on a small collection of chitons from papua new guinea ... · on a small collection of chitons from...

VENUS 65 (1-2): 97-112, 2006

On a Small Collection of Chitons from Papua New Guinea (Mollusca: Polyplacophora)

Enrico Schwabe

Zoologische Staatssammlung München, Münchhausenstrasse 21, D-81247 München, Germany; [email protected]

Abstract: Three species of Polyplacophora, Callistochiton granifer, Chiton (Tegulaplax) hululensis and Leptoplax unica, are recorded from Papua New Guinea for the first time. The occurrence of Lucilina lamellosa in New Guinea is also confirmed from new material. Specific diagnostic features are illustrated and short notes are given on each species. In addition, a compilation of Polyplacophora known from the New Guinea region is provided.

Keywords: Mollusca, Polyplacophora, Pacific Ocean, Papua New Guinea, distribution

Introduction

The Papua New Guinea zoogeographic region spans 462840 km², extending from 1˚ S to 11˚ S and from the Indonesian Border (140˚55´ E) to the Solomons (156˚ E). Although situated between two faunistic hotspots, namely the diverse Indonesian region (see Nierstrasz, 1905; Strack, 2001; Burghardt et al., in press) and the Australian region (Cotton, 1964; Gowlett-Holmes, 2001), the polyplacophoran fauna of the Papuan region has been investigated only sparsely, most notably by Ashby (1923) and Leloup (1981). Since then, only a few additional species have been reported from New Guinea (e.g. Kaas & Van Belle, 1985, 1985a, 1994), most of them new to science. This report is based on recently collected material that includes new reports for Papua New Guinea, often extending the known range of distribution of these species. An up-to-date species listing of the chitons known from New Guinea is presented together with a reference list of relevant sources.

Abbreviations: AMS ̶ Australian Museum Sydney, Australia; MNHN ̶ Muséum national d’Histoire naturelle, Paris, France; NHM ̶ Natural History Museum, London, UK; pd ̶ partly disarticulated specimen (used for Scanning Electron Microscopy); PNG ̶ Papua New Guinea; FLMNH ̶ Florida Museum of Natural History, Florida, USA; UF ̶ University of Florida, Florida, USA.

Systematics

Class Polyplacophora Gray, 1821Subclass Neoloricata Bergenhayn, 1955

Order Chitonida Thiele, 1909Suborder Chitonina Thiele, 1909

Superfamily Chitonoidea Rafinesque, 1815Family Callistoplacidae Pilsbry, 1893

Genus Callistochiton Dall, 1879Type species: Callistochiton palmulatus Carpenter MS, Dall, 1879, designated by monotypy.

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Genus distribution: Tropical and subtropical waters, Oligocene-Holocene.

Callistochiton granifer Hull, 1923(Figs. 1A, 2A-F, 3, 4)

Callistochiton granifer Hull, 1923: 161, pl. 25, figs. 5-8.Type: Holotype, AMS C. 009306 [not seen].Type locality: Australia: Queensland, Palm Island, 18˚40´ S, 146˚33´ E, 27 m.Material examined: UF 327877 ̶ 1 specimen, 11.2 × 5.8 mm (curled), PNG, leg. J. Starmer,

1 June 1998 (PNG-065), 75% ethanol.Habitat: The species is known to inhabit muddy to somewhat coarser sediments,

bathymetrically from 0-53 m. In Indonesia it was mainly found under pieces of dead coral, under stones, or sometimes mixed in with algae (personal observation).

Distribution: The species is known from Australia, New Caledonia, the Coral Sea, Samoa, American Samoa, and Indonesia. This new record fills the gap between the Indonesian and the Queensland reports.

Remarks: The single specimen agrees well with material examined from other localities (Samoa Island, New Caledonia, and Indonesia). Other congeners in the New Guinea region are:

Fig. 1. Dorsal view of complete specimens, anterior to the left. A. Callistochiton granifer Hull, 1923, UF 327877, 11.2 × 5.8 mm. B. Chiton (Tegulaplax) hululensis (E. A. Smith, 1903), UF 297697, 10.2 × 5.3 mm. C. Lucilina lamellosa (Quoy & Gaimard, 1835), UF 322444, ca. 12 × 7.9 mm. D. Leptoplax unica (Nierstrasz, 1905, UF 297697, ca. 10.7 × 6.9 mm. Scale bar = 5 mm (A, B, D); 2.5 mm (C).

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Callistochiton belliatus Kaas & Van Belle, 1994, Callistochiton biakensis Kaas & Van Belle, 1994 and Callistochiton squamigercostatus Kaas & Van Belle, 1994. Based on the original descriptions, Callistochiton granifer Hull, 1923 differs from C. belliatus by having 12-14 slits in the head valve (Fig. 2D), a coarser tegmentum sculpture (Figs. 2A-C), and fewer radial ribs on the dorsal girdle scales (about 8 in contrast to 11 in C. belliatus) (Fig. 3A). Likewise, it can be separated from C. squamigercostatus by the more broadly spaced (and fewer) radial ribs on the head valve, the more triangular shape of the tail valve with a more posterior mucro, the lack of distinct longitudinally arranged latticed riblets in the intermediate valves, and by stronger (and fewer) radial ribs on the dorsal girdle scales, which reach the distal end of the scales. C. biakensis has

Fig. 2. A-F. Callistochiton granifer Hull, 1923, UF 327877. A. Dorsal view of the head valve. B. Dorsal view of valve II. C. Dorsal view of the tail valve. D. Ventral view of the head valve. E. Ventral view of valve II. F. Ventral view of the tail valve. G-L. Chiton (Tegulaplax) hululensis (E. A. Smith, 1903), UF 297697. G. Dorsal view of the head valve. H. Dorsal view of valve II. I. Dorsal view of the tail valve. J. Ventral view of the head valve. K. Ventral view of valve II. L. Ventral view of the tail valve. Arrangement of the valves: anterior at the top. Scale bar = 1 mm.

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fewer radial ribs on the terminal valves, a reticulated tegmentum, and a rectangular second valve.The specimen examined herein has a 3.5 mm long radula (Fig. 4), of which 1.7 mm were

taken up by the radula bolster. The radula consists of 48 rows of teeth, of which 39 appeared to be already mineralized.

A detailed description of this species was given by Kaas & Van Belle (1994: 190; fig 78). This account adds the first SEM images of the girdle elements and the radula (Figs. 3, 4).

Family Chitonidae Rafinesque, 1815Subfamily Chitoninae Rafinesque, 1815

Genus Chiton Linnaeus, 1758Type species: Chiton tuberculatus Linnaeus, 1758, subsequent designated by Dall (1879: 297).Genus distribution: Worldwide except for the cold-temperate regions, excluding South

America, Cretaceous-Holocene.

Subgenus Tegulaplax Iredale & Hull, 1926Type species: Chiton howensis Hedley & Hull, 1912 = Ischnochiton hululensis E. A. Smith,

1903 (fide Kaas, 1979: 866), by original designation.Subgenus distribution: Tropical and subtropical waters of the Indo-Pacific, also in the

Mediterranean Sea, Holocene.

Fig. 3. Girdle elements of Callistochiton granifer Hull, 1923, UF 327877, in situ. A. Dorsal girdle scales. B. Ventral girdle scales. Scale bar = 30 µm (A); 100 µm (B).

Fig. 4. Radula of Callistochiton granifer Hull, 1923, UF 327877, anterior rows. Scale bar = 100 µm.


Chiton (Tegulaplax) hululensis (E. A. Smith, 1903)(Figs. 1B, 2G-L, 5)

Ischnochiton hululensis E. A. Smith, 1903: 619, pl. 36, figs. 3-6.Type: Holotype, NHM 1903.9.17.27.Type locality: Maldives, Kaafu Atholhu, Hulhule, 04˚10´ 59´´ N, 73˚31´ 58´´ E [Stn. IX],

1.8-11 m [1-6 fathoms].Material examined: UF 323452 ̶ 1 specimen, 9.6 × 5.4 mm, PNG: West New Britain, Kimbe

Bay, Walindi Plantation Resort, reef flat, off jetty/boat mooring, sand and small patch reef, 2-10 m, 05˚26´ 12´´ S, 150˚05´ 17´´ E, leg. L. Kirkendale, 19 June 2003 (LAK-144), 95% ethanol. UF 297697 ̶ 1 specimen (bold marked material indicates the specimen used for SEM-study), 10.2 × 5.3 mm, PNG: north coast of Basilisk Bay, Hiliwau, 1-4 m, under rocks, 10˚45´ 39´´ S, 150˚ 42´ 45´´ E, leg. Gustaf Paulay, 27 May 1998 (GP-552), 75% ethanol.

Habitat: The species bathymetrically ranges from 0-45 m. It may be found under rubble, dead shells, and stones. According to data with material in the ZSM collection the species has a preference for fine to moderately coarse coral sand.

Distribution: For distribution comments for this species see Schwabe (2004: 3170); this new record is just a logical continuation of known occurrences.

Remarks: The excellent descriptions of this species by Kaas (1979: 866, pl. 2, figs. 11-19),

Fig. 5. Chiton (Tegulaplax) hululensis (E. A. Smith, 1903), UF 297697. A. Half side of the anterior part of the radula. B. Dorsal girdle scales from mid-girdle, in situ. C. Dorsal girdle scales (left side), tips of clapper (central), and spicules from marginal fringe (right side), in situ. D. Ventral girdle scales, in situ. Scale bar = 20 µm (A, C, D); 100 µm (B).

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Strack (1993: 12, pl. 3, fig. 9, pl. 7, figs. 8-9), Saito (1998: 153, figs. 2H, 5), and Dell’Angelo & Smriglio (2001: 184, pls. 62-63, fig. 112) fits well with the specimens presented herein. It is the first time that detailed illustrations of the tegmentum (Figs. 2G-I), the radula (Fig. 5A), and the perinotum (Figs. 5B-D) of a specimen from outside the Red Sea area are given.

Subfamily Toniciinae Pilsbry, 1893

Genus Lucilina Dall, 1882Type species: Chiton confossus Gould, 1846 = Chiton lamellosus Quoy & Gaimard, 1835 (fide

Thiele, 1909b: 98), subsequent designation by Pilsbry (1893: 210).Genus distribution: Indo-Pacific Ocean, Pliocene – Holocene.

Lucilina lamellosa (Quoy & Gaimard, 1835)(Figs. 1C, 6A-F, 7)

Chiton lamellosus Quoy & Gaimard, 1835: 386, pl. 74, figs. 29-32.Type: Lectotype, MNHN, selected by Strack (1986: 194).Type locality: Tonga Tabou.Material examined: UF 295047 ̶ 1 specimen: ca. 19 × 12 mm (curled), PNG: Louisades

Archipelago, Deboyne Islands lagoon, northwest side of Nivani Islet, under rocks, 7-10 m, 10˚47´ 28´´ S, 152˚23´ 05´´ E, leg. Gustaf Paulay, 30 May 1998 (GP-554), 75% ethanol. UF 294972 ̶ 1 specimen: ca. 17 × 10.3 mm (curled), PNG: Louisades Archipelago, west side of Pana Voli Udi Island, 2-8 m, 11˚02´ 31´´ S, 152˚28´ 43´´ E, leg. Gustaf Paulay, 1 June 1998 (GP-560A), 75% ethanol. UF 322183－1 specimen, ca. 17 × 10.3 mm (curled), PNG: Bismarck Archipelago west end Sabben Island group, Sabben Point forereef, gentle coral slope with abundant Halimeda cover, 3-25 m, 02˚08´ 51´´ S, 146˚10´ 26´´ E, leg. L. Kirkendale, 29 June 2003 (LAK-166), 95% ethanol. UF 323808 ̶ 1 specimen, 15 × 9.2 mm, PNG: Bismarck Archipelago South New Hannover, East of Cape Botiangin forereef, small cut at steep wall dive with abundant ledges, 3-25 m, 2˚40´ 26´´ S, 150˚11´ 57´´ E, leg. L. Kirkendale, 1 July 2003 (LAK-168), 95% ethanol. UF 322444 ̶ 2 specimens, ca. 12 × 7.9 mm and ca. 25 × 12 mm (curled), PNG: West New Britain, Kimbe Bay, Venessa’s reef dive site, forereef, long narrow reef ridge/patch reef, 3-37 m, 5˚17´ 39´´ S, 150˚07´ 42´´ E, leg. L. Kirkendale, 17 June 2003 (LAK-142), 95% ethanol.

Description: Animal elongate oval. Coloration highly variable, generally tones of chestnut brown and greyish-green dominant. Valves appear smooth except for longitudinal to transverse lamellae on head valve and post-mucronal area, which are very fine and more distinct along diagonal ridges (Figs. 6A-C). Lamellae interrupted by radial rows of large lenses (diameter up to 48.35 µm), appearing as silver-black dots. Lenses have their highest density in lateral areas along valve margin. Head valve semicircular with wide V-shaped posterior margin. Intermediate valves broadly rectangular, with straight posterior margin on both sides of protruding apex. Jugal area slightly or not elevated, but distinguishable by coloration and smoother sculpture. Lateral areas slightly elevated. Tail valve broadly triangular with rounded posterior edge. Mucro situated at posterior fourth, directed slightly forwards, and elevated. Post-mucronal area short but very steep. Articulamentum thick and white (Figs. 6D-F), forming large apophyses and insertion plates. Apophyses connected by short jugal lamina, distinctly crenulated in middle. Insertion plates roughly pectinated on outside. Insertion teeth rather short, slightly forward-directed with sharp edges. Slit formula of disarticulated specimen: 8/1/14. Slit rays indistinct, and not visible on tail valve. Valves surrounded by wide, uniform, “naked” girdle. Dorsally covered with very small calcareous spicules, which measure 10 × 6 µm and deeply embedded in very thick cuticle (Fig.


7B). In addition more slender spicules (17 × 4 µm) can found distributed randomly over girdle (Fig. 7C). Ventrally, radial rows of short rectangular scales, which measure 30 × 25 µm with distinct radial ribs (Fig. 7D).

Central tooth of radula (Fig. 7A) measures 70 µm × 19 µm and has single broad and slightly forward-directed blade. Basal shaft of central tooth slightly extended. First lateral tooth nearly twice as long as central one. First lateral measures 120 µm × 28 µm; shaft simple and slender with single inwardly directed blade. Second lateral tooth with shaft 195 µm long; tooth strongly keeled in upper part, bearing large, roundish head with 3-4 denticles. Innermost denticle smallest and only well developed in few rows. Second denticle from inside longest, with keeled elevated

Fig. 6A-F. Lucilina lamellosa (Quoy & Gaimard, 1835), UF 322444. A. Dorsal view of the head valve. B. Dorsal view of valve II. C. Dorsal view of the tail valve. D. Ventral view of the head valve. E. Ventral view of valve II. F. Ventral view of the tail valve. G-L. Leptoplax unica (Nierstrasz, 1905), UF 297697. G. Dorsal view of the head valve. H. Dorsal view of valve II. I. Dorsal view of the tail valve. J. Ventral view of the head valve. K. Ventral view of valve II. L. Ventral view of the tail valve. Adjustment of the valves: anterior at the top. Scale bar = 1 mm.

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back; sharply pointed, whereas tips of remaining denticles more obtuse. Spoon-like uncinal tooth ca. 200 µm long.

Ctenidia holobranchially arranged. Distribution. The species has a wide Indo-Pacific distribution. It occurs from Australia to the

Andaman Sea (the latter a new record from the author’s collection: 1045 [h]). The easternmost record is from Tutuila Island (American Samoa) (also in the author’s collection).

Suborder Acanthochitonina Bergenhayn, 1930Superfamily Cryptoplacoidea H. & A. Adams, 1858

Family Acanthochitonidae Pilsbry, 1893Subfamily Acanthochitoninae Pilsbry, 1893

Genus Leptoplax Dall, 1882Type species: Chiton coarctatus Sowerby, 1841, designated by monotypy.Genus distribution: Indo-Pacific Ocean, Holocene.

Leptoplax unica (Nierstrasz, 1905)(Figs. 1D, 6G-L, 8-10)

Acanthochites (Notoplax) unicus Nierstrasz, 1905: 62, pl. 1, fig. 20; pl. 4, figs. 115-117; pl. 5, fig. 118.

Fig. 7. Lucilina lamellosa (Quoy & Gaimard, 1835), UF 322444. A. Half side of the anterior part of the radula. B. Dorsal girdle spicules from mid-girdle, in situ. C. Isolated dorsal girdle spicule from mid-girdle, in situ. D. Ventral girdle scales, in situ. Scale bar = A 100 µm; B 10 µm; C 2 µm; D 20 µm.


Type: Holotype, ZMA 1899.05.07.Type locality: Indonesia, “bank between the Bahuluwang and Tambolungan Islands, South

of Saleyer, Siboga Exp. Station 66”, 8-10 m, bottom, dead coral, Halimeda, Lithothamnion. The type locality is herein restricted to halfway between Pulau Bahuluang and Pulau Tambulongan, 6˚32´ 32´´ S 120˚25´ 34´´ E.

Material examined: UF 322108 ̶ 1 specimen, ca. 8 × 6.5 mm (curled), PNG: off Port Moresby, Motupore Island, Motupore Island Research Station, reef flat, turbid, shallow live

Fig. 8. Leptoplax unica (Nierstrasz, 1905), UF 297697. A. Dorsal view of the head valve, anterior at the top. B. Dorsal view of valve II, anterior at the top. C. Close up of the pleural area of valve II. D. Dorsal view of the tail valve, anterior at the top. E. Close up of the ante-mucronal area of the tail valve, posterior at the top. F. Close up of the jugal area of the tail valve, posterior at the top. Scale bar = A, B, D 200 µm; C, E, F 20 µm.

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and dead reef, 1-2 m, 9˚35´ S, 147˚17´ E, leg. L. Kirkendale, 15 June 2003 (LAK-140), 95% ethanol. UF 297697 ̶ 3 specimens, ca. 7.2 × 4 mm, ca. 10.7 × 6.9 mm (curled) and ca. 11.4 × 7 mm (curled), PNG: north coast of Basilisk Bay, Hiliwau, 1-4 m, under rocks, 10˚15´ 39´´ S, 150˚42´ 45´´ E, leg. Gustaf Paulay, 27 May 1998 (GP-552), 75% ethanol.

Description: Animal elongate oval. Valves subcarinated and moderately elevated. Coloration varies from cream to dark yellowish, generally speckled with darker tones. Wide perinotum extends between valves. Head valve semicircular with nearly straight posterior valve margin. Tegmentum covers only about 50% of entire dorsal valve surface (Fig. 6G, Fig. 8A). Intermediate valves trapezoidal with anterior margin only half width of posterior one (Fig. 6H, Fig. 8B). Apex

Fig. 9. Leptoplax unica (Nierstrasz, 1905), UF 297697. A. Right lateral view of the tail valve, anterior to the right. B. Dorsal girdle spicules and tuft, in situ. C, D. Dorsal girdle spicules from the mid-girdle, in situ. E, F. Ventral girdle spicules, in situ. Scale bar = A 200 µm; B 100 µm, C-F 20 µm.


beaked. Posterior and anterior valve margins straight. Jugal area wedge-shaped, occupying whole width of anterior tegmentum portion. Tail valve round with nearly central, slightly elevated mucro (Fig. 6I, Fig. 8D, Fig. 9A). Jugal zone of tail valve much narrower than on intermediate valves, appearing nearly parallel-sided. Tegmentum (Figs. 8C, E) sculpture consists of drop-shaped, moderately raised granules (ca. 93 × 60 µm), arranged more or less symmetrically (radially) on head valve, pleural areas, and ante-mucronal area. Granules less regularly arranged and more roundish in pleuro-lateral and post-mucronal areas. Granules have central macroesthete (ca. 8.5 µm in diameter) and two microesthetes (ca. 6.6 × 11.6 µm), which lie in open end of granule. Jugal zone bears irregularly arranged micropores with diameter up to 12.5 µm. Somewhat smaller pores (up to 10 µm) present among granules.

Articulamentum well developed and thickened, white with large areas of pinkish red; dorsal side, in particular, nearly completely red except for apophyses (Figs. 6J-L). Apophyses wide, wing-shaped and unconnected. 5 slits in head valve, appearing broad and short on ventral side to groove-like on dorsal side. Intermediate valves with single slit on each side. Beside slit rays, dorsal grooves present that correspond with enlarged “diagonal ridge”. Disarticulated specimen has 9 slits in tail valve; slit rays indistinct and dorsal grooves resemble pectination.

Perinotum very wide and fleshy. 18 tufts of rather long white spicules, approximately 20 per tuft. Spicules up to 205 µm long, slender and only slightly curved in upper half (Fig. 9B). Main dorsal coverage small slender, sharply pointed spicules (Figs. 9B-D), 10.6 × 3.5 µm in size, interrupted by two other kinds of spicules. Fist kind are thick, their upper half curved, obtusely pointed, with fine oblique and irregular riblets. These spicules attain length up to 150 µm (Fig. 11C). Other kind much smaller, up to 32 µm in length, straight, smooth, and sharply pointed (Fig. 11D). Randomly arranged among two kinds of spicules are also straight, conical, obtusely pointed spicules measuring up to 200 µm in length. Ventral girdle shows dense coverage of sharp to obtusely pointed spicules that may attain length of 75 µm (Figs. 9E-F).

Central radular tooth rectangular, 24 µm in length, with simple forwardly directed blade (Figs. 10A-B). First lateral tooth wing-shaped, covering basal half of central tooth, latter slightly keeled in this region. Second lateral tooth with shaft about 100 µm long bearing a tricuspid head. Innermost denticle sharpest and largest and more keeled dorsally than others. Major uncinal tooth slender, about 113 µm long, bearing spoon-like extended head with or without slightly pointed edge.

Due to curled condition of specimens exact number of ctenidia could not counted, but they extend anteriorly beneath valves v-iv.

Fig. 10. Leptoplax unica (Nierstrasz, 1905), UF 297697. A. Anterior part of the radula. B. Detail of figure A, showing the central, first and second lateral teeth. Scale bar = A 100 µm; B 20 µm.

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Distribution: The species was known so far from the type locality only. The herein presented material extends its distributional range southwards.

Remarks: The use of the genus Leptoplax for acanthochitonids with a multifissured tail valve and short sutural tufts on a wide perinotum is controversial. Gowlett-Holmes (1991) separated the Australasian genus Notoplax H. Adams, 1861 from the genus Leptoplax. While Van Belle (1999) did not follow this opinion, radula studies of Saito (2004) have shown that generic separation is justified.

Discussion

The Papuan chiton fauna has never been investigated in detail. Besides two short papers on chitons from Papua New Guinea by Ashby (1923) and Leloup (1981), there are only sporadic literature records of chitons of New Guinea, which is divided politically into the Indonesian province of Iriyan Jaya in the west and the country of Papua New Guinea in the east. A list of taxa recorded so far from this region may be found under ‘Appendix’.

In addition to the present taxa, three unidentified chitons were obtained during an investigation of the Raja Ampat Islands (Wells, 2002a). The table contains only taxa explicitely reported from New Guinea, and not even nearby vicinities. The compilation includes a total of 19 species belonging to 7 families and 12 genera. All species have a wider distribution than New Guinea except for Parachiton fornix (Kaas & Van Belle, 1985), Callochiton cinnabaris Kaas & Van Belle, 1985, Callistochiton biakensis Kaas & Van Belle, 1994, Callistochiton belliatus Kaas & Van Belle, 1994 and Callistochiton squamigercostatus Kaas & Van Belle, 1994. The ecology and distribution of these latter species are still too little known to consider them endemic to the New Guinea region. Of species reported from New Guinea, only Ischnochiton (Haploplax) adelaidensis (Reeve, 1847) was previously known exclusively from Australia, whereas Notoplax holosericea (Nierstrasz, 1905) seems to be a typical Indonesian faunistic element. It is likely that a thorough investigation of this island, as well of its satellite islands, will greatly increase our knowledge of the distribution of Asian and Oceanian chitons. Species such as Nierstraszella lineata (Nierstrasz, 1905), reported from Vanuatu and Indonesia, probably also occur in New Guinea. The same is true of chitons reported from the Molluccas (e.g. Strack, 2001). It seems that the chiton fauna is highly diverse, as is that of the Indonesian region (personal observation), but that individuals occur only in low numbers. That is likely the reason why chitons of the New Guinea region have been largely neglected, even though it would seem that this region could serve as a bridge between the Asian and Oceanian chiton faunas and thus should be of the utmost interest in understanding the extent of connectivity between these regions.

It would also be interesting to assess the contribution of chitons to the molluscan diversity of the region but unfortunately such estimates are not yet possible. Only the results of the Raja Ampat Islands Expedition might provide some basis for speculation. During this expedition a total of 699 mollusc species were obtained, of which only three were chitons. If the true number of chitons is least 6 times larger (as in this study) then one gains an appreciation of the contribution that chitons make to the biodiversity of this region.

Acknowledgement

I thank Dr. Gustav Paulay and Dr. John Slapinsky (FLMNH) for providing the material for study. Dr. Douglas Eernisse (California State University, Fullerton; USA) and Dr. Alan Beu (Institute of Geological & Nuclear Sciences Lower Hutt, New Zealand) kindly polished the English and provided helpful comments. I thank Dr. Boris Sirenko (Zoological Institute of Russian Academy of Sciences St. Petersburg, Russia), another referee, Dr. Michael Schrödl and Michael Bohn (Zoologische Staatssammlung München, Germany) for their constructive criticism. This material was collected on a


study organized by the Coral Reef Research Foundation, supported by funding from the National Cancer Institute.

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Nierstrasz, H. F. 1905. Die Chitonen der Siboga-Expedition. Siboga Expeditie 48: 1-112, pls. 1-8.Nierstrasz, H. F. 1905a. Bemerkungen über die Chitonen-Sammlung im Zoologischen Museum zu

Leiden. Notes from the Leyden Museum 25: 141-159.Pilsbry, H. A. 1892-1894. Monograph of the Polyplacophora. In: Tryon, G. W. (ed.), Manual of

Conchology, 14: 1-128, pls. 1-30 (1892); i-xxxiv, 129-350, pls. 31-68; 15: 1-64, pls. 1-10 (1893); 65-133, pls. 11-17 (1894). Academy of Natural Sciences, Philadelphia.

Powell, A. W. B. 1937. New species of marine Mollusca from New Zealand. Discovery Reports 15: 153-222.

Quoy, J. R. C. & Gaimard, J. P. 1835. Voyage de découvertes de l’ “Astrolabe”. Exécuté par ordre du Roi, pendant les années 1826-1827-1828-1829, sous le commandement de M. J. Dumont d’Urville. Zoologie 3, Mollusques, Genre Oscabrion-Chiton, Linné: 369-411, pls. 73-75. J. Tastu, Paris.

Rochebrune, A. T. de 1882. Diagnoses d’espèces nouvelles de la famille des Chitonidae (premier supplément). Bulletin de la Société Philomathique de Paris (7) 6: 190-197.

E. Schwabe110

Saito, H. 1996. Seven new species of the genus Parachiton (Polyplacophora: Leptochitonidae) from the northwest Pacific. Venus (Japanese Journal of Malacology) 55: 161-187.

Saito, H. 1998. The chitons (Mollusca: Polyplacophora) of the Goto Islands, west coast of Kyushu, Japan. Memoirs of the National Science Museum, Tokyo (31): 145-163.

Saito, H. 2004. Phylogenetic significance of the radula in chitons, with special reference to the Cryptoplacoidea (Mollusca: Polyplacophora). Bollettino Malacologico, Suppl. 5 (2003): 83-104.

Schwabe, E. 2004. The Polyplacophora (Mollusca) collected during the First International Marine Biodiversity Workshop for Rodrigues (western Indian Ocean), with the description of a new species. Journal of Natural History 38 (23/24): 3143-3173.

Smith, E. A. 1903. Marine Mollusca. In: Gardiner, J. S. (ed.), The fauna and geography of the Maldive and Laccadive Archipelagoes, etc. 2 (2 no.1): 589-630, pls. 35-36.

Strack, H. L. 1986. Notes on New Caledonian chitons. I. The species described by St.-M. Souverbie. Basteria 50: 193-198.

Strack, H. L. 1993. The Polyplacophora of the Red Sea. Journal of the Malacological Society of Australia 14: 1-40.

Strack, H. L. 2001. Studying the chiton fauna of the Moluccas (Indonesia): preliminary results. 4th International Workshop of Malacology (of Italian Malacological Society). “Systematics, Phylogeny and Biology of Polyplacophora”, Menfi: 11 (Abstract).

Thiele, J. 1909a. Revision des Systems der Chitonen. I. Teil Zoologica. Original-Abhandlungen aus dem Gesamtgebiete der Zoologie, Stuttgart 22 (56/1): 1-70, pls. 1-6.

Thiele, J. 1909b. Revision des Systems der Chitonen. II. Teil Zoologica. Original-Abhandlungen aus dem Gesamtgebiete der Zoologie, Stuttgart 22 (56/2): 71-132, pls. 7-10 (“1910” on title page; listings on subsequent journal covers show it as of 1909).

Van Belle, R. A. 1999. Polyplacophora: Classification and synonymy of recent (sub)genera. The Festivus 31: 69-72.

Wells, F. 2002a. Chapter 2: Molluscs of the Raja Ampat Islands, Papua Province, Indonesia. In: McKenna, S. A., Allen, G. R. & Suryadi, S. (eds.), A marine Rapid Assessment of the Raja Ampat Islands, Papua Province, Indonesia, pp. 37-45. RAP Bulletin on Biological Assessment 22, Conservation International, Washington, DC: 1-191.

Wells, F. 2002b. Appendix 3: Molluscs recorded at the Raja Ampat Islands. In: McKenna, S. A., Allen, G. R. & Suryadi, S. (eds.), A marine Rapid Assessment of the Raja Ampat Islands, Papua Province, Indonesia, pp. 113-131. RAP Bulletin on Biological Assessment 22, Conservation International, Washington, D.C.

(Received October 1, 2005 / Accepted February 22, 2006)

Appendix

Annotated checklist of Polyplacophora occuring in the New Guinea region

Family Leptochitonidae Dall, 1889Parachiton fornix (Kaas & Van Belle, 1985) comb. nov.

Reference: Kaas & Van Belle (1985: 182; fig. 86) as Leptochiton (Parachiton) fornix sp. nov.Remarks: Following the recent use of the genus Parachiton (Thiele, 1909a) as explained in Saito

(1996), the species is recombined herein.Parachiton acuminatus (Thiele, 1909)

Reference: Thiele (1909a: 13; pl. 1, figs. 61-73) as Lepidopleurus acuminatus n. sp.Remarks: Placed in the genus Parachiton by Powell (1937: 219).

Family Callochitonidae Plate, 1901Callochiton cinnabaris Kaas & Van Belle, 1985

Reference: Kaas & Van Belle (1985a: 46; fig. 19).


Family Ischnochitonidae Dall, 1889Ischnochiton (Haploplax) adelaidensis (Reeve, 1847)

Reference: Kaas & Van Belle (1994: 79).Remarks: Ischnochiton (Haploplax) misimaensis Ashby, 1923 (Ashby, 1923: 228; pl. 16, figs.

6, 6a-c), Ischnoradsia papuaensis Ashby, 1923 (Ashby, 1923: 227; pl. 17, figs. 2a-c), and Chiton vangoethemi Leloup, 1981 (Leloup, 1981: 2; figs. 1-2) originally described from New Guinea were shown to be conspicific with I. adelaidensis by Kaas & Van Belle (1994: 77).Ischnochiton (Haploplax) quoyanus Thiele, 1909

Remarks: The species originally described by Quoy & Gaimard (1835: 396; pl. 75, figs. 43-47) as Chiton tessellatus from New Guinea was preoccupied by Chiton tessellatus Wood, 1815. Thiele (1909a: 83; pl. 8, fig. 30) solved this taxonomic conflict by renaming the species.

Family Callistoplacidae Pilsbry, 1893Callistochiton biakensis Kaas & Van Belle, 1994

Reference: Kaas & Van Belle (1994: 153; fig. 63).Callistochiton belliatus Kaas & Van Belle, 1994

Reference: Kaas & Van Belle (1994: 151; fig. 62).Callistochiton squamigercostatus Kaas & Van Belle, 1994

Reference: Kaas & Van Belle (1994: 155; fig. 64).Callistochiton granifer Hull, 1923

Reference: Herein.

Family Chitonidae Rafinesque, 1815Chiton (Rhyssoplax) densiliratus Carpenter in Pilsbry, 1893

Reference: Bullock (1989: 809) as Rhyssoplax densiliratus (Carpenter in Pilsbry, 1893).Remarks: For taxonomic decision see Kaas & Van Belle (1998).

Chiton (Rhyssoplax) rhynchota (de Rochebrune, 1884)Reference: Bullock (1988: 691) as Rhyssoplax (Anthochiton) rhynchota (de Rochebrune, 1884).Remarks: For taxonomic decision see Kaas & Van Belle (1998).

Lucilina lamellosa (Quoy & Gaimard, 1835)Reference: Wells (2002b: 113) as Tonicia lamellosa (Quoy & Gaimard, 1835).Remarks: For taxonomic decision see Schwabe (2004).

Onithochiton sp.Remarks: According to Hermann Strack (the Netherlands, personal communication) the Indonesian

specimens may be a new species and are under study. Most probably the following interpretations refer also to this new species.

Onithochiton lyellii; Leloup (1981: 4).Onithochiton undulata; Nierstrasz (1905: 106; 1905a: 157).

Acanthopleura gemmata (de Blainville, 1825)Reference: Ferreira (1986: 227).Remarks: The following synonyms were also described from New Guinea:Chiton aculeatus “Gmelin”; Quoy & Gaimard, 1835: 373 (syn. by Ferreira,1986: 226).Acanthopleura rawakiana de Rochebrune, 1882: 195 (syn. by Kaas & Van Belle, 1980: 109).Acanthopleura spinigera (Sowerby, 1840) by Nierstrasz, 1905a: 152 (syn. by Ashby, 1922: 29).Acanthopleura granulata [non Acanthopleura granulata (Gmelin, 1791)]; Leloup 1981: 1 (syn. nov.

herein).Acanthopleura spinosa (Bruguière, 1792)

Reference: Nierstrasz (1905a: 152).Squamopleura miles (Carpenter in Pilsbry, 1893)

E. Schwabe112

Reference: Ferreira (1986: 240) as Acanthopleura miles (Carpenter in Pilsbry, 1893).Remarks: For taxonomic decision see Kaas & Van Belle (1998).

Family Cryptoplacidae Ashby, 1928Cryptoplax oculatus (Quoy & Gaimard, 1835)

Reference: Quoy & Gaimard (1835: 411) [“provient de la Nouvelle-Guinée ou de Vanikoro”].Remarks: Specimens reported in Leloup (1981: 3) as Cryptoplax striata (Lamarck, 1819), may

probably be juveniles of this species.

Family Acanthochitonidae Pilsbry, 1893Notoplax holosericea (Nierstrasz, 1905)

Reference: Nierstrasz (1905: 66; pl. 2, fig. 23, pl. 5, figs. 130-133) as Acanthochites (Loboplax) holosericeus nov. spec.

Remarks: For taxonomic decision see Kaas & Van Belle (1980).Leptoplax unica (Nierstrasz, 1905)

Reference: Herein.

パプアニューギニアから採集された多板類 4種について

E. シュワーベ

要　約

　パプアニューギニアの多板類相についての研究はほとんど行われていない。同地より 4種の多板類が

採集されたので報告する。3種，Callistochiton granifer Hull, Chiton (Tegulaplax) hululensis (E. A. Smith), お

よび Leptoplax unica Nierstrasz, は同地からの初記録である。Lucilina lamellosa (Quoy & Gaimard) の分布も

確認された。各種について種の標徴となる形態をカラー写真と電子顕微鏡写真で示した。また，これま

でに同地から報告されている全種，7科 12属 19種のリストを作成した。このリストには新組み合わせ

1，新異名 1が含まれる。

on a small collection of chitons from papua new guinea ... · on a small collection of chitons from...

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