000. Chapter 1. ClassCephalaspidomorphi - Lampreys. Class Chon-drichthyes - Cartilaginous Fishes. Class Holocephali -Chimaeras. Class Osteichthyes - Bony Fishes. Cata-log of vertebrates of Kamchatka and adjacent waters.Kamchatskiy Pechatniy Dvor: Petropavlovsk-Kam-chatsky. : 7-69 (In Russian).

Taranets, A. J., 1937. Handbook for identification offishes of Soviet Far East and adjacent waters.Izvestiya TINRO 11: 1-200 (In Russian).

Tokranov, A. M. & A. V Vinnikov, 2000. Capture ofrex sole Glyptocephalus zachirus Lockington(Pleuro nectidae) in waters of the southeastern Kam-chatka. Voprosy Ikhtiologii 40 (3): 397-398 (In Russ-ian).

Tokranov, A. M. & A. M. Orlov, 2001a. Distributionand some biological features of the new for theRussian fauna species longfin Irish lord Hemilepido-tus zapus Gilbert & Burke, 1912 (Cottidae) in thePacific Ocean waters of the northern Kuril Islands.Biological Grounding of the Sustainable Develop-ment of the Coastal Marine Ecosystems. Abs. Int.Conf., Murmansk, April 25-28, 2001. Kola ScienceCenter: Apatity. :36-237 (In Russian).

Tokranov, A. M. & A. M. Orlov, 2001b. Some biologi-cal features of rare liparid species (Liparidae) in thePacific waters of northern Kuril Islands and south-eastern Kamchatka. Conservation of Biodiversity ofKamchatka and Coastal Waters. Mat. II Sci. Conf.,Petropavlovsk-Kamchatsky, April 9-10, 2001.Kamshat: Petropavlovsk-Kamchatsky. : 187-190. (InRussian).

Wilimovsky, N. J., 1954. List of fishes of Alaska.Stanford Ichthyological Bulletin 4 (5): 279-294.

Wilimovsky, N. J., 1964. Inshore fish fauna of theAleutian Archipelago. Proceedings of the 14thAlaskan Scientific Conference 1963 14: 172-190.

Yabe, M. & A. Soma, 2000: A rare fish, Archaulus bis-eriatus, collected from the Central Kuril Archipelago(Scorpaeniformes: Cottidae). Bulletin of the Facultyof Fisheries Hokkaido University 50 (3): 159-163.

aqua vol. 5 no. 1 - 200119

KeywordsIchthyology, systematics, Gobiidae, Trimma, Trim-

matom, new species, Indo-West Pacific

AbstractTwo new gobiid fish species are described. Trimma

stobbsi has no scales in the predorsal midline, a slightinterorbital trench, unbranched fifth pelvic fin ray, and adistinct dark spot above and just anterior to the post -erodorsal corner of the operculum. Trimmatom pharushas a scaled body, a reduced (20% or less of the lengthof fourth ray) and unbranched fifth pelvic fin ray, and thefirst four pelvic fin rays branched. Numerous dark bars(red in life) are present on head and body. Trimmatompharus is considered to be part of the T. eviotopsspecies group. Both new species are found in theIndian and western Pacific Oceans.

ZusammenfassungZwei neue Grundelarten werden beschrieben. Trimma

stobbsi ist in der predorsalen Mittellinie schuppenlos,hat eine flache inter-orbitale Furche, einenunverzweigten, fünften Bauchflossenstrahl, sowie einendeutlich dunklen Punkt über und genau am Anfang derder hinteren dorsalen Ecke des Kiemendeckels. Trim-matom pharus hat einen beschuppten Körper, einenreduzierten (20% oder weniger von der Länge desvierten Strahls) und unverzweigten, fünften Bauch-flossenstrahl. Kopf und Körper bedeckt mit einer Anzahldunkler Balken (rot in lebenden Exemplaren). Trim-matom pharus wird als zugehörig zur T. eviotops-Arten-gruppe angesehen. Beide dieser neuen Arten kommenim Indischen Ozean und im Westlichen Pazifik vor.

RésuméDeux espèces nouvelles de Poissons gobiides sont

déscrites. Trimma stobbsi a la ligne prédorsale médi-ane dépourvue d’écailles, un faible sillon interorbitaire,le cinquième rayon pelvien non ramifié, et une tachenoire bien délimitée au-dessus et juste en avant del’angle postérieur de l’opercule. Trimmatom pharus a lecorps recouvert d’écailles, le cinquième rayon pelviennon ramifié et réduit (20% ou moins de la longueur dequatrième), et les quatre premiers rayons pelviens ra -mi fiée. De nombreuses barres foncées (rouges in vivo)sont présentes sur la tête et le corps. Trimmatom

pharus ferait partie du groupe d’espèce T. eviotops. Lesdeux espèces nouvelles se recontrent dans l’OcéanIndien et l’Océan Pacifique occidental.

SommarioIn questo articolo vengono descritte due nuove specie

di ghiozzi. Trimma stobbsi è una specie priva di scagliesulla linea predorsale, ha una leggera fossa interor-bitale, il quinto raggio pelvico non ramificato e una bendelimitata macchia nera nella parte superiore dell’oper-colo proprio davanti all’angolo posterodorsale. Trim-matom pharus ha il corpo coperto di scaglie, il quintoraggio pelvico non ramificato e ridotto (20% o menodella lunghezza del quarto raggio) e i primi quattro raggipelvici ramificati. Sul capo e sul corpo sono presentinumerose striature scure (rosse in vivo). Si ritiene cheTrimmatom pharus faccia parte del complesso di specieT. eviotops. Entrambe le due nuove specie descritte abi-tano l’oceano Indiano e il Pacifico occidentale.

IntroductionTrimma is a large group of about 80 species of small

(30 mm SL or less), usually colourful, coral reef fisheswhich can be recognized by the lack of cephalic sen s -ory canal pores, much reduced cephalic sensory papil-lae pattern, wide gill opening extending to below the ver-tical limb of the preopercle or anterior to this, lack ofspicules on the outer gill rakers of the first gill arch, lessthan 12 dorsal or anal fin rays, and a fifth pelvic fin raythat is equal to or more than half the length of the fourthpelvic fin ray.

Trimmatom was described by Winterbottom and Emery(1981). Winterbottom (1989) redefined the genus toinclude gobiids with the following characters: first ele-ment of the anal fin a segmented or unsegmented, bilat-erally paired, element (as opposed to a spine); head,breast, and pectoral base scaleless; no head pores; gillopening extending anteroventrally to below the verticallimb of the preopercle or below the pupil; and fifth pelvicfin ray unbranched and reduced to 15% or less of thelength of the fourth ray. This last value has now beenincreased to 20% in order to include the new species.

The genus Trimmatom is currently made up of twogroups, the Trimmatom nanus species complex (mono-phyletic - Winterbottom, 1989) and the T. eviotops spec -ies group (monophyly not determined). The Trimmatom


Two new gobiid fish species in Trimma and Trimmatom(Teleostei: Gobiidae) from the Indian and Western Pacific Oceans

Richard Winterbottom

Centre for Biodiversity and Conservation Biology,Royal Ontario Museum, 100 Queen’s Park, Toronto, ON, Canada, M5S 2C6; and Department of Zoology, University of Toronto,Toronto, ON, Canada M5S 3G5

Accepted 19.11.2001

aqua vol. 5 no. 1 - 2001 20

Two new gobiid fish species in Trimma and Trimmatom from the Indian and Western Pacific Oceans

nanus complex includes five described species; T. na -nus, T. macropodus, T. zapodes, T. officius, and T. sag -ma. The T. eviotops group consists of T. eviotops plus sixundescribed species, one of which is described here.

Trimmatom pharus has been previously referred to asTrimma eviotops (Winterbottom and Emery, 1986), withTrimma eviotops being transferred to Trimmatom byWinterbottom (1989), and also as Trimmatom sp. 6 (seesynonymy below). The two species are very similar inappearance and share numerous meristic characteris-tics, but can be differentiated on the basis of colour pat-tern in both the fresh and the preserved state.

MethodsMethods follow Winterbottom (1995). Lengths are

given as standard length (SL). Institutional abbreviat -ions are: AMS - Australian Museum, Sydney; ANSP –Academy of Natural Sciences of Philadelphia; BPBM -Bernice P. Bishop Museum, Honolulu; CAS - CaliforniaAcademy of Sciences, San Francisco; LICPP -CrownPrince’s Palace, Laboratory of Ichthyology, specimensnow housed at the Akasaka Imperial Palace, Tokyo;NTM - Northern Territory Museum, Darwin; ROM -Royal Ontario Museum, Toronto; RUSI - Rhodes Uni-versity, Smith Institute, Grahamstown; USNM - NationalMuseum of Natural History, Washington, and WAM -Western Australian Museum, Perth.

Trimma stobbsi n. sp.(Figs. 1 & 2)

Material ExaminedA total of 16 lots, 242 specimens.

Holotype: ROM 72488, 19.1 mm SL male, New Cale-donia, Port de Goro, W. of concrete lighthouse,22°20’00”S, 167°00’20”E,18.3-25.9 m, R. Winter -bottom, G. Klassen and P. Tirard, 3 Sept. 1991.Paratypes: Indonesia: ROM 70723, 1(18.5 mm SL)Ambon Bay, base of fringing reef in 15 m, N.W. side ofbay at Hative Besar, J .E. Randall and D. Pelasula, 1Oct. 1987; USNM 210384, 7(14.4-16.0), Saparua Reef

off Kulur (Kulor), 0-6.1 m, V. G. Springer and M. F.Gomon, 18 Jan. 1973. Maldives: BPBM 32919, 6 (13.1-18.6), South Malé Atoll, Maaniyafushi Island, reef, 25-30m, J. E. Randall, R. C. Anderson, M. S. Adam, 17 March1988. New Caledonia: ROM 63938, 1(20.3) Port deGoro, fringing reef off road, 22°20’00”S, 167°00’20”E,18.3-27.4 m, R. Winterbottom and G. Klassen, 15 Sept.1991; ROM 63939, 2 (17.4-17.6), Port de Goro, W. ofconcrete lighthouse, 22°20’00”S, 167°00’20”E, 18.3-25.9 m, R. Winterbottom, G. Klassen, P. Tirard, 3 Sept.1991. Papua New Guinea: ROM 68017, 1 (9.0), Fer-guson Is. reef, D’Entrecasteau Islands, 09°43’30”S,150°50’30”E, 15 m, J. L. Earle, 12 Dec. 1993; USNM243929, 2 (15.6-16.6), Amot Island, ocean side of reefon drop-off, 01°33’S, 144°59’E, 0-45.7 m, V. G. Springeret al., 31 Oct. 1978; WAM P. 28170-002, 5 (14.9-15.8), 6km S.E. of Rabaul, near Bai village at steep drop-off,04°11’S, 152°12’E, 25-34 m, G. Allen, 7 Oct. 1983.Philippines: ROM 49231, 31 (8.1-18.2), Cebu, BoholStrait, drop-off near point about 0.5 km S. of HudsonBeach (2 km S. of Tambuli Beach Resort), 10°15’N,124°00’E, 12-18 m, R. Winterbottom and E. Murdy, 8Aug. 1985. ROM 53011, 148 (8.3-20.0), Cebu, SumilonIs., Bohol Strait, W. side of island, (09°26’11”N,123°23’06”E, 9.1-22.9 m, G. Johnson, E. Downar, D.Catada, and V. Deran, 21 May 1987; ROM 53013, 3(15.3-17.4), Tonga Point, 09°12’17”N, 123°27’14”E, 9.1-21.3 m, R. Winterbottom, G. Johnson, M. Burridge-Smith, 22 May 1987; ROM 1308CS, 10 (14.2-19.5), ex-ROM 53011 (cleared and stained specimens); USNM264521, 3 (14.9-18.0), S.E. side of island, 09°04’38”N,123°16’44”E, 0-39.6 m, V.G. Springer et al., 7 June1978; Solomon Islands: ROM 46048, 14 (9.1-17.0),Guadalcanal Island, WWII Japanese wreck Bonegi 1,11.7 km N.W. of Honiara, 09°20’S, 159°45’E, 18-22 m,R. Winterbottom, R. Mc Kinnon, and P. Nichols, 14 March1983; ROM 841CS, 8 (10.0-17.2), wreck of Japanesewarship Ruaniu about 12 km N.W. of Honiara, 09°20’S,159°45’E, 20-22 m, P. Nichols and D. Evans, 23 April1983 (cleared and stained specimens).Non-types: Australia: WAM. Indonesia: BPBM, CAS,

Fig. 1. Trimma stobbsi n. sp., Ataoru, Indonesia. Specimen collected (BPBM 37386, 17 mm SL). Photographed under-water but probably either freshly dead or anaesthetised (scales in shoulder region apparently abraded off). Photo by J. E. Randall.

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ROM, USNM. Maldives: BPBM. New Caledonia: ROM.Papua New Guinea: BPBM, USNM, WAM. Philippines:LICPP, ROM, USNM. Solomon Is: AMS, ROM, WAM.

DiagnosisA species of Trimma with a yellow head, a grey-brown

body, and a distinct oval dark spot above and just ante-rior to the posterodorsal corner of the operculum. Thisspot is preceded by a shallow groove which extendsalong the dorsal margin of the operculum. No predors -al scales, posterior half of the nape with a slightly devel-oped longitudinal ridge in the midline, scales present oneither side of the ridge with a very narrow scaleless gapbetween them; slight interorbital trench which extendsposteriorly barely beyond mid pupil, no postorbitaltrench; fifth pelvic fin ray unbranched and 50-70% ofthe length of the fourth.

DescriptionThe description is based on the holotype and 242

specimens (values for the holotype in bold whereappropriate).

Dorsal fins VI + I 9-10, (x = 9.1, n = 47), second spinenot elongate or occasionally slightly elongate, reachingposteriorly to the base of the spine or first ray of the sec-ond dorsal fin when depressed. First ray of the seconddorsal fin may be branched or unbranched, all remain-ing rays branched; anal fin I 8-9 (x = 9.0, n = 47, 8 twice);P 16-18-19, (x = 17.6, n = 47, 16 twice, 19 twice), reach-ing posteriorly to a vertical through the base of the firstanal fin ray or just anterior to this. A variable number ofuppermost and lowermost rays unbranched withbranched rays in between (n = 47); V I 5, no frenum,basal membrane vestigial, first four rays with a singlesequential branch, fifth ray unbranched (one dichoto-mous branch on one side in three specimens), 50-70%of the length of the fourth ray; the fourth ray reachingposteriorly to the first to fifth elements of the anal fin.

Lateral scales 22-24 (x = 23.4, n = 38), anterior trans-verse scales 7-8-10 (x = 8, n = 43, 10 twice), posteriortransverse scales 7-8 (x = 7.4, n=43); no predorsal

scales in midline; a slightly developed, raised, longitud -inal fleshy ridge from the anterior of the dorsal fin to midnape, scales on either side of the ridge with a narrowscaleless gap between them, gap widens towards thehead where the ridge ends; two specimens had oneand two scales respectively across the nape anterior tothe ridge; no scales on cheek or opercle; scales onbreast, belly, and pectoral base cycloid; scales extendanteriorly 1/2 to one scale width posterior to the eye.

Ventral attachment of gill opening anywhere betweenthe vertical through posterior margin and mid point ofpupil. Teeth in both jaws consist of an outer row ofcurved, spaced, enlarged canines, with an inner row ofsmaller conical teeth. In some specimens large outercanines on the lower jaw appeared to be in pairs, with agap between.each pair. Tongue truncate or rounded.Gill rakers on first arch 2-4 (2 twice) + 11-14-15 (11, 15once) (x = 3.5 + 12.9, n = 34). Anterior nasal openinga long narrow tube, posterior nasal opening a pore witha raised rim. Bony interorbital 1/4 - 1/2 pupil width, witha poorly developed interorbital trench which does notextend posteriorly beyond the posterior 1/3 of the pupil;no postorbital trench.

Colour pattern in life: (from 35mm colour slides of liv-ing specimens from Flores (not collected), Ataoru(17mm), and Sabah (19 mm)). Distinct round to ovalspot (vivid red to dark red-brown) above and just ante-rior to the posterodorsal corner of the opercle. Head yel-low, with brown chromatophores, yellow pigmentextending around eyes and along the sides of the headjust beyond the opercular spot. Tinges of pink may bepresent on the opercle (probably from the gill filaments)and pectoral base. Body dull grey brown, with colourextending anteriorly to behind the pectoral base andalong the nape just posterior to the eye. Scale pocketsfaintly outlined with brown chromatophores. Dorsal finswith brown chromatophores, a yellow stripe just abovethe base. The specimen from Flores has a yellow headand the body appears to be a bright salmon pinkalthough brown chromatophores are present. Iridocytespresent on pectoral fins of the Flores specimen only.

Fig. 2. Trimma stobbsi n. sp., (freshly collected), Port de Goro, New Caledonia, ROM 63938 (paratype). Note piece ofextraneous mucus on snout. Photo by R. Winterbottom.

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Colour pattern freshly dead: (from 35mm colourslides of freshly dead specimens from the Philippines,Indonesia, New Caledonia, and Vanuatu). Backgroundcolour of head and body uniform orange with numerousbrown chromatophores throughout. Distinct black spot(1/3 pupil size) above and anterior to the posterodorsalcorner of the opercle, preceded by a groove which runs2/3 of the dorsal margin of the opercle. Greatest con-centration of brown chromatophores on body justabove the pectoral fin and posterior to the opercularspot. Scale pockets outlined with orange and brownchromatophores. Base of dorsal and anal fins withbrown chromatophores, a single row of orange spotson the fin rays of both dorsal fins, orange spots on thebase of the caudal fin; opercle, pectoral fin base, andpectoral fin pinkish. Two of the three slides of speci-mens from New Caledonia show specimens with a yel-low (rather than orange) background colour, dorsal andcaudal fin spots, and scale pockets.

Preserved coloration: background colour of headand body pale straw yellow sprinkled heavily withbrown chromatophores, body appears straw yellow tolight brown, head and belly (with fewer chrom -atophores) straw yellow. Dorsal and anal fins dusky,with a row of light spots just above the bases of thedors al fin rays; pectoral fins hyaline. Caudal and pelvicfins sprinkled lightly with chromatophores; scale pock-ets clearly outlined on anterior half of body.

AffinitiesTrimma stobbsi shares the characteristics of a distinct

opercular spot and no scales in the predorsal with T.RW sp. 65, T. sheppardi, and T. winterbottomi, but thesimpler colour pattern of T. stobbsi easily distinguishesit from these three species in both the live and the pre-served state. Trimma RW sp. 65 differs from T. stobbsiin possessing a pattern of spots and blotches on thehead, a full basal membrane and a fifth pelvic fin raywhich branches dichotomously twice. Trimma winter-bottomi can be distinguished from T. stobbsi by the darkbanding pattern on the upper part of the body, welldeveloped interorbital and postorbital trenches, fullbasal membrane and a fifth pelvic fin ray which is sub -equal to the fourth and branched dichotomously twice.Trimma sheppardi and T. stobbsi both have a raisedlongitudinal ridge that runs anterior from the dorsal finto the mid-nape and the dark spot above the opercle.The spot on T. sheppardi is an elongate oval (or tworounder spots side by side) and tends to be more post -erior on the body so that much of the spot is above thepectoral base, rather than above just the opercle as inT. stobbsi. Trimma sheppardi also has vertical bars onthe head, dark internal blotches along the vertebralcolumn, and no interorbital trench.

Distribution The new species has been found in the Indian Ocean

at the Maldive Islands. In the Pacific it has been

recorded from Indonesia, the Philippines, Papua NewGuinea, Solomon Islands, New Caledonia, and west-ern Australia. The specimens have been collected in1-40 m of water, on reefs and drop-offs, and in caves.

EtymologyNamed for Robin E. Stobbs, friend, guru, and col-

league, whose expertise in so many things was in -strumental in launching my career (especially the field-work aspects) all those years ago at the JLB SmithInstitute of Ichthyology in Grahamstown, South Africa.

This species has been informally referred to asTrimma RW sp. 23.

Trimmatom pharus n. sp. (Fig. 3)

Trimma eviotops (non Schultz - Samoa); Winterbottomand Emery, 1986: 62, Winterbottom, 1984: 698 (Figs.12-13).

Trimmatom RW sp. 6, Winterbottom and Anderson,1997: 21;1999: 115

Material examined A total of 12 lots, 75 specimens.

Holotype: ROM 72493, 16.6 mm SL female, Sey-chelles Is., inner reef just N. of Anonyme Is., 0-2.7 m, J.Böhlke et al., 2 Feb. 1964. ex-USNM 293526.Paratypes: Chagos Archipelago: ROM 40668, 1 (12.5mm SL), Great Chagos Bank, reef top on N. tip of EagleIs., R. Winterbottom and A. Emery, 25 Feb. 1979; ROM40669, 3 (10.7-11.1), Great Chagos Bank, inner lagoon(N. E. side) of the middle of Three Brothers Is., R. Win-terbottom and A. Emery, 28 Feb. 1979; USNM 261264,1 (13.2), Diego Garcia atoll, reef S.E. of Middle Is.,07°13’49” S 072°24’31”E, 0-2.4 m, H. A. Fehlmann andC. F. Rhyne, 21 June 1967; Seychelles: ANSP Stn F66,Seychelles Island Program 1964, 1 (15.4),Curieuse Is., shallows, S. of Rouge Pt. 10.7-15.2 m, J.Böhlke et al., 24 Feb. 1964; ANSP STN F-82, Sey-chelles Island Program 1964, 17 (9.7-15.4), AmiranteIs., Remire Reef, N. and a bit E. of Eagle Is. on the flats,0-9.1 m, J. Böhlke et al., 4 March 1964; ROM 1264 CS, 5 (9.7-12.7), AmiranteIs., 0-4.6 m, ex USNM 293530; USNM 293526, 3 (14.3-17.0), Mahé vicinity, inner edge of reef where seasbreak, just N. of Anonyme Is. (Adm Ch. 1072), 0-2.7 m.,J. Böhlke et al., 2 Feb. 1964; USNM 293530, 28 (9.8-14.8), Amirante Is., African Is., S.E. of South Is. (Adm.Ch. 724) 0-4.6 m, J. Böhlke et al., 2 March 1964; Maur -itius: USNM 263555, 2 (15.9-17.7), Cargados CarajosShoals, 16°15’S, 059°35’ E, just N.E. of Siren Is., 16.8-21.3 m, V.G. Springer et al., 12 April 1976; USNM263558, 3 (8.9-17.1), Cargados Carajos Shoals,16°15’S, 059°35’E, off N.W. shore of Albatross Is., 0-18.3 m, V. G. Springer et al., 14 April 1976; USNM293531, 10 (10.5-17.4), Cargados Carajos Shoals,16°25’S, 059°36’ E, off N. tip of St. Brandons Shoals

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(contiguous portion), Albatross Is., 6.1-10.7 m, V. G.Springer et al., 6 April 1976. Non-types: Timor Sea: NTM, WAM. Indonesia: USNM.Philippines: AMS, USNM. New Guinea: USNM.Solomon Islands: ROM. Japan: NTM.

DiagnosisTrimmatom pharus differs from T. nanus, T. offucius,

and T. sagma in possessing scales on the body (vsnaked) and branched pelvic fin rays (vs unbranched).Trimmatom zapotes, T. macropodus, and T. pharus allhave body scales but T. zapotes has unbranchedpelvic fin rays, and T. macropodus has the first threepelvic fin rays branched, whereas T. pharus has the firstfour pelvic fin rays branched.

Trimmatom pharus shares many meristic character-istics with T. eviotops including the presence of bodyscales and the branching of the first four pelvic finrays; the two species do, however, differ in details ofcolour pattern. In preserved specimens the first bodybar on T. eviotops crosses the pectoral base andextends over the dorsum, passing backwards to thefirst dorsal fin. In Trimmatom pharus the body barwhich crosses the pectoral base crosses the dorsalsurface anterior to the dorsal fin. Trimmatom eviotopshas a broad dark saddle on the dorsal half of thecaud al peduncle, while Trimmatom pharus has anarrow body bar or small dark saddle.

DescriptionBased only on specimens from the western Indian

Ocean except where otherwise stated. Includes theholotype and 29 paratypes (values for the holotype inbold where appropriate).

D VI+9, third spine longest, reaching to the origin ofthe second dorsal fin; A 9; rays of both dorsal and analfins unbranched; P 17-18-20 (x = 18.3), reaching post -eriorly to a vertical in line with the anus, raysunbranched; V I 5, no frenum, a rudimentary basalmembrane, fifth ray unbranched, 10-20% length of thefourth ray, first four rays with a single bifurcation, fourth

ray reaching posteriorly to base of second anal ray. Lateral scales 19-23-25 (x = 22.3, n = 9); anterior

transverse scales 6-7; posterior transverse scales 7.No scales on the pectoral and prepelvic regions.

Gill opening wide, reaching to below the posteriormargin of the orbit anteroventrally. Mouth terminal,inclined dorsally; both jaws with an outer row ofenlarged, curved, spaced canines (the largest at thebend of the dentary) and inner rows of small conicalteeth. Anterior nasal opening tubular, posterior nasalopening tubular or with a well developed raised rim.Tongue truncate or emarginate. No trough or trench inthe interorbital region. Bony interorbital less than halfpupil diameter. First gill slit open, gill rakers 1-2-3 + 8-9-11 = 9-14 (x = 2.2 +10). Head pores absent, headpapillae as in fig. 13 in Winterbottom, 1984.

Colour pattern freshly dead: (based on a slide ofa non-type specimen, AMSI.21903, from Bolinao,Philippines) background translucent but heavilysprink led with melanophores. Twelve red bars acrosshead and body. First bar extending beneath the eye inline with the anterior margin of the pupil to the post -erior edge of the mouth, with a short dark bar on eachside; second bar just behind the posterior edge of eye;third bar anterior to and curving with the pectoralbase; fourth bar at anterior edge of first dorsal fin,slightly curving anteriorly and joined ventrally to thefifth bar; fifth bar centred between first and secondspines of the first dorsal fin and joined with the fourthbar; sixth bar between fourth and fifth spines of firstdorsal fin; seventh bar anterior to spine of seconddors al fin; eighth bar between the base of the spineand first ray of second dorsal fin; ninth and tenth barsdifficult to determine; eleventh bar at base of last rayof second dorsal fin; and twelfth bar just posterior tosecond dorsal fin. Pelvic and pectoral fins pale orangearea posterior to twelfth bar, and caudal fin, suffusedwith red-orange. Dorsal fins with an orange longitudi-nal stripe just above the base. Darker melanophore pat-tern bordering the posterior edge of pectoral base.

Preserved coloration: (based on the type series -


Fig. 3. Trimmatom pharus n. sp. (freshly collected), Philippines, Bolinao, AMS I21903 (non-type specimen). Note: darkrounded object below anal fin is an artifact. Photo by D. F. Hoese.

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aqua vol. 5 no. 1 - 2001 24


see also Winterbottom, 1984, figs. 12-13). In preservedspecimens, areas of red pigmentation become a lightstraw colour, while the light areas between the red barsdarken significantly to produce the dark bars seen inthe preserved state.

Background colour pale straw yellow, sprinkled withchromatophores on head and body A short dark barbelow middle of eye, another across head just behindeye, and a third across opercle. Four to eight barsacross the body, often with incomplete bars (do notcross the dorsal surface) between the main bars. Firstbody bar across pectoral base and crossing midlineanterior to first dorsal fin. The position of subsequentbars varies depending on the number of complete andincomplete bars present. The final body bar is just ante-rior to the anteriormost unbranched caudal fin ray andmay either appear as a small saddle across the back orextend below the midlateral septum. Dorsal, anal, andpelvic fins with chromatophores, caudal fin and most ofpectoral fin hyaline.

AffinitiesTrimmatom pharus differs from the species in the T.

nanus complex in having four branched pelvic fin rays.Although very similar to T. eviotops in meristic charac-teristics, T. pharus differs from T. eviotops in details ofcolour pattern. In preserved specimens, Trimmatomeviotops has eight vertical bars across the head andbody. The bar which crosses the pect oral baseextends back over the dorsum to the first dorsal fin. InTrimmatom pharus the number of body bars are vari-able and the body bar which crosses the pectoralbase crosses the dorsal surface anterior to the dorsalfin. Trimmatom eviotops also has a broad dark saddleon the dorsal half of the caudal peduncle, while T.pharus has a small dark saddle or narrow body barover the caudal peduncle. In fresh specimens, T.eviotops exhibits dark bars on an orange backgroundwith the saddle over the caudal peduncle clearly visi-ble. Trimmatom pharus has orange bars over atranslucent background. The area of the caud alpeduncle is suffused with red-orange pigment and nobars are clearly visible.

DistributionTrimmatom pharus has been found in the Indian

Ocean at Amirantes Islands, Seychelles, CargadosCarajos, Sumatra, and Chagos Archipelago. The geo-graphic distribution extends into the western Pacificand includes Japan, Philippines, Solomon Islands,Papua New Guinea, and the Timor Sea. Specimenswere collected at a wide range of depths from 0-28 m,on shoals and reefs, and in lagoons.

EtymologyFrom the Latin pharus meaning a lighthouse or beac -

on, both of which are usually painted with alternatingred and white bands, alluding to the live/freshly col-

lected colour pattern of the new species. To be treatedas a noun in apposition.

AcknowledgementsMany thanks to the numerous curators and collect ions

managers (especially S. Jewett of the USNM) whomade material available, and to Marty Rouse andKaren Dietz (of the ROM) for curating these collections.Also, grateful thanks to the numerous part-time ortemp orary research assistants who compiled much ofthe data on which this contribution is based, and espe-cially Margaret Zur who performed the final compilationand description. I am grateful to Doug Hoese, of theAustralian Museum, who, perhaps unwittingly, providedthe colour slide used to illustrate a freshly collected(non-type) specimen of Trimmatom pharus, and to JackRandall for use of his photograph of Trimma stobbsi.

This paper was supported by a National Science andEngineering Research Council of Canada ResearchGrant OGP0007619 to the author. Field work was gen-erously supported in part by the ROM Foundation. Thisis Contribution No. 241 of the CBCB ROM which is sub-mitted for publication to aqua, Journal of Ichthyo -logy and Aquatic Biology.

References Winterbottom R. 1984. A review of the gobiid fish

genus Trimma from the Chagos Archipelago, centralIndian Ocean, with the description of seven newspecies. Canadian Journal of Zoology 62: 695-715.

Winterbottom R. 1989. A revision of the Trimmatomnanus species complex (Pisces, Gobiidae), with de -s criptions of three new species and redefinition of Trim-matom. Canadian Journal of Zoology 67: 2403-2410.

Winterbottom, R. 1995. Red Sea gobiid fishes of thegenus Trimma, with the description of two newspecies. Revue francaise d’Aquariologie 22: 93-98.

Winterbottom R. & R. C. Anderson 1997. A revisedchecklist of the epipelagic and shore fishes of theChagos Archipelago, Central Indian Ocean. Ichthy-ological Bulletin, Smith Institute 66: 1-28.

Winterbottom R. & R.C. Anderson 1999. Fishes of theChagos Archipelago. In: Ecology of the Chagos Arch i -pelago (Eds. C. R. C. Sheppard & R. C. Anderson)Linnaean Society Occasional Publications, London.101-107.

Winterbottom R. & A.R. Emery 1981. A new genusand two new species of gobiid fishes (Perciformes)from the Chagos Archipelago, Central Indian Ocean.Environmental Biology of Fish, 6: 139-149.

Winterbottom R. & A.R. Emery 1986. Review of thegobiid fishes of the Chagos Archipelago, CentralIndian Ocean. Royal Ontario Museum, Life ScienceContributions (142): v+82 pp.

aqua vol. 5 no. 1 - 200125

KeywordsBlenniidae, Meiacanthus, Allomeiacanthus, fang-

blenny, new species, Indian Ocean, buccal toxic glands,mimicry

AbstractThe 3 subgenera and 25 species of Indo-Pacific

blenniid fishes of the fangblenny genus Meiacanthusare differentiated in a key. Meiacanthus urostigma, newspecies, is described from the Surin Islands and north-ern Sumatra. This region of the Indian Ocean appearsto be a localized area of endemism, attributable toglacial sea-level lowering events. The new species isdistinguished from its congeners by its colour patterncharacterized by a uniformly pale tan body with a nar-row dark lateral stripe extending from the snout to nearthe beginning of the bright orange-yellow caudalpeduncle where it is typically interrupted and replacedby an elongate black spot. The new species is the sec-ond known member of the subgenus Allomeiacanthus(type species Meiacanthus ditrema Smith-Vaniz). Thissubgenus differs from the other subgenera mostnotably in having a toxic buccal gland that is ventrallypositioned and encapsulated by the dentary bone,absence of a lateral line, and only 2 pores (3 in theother subgenera) in the mandibular and posttemporalseries. Juveniles of the new species appear to be socialmimics of similar-sized individuals of the cardin alfishCheilodipterus quinquelineatus. Mimetic relationshipsinvolving species of Meiacanthus are discussed andcolour photographs are given of selected mimetic pairs.

ZusammenfassungDie drei Untergattungen (mit 25 Arten) der indo-pazi-

fischen Säbelzahn-Schleimfisch-Gattung Meiacanthussind in einem Schlüssel differenziert. Meiacanthusurostigma wird als neue Art von den Surin-Inseln unddem nördlichen Sumatra beschrieben. Diese Gegenddes Indischen Ozeans scheint ein lokalisiertes Gebietvon Endemismus zu sein, verursacht durch eiszeitlich-bedingte Senkung der Meeresoberfläche. Die neue Artunterscheidet sich von ihrer Gattungsverwandten durch

ein Farbmuster bestehend aus einheitlich blass gelb-braunen Körper mit einem schmalen, dunklen Mittel-streifen, der sich von der Schnauzenspitze bis zumAnfang des hell, orange-gelben Schwanzstiehleserstreckt, wo er durch einen länglichen, schwarz Punktersetzt wird. Die neue Art ist das zweite bekannte Mit-glied der Untergattung Allomeiacanthus (Typ-SpeziesMeiacanthus ditrema Smith-Vaniz). Diese Untergattungunterscheidet sich von den anderen Untergattungenbesonders durch die Anwesenheit einer giftigen Wan-gendrüse in ventraler Lage und ist dort vom Zahnbeineingeschlossen, Abwesenheit einer Seitenlinie, und nurmit 2 Poren (im Gegensatz zu 3 in den anderen Unter-gattungen) in der mandibularen und post-temporalenSerie. Jungtiere der neuen Art scheinen sozialeKopierer von etwa gleich-großen Exemplaren des Kar-dinalbarsches Cheilo dipterus quinquelineatus zu sein.Mimetische Verwandtschaften unter Meiacanthus-Artenwerden diskutiert und sind begleitet bei einer Auswahlvon Farbfotos mimetischer Paare.

RésuméLes 3 sous-genres et les 25 espèces de blennies à

dents de sabre Indo-Pacifiques du genre Meiacanthussont différenciés dans une clé. Meiacanthus urostigma,n. sp. est décrit des Iles Surin et du nord Sumatra. Cetterégion de l’Océan Indien apparaît comme une airelocalisée d’endémisme attribuable aux abaissementsdu niveau marin provoqués par les glaciations. L’e-spèce nouvelle se distingue de ses congénères parson patron de coloration consistant en une couleur uni-formément brun-clair du corps, avec une bande foncéeétroite du museau au voisinage du début du pédiculecaudal, lequel est jaune-orangé vif; là, la bande est typ-iquement interrompue et remplacée par une tachenoire allongée. L’espèce nouvelle est le second mem-bre connu du sous-genre Allomeiacanthus (espèce-type Meiacanthus ditrema Smith-Vaniz), qui diffère enparticulier des autres sous-genres par la possessionsd’une glande buccale toxique située ventralement etencapsulée dans l’os dentaire, l’absence d’une lignelatérale et seulement 2 pores (cf 3 chez les autres


Meiacanthus urostigma, a New Fangblenny from the Northeastern IndianOcean, with Discussion and Examples of Mimicry in Species of

Meiacanthus (Teleostei: Blenniidae: Nemophini).

William F. Smith-Vaniz1, Ukkrit Satapoomin2, and Gerald R. Allen3

1) U.S. Geological Survey, Florida Caribbean Science Center, 412 NE 16th Avenue–Room 250, Gainesville, FL 32601-3701, USA

2) Phuket Marine Biological Center, P.O. Box 60, Phuket 83000, Thailand3) Department of Aquatic Zoology, Western Australian Museum, Francis St., Perth, WA 6000

and Conservation International, 1919 M St. N.W., Suite 600 Washington, DC 20036, USA

Accepted 15.11.2001

sous-genres) en rangées mandibulaire et post-tempo-rale. Les jeunes de l’espèce nouvelle sont apparem-ment des mimes sociaux d’individus de même taille duPoisson-cardinal Cheilodipterus quinquelineatus. Lesrelations mimétiques impliquant des espèces de Meia-canthus sont discutées et des clichés-couleur de pairesmimétiques sélectionnées sont présentés.

SommarioViene presentata una chiave dicotomica per l’identifi-

cazione dei 3 sottogeneri e delle 25 specie di bavosedell’Indo-Pacifico appartenenti ai blennidi denti a scia-bola del genere Meiacanthus. È inclusa anche ladescrizione di una nuova specie, Meiacanthusurostigma, sulla base di esemplari raccolti nelle IsoleSurin e a nord di Sumatra, un’area ricca di specieendemiche, originatasi grazie ad abbassamenti del liv-ello del mare durante le glaciazioni. La nuova specie sidistingue principalmente per la livrea di marrone chiarouniforme, attraversata da una sottile stria scura che dalmuso si estende fino al peduncolo caudale, di un vivacegiallo-arancio, dove viene interrotta e sostituita da unamacchia nera allungata. Si tratta della seconda speciedel sottogenere Allomeiacanthus (specie-tipo Meiacan-thus ditrema Smith-Vaniz). Questo sottogenere si con-traddistingue per avere una ghiandola boccale tossicain posizione ventrale e incapsulata nell’osso dentale,per l’assenza della linea laterale e per avere solo 2 pori(3 negli altri sottogeneri) nelle serie mandibolare e post-temporale. Gli individui giovani assumono colorazionemimetica simile ad individui della stessa taglia di pescicardinale della specie Cheilodipterus quinquelineatus.Viene discusso il mimetismo nel genere Meiacanthus e vengono mostrate fotografie di alcune coppiemimetiche.

IntroductionThe tribe Nemophini, generally known as the saber-

toothed blennies, is one of six currently recognizedtribes (Williams, 1990) used to classify the approxi-mately 350 species of the Blenniidae. This essentiallyIndo-Pacific tribe of blennies (one species, Pla-giotremus azaleus (Jordan and Bollman), occurs in theeastern Pacific Ocean) derives its common name froman impressive pair of dentary canines which are usedonly in territorial threat displays or for defensive pur-poses. These canines are present in each of the fivenemophinine genera: Petroscirtes Rüppell, 1830; Aspi-dontus Cuvier, 1834; Xiphasia Swainson, 1839; Pla-giotremus, Gill, 1865; and Meiacanthus Norman, 1943.Smith-Vaniz (1976) defined the tribe and its componentgenera, treating all previously described taxa plus 13new species. In an update of his monograph, Smith-Vaniz (1987) described additional new taxa, bringing to48 the total known species of nemophinine blennies.

One of the most interesting specializations is the toxicbuccal gland present in Meiacanthus, which isunknown in any other fishes (Fig. 1). In addition to the

nominal subgenus, two others are recognized,Allomeiacanthus Smith-Vaniz, 1976 and Holomeiacan-thus Smith-Vaniz, 1976, each with a different glandarrangement (Fig. 2). The glands are positioned nearthe base of a pair of deeply grooved canines (Figs. 3-4). Springer (1968) first called attention to these uniqueglands. Springer and Smith-Vaniz (1972) subsequentlydescribed the general histology of the glands of Meia-canthus grammistes, and Fishelson (1974) gave adetailed description of the histology and ultrastructureof the glands of M. nigrolineatus. Field and laboratoryexperiments and observations have revealed thatspecies of Meiacanthus can use their fangs to inject anoxious substance that causes some predatory fishesto avoid or reject them as potential prey (Losey, 1972;Springer and Smith-Vaniz, 1972). Slight pressure onthe gland, which lacks ducts, produces a milky secret -ion that tends to be channeled along the groove of thecanine tooth. The physiological reactive agent of thegland has not been determined and could be distaste-ful, venomous, or both, but it has a powerful effect. Thefew people who have accidentally or deliberately beenbitten by a Meiacanthus experienced only mild pain, butswelling surrounding the site of the fang punctures indi-cated a biological response disproportional to themechanical injury. After ingesting a living Meiacanthus,the usual reaction of most naïve fish predators is im -mediately to spit out the blenny (which typically swimsaway apparently unharmed), followed by signs of dis-tress such as mouth gaping and rapid opening andclosing of the opercula. In contrast, dead or defanged

aqua vol. 5 no. 1 - 2001 26

Meiacanthus urostigma, a New Fangblenny, with Discussion and Examples of Mimicry in Species of Meiacanthus

Fig. 1. Meiacanthus nigrolineatus: section of toxic buccalgland (g) and canine (c), x 80. Modified from Fishelson,1974; used with permission.

Meiacanthus are ingested with impunity. This reduced vulnerability to predation has allowed

species of Meiacanthus to occupy a wide range ofhabitats and to spend time in the open away from pro-tective cover. Some species also have very conspicu-ous or bright coloration, which may have an apose-matic function (warning signal) similar to that of certainunpalatable insects and their mimics (Wickler, 1968).

At least 11 species of Meiacanthus, including the newspecies described in this paper, are known or sus-pected to be mimetic models in relationships with otherfishes. These cases are discussed in a following sect -ion on mimicry.

The genus Meiacanthus includes 24 currently recog-nized species (Smith-Vaniz, 1987). Adults range in sizefrom about 30 to 87 mm SL, and most species occupyshallow reef habitats (deepest record of occurrence 37m). One notable exception is Meiacanthus anema(Bleeker), the only member of the subgenus Holomeia-canthus, which typically occurs in estuarine or nearlyfreshwater habitats, often where mangroves are abund -ant. Some collections have come from 1.5 km upstream in a small river where the water was fresh to the

taste. The combination of a well-developed swim -bladder (absent in most blenniids) and reducedvulnera bility from predation has allowed species ofMeiacanthus to forage over a wide area away from pro-tective cover. These diurnally active fishes rarely rest onthe substrate and spend most of the day activelysearching for small benthic invertebrates or pickingplankton from the water column. As Fishelson (1975)observed for M. nigrolineatus, they tend to jerk fromspot to spot and, hovering over one place, detect preyvisually and seize it with a short strike. Juveniles usu-ally occur in groups of 5-10 individuals but the adults ofmost species are strongly territorial. Adults use tubes ofsponges and empty shells for shelter. Losey (1972)noted that at Eniwetak Atoll, M. atrodorsalis formedloose aggregations of up to 50 individuals feeding onplankton while hovering less than 1 m above the reef.Relatively compact and stationary schools of 40-50individuals of M. ditrema have also been observedfeeding in the water column.

We first became aware of the existence of the newMeiacanthus described herein in January 1997, whenfour specimens were collected at Surin Neur Island offthe southwest coast of Thailand. The same species ofMeiacanthus was subsequently discovered off northernSumatra. Not only has this fangblenny proved to be anew species, it is also the second known species of thesubgenus Allomeiacanthus. The new Meiacanthus has

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William F. Smith-Vaniz, Ukkrit Satapoomin, and Gerald R. Allen

Fig. 2. Lower jaws (lateral, dorsal, and mesial views) ofthe three subgenera of Meiacanthus: top, M. (Allomeia-canthus) ditrema, ANSP 124891, 26.2 mm SL; middle,M. (Meiacanthus) grammistes, ANSP 128536, 42.9 mmSL; bottom, M. (Holomeiacanthus) anema, ANSP124867, 40.3 mm SL. Abbreviations: d, dentary; ar,anguloarticular; a, retroarticular; rc, replacement canine.Modified from Smith-Vaniz (1976).

Fig. 3. Anterodorsal view of right dentary canine of Meia-canthus atrodorsalis, showing deep groove along ante-rior surface (dentary gland removed); scanning electronphotomicrograph, x 50, after Smith-Vaniz (1976).

all the diagnostic characters originally used to definethe subgenus, including a dentary gland that is ventrallypositioned and encapsulated in the dentary bone,absence of a lateral line, mid-point of supratemporalcanal ending in a pair of pores, and only 2 pores eachin the mandibular and lateral temporal series; thereduction in number of lateral temporal pores is corre-lated with a greatly reduced posttemporal bone (seeSmith-Vaniz, 1976: Fig. 5).

Materials and Methods Procedures for taking counts and measurements

are those of Smith-Vaniz (1976), except that sensorycanal and pore terminology has been modified toagree with that of Hastings and Springer (1994). Thecanal that extends from the dorsal end of the preop-ercle, arching dorsally and extending posteriorlyabove the opercle and passing through the posttemp -oral bone (except in Allomeiacanthus, in which thatbone is greatly reduced) is now referred to as theposttemporal canal series; and pores associated with

that series are referred to as posttemporal poresinstead of lateral temporal pores. Pores in thesupratemporal canal series are identified as lateralsupratemporal (LST) pores and median supratempo-ral (MST) pores. All species of Meiacanthus have 1LST pore on each side; the subgenus Meiacanthushas 1 MST pore and the other subgenera typicallyhave 2 MST pores.

Abbreviations used for institutional specimen depos-itories are as follows: Academy of Natural Sciences ofPhiladelphia (ANSP); Phuket Marine Biological Cen-ter, Thailand (PMBC); Royal Ontario Museum, Toronto(ROM); National Museum of Natural History, Wash-ington, D.C. (USNM); Western Australian Museum,Perth (WAM).

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Fig. 4. Anteromesial view of right dentary canine of Meia-canthus ditrema, showing deep groove along anteriorsurface (dentary gland and flange of dentary bone thatwraps around base of canine removed); scanning elec-tron photomicrograph, x 110.

Fig. 5. General physiognomy and cephalic sensory porepatterns in selected species of Meiacanthus: (a) M.(Allomeiacanthus) urostigma n. sp., USNM 348776, holo-type, male, 34.2 mm SL, Surin Neur Island; (b) M.(Holomeiacanthus) anema, USNM 211959, male, 42.0mm SL, Indonesia, Banda Sea; (c) M. (Meiacanthus)grammistes, ANSP 124879, female, 43.2 mm SL, PalauIslands. Small arrows identify ventralmost supraorbitaland dorsalmost preopercular pores in both lateral anddorsal views.

Meiacanthus (Allomeiacanthus) urosti gma n. sp.(Figs. 5a, 6-8)

Holotype: USNM 348776, 34.2 mm SL, male, SurinIslands, Surin Neur Island, south coast, PhangngaProvince, 9°24’56”N, 97°52’40”E, 7 m, upper reefslope, collected with hand-net and quinaldine by UkkritSatapoomin, 7 Jan. 1997.Paratypes: 8 specimens 15.8-37.2 mm SL. PMBC13711 (1, 27.2), female; ROM 71661, (1, 23.0), female;USNM 348777 (1, 17.2), juvenile, cleared & stained, allcollected with the holotype. PMBC 16136 (1, 28.0)

female and (2, 15.8-16.7) juveniles, Surin Islands, SurinNeur Island, Meyai Bay, 9°26’00”N, 97°53’25”E, 13 m,hand-net, Ukkrit Satapoomin, 7 Apr. 2000. WAMP.31527-001 (2, 30.8-37.2), males, northern Sumatra,Aceh, Weh Island, Gapang Lagoon, 5°51.81’N,95°16.05’E, 3-5m, Gerald R. Allen, 27 Jan. 1999.

DiagnosisA species of Meiacanthus with dentary glands pos -

itioned ventrally and encapsulated in dentary bone; nolateral line; mid-point of supratemporal canal ending inpair of pores; only 2 pores each in mandibular and post-temporal series; postemporal bone reduced, wedge-

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Fig. 6. Meiacanthus urostigma n. sp., male, 34.2 mm SL, holotype, Surin Neur Island. Photo by U. Satapoomin.

Fig. 7. Meiacanthus urostigma n. sp., male, 37.2 mm SL, paratype, northern Sumatra. Photo by G. R. Allen.

Fig. 8. Meiacanthus urostigma n. sp., female, 27.2 mm SL, paratype, Surin Neur Island. Photo by U. Satapoomin.

shaped without ventral arm; 4 infraorbital bones; andcolour pattern characterized by uniformly pale tan bodywith narrow dark lateral stripe extending from snout tonear beginning of bright orange-yellow caudal pedun-cle, where it is typically interrupted and replaced byelongate black spot.

Description(See Table I for frequencies of certain meristic charac-ters.)

Dorsal fin IV or V, 22-24, total 27-29. Anal fin II, 15 or16. Caudal fin: procurrent rays 5-7+5-7 = 12 or 14; seg-mented rays 13. Vertebrae: precaudal 11 or 12, caudal21 or 22, total 32-34, usually 33. A pair of canines post -eriorly in each jaw; incisor teeth in adults: lower jaw 16-19; upper jaw 16-18. No lateral line; mandibular pores 2;posttemporal pores 2; median supratemporal pores 2.

Sexual dimorphism absent in pelvic fins and welldeveloped in caudal fins (in 3 males 30.8, 34.2, 37.2mm SL and 2 females 27.2, 28.0 mm SL); pelvic fin:males 11.0, 11.7, 9.1 % SL, females 10.3, 10.0 % SL;longest caudal fin ray: males 40.1, 43.9, 58.3 % SL,females 21.3, 22.1 % SL.

Colour in life (Fig. 7): light grey over most of headand body, grading to white on abdominal region; pro -minent mid-lateral black stripe from snout, passingthrough eye to just above upper pectoral fin base andcontinuing to caudal peduncle where it either term -inates or connects to horizontally elongate black spotsurround by yellow-orange coloration that covers entirecaudal peduncle; dorsal and anal fins dusky grey withnarrow white margin, frequently with narrow blackstripe along base; remainder of fins whitish to trans -lucent with slight yellowish wash covering middle cau-dal fin rays.

Colour in alcohol: generally tannish, becomingdusky grey along uppermost portion of back and abovebase of anal fin; prominent mid-lateral black stripe fromsnout, passing through eye to just above upper pec-

toral fin base and continuing to caudal peduncle whereits width is expanded and surrounded by white col-oration that covers entire caudal peduncle; dorsal andanal fins dusky grey with narrow white distal mar-gin; remainder of fins whitish except dusky submarginalstreak sometimes present on upper and lower edges ofcaudal fin. In most specimens mid-lateral stripe termi-nates just anterior to caudal peduncle, which has iso-lated, horizontally elongate, black spot on middle por-tion. The largest Sumatran male paratype (Fig. 7) isexceptional in having dark lateral stripe continuous withpeduncular spot on left side only.

Preserved and fresh specimens frequently exhibitnarrow black stripe just below dorsal fin base and alonganal fin base.

DistributionKnown only from the northeastern Indian Ocean at the

Surin Islands and northern Sumatra (Fig. 9). Meiacan-thus (Meiacanthus) smithi is the only other species ofthe genus known from the northeastern Indian Ocean.

RemarksMeiacanthus urostigma and M. ditrema are the only

known members of the subgenus Allomeiacanthus,and these sister species have allopatric distributions(Fig. 9). They can easily be distinguished from eachother by differences in colour pattern. M. ditrema (Fig.10) differs from the new species most obviously by hav-ing a dark mid-lateral stripe that forks at the front of thepectoral fin and is continuous to the base of the caudalfin, and a caudal peduncle the same colour as adjacentparts of the body.

Both species inhabit shallow protected reefs and fre-quently form schools while hovering well above the bot-tom to feed on zooplankton. In the Surin Islands adultsof the new species were observed hovering above coraloutcrops in small to large aggregations, the largest con-sisting of over 100 individuals. In northern Sumatra a

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Dorsal fin spines Dorsal fin rays Total dorsal fin elements

Species 4 5 6 x 22 23 24 25 26 x 27 28 29 30 31 x

M. urostigma 1 8 - 4.9 3 3 3 - - 23.0 3 4 2 - - 27.9M. ditrema 3 59 5 5.0 2 9 39 16 1 24.1 - 10 41 15 1 29.1

Anal fin rays Total pectoral fin rays Total caudal fin rays

Species 15 16 17 18 x 26 27 28 29 30 x 21 22 23 24 25 x

M. urostigma 3 5 1 - 15.8 - - 8 - 1 28.2 - - 2 2 4 24.3M. ditrema 2 21 41 3 16.7 7 10 45 3 2 27.7 19 17 24 - - 22.1

Precaudal vertebrae Caudal vertebrae Total vertebrae

Species 11 12 x 21 22 23 24 x 32 33 34 35 x

M. urostigma 8 1 11.1 1 8 - - 21.9 1 7 1 - 33.0M. ditrema 29 37 11.6 12 34 18 2 22.2 - 22 40 4 33.7

Table I. Frequency distributions for certain meristic characters of two species of Meiacanthus, subgenusAllomeiacanthus.

– – –

–––

– – –

solitary fish and a group of approximately 10 individu-als of M. urostigma were seen on two occas ions atGapang Lagoon in an area with abundant live coral.

Several species of shore fishes either have restricteddistributions closely matching that of Meiacanthusurostigma (eg Cephalopholis polyspila Randall & Sat-apoomin, Archamia ataenia Randall & Satapoomin,Blenniella leopardus (Fowler), Siganus magnificus

(Burgess), Halichoeres kallochroma Bleeker, and anundescribed Scarus), or are possibly endemic to theAndaman Sea (eg Pseudochromis andamanensis Lub-bock, Plesiops thrysanopterus Mooi, Pomacentrusalleni Burgess, P. polyspinus Allen, Pomadasysandamanensis McKay & Satapoomin, Plectorhinchusmacrospilus Satapoomin & Randall, and Hapalogenysmerguiensis Iwatsuki, Satapoomin, & Amaoka). Other

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Fig. 9. Distribution of Meiacanthus urostigma n. sp. and M. ditrema, the only known species of the subgenus Allomeia-canthus.

Fig. 10. Meiacanthus ditrema, about 60 mm TL, Flores, Indonesia. Photo by R. Steene.

species have distributions largely restricted to the east-ern margin of the Indian Ocean but range further southalong the western margin of Indonesia (eg Ecseniuslubbocki Springer, E. paroculus Springer, Pomacentrusazuremaculatus Allen, P. xanthosternus Allen, Hoplo-latilus luteus Allen & Kuiter, and an undescribed Opis-tognathus). Like the two species of Allomeiacanthus, anumber of these appear to be paired with a closelyrelated central Pacific species. Springer and Williams(1990, 1994) and Randall (1998) document otherexamples of probable species pairs found on oppositesides of the region extending from the Thailand Penin-sula to southwestern Indonesia. They also discusshypotheses associated with glacial sea-level loweringto account for such phylogeographic patterns.

EtymologyThis species of Meiacanthus is named urostigma, a

combination of the Greek oura (tail) and stigma (spot),in reference to the prominent basicaudal spot, the mostdiagnostic feature of its colour pattern. Urostigma ishere used as a noun in apposition.

Key to the species of Meiacanthus1a. Dentary gland ventrally positioned and encapsul -

ated in dentary (Fig. 2, top); mandibular and post-temporal canal series each with 2 pores (Fig. 5a);lateral line absent (subgenus Allomeiacanthus)..........................………………………………...…2

1b. Dentary gland dorsolaterally positioned and notencapsulated in dentary; mandibular and post-temporal canal series each with 3 pores (Figs. 5b-c); short lateral line present .......….....................3

2a. Dark mid-lateral stripe forks at front of pectoral fin,with dorsal arm extending through eye and ventral arm extending to gape; dark lateral stripecontinuous posteriorly and caudal peduncle notconspicuously coloured in life (western and central Pacific) ………..........................................................Meiacanthus ditrema Smith-Vaniz, 1976

2b. Dark lateral stripe not forked at front of pectoralfin; dark lateral stripe interrupted slightly anteriorto caudal peduncle (continuous on one side onlyin one specimen) and caudal peduncle conspicu-ously coloured, yellow-orange in life (northeasternIndian Ocean) ….................................................................Meiacanthus urostigma, new species

3a. Dorsal fin spines 6-10 (rarely 6); segmented dors -al fin rays 20-24; supratemporal canal typicallywith 2 median pores (Fig. 5b), 3 of 205 specimenswith a single pore; dentary gland supported bydentary and anguloarticular bones and held inplace laterally by flange of dentary (Fig. 2,bottom); infraorbital bones 4 (subgenusHolomeiacanthus) (western and central Pacific)……………..Meiacanthus anema (Bleeker, 1852)

3b. Dorsal fin spines 3-6 (rarely 6); segmented dorsal

fin rays 23-28; mid-point of supratemporal canaltypically ending in single pore (Fig. 5c); dentarygland supported solely by dentary and held inplace laterally by flange of dentary (Fig. 2,middle); infraorbital bones 3 (subgenusMeiacanthus) .........…………………………….....4

4a. Adults with one or more conspicuous lateralstripes on body, and/or belly and underside ofhead dark and strongly vermiculated .................5

4b. Adults without lateral stripes on body (except M.nigrolineatus, which has an oblique lateral stripe -see 20a), and belly and underside of head notdark and strongly vermiculated ….....................15

5a. Caudal fin heavily pigmented on dorsal and ven-tral margins and/or middle fin rays distinctly spot-ted; dark stripes on body interrupted posteriorly orreplaced by conspicuous dark spots ...................6

5b. Caudal fin pale or with dark stripes restricted toproximal fourth of fin; dark stripes on sides clearlydefined posteriorly (except in M. naevius, see 9a)……………………...…..….. . . . . . . . . . . . . . . . . . .7

6a. Ventral surface of head and belly uniformly pale(throat with 2 or 3 spots in some specimens); dark stripes on head approximately equal in width to pale interspaces (western and centralPacific) …………........................................................Meiacanthus grammistes (Valenciennes, 1836)

6b. Ventral surface of head and belly dark or vermic-ulated; dark stripes on head, if present, approxi-mately twice width of pale interspaces (Japan andRyukyu Islands) ................................……………..……….Meiacanthus kamoharai Tomiyama, 1956

7a. Adults with two dark lateral stripes in addition toone at dorsal body contour …….….....................8

7b. Adults with a single dark lateral stripe in additionto one which may be present at dorsal body contour ….………………..…..……………….....12

8a. Chin, including lower lip, broadly dark; anal finbase with narrow dark stripe (Bismarck Archipel-ago) …..Meiacanthus limbatus Smith-Vaniz, 1987

8b. Chin, including lower lip, pale or narrowly dusky;anal fin base without narrow dark stripe .............9

9a. Caudal peduncle pale except for elongate basi-caudal spot; distal half of dorsal fin pale poster -iorly; pectoral fin rays 12 or 13 (western Australia,Rowley Shoals) …….…….....................................………...Meiacanthus naevius Smith-Vaniz, 1987

9b. Caudal peduncle typically with two dark stripesthat extend at least to caudal fin base; distal halfof dorsal fin with dark stripe; pectoral fin rays 14-16 (except 12 or 13 in M. crinitus) …………….10

10a. Dark stripe on snout, extending through eye, separated from margin of upper lip by pale area approximately equal to width of stripe (eastern Australia) ……………….…...................... ………..........Meiacanthus lineatus (DeVis, 1884)

10b. Dark stripe on snout, extending through eye,

aqua vol. 5 no. 1 - 2001 32


touches margin of upper lip …..….....................1111a. Pectoral fin rays 14 or 15; pale area above and

adjacent to dark mid-lateral head stripe continuesuninterrupted across snout; adult males with innercaudal fin rays not elongated and interradialmembranes not deeply incised (Sulu Archipelagoand off Sumbawa, Indonesia) ...............................................Meiacanthus abditus Smith-Vaniz,1987

11b. Pectoral fin rays 12 or 13; pale area above andadjacent to dark mid-lateral head stripe, if contin-ued onto snout, interrupted at mid-line; adultmales with inner caudal fin rays elongated andinterradial membranes deeply incised (Irian Jaya)……….....Meiacanthus crinitus Smith-Vaniz, 1987

12a. Dark lateral stripe not centred as it extends ontocaudal fin, at most only dorsal margin of stripealigned with centre of fin (northern Borneo andPhilippine Is.) ……………….................................. .……Meiacanthus geminatus Smith-Vaniz, 1976

12b. Dark lateral stripe approximately centred as itextends onto caudal fin ……………...................13

13a. Dorsal fin conspicuously bicolored, distal half offin immaculate and basal half abruptly darkbrown; width of dark stripe on snout distinctly nar-rower than width of stripe immediately posterior toeye; dark lateral stripe does not extend onto dors -al part of pectoral fin base (Sulawesi) ...............………….Meiacanthus vicinus Smith-Vaniz, 1987

13b. Dorsal fin not conspicuously bicolored; width ofdark stripe on snout not distinctly narrower thanwidth of stripe immediately posterior to eye; darklateral stripe extends at least slightly onto dorsalpart of pectoral fin base ....................................14

14a. Pectoral fin rays usually 13; dark lateral stripeextends conspicuously onto dorsal part of pect -oral fin base; in life, body coloration above darkmid-lateral stripe pale grey; adult males with innercaudal fin rays elongated and interradial mem-branes deeply incised (Papua New Guinea andNew Britain) …....…...............................................................Meiacanthus vittatus Smith-Vaniz, 1987

14b. Pectoral fin rays usually 15 or 16; dark lateralstripe extends very slightly onto dorsal part ofpectoral fin base; in life, body coloration abovemid-lateral stripe bright yellow; adult males withinner caudal fin rays not elongated and interradialmembranes not deeply incised (Australia)……..........Meiacanthus luteus Smith-Vaniz, 1987

15a. Dark spot, approximately equal to pupil diameter,on ventral half of pectoral fin axil ......................16

15b. No dark spot on pectoral fin axil …...................1816a. Body and fins uniformly bright yellow, except

dors um of head sometimes olive in large individ-uals (Fiji Islands) …………..…............................... ..........Meiacanthus oualanensis (Günther, 1880)

16b. Body and fins not uniformly yellow.….….….….17

17a. In life, body bright yellow-green; dorsal fin stripeuniformly dark, typically extending entire length offin and restricted to basal 1/2 or 3/4 of fin (TongaIslands) …………...………………...................................Meiacanthus tongaensis Smith-Vaniz, 1987

17b. In life, body usually bluish-grey anteriorly, becom-ing pale yellow posteriorly, never entirely brightyellow-green; dorsal fin stripe variably developed(western and central Pacific, excluding Fiji andTonga islands) …................................................... ............Meiacanthus atrodorsalis (Günther, 1877)

18a. Anal fin pale ……………….…………................1918b. Anal fin dark ……………………........................2219a. Outer lobes of caudal fin not elongated, middle

rays longest; dark stripe extends from eye to orig -in of dorsal fin (Maldive Islands, Sri Lanka, andwestern Java Sea) …….………..…...................... …................Meiacanthus smithi Klausewitz, 1961

19b. Outer lobes of caudal fin elongated, at least inadults; colour pattern not as above ……...........20

20a. Narrow dark stripe extending obliquely from eyeto upper margin of caudal peduncle or belowpost erior third of dorsal fin (Red Sea, includingGulfs of Aqaba and Aden)…….............................. ...…Meiacanthus nigrolineatus Smith-Vaniz, 1969

20b. Colour pattern not as above ………..................2121a. Dorsal fin heavily and uniformly pigmented,

except for pale tips of rays; posterior third of body uniformly pale (Cargados Carajos, westernIndian Ocean) ….....……………………..................……….…Meiacanthus fraseri Smith-Vaniz, 1976

21b. Dorsal fin dark with central pale stripe; posteriorthird of body dark dorsally, and spotted or speck-led in large specimens (Tonga Islands)……….…Meiacanthus procne Smith-Vaniz, 1976

22a. Caudal fin immaculate, yellow in life (Africancoast, Comoro Is. and Madagascar) ..............….. ………......Meicanthus mossambicus Smith, 1959

22b. Outer lobes of caudal fin heavily pigmented .....2323a. Head and body with numerous dark speckles; pec-

toral fin rays 14 (Solomon Sea and Osprey Reef,Coral Sea) ….……….……..……................. ...........Meiacanthus reticulatus Smith-Vaniz, 1976

23b. Head and body without dark speckles; pectoral finrays 15 or 16 ……......…..…………….............. 24

24a. Outer lobes of caudal fin not distinctly darker thanposterior fifth of body; head and body very darkexcept for pale wedge-shaped area (yellow-orange in life), base of which covers postorbitalregion of head (Fiji and Tonga islands)……..…Meiacanthus bundoon Smith-Vaniz, 1976

24b. Outer lobes of caudal fin distinctly darker than posterior fifth of body; head and body uniformly light brown, at least in preservation(New Caledonia) ........…………............................ ...............Meiacanthus phaeus Smith-Vaniz, 1976

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Mimetic associations involving species ofMeiacanthus

Randall and Randall (1960) reviewed the phenom -enon of mimicry in fishes and reported new examples.Although mimicry is still relatively uncommon in marinefishes, many new cases have been documented(Springer & Smith-Vaniz, 1972; Allen et al., 1975;Russell et al., 1976; Randall & McCosker, 1993). Smith-Vaniz (1987: 45) briefly referenced all known or sus-pected cases of mimicry involving species of Meia-canthus.

Mimetic relationships can be quite complex, and in thecase of one well-studied mimetic trio of blennies(Springer & Smith-Vaniz, 1972), elements of all threefamiliar kinds of mimicry appear to be involved. Theseare: 1) Batesian mimicry (harmless palatable speciesmimics unpalatable species); 2) Müllerian mimicry(two or more unpalatable species share similar colourpatterns and reinforce their deterrent attributes; thus,they are simultaneously models and mimics); and3) Aggressive mimicry (predatory species resemblesa harmless or beneficial species and thus is able to getcloser to prey). A less familiar type of mimicry, calledSocial mimicry (where one or more species mixeswith aggregations of a similarly-coloured species andbenefits from the protective advantage of schooling),appears to apply in two cases involving juveniles ofMeiacanthus nigrolineatus and M. urostigma.

Conditions for the development and maintenance ofBatesian mimicry typically require that models greatlyoutnumber mimics. Springer and Smith-Vaniz (1972)listed a number of situations where the mimetic associ-ation might persist even when the relative abundancesof mimics and models differ from expectations. The fol-lowing two such situations almost certainly apply toMeiacanthus: 1) where the models are unharmed in the

process of being tested by the predators - this permitsa model to be tested repeatedly, thus increasing theeffective number of models without increasing theiractual number; and 2) where negative experiences ofthe predators have a stronger, more lasting, effect thanpositive experiences.

The following 11 species of Meiacanthus appear to beengaged in mimetic relationships involving a total of 4families and at least 14 other species of fishes. Five ofthese cases consist of a mimetic ring of three species.Single letters (A = Aggressive, B = Batesian, M = Müllerian, S = Social) after the family names indicatethe known or possible types of mimicry that areinvolved.

Meiacanthus nigrolineatus: Ecsenius gravieri(Blenniidae, B), Plagiotremus townsendi (Blenniidae, AM B), Cheilodipterus spp. (Apogonidae, S)

Based on laboratory experiments and field observ -ations, Springer and Smith-Vaniz (1972) provided evid -ence indicating that Ecsenius gravieri (Pellegrin) is aBatesian mimic of M. nigrolineatus. It is difficult to dis-tinguish these two species from each other in the wild(Fig. 11). Furthermore, both species also exhibit parallelchanges in colour pattern correlated with geographicdistribution. The role of P. townsendi in the mimetic com-plex needs more study. All three species are blue toblue-grey anteriorly, shading to pale yellow posteriorly,but in morphology and certain details of its colour pat-tern P. townsendi can be easily distinguished from theother two species; and unlike the other two blennies,specimens from outside the Gulf of Aqaba do not havea more melanistic colour pattern (Smith-Vaniz, 1987).The Plagiotremus feeds on mucus and epidermis(including scales) of other fishes and is undoubtedly anAggressive mimic, its resemblance to the non-aggres-sive fangblenny and Ecsenius allowing it to get closer to

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Fig. 11. Meiacanthus nigrolineatus (left) and Ecsenius graveri (right), both fishes about 60 mm SL, Gulf of Aqaba, RedSea. Photo by V. G. Springer.

potential prey. Because some predatory fishes ingestand then reject P. townsendi (both live and dead individ-uals), at least in some cases it also appears to be a Mül-lerian mimic of the Meiacanthus. Natural selection gen-erally results in a Batesian mimic developing into asclose a replica of its models as possible, but the resem-blance does not need to be as exact in the case ofAggressive and Müllerian mimicry. In the case of P.townsendi, either the latter two types of mimicry aremore important and Batesian mimicry plays a minor roleor its co-occurrence with M. nigrolineatus is relativelyrecent and there has not been enough time for selectionforces to produce a closer match.

Dafni and Diamant (1984) reported that juveniles ofMeiacanthus nigrolineatus exhibit a colour pattern thatis different from the adults and very similar to that of thestriped juveniles of two species of cardinalfishes(Cheilodipterus spp.), probably C. quinquelineatusCuvier and C. lachneri Klausewitz (see Gon, 1993).These juvenile cardinalfishes and blennies are charac-terized by black stripes and a broad yellow area arounda black spot near the base of the caudal fin. The authorsproposed that the juvenile blennies were less vulnerableto predation when they mingled with schools of the sim-ilar-sized juvenile cardinalfishes. Presumably juvenileMeiacanthus are “less venomous” than adults, and thetransitional nature of their colour pattern also reduces itswarning effectiveness. Dafni and Diamant consideredthis to be a new type of mimicry in fishes, which they

termed school-oriented mimicry. Randall and McCosker(1993) cited many other cases of two or more species offishes with similar colour patterns and swimming behav-iour schooling together for mutual protection, and rec-ommended that such associations be called social mim-icry, a term previously proposed by Moynihan (1968) formixed flocks of birds. Randall and McCosker also notedthat cardinalfishes often shelter among the spines of thesea urchin Diadema setosum (Leske) and that “the pro-tection afforded by the urchin spines could be the fea-ture which attracts both the blenny and cardin alfishes,and not schooling per se.” However, they agreed that thejuvenile Meiacanthus seems to be a mimic, in partbecause the blenny was far less common than the car-dinalfish models, and because the large yellow areaaround the basicaudal spot is otherwise restricted tocertain species of Cheilodipterus and juven iles ofApogon compressus (Smith and Radcliffe), which Kuiter(1990, 1992) has shown to be social mimics of youngCheilodipterus macrodon (Lacépède).

Meiacanthus urostigma: Cheilodipterus quinquelin-eatus (Apogonidae, S)

Juveniles of Meiacanthus urostigma andCheilodipterus quinquelineatus also appear to be socialmimics and both species are characterized by blackstripes and a broad yellow area around a black spotnear the base of the caudal fin. Ukkrit Satapoominobserved M. urostigma, mostly young and small

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Fig. 12. Mimetic pair, Great Barrier Reef, Australia: (a) Meiacanthus atrodorsalis and (b) Plagiotremus laudandus lau-dandus, both fishes about 55 mm TL. Photos by R. Steene.

juveniles, aggregating with juveniles of Cheilodipterusquinquelineatus beneath coral outcrops, eg massivePorites and branching Acropora corals. The blenniesbehaved like the cardinalfishes, mostly remaining stat -ionary in the water column. When an attempt wasmade to catch some of the blennies, the larger onesactively swam away while the smaller juveniles usuallyjoined the school of cardinalfishes.

Meiacanthus atrodorsalis: Plagiotremus laudanduslaudandus (Blenniidae, A M B), ?Ecsenius bicolor(Blenniidae, B)

Springer and Smith-Vaniz (1972) reported a possiblemimetic complex including the above three species,and Losey (1972) described the association in muchgreater detail. There is no doubt that Plagiotremus laud -andus (Whitley) is a mimic of M. atrodorsalis (Fig. 12).

Both species exhibit parallel shifts in colour patternscorresponding to geographic distribution. Russell et al.(1976) were skeptical that Ecsenius bicolor (Day) wasactually a mimic, stating that at most localities they hadvisited, “any resemblance between E. bicolor and M.atrodorsalis - either morphological, behavioural or eco-logical - is very superficial.” In a revision of Ecsenius,Springer (1988: 47) discussed the life coloration of E.bicolor and also concluded that it was an improbablemimic of the Meiacanthus.

Meiacanthus oualanensis: Plagiotremus laudandusflavus (Blenniidae, A M B), Scolopsis bilineatus(Scolopsidae, B) (Fig. 13)

Springer and Smith-Vaniz (1972) first suggested thatin the Fiji Islands, where both species are entirely brightyellow in life, this endemic Meiacanthus (sometimes

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Fig. 13. Mimetic trio, all from Fiji: (a) Meiacanthus oualanensis, (b) Plagiotremus laudandus flavus, (c) Scolopsis bilin-eatus juvenile, all fishes about 50-65 mm TL. Photos by G. R. Allen.

misspelled M. ovalauensis) and Plagiotremus laud -andus are mimics. Smith-Vaniz (1976) subsequentlydescribed the Plagiotremus as the new subspecies P.laudandus flavus, noting that only colour patterndisting uished it from the allopatric subspecies P. lau-dandus laudandus. He noted that each member of thesubgenus Musgravius Whitley, including Plagiotremustownsendi, laudandus, and phenax, has a colour pat-tern very similar to a sympatric species of Meiacanthusand that each of these mimetic pairs has an allopatricdistribution. This suggests that speciation in theseclosely related species has been influenced (or con-trolled) by the distribution of a species of Meiacanthus.Specimens of P. laudandus flavus were subsequentlycollected in the Tonga Islands together with a secondmember of the M. atrodorsalis complex, M. tongaensis,which is easily distinguished by the presence of a black

stripe along the base of the dorsal fin (Smith-Vaniz,1987). The lack of agreement in colour patternsbetween these two blenniids was interpreted as strongevidence that the Plagiotremus had become estab-lished in the area more recently than the Meiacanthus.

Allen et al. (1975) and Russell et al. (1976) reportedthat juveniles of Scolopsis bilineatus (Bloch) on Fijianreefs are also uniformly yellow, unlike those occurringelsewhere in the Indo-Pacific, and are probableBatesian mimics of M. oualanensis.

Meiacanthus smithi: Plagiotremus phenax(Blenniid ae, A M B), Scolopsis bilineatus (Scolops -idae, B) (Fig. 14)

As discussed in the preceding account, Plagiotremusphenax Smith-Vaniz is a member of one of severalallopatric Plagiotremus-Meiacanthus mimetic pairs.

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Fig. 14. Mimetic trio, Andaman Sea: (a) Meiacanthus smithi, (b) Plagiotremus phenax, (c) Scolopsis bilineatus juvenile,all fishes about 50-65 mm TL. Photos by R. Steene.

Springer and Smith-Vaniz (1972) first suggested, onthe basis of circumstantial evidence, that these twoblennies were involved in a mimetic relationship. Basedon life colour observations of specimens from the Mal-dive Islands, Smith-Vaniz (1976) added additional sup-port for the mimetic relationship, and also reported thatjuveniles of an unidentified species of Scolopsis (aprobable Batesian mimic) had markings identical tothose of M. smithi. We herein identify the scolopsid asS. bilineatus and further document this mimetic trio ofspecies.

Meiacanthus lineatus: Petroscirtes fallax (Blenni-idae, B), Scolopsis bilineatus (Scolopsidae, B) (Fig. 15)

Springer and Smith-Vaniz (1972) first proposed thatPetroscirtes fallax Smith-Vaniz and M. lineatus wereBatesian mimics. Allen et al. (1975) and Russell et al.(1976) concurred with that suggestion, and, with theaddition of Scolopsis bilineatus juveniles, documentedanother mimetic trio; the latter authors also providedtables of visual field counts and photographs of livefishes to support their observations.

Meiacanthus vittatus: Cheilodipterus parazonatus(Apogonidae, B ?A), Scolopsis margaritifer (Scolopsi-dae, B) Petroscirtes breviceps (Blenniidae, B) (Fig. 16)

Another remarkable mimetic trio, documented byAllen et al. (1975) and Russell et al. (1976) with field

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Fig. 15. Mimetic trio, Great Barrier Reef, Australia: (a) Meiacanthus lineatus, (b) Petroscirtes fallax, (c) Scolopsisbilineatus juvenile, all fishes about 50-65 mm TL. Photos by R. Steene.

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Fig. 16. Mimetic fishes, Madang, Papua New Guinea: (a) Meiacanthus vittatus, (b) Cheilodipterus parazonatus,(c) Scolopsis margaritifer, (d) Petroscirtes breviceps, all fishes about 45-60 mm TL. Photos by G. R. Allen.

observations and excellent photographs, involves juv -eniles of Scolopsis margaritifer Cuvier, a species of thecardinalfish genus Cheilodipterus, and Meiacanthus vit-tatus. In his revision of Cheilodipterus, Gon (1993: 41)noted that several recently published photographs ofcardinalfishes identified as C. parazonatus Gon (Allenet al., 1975; Burgess and Axelrod, 1975; Russell et al.,1976; Burgess et al., 1988; Randall et al., 1990; Kuiter,1992) actually depict C. zonatus Smith & Radcliffe.Similarly, the reported Batesian mimicry involving M. vit-tatus and C. zonatus (Allen et al., 1975; Russell et al.,1976; Smith-Vaniz, 1976) refers to M. parazonatus.

This and the following two mimetic associations involv-ing adults of Cheilodipterus are especially convincing.

The colour patterns of these cardinalfishes and theirMeiacanthus models are so similar that at distancesgreater than about a metre they are virtually indistin-guishable underwater. Although most cardinalfishes arenocturnal, all three species (Cheilodipterus parazona-tus, zonatus, and nigrotaeniatus) have adopted a diur-nal lifestyle, swimming out in the open away from pro-tective cover in association with and imitating the forag-ing behaviour of their Meiacanthus counterparts. Allenet al. (1975) and Russell et al. (1975) made the impor-tant observation that these species of Cheilodipterusare perhaps also Aggressive mimics. Association with anon-piscivorous Meiacanthus might allow theCheilodipterus, which feeds primarily on small fishes

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Fig. 17. Mimetic trio, Calamianes Islands, Philippines: (a) Meiacanthus geminatus, (b) Cheilodipterus zonatus,(c), Scolopsis margaritifer, all fishes about 55-70 mm TL. Photos by G. R. Allen.

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and crustaceans, to have more success capturing prey.Although seen less frequently than the other mimetic

fishes at Madang, Petroscirtes breviceps is occasion-ally sighted with a colour pattern (Fig. 16d) that closelyapproximates that of Meiacanthus vittatus. The twospecies are sometimes seen in close proximity and itseems likely that P. breviceps is a Batesian mimic.

Meiacanthus geminatus: Cheilodipterus zonatus(Apogonidae, B ?A) , Scolopsis margaritifer (Scolops -idae, B) (Fig. 17)

Based on field observations and colour photographsprovided by G. R. Allen, Gon (1993: 54, Pl. V) firstrevealed (see preceding account) this Meiacanthus-

Cheilodipterus mimetic pair, and Scolopsis margaritiferis herein added as another Batesian mimic on the basisof recent observations by Allen in the Philippines.

Meiacanthus grammistes: Cheilodipterus nigro -taeniatus (Apogonidae, B ?A), Petroscirtes breviceps(Blenniidae, B) (Fig. 18)

Based on observations and a colour photograph pro-vided by Dr. Hitoshi Ida, Smith-Vaniz (1987) first sug-gested that C. nigrotaeniatus Smith and Radcliffe is aBatesian mimic (see also discussion of Meiacanthusvittatus, above). Both species have dark body stripes,spotted caudal peduncle and fin, and yellow tinge onthe anterodorsal part of head and body. Cheilodipterus

Fig. 18. Mimetic trio: (a) Meiacanthus grammistes, Papua New Guinea; (b) Petroscirtes breviceps, Sabah, Malaysia; (c) Cheilodipterus nigrotaeniatus, Irian Jaya, all fishes about 55-65 mm TL. Photos by G. R. Allen.

c

nigrotaeniatus is known from the Philippines andMolucca Islands, Indonesia (Gon, 1993) and Irian Jaya,all localities where M. grammistes occurs.

Springer and Smith-Vaniz (1972) noted that somemuseum collections (supposedly sorted to species)contained mixtures of Petroscirtes breviceps Valenci-ennes, which they identified as P. polyodon (Bleeker),and Meiacanthus grammistes. They provided photo -graphs of preserved specimens of both species andsuggested that they too might be Batesian mimics,especially in view of the probable mimetic relationshipbetween Petroscrites fallax and Meiacanthus lineatus.Smith-Vaniz (1976) stated that life colour observationsof both species added more support to the suggestionthat they are mimics. Kuiter and Debelius (1994: 246)include an excellent colour photograph of both speciesswimming together.

Meiacanthus kamoharai: Petroscirtes breviceps(Blenniidae, B)

Yatsu et al. (1983) noted that the colour pattern of aspecimen of Petroscirstes breviceps from Japan closelymatched that of M. kamoharai. Because P. brevicepshad been previously reported as a possible mimic of M.grammistes, these authors stated “establishment of asecond mimetic relationship with the closely related andallopatric M. kamoharai might be expected.”

Meiacanthus crinitus: Pentapodus trivittatus(Nemipteridae, B) (Fig. 19)

Recent fieldwork by Gerald Allen at the Raja AmpatIslands, immediately west of the New Guinea mainlandin the Indonesian province of Irian Jaya, revealed apossible mimetic pair involving Meiacanthus crinitusSmith Vaniz and juveniles of Pentapodus trivittatus(Bloch). The mimicry is similar to that described abovefor juveniles of Scolopsis bilineatus and S. margaritiferand various Meiacanthus species. Small young of P.trivitattus are very similar in appearance to M. crinitus.Unfortunately, no photos of small P. trivittatus are avail-able, but we have included a photograph of a subadult,that still bears some resemblance to the model species.

AcknowledgementsWe thank Richard Winterbottom for calling the exist -

ence of the new Meiacanthus to the first author’s attent -ion and encouraging us to describe this species. Figure4 was provided courtesy of Fred Bennett and KarenKelly, Electron Microscopy Core Laboratory of the Inter-disciplinary Center for Biotechnology Research, Univer-sity of Florida. Sherry Bostick and Douglas C. Weaverassisted with scanning of photographs, and Victor G. Springer reviewed an early draft of the manuscript

aqua vol. 5 no. 1 - 2001 42


Fig. 19. Mimetic pair, Raja Ampat Islands, Irian Jaya, Indonesia: (a) Meiacanthus crinitus, about 70 mm SL, (b) Penta -podus trivittatus, about 130 mm TL. Photos by G. R. Allen.

b

a

and made helpful suggestions, and provided Fig. 11.Roger Steene provided excellent underwater photo -graphs. Financial support for fieldwork by the secondauthor came from the Coral Reef Management Pro-gram of the Department of Fisheries, Thailand. This iscontribution No. 42 of the Phuket Marine BiologicalCenter. Gerald Allen’s fieldwork at Sumatra was fundedby Conservation International - Indonesia.

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Starck, II, 1975. Mimicry in marine fishes. TropicalFish Hobbyist 24 (1): 47, 49, 52-56.

Burgess, W. & H. R. Axelrod, 1975. Pacific MarineFishes, Book 6. T.F.H. Publications, Inc., Neptune City,New Jersey : 1387-1654.

Burgess, W., Axelrod, H. R., & R. E. Hunziker, 1988.Dr Burgess’s Atlas of Marine Aquarium Fishes. T.F.H.Publications, Inc., Neptune City, New Jersey, 736 pp.

Dafni, J. & A. Diamant, 1984. School-oriented mimicry,a new type of mimicry in fishes. Marine Eco l -ology, Progress Series 20: 45-50.

Fishelson, L., 1974. Histology and ultrastructure of therecently found buccal toxic gland in the fishMeiacanthus nigrolineatus (Blenniidae). Copeia 1974(2): 386-392.

Fishelson, L., 1975. Observations on behaviour of thefish Meiacanthus nigrolineatus Smith-Vaniz (Blenni-idae) in nature (Red Sea) and in captivity. AustralianJournal of Marine and Freshwater Research 26 (3):329-341.

Gon, O., 1993. Revision of the cardinalfish genusCheilo d ipterus (Perciformes: Apogonidae), withdescription of five new species. Indo-Pacific Fishes22: 1-59.

Hastings, P. A. & V. G. Springer, 1994. Review ofStathmonotus, with redefinition and phylogeneticanalysis of the Chaenopsidae (Teleostei: Blennioidei).Smithsonian Contributions to Zoology 558: 1-48.

Kuiter, R. H., 1990. Nature’s copies. Sportdiving 23:114-116.

Kuiter, R. H., 1992. Tropical reef-fishes of the westernPacific Indonesia and adjacent waters. Penerbit PTGramedia Pustaka Utama, Jakarta, 314 pp.

Kuiter, R. H. & H. Debelius, 1994. Southeast Asia trop-ical fish guide. IKAN-Unterwasserarchiv, Frankfurt,321 pp.

Losey, G. S., 1972. Predation protection in the poison-fang blenny, Meiacanthus atrodorsalis, and its mimicsEcsenius bicolor and Runula laudandus (Blenniidae).Pacific Science 26 (2): 129-139.

Moynihan, M., 1968. Social mimicry; character conver-

gence versus character displacement. Evolution 22(2): 315-331.

Randall, J. E., 1998. Zoogeography of shore fishes ofthe Indo-Pacific region. Zoological Studies (AcademiaSinica) 37 (4): 227-268.

Randall, J. E., Allen, G. R., & R. C. Steene, 1990.Fishes of the Great Barrier Reef and Coral Sea. Craw-ford House Press, Bathurst, New South Wales, 507pp.

Randall, J .E. & J. E. McCosker, 1993. Social mimicryin fishes. Revue française d’Aquariologie 20 (1): 5-8.

Randall, J. E. & H. A. Randall, 1960. Examples ofmimicry and protective resemblance in tropical marinefishes. Bulletin of Marine Sciences Gulf & Caribbean10 (4): 444-480.

Russell, B. C., Allen, G. R., & H. R. Lubbock, 1976.New cases of mimicry in marine fishes. Journal ofZoology, London 180: 407-423.

Smith-Vaniz, W. F., 1976. The saber-toothed blennies,tribe Nemophini (Pisces: Blenniidae). Academy ofNatural Sciences of Philadelphia, Monograph16: 1-196.

Smith-Vaniz, W. F., 1987. The saber-toothed blennies,tribe Nemophini (Pisces: Blenniidae): an update.Proceedings of the Academy of Natural Sciences ofPhiladelphia 139: 1-52.

Springer, V. G., 1968. Osteology and classification ofthe fishes of the family Blenniidae. United StatesNational Museum Bulletin 284: 1-83.

Springer, V. G., 1988. The Indo-Pacific blenniid fishgenus Ecsenius. Smithsonian Contributions to Zool-ogy 465: 1-134.

Springer, V. G. & W. F. Smith-Vaniz, 1972. Mimeticrelationships involving fishes of the family Blenniidae.Smithsonian Contributions to Zoology 112: 1-36.

Springer, V. G. & J. T. Williams, 1990. Widely distri b -uted Pacific Plate endemics and lowered sea levels.Bulletin of Marine Sciences, 47 (3): 631-640.

Springer, V. G. & J. T. Williams, 1994. The Indo-Pacificblenniid fish genus Istiblennius reappraised: a revisionof Istiblennius, Blenniella, and Paralticus, new genus.Smithsonian Contributions to Zoology 565: 1-193.

Wickler, W., 1968. Mimicry in plants and animals. Mac-Graw-Hill, New York, 255 pp.

Williams, J. T., 1990. Phylogenetic relationships andrevision of the blenniid fish genus Scartichthys.Smithsonian Contributions to Zoology 492: 1-30.

Yatsu, A., Iwata, A., & M. Sato, 1983. First records ofthe blenniid fishes, Petroscirtes springeri andPetroscirtes variabilis, from Japan. Japanese Journalof Ichthyology 30 (3): 297-300.

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****************************************************************************************************************************************ERRATUMaqua 4 (4): Jean-Pierre Gosse (1924 - 2001) Our humble apologies to King Leopold III of Belgium, erroneously described as King Leopold II throughout this obituary.

aqua vol. 5 no. 1 - 2001 44

Index of aqua Vol 4 (1-4)(Indexed by: 1. Author(s); 2. New Taxa; 3. Biology/Ecology/Biography/Reviews)

Author(s):Alexander, Gavin D. and Adams, Colin E.: The phenotypic diversity of Arctic charr, Salvelinus alpinus (Salmonidae) in Scotland and Ireland. aqua 4 (2) 77-88,

December 2000.Allen, Gerald R.: Description of a New Wrasse (Pisces: Labridae; Cirrhilabrus) from Northern Sumatra, Indonesia. aqua 4 (2) 45-50, December 2000.Allen, Gerald R.: Lentipes multiradiatus, a New Species of Freshwater Goby (Gobiidae) from Irian Jaya, Indonesia.aqua 4 (3) 121-124, April 2001.Allen, Gerald R.: Description of Two New Gobies (Eviota, Gobiidae) from Indonesian Seas. aqua 4 (4) 125-130, August 2001.Allen, Gerald R.: Two New Species of Cardinalfishes (Apogonidae) from the Raja Ampat Islands, Indonesia. aqua 4 (4) 143-149, August 2001.Aragon-Noriega, Eugenio Alberto and Calderon-Aguilera, Luis Eduardo: Age and growth of shrimp (Decapoda: Penaeidae) postlarvae in the Upper Gulf of

California. aqua 4 (3) 99-104, April 2001.Gasparini, João Luiz, Rocha, Luiz A. and Floeter, Sergio R.: Ptereleotris randalli n. sp., a new dartfish (Gobioidei: Microdesmidae) from the Brazilian Coast.

aqua 4 (3) 105-108, April 2001.Heiser, J. B., Mourra, R. L. and Robertson, D. R.: Two new species of Creole Wrasse (Labridae: Clepticus) from opposite sides of the Atlantic.

aqua 4 (2) 67-76, December 2000.Mitrofanov, Igor V.: The Biodiversity of the genus Leuciscus in Central Asia (Cyprinidae). aqua 4 (1) 35-43, June 2000.Randall, John E. and Carlson, Bruce A.: The Pygmy Angelfish Centropyge woodheadi Kuiter, 1988, a Synonym of C. heraldi Woods and Schultz, 1953.

aqua 4 (1) 1-4, June 2000.Randall, John E. and Frische, Joachim: Hybrid Surgeonfishes of the Acanthurus achilles Complex. aqua 4 (2) 51-56, December 2000.Randall, John E. and Pyle, Richard: Three New Species of Labrid Fishes of the Genus Cirrhilabrus from Islands of the Tropical Pacific. aqua 4 (3) 89-98, April 2001.Randall, John E., Pyle, Richard L. and Myers, Robert F.: Three Examples of Hybrid Surgeonfishes (Acanthuridae). aqua 4 (3) 115-120, April 2001.Randall, John E. and Miroz, Aharon: Thalassoma lunare x Thalassoma rueppellii, a Hybrid Labrid Fish from the Red Sea. aqua 4 (4) 131-134, August 2001. Rocha, Luiz A., Guimarães, Ricardo Z. P. and Gasparini, João L.: Redescription of the Brazilian Wrasse Thalassoma noronhanum (Boulenger, 1890) (Teleostei:

Labridae). aqua 4 (3) 105-108, April 2001.Rocha, Luiz A. and Rosa, Ricardo S.:Halichoeres brasiliensis (Bloch, 1791), a valid wrasse species (Teleostei: Labridae) from Brazil, with notes on the Caribbean

species Halichoeres radiatus (Linnaeus, 1758). aqua 4 (4) 161-166, August 2001.Springer, Victor G. and Allen, Gerald R.: Ecsenius ops, from Indonesia, and E. tricolor, from Western Philippines and Northwestern Kalimantan, New Species of

Blenniid Fishes in the Stigmatura Species Group. aqua 4 (4) 151-160, August 2001.Walker, Shelley and Neira, Francisco J.: Aspects of the reproductive biology and early life history of black bream, Acanthopagrus butcheri (Sparidae), in a brackish

lagoon system in southeastern Australia. aqua 4 (4) 135-142, August 2001.Watson, Ronald E., Marquez, Gérard and Pöllabauer, Christine: New Caledonia Fish Species of the genus Sicyopterus (Teleostei: Gobioidei: Sicydiinae).

aqua 4 (1) 5-34, June 2000.Winterbottom, Richard: Four new species of Trimma (Gobidae), from the Indian and Western Pacific Oceans. aqua 4 (2) 57-66, December 2000.

New Taxa:Apogon leptofasciatus n. sp. Two New Species of Cardinalfishes (Apogonidae) from the Raja Ampat Islands, Indonesia. aqua 4 (4) 143-149, August 2001.Apogon oxygrammus n. sp. Two New Species of Cardinalfishes (Apogonidae) from the Raja Ampat Islands, Indonesia. aqua 4 (4) 143-149, August 2001.Cirrhilabrus claire n. sp. Three New Species of Labrid Fishes of the Genus Cirrhilabrus from Islands of the Tropical Pacific. aqua 4 (3) 89-98, April 2001.Cirrhilabrus earlei n. sp. Three New Species of Labrid Fishes of the Genus Cirrhilabrus from Islands of the Tropical Pacific. aqua 4 (3) 89-98, April 2001.Cirrhilabrus joanallenae n. sp. Description of a New Wrasse (Pisces: Labridae: Cirrhilabrus) from Northen Sumatra, Indonesia. aqua 4 (2) 45-50, December 2000.Cirrhilabrus walshi n. sp. Three New Species of Labrid Fishes of the Genus Cirrhilabrus from Islands of the Tropical Pacific. aqua 4 (3) 89-98, April 2001.Clepticus africanus n. sp. Two new species of Creole Wrasse (Labridae: Clepticus) from opposite sides of the Atlantic. aqua 4 (2) 67-76, December 2000.Clepticus brasiliensis n. sp. Two new species of Creole Wrasse (Labridae: Clepticus) from opposite sides of the Atlantic. aqua 4 (2) 67-76, December 2000.Ecsenius ops n. sp. Ecsenius ops, from Indonesia, and E. tricolor, from Western Philippines and Northwestern Kalimantan. New Species of Blenniid Fishes in the

Stigmatura Species Group., aqua 4 (4) 151-160, August 2001.Ecsenius tricolor n. sp. Ecsenius ops, from Indonesia, and E. tricolor, from Western Philippines and Northwestern Kalimantan. New Species of Blenniid Fishes in the

Stigmatura Species Group., aqua 4 (4) 151-160, August 2001.Eviota mikiae n. sp. Description of Two New Gobies (Eviota, Gobiidae) from Indonesian Seas. aqua 4 (4) 125-130, August 2001.Eviota raja n. sp. Description of Two New Gobies (Eviota, Gobiidae) from Indonesian Seas. aqua 4 (4) 125-130, August 2001.Lentipes multiradiatus n. sp., a New Species of Freshwater Goby (Gobiidae) from Irian Jaya, Indonesia. aqua 4 (3) 121-124, April 2001.Ptereleotris randalli n. sp., a new dartfish (Gobioidei: Microdesmidae) from the Brazilian Coast. aqua 4 (3) 109-114, April 2001.Trimma anaima n. sp. Four new species of Trimma (Gobiidae), from the Indian and Western Pacific Oceans. aqua 4 (2) 57-66, December 2000.Trimma bisella n. sp. Four new species of Trimma (Gobiidae), from the Indian and Western Pacific Oceans. aqua 4 (2) 57-66, December 2000.Trimma halonevum n. sp. Four new species of Trimma (Gobiidae), from the Indian and Western Pacific Oceans. aqua 4 (2) 57-66, December 2000.Trimma omanensis n. sp. Four new species of Trimma (Gobiidae), from the Indian and Western Pacific Oceans. aqua 4 (2) 57-66, December 2000.

Biology/Ecology/Biography/Reviews:Age and growth of shrimp (Decapoda: Penaeidae) postlarvae in the Upper Gulf of California. aqua 4 (3) 99-104, April 2001.Aspects of the reproductive biology and early life history of black bream, Acanthopagrus butcheri (Sparidae), in a brackish lagoon system in southeastern

Australia. aqua 4 (4) 135-142, August 2001.Halichoeres brasiliensis (Bloch, 1791), a valid wrasse species (Teleostei: Labridae) from Brazil, with notes on the Caribbean species

Halichoeres radiatus (Linnaeus, 1758).aqua 4 (4) 161-166, August 2001.Hybrid Surgeonfishes of the Acanthurus achilles Complex. aqua 4 (2) 51-56, December 2000.Jean-Pierre Gosse (1924 - 2001). aqua 4 (4) 150, August 2001.New Caledonia Fish Species of the genus Sicyopterus (Teleostei: Gobioidei: Sicydiinae). aqua 4 (1) 5-34, June 2000.Redescription of the Brazilian Wrasse Thalassoma noronhanum (Boulenger, 1890) (Teleostei: Labridae). aqua 4 (3) 105-108, April 2001.Thalassoma lunare x Thalassoma rueppellii, a Hybrid Labrid Fish from the Red Sea. aqua 4 (4) 131-134, August 2001.The Biodiversity of the genus Leuciscus in Central Asia (Cyprinidae). aqua 4 (1) 35-43, June 2000.The phenotypic diversity of Arctic charr, Salvelinus alpinus (Salmonidae) in Scotland and Ireland. aqua 4 (2) 77-88, December 2000.The Pygmy Angelfish Centropyge woodheadi Kuiter, 1988, a Synonym of C. heraldi Woods and Schultz, 1953. aqua 4 (1) 1-4, June 2000.Three Examples of Hybrid Surgeonfishes (Acanthuridae). aqua 4 (3) 115-120, April 2001.

Day, J. H., Blaber, S. J. M., & J. H. Wallace. 1981. EstuarineFishes. In: Estuarine Ecology with Particular Reference toSouthern Africa. (Ed. J.H. Day.) : 197-221. A. A. Balkema, Rotterdam.

Dimmich, W. W. 1988. Ultrastructure of North American cyprinidmaxillary barbels. Copeia 1988 (1): 72-79.

Trewavas, E. 1983. Tilapiine Fishes of the Genera Sarotherodon,Oreochromis and Danakilia. British Museum (Natural History),London, 583 pp.7. Author details: these should be placed at the beginning of the

manuscript, immediately after the title, and contain: full name(s) ofauthor(s), place(s) of work, and address(es) (including e-mail) forcorrespondence.

8. Submission of manuscripts and illustrative material: allmaterial except original photographs (see below) must be submit-ted to the Scientific Editor:

Dr. Walter lvantsoff, Scientific Editor, aqua - Journal of Ichthyology and Aquatic Biology, Department of Biological Sciences, Macquarie University, N.S.W. 2109, Australia e-mail: [email protected]; Phone: +61 2 9850 8167; Fax: +61 2 9869 8886

to whom all subsequent correspondence should be addressed. Unless otherwise agreed with the Scientific Editor, all texts,

tables, graphs, and drawings must be submitted in Microsoft-com-patible electronic form, preferably as email attachments (this willconsiderably speed up publication time) but alternatively on CD or3.5" diskette. All electronic material must be checked for virusesbefore transmission. Texts should be in Word or WordPerfect form -at; tables submitted as Excel (or Excel-compatible) spreadsheetfiles; graphs and drawings as graphics files (JPEG, TIF, etc).Authors are encouraged to submit quality colour photographswhich will be published free of charge. These must be clear andwithout too much contrast, and if possible should be submitted ashigh-resolution scans, again using graphics files, but hard-copyphotographs (prints or transparencies) will also be accepted ifscans are not feasible. In this case three copies will be required (forreferees).

Original photographs (ideally transparencies; otherwise glossyprints, preferably in the size in which they are eventually to appear- the type area of aqua is 158 x 224 mm, one column is 76 mmwide) must be sent by registered mail to:

Aquapress, The Managing Editor Via G. Falcone 11, I-27010 Miradolo Terme (Pavia), Italy

Authors should retain a copy of all material for reference.A fax number must be provided for the senior author, to

which proofs of accepted papers will be sent for approval.9. Labelling of figures and tables: captions for photographs,

drawings, and graphs should be included at the end of themanu script file, in the order in which they are to appear, andlabelled Fig. 1, Fig. 2a, etc. Hard copy illustrations and/or graph-ics files should be labelled/titled accordingly, to avoid any poss -ibility of confusion; authors should also indicate correct orientat -ion for their illustrations (including from which side transparenc -ies are to be viewed) if there is any room for doubt. Table head-ings should be labelled Table I, etc, and should be included atthe head of the relevant spreadsheet files, which should in turnbe titled Table I, etc.

The author(s) may indicate approximate positions for illustrativematerial in the text by means of a note, clearly recognisable assuch, ideally in parentheses and including the initials of the (senior)author, eg "(Note: Fig. 1 here. AZ)".

10. Evaluation of manuscripts: manuscripts submitted to aquawill be evaluated by the editors and referees on the basis of theircontents. Papers are accepted on the understanding that theyhave not and will not be published elsewhere.

11. Reprints: 50 reprints of each paper will be provided free ofcharge. Additional reprints may be ordered from Aquapress.

Instructions to Authorsaqua is an international journal which publishes original sci-

entific articles in the fields of systematics, taxonomy, ethology,ecology, biogeography, and general biology of fishes, amphibians,aquatic invertebrates and plants. Papers dealing with freshwater,brackish, and marine organisms will be considered for publication.Scientific articles of interest to a wide readership are especiallywelcome. Full length research papers and short notes will also beconsidered for publication.

1. Manuscript preparation: manuscripts must be submitted inEnglish. In exceptional cases aqua may provide translations ofmanuscripts written in French, German, Italian, or Spanish.

Manuscripts must be word-processed, preferably in Word orWordPerfect format, double-spaced throughout. Pages should benumbered consecutively. Generic, specific, and subspecific namesmust be italicised. All papers must conform to the latest edition ofthe “International Code of Zoological Nomenclature".

2. Title: the title must be short and should precisely identify themain topic of the article. If the name of a genus or species isincluded, the name of the systematic group to which it belongsshould follow in parentheses. Author name(s) should be given infull immediately beneath the title.

3. Abstract: the abstract should be concise and intelligible, andshould draw attention to the significant contents of the paper andprincipal conclusions. It should not exceed 250 words nor containany uncommon abbreviations or literature citations. The inclusionof summaries in other languages is optional.

4. Keywords: up to eight keywords should be suggested by theauthor(s).

5. Subject matter: the text of the manuscript is usually arrangedin four main sections: introduction, materials and methods (includ-ing a key to abbreviations used in the text), results, and discus-sion. Other subdivisions may be chosen depending on the mater-ial presented. Acknowledgements should be placed between thetext and references.

Scientific names of genera, species, and subspecies should begiven in full on first mention and should be followed by the name(s)of author(s) and the year of publication.

When the name of a taxon proposed as new to science is given,it must be followed by the abbreviation n. gen., n. spec., or n. ssp.The description must contain the following sections: Material, Diag-nosis, Description, and Affinities. Holotype and paratypes must beclearly identified, the museum or institution in which the type mate-rial has been deposited named, and the catalogue numbers given.Author's collections are not acceptable as repositories for holo-types.

Synonyms should be arranged in chronological order.Authors may choose either to use “telegraphic style” when

describing taxa, or use conventional descriptions which include theuse of indefinite and definite articles and participles. A mix of con-ventional and telegraphic styles will not be accepted.

Identification keys should be dichotomous.The metric system should be used for measures and weights. SI

units and symbols should be used. Temperatures should be givenin degrees Celsius. Only decimal notation is acceptable: fractionsshould not be used.

Footnotes should be avoided unless thought to be absolutelynecessary.

6. References to literature: In both the text and the reference list,the name-year system must be used. The list of references shouldbe placed at the end of the paper, alphabetically arranged accord-ing to author name. Only those publications cited in the paper maybe included. Titles of journals should be given in full.

Examples of correct reference formats:Blaber, S. J. M. 1980. Fish of the Trinity Inlet System of North

Queensland, with Notes on the Ecology of Fish Fauna of Trop ic -al Indo-Pacific Estuaries. Australian Journal of Marine and Fresh-water Research 31:137-46.

aquaJournal of Ichthyology and Aquatic Biology

Vol. 5 (1), December 2001

Contents:

Thelma L. P. Dias, Ierecê L. Rosa & Bertran M. Feitoza: Food Resource and Habitat Sharing by the Three Western South Atlantic Surgeonfishes (Teleostei: Acanthuridae: Acanthurus)off Paraíba Coast, North-eastern Brazil Pages 167-176

Alexei M. Orlov, Alexei M. Tokranov, and Andrei V. Vinnikov: Additional records of scaled sculpin Archaulus biseriatus Gilbert & Burke, 1912 (Cottidae, Teleostei) from the North Pacific Pages 177-184

Richard Winterbottom: Two new gobiid fish species in Trimma and Trimmatom from the Indian and Western Pacific Oceans Pages 185-190

William F. Smith-Vaniz, Ukkrit Satapoomin, and Gerald R. Allen: Meiacanthus urostigma,a New Fangblenny from the Northeastern Indian Ocean, with Discussion and Examples of Mimicry in Species of Meiacanthus (Teleostei: Blenniidae: Nemophini) Pages 191-209

Index of aqua Vol 4 (1-4) Page 210

Papers appearing in this journal are indexed in: Zoological Record; Biolis - Biologische Literatur Information Senckenberg;

www.aquageo.com; www.Joachim-Frische.com

Cover photo: Plagiotremus laudandus laudandus, Great Barrier Reef, Australia, about 55 mm TL. Photo by R. Steene.

Solitary juvenile Acanthurus coeruleus foraging with juvenile A. bahianus and A. chirurgus at Picãozinho reef, Paraíba,Brazil. Photo by B. M. Feitoza.

aqua1).pdfaqua vol. 5 no. 1 - 2001 2 food resource and habitat sharing by the three western south...

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