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A report on the cheilostomeBryozoa of the Sudanese Red SeaJ.P.C. Dumont aa Biology Department , Stanford University , Stanford,California, 94305, U.S.A.Published online: 17 Feb 2007.

To cite this article: J.P.C. Dumont (1981) A report on the cheilostome Bryozoaof the Sudanese Red Sea, Journal of Natural History, 15:4, 623-637, DOI:10.1080/00222938100770441

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JOI'RNAI, <>F NATI'RAI, It,STO~V, 1981, 15:623 637

A repor t on the c h e i l o s t o m e B r y o z o a of the S u d a n e s e Red Sea

J. P. C. DUMONT

Biology Depar tment , Stanford Universi ty, Stanford, California 94305, U.S.A.

Introduction The Red Sea B .ryozoa fauna has been the subject of a number of previous studies.

Audouin and Savigny (1826) named 67 species. Of these 10 were taken from the Mediterranean and 17 from the Red Sea. No localities were given for the remaining 40 species. Waters (1909, 1910) reported on species collected from the Sudanese Red Sea, and Hast ings (1927) reported 24 species from the Suez Canal Zone, collected by the Cambridge Expedi t ion (1924). In 1928-1929 Dollfus found 38 species in the Nor thern Red Sea, which were identified by Balavoine (1959). In 1934 H a r m e r collected a number of species from Ghardaqua in the Nor th Red Sea~ the results of which were included in the Siboga Repor t (1957). Powell (1967) collected specimens from the Massawa area and the Dhalae Archipelago, and Redier (1970) collected from the Eas te rn shore of the Red Sea. All these collections relied on native divers and on dredging for collecting non-littorM specimens, with the resulting inherent drawbacks. To the best of my knowledge no previous a t t e m p t has been made to detect depth distributions of species of Bryozoa over a range of only 30 m.

The present s tudy was conducted on behalf of the Saudi-Sudanese Jo in t Commission for the Development of the Red Sea Resources, under the Directorship of Dr. Zaki Mustafa, as par t of a general faunal survey of the coral reefs. The aim was to discover which species of Bryozoa inhabit the reefs and to a t t e m p t to detect any depth-related distribution of these species.

Methods Bryozoa were collected by hand during scuba or snorkel dives from transects

across the reef top and down the South-Eas t face of Shaab Bara ja (25 °52 'N , 37 ° 24' E), and f rom various other environments represented on the reef, i.e. eaves and the lagoon. For comparison, samples were also taken from H a r v e y reef ( 19 ° 30' N, 37 ° 20' E). The samples were washed in fresh water and dried in the sun, as the skeletal materiM is adequate for identification. The samples were then shipped back to the British Museum (Natural History) in London, where I identified them with the assistance of Miss P. L. Cook.

Populat ion counts were made using colonies as the basic units. Species frequency was expressed as a percentage of the total number of colonies found in one sample.

Measurements are given in millimetres as follows: Lz - - l eng th ofzooid, l z - -wid th of zooid, L o ~ e n g t h of orifice, lo---width of orifice, L o v - - l e n g t h of ovicell, l o v - - width of ovicell, L m - - l e n g t h of mandible. Holotypes of new species are stored a t the British Museum (Natural History).

Eighty-six species of Bryozoa were found, of which 30 have not been reported from the Red Sea before (Appendix). Four new species are described, and examinat ion of some of these indicates tha t a reappraisal of the classification of the two sehizoporelloid genera, Emballotheca and Calyptotheca, is necessary.

0022 2933/Sl/15()4 0623 s02.110 I I!)Sl Ta:,lor ~ I:ranci~ lad

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624 J . P . C . Dumon t

Emballotheca L e v i n s e n and Calyptotheca H a r m e r In the original description of Emballotheca Levinsen (1909), dimorphie orifices

were not used as a distinguishing feature of the genus. When H a r m e r (1957) separated Calyptotheca from Emballotheca, he described both genera as having dimorphie orifices, and distinguished them on the basis of whether the proximal edge of the orifice was sinuate ( 'schizoporelloid') in Calyptotheca, or 'near ly straight, convex or concave ' in E~nbaltothe~a. Both of these s ta tements are unsatisfactory. In Calyptotheca, three species, C. tenuata Harmer , C. parcimunita Harmer and C. fossulata Harmer do not have dimorphic orifices (Harmer 1957), and in C+ wasinensis (Waters) the dimorphism is very slight. However, in all species of Emballotheca described by H a r m e r (1957), the orifices are dimorphie. As for the shape of the orifices, it is difficult to see what difference there is between a concave proximal edge and a sinus. Of Ha rm er ' s (1957) three species of Emballotheca, E. quadrata and E. pacifica have convex proximal edges and E. acutirostris has a s t raight or slightly convex proximal edge to the orifice. Therefore the use of the word concave in the definition of Emballotheca is unnecessary and misleading. I t would seem sensible to accept tha t there is very little difference between a concave proximal edge and a sinus, and tha t a species with either of these forms of orifice belongs to Calyptotheca. Rogick (1955) divided Emballotheca into two groups of species remarking " I t is on the bases of the type orifice tha t the genus should be split". She even used a similar te rm to Harmer ' s , 'schizoporellid', to describe the orifice of the gene~ie grouping which she distinguished from Emballotheca sensu stricto, but did not name. Rogick (1955) listed m a n y of the species belonging to Emballotheca and to the new grouping. Her division of these groups agrees with tha t of Harmer , al though she mentioned a number of species which Ha rm er omitted, and omit ted a few which he described. l%ogiek avoided Harmer ' s confusing s t a t ement on orifice shape, but it is clear tha t the grouping she described is exact ly the equivalent of Calyptotheca Harmer . Rogiek (1955) also renamed Mucronella quadrata Busk (1884) (not Lepralia quadrata MaeGillivray, the type species of Emballotheca) as Emballotheca buskii. This name predates tha t given to the same species by H a r m e r (1957), E. pacifu'a.

Although a large number of species are fully described by Rogick (1955) and by H a r m e r (1957), several species need to be reassigned.

Calyptotheca capensis (O'Donoghue and de Wattevil le) Emballotheca capensis O'Donoghue and de Watteville, 1937 : 19, fig. 4.

This species was originally introduced prior to the separat ion of Calyptotheca and Emballotheca by H a r m e r (1957) who was obviously unaware of the existence of its description (see In t roduc to ry Note in Ha rm er (1957)). The orifice has a distinct sinus and the species therefore belongs to Calyptotheca. Moreover, O'Donoghue and de Wattevil le (1937) compared E: capen~is to E. nivea (Busk 1884), a species which was one of those subsequently referred to Calyptotheca by H a r m e r (1957).

Calyptotheca subirnmersa (MacGillivray) Lepralia subimmersa MaeGillivray, 1879 : 23, pl. 35, fig. 5. Emballotheca subimmersa:Levinsen, 1909 : 333.

Hast ings (1932) noted tha t this species was not congeneric with Eschara quadrata MacGillivray, the type species of Emballotheca Levinsen. H a r m e r (1957:1087) suggested tha t L. subimmersa belonged to Calyptotheca, which in view of the sinuate orifice, appears to be the correct genus.

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Cheilostome Bryozoa of the Sudanese Red Sea 625

The following species require redefinition:

Calyptotheca thornelyae sp. nov. Lepralia subimmersa: Thornely, 1905 : 122. not L. subimmersa MacGillivray, 1879 : 23, pl. 35, fig. 5. LECTOTYPE (chosen here): specimen from Ceylon, Thornely Collection, Lepralia subimmersa BMNH 1979.7.2.2.

labelled

Descr@tion Colony encrusting, brown. Zooids rectangular, flat, in linear series, separated by

clear suture lines (Lz 0-47 0-69 mm, lz 0'34-0'49 mm). Fronta l wall of zooids and ovieells ret ieulato-punctate, heavily calcified and tubercular, slightly raised prox- imal to the orifice, with a single row of marginal pores. Orifice rounded, shallowly sinuate. There is a ledge of variable width between the proximal lip of the orifice and the peristome. Ordinary zooids, orifice as wide as long; fertile zooids, orifice wider than long, with no sinus. Ovieells flat, circular, immersed, formed by the distal zooid only (Lov 0"37 0"52 mm, lov 0"38-0"43 mm). Small, acute, sutural avicularia present, sometimes in large numbers, position variable bu t frequently lying along the lip of the peristome. Distribution: Ceylon, Australia and China Sea. Etymology: Named after Miss L. Thornely who first listed this species (Thornely 1905).

RegnctT' ]c8 C. thornelyae differs from C. subimmersa MaeGillivray in the size and position of

the avicularia and the size of the zooids. C. thornelyae also lacks the sub0ral umbo of C. subimmersa, and the dimorphism of the orifice of ovicelled zooids is more marked (Harmer 1957 : 1014).

Emballotheca harmeri n o r a . nov. Emballotheca acutirostris Harmer, 1957 : 1086, pl. 67, figs. 1, 2. not Emballotheca acutirostris Canu and Bassler, 1929 : 298, pl. 32, figs. 8-10. LECTOTYPE (chosen here): Harmer 's specimen 472AI (Amsterdam Zoological Museum), which is the specimen figured in the original description by Harmer (1957).

This species differs from E. acutirostris Canu and Bassler in the shape and position of the avicularia and the shape of the orifice.

Calyptotheca acutirostris Canu and Bassler Eraballotheca acutirostris Canu and Bassler, 1929 : 298, pl. 32, figs. 8-10. not Emballotheca acutirostris: Harmer, 1957 (=E. harmeri, see above).

This species has a distinct sinus and is therefore referable to Calyptotheca.

While these reassignments clear up several ambiguities, it should be mentioned that there is no distinction between Calyptotheca and Emballotheca in the range of variation of other characteristics examined, i.e., position and shape of the avicularia, size of the zooids, form of the ovicells, development of,the frontal wall and sutural lines. While the orificial condyles of Emballotheca are larger than those of Calyptotheca and are directed proximally, the size is not a reliable character, and the condyles of C. inaequalis Harmer (1957) are also directed proximally. A fur ther revision of these two generic groupings would appear to be necessary.

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626 J . P . C . Dumont

Calyptotheca heteroavicularia sp. nov. (Fig. 2, B and C)

HOLOTYPE: Sudanese Red Sea, BMNH 1980.2.14.3.

Description Colony encrusting, yellow. Zooids rectangular, flat, in linear series, separated by

marked sutural lines; frontal wall of zooids and ovicells ret iculato-punctate, proximal lip of orifice slightly raised; single row of marginal pores present. Orifice rounded, slightly sinuate, with small condyles. Autozooids polymorphic with respect to size. Zooids with large avieularia (Lm c. 0-25 ram) are the larger (Lz 0"60-0"80 mm, lz 0"40 0"50 ram). The avieularian mandible is broad and spathulate, with a single dentiele at the tip, and its rostrum runs the whole length of the zooid frontal wall. The smaller autozooids (Lz 0"44 0"50, lz 0-33-0"47 ram) may have a single, small, rounded, medial suboral avieularium pointing proximally. In addition, fertile zooids have larger orifices (Lo 0'16-0"2(1 mm, lo 0"11-0'13 ram) compared with those of all autozooids (Lo 0"11-0'125 mm, lo 0-095-0"105 ram). The ovieell is fiat and has sutural lines, although they may not always be clear. The sutural lines typically form a Y- shape, dividing the ovicell wall into three, but al ternative forms are found. The orifice of the ovieell is closed by the opereulum; some orifices are blocked by calcification.

Distribution." reeftop of both reefs. Etymology: this species is named after the two characteristic forms of avicularia.

Remarks The position and shape of the types of avieularia distinguish this species from all

other species of Calyptothe<:a.

Calyptotheca nigra sp. nov. (Fig. 1, B)

HOLOTYrE: Sudanese Red Sea, BMNH 1980.2.14.4.

Description Colony encrusting, black. Zooids large (Lz 0-83-0'99mm, lz 0"46 0"59ram),

convex, arranged in linear series, separated by deep grooves with faint sutural lines. Zooid surface reticulato-punetate. Orifices wider than long (Lo 0"085 0'165 ram, lo 0"14 0-155mm), i'ounded, but with rather s traight lateral edges, and a broad, shallow sinus with small condyles. Peristome shallow, irregular. Avieularia rare; large, spathulate (Lm 0"27-0"40mm). Subrostral chamber 0"45-0"58 mm long and 0-25-0-31 mm wide, surface like tha t of zooid, si tuated in the proximal corner, but extending across the whole zooid. Ovieells rare, large (Lov 0'40 0"50mm, lov 0-51- 0'60 mm), globose, surface as zooids, orifice closed by the opereulum, orifice slightly broader than in autozooids. Secondary calcification immerses the peristomes and increases the depth of the orifice, which may also beeonle blocked by calcification. Distribution: both reefs and Jeddah, 0-30 m.

R~wbar]c8 While the pat tern of calcification of this species is a little unusual for the genus,

the features that place it in Calyptotheca are: the shape of the orifice, the position of the sutural lines which meet the orifice at the disto-laterM corners, the position and shape of the condyles and the distinctive 'knobbly' peristome. C. nigra is

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Chei los tome B r y o z o a of the S u d a n e s e R e d Sea 627

(a)

(b)

F~(;. 1. ,~EM mierographs. (A) Escharoides longirostr@ sp. nov. View from growing edge of colony, showing ontogenetic changes, x 30. (B) Calyptc, theca nigra sp. nov. Par t of colony showing ovicells and two large avicularia, x 24.

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628 J . P . C . D u m o n t

(a)

(b) (<')

Fro. 2. SEM micrographs. (A) Calyptotheca sudanensis sp. nov. Zooids wi th avicular ia and ovicells, x 76. (B) Calyptotheca heteroavicularia sp. nov. P a r t of colony showing ovicells with suture lines, x 32. (C) C. heteroavicularia. Zooids wi th small and large avicularia. x 46.

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Cheilostome Bryozoa of the Sudanese Red Sea 629

distinguished from other members of the genus by the shape of the avicularia, the convexity of the zooids and the colour.

Calyptotheca sudanensis sp. nov. (Fig. 2, A)

Hippodiplosia pertusa Balavoine, 1959 : 273, pl. 3, fig. 6. not Cellepora pertusa Esper, 1796 : 149, pl. 10, figs. 1, 2 (see Hayward and Ryland, 1979 : 92,

fig. 31). HOLOTYPE: Sudanese Red Sea, BMNH 1980.2.14.2.

Description Colony enerusting, small (0-5 cm across), brown or green. Zooids convex, with

large, marginal areolae, separated by a prominent sutural ridge (Lz 0'60-0"69 mm, lz 0"30-0"37 ram). Frontal wall of zooids obviously cryptoeystidean, with fine reticu- lations and deep areolae. Large tubercles are present at the intersection of reticulations. Pr imary orifice sunken, sinuate (Lo 0"12-0"25 mm, lo 0"14-0-18 mm), with small, distinct condyles at the proximo-lateral corners. Distal par t of operculum approximately parallel with frontal wall, but proximal par t raised so tha t the operculum forms an oblique angle. Peristome raised, thin walled and irregular. There is a shelf of variable width between the proximal lip of the orifice and the peristome, which often has a median cleft, with a small acute, curved avieularium, directed laterally and vertically. Ovieells developed from the distal zooid only, globose, becoming immersed by secondary calcification, closed by the operculum (Lov 0"29-0'33mm, lov 0"33-0"39 mm). Ovieells may be developed as early as three zooid generations from the aneestrula. Distribution: both reefs, 0-20 m.

Remarks While the overall appearance of this species is ra ther different from tha t of other

members of the genus, most of the characters are present, if less marked, in other species. The characteristics which might cast doubt on the positioning of this species in Calyptotheca are the early development of the ovieells and the form of the peristome. However, in view of the shape of the orifice and the close resemblance to C. capensis (O'Donoghue and de Watteville 1937) in the form of the frontal wall, and the shelf between the orifice and the peristome, this species would appear to belong to Calyptotheca. I f differs from all other members of the genus in the form and position of the suboral avieularium, in the extensive development of the peristome and sutural ridges, and the early deve lopment of the ovicells.

Balavoine (1959) identified a specimen found by Dollfus on the Saudi Arabian coast as Hippod@losia pertusa. Judging from the plate (no description is included), this specimen belongs to C. sudanensis. The figured specimen differs from H. pertusa (Esper) in a number of ways, notably the presence of suboral avicularia and the fact tha t the ancestrula is not tat iform (see Hayward and Ryland 1979).

Calyptotheca wasinensis (Waters) Schizoporella nivea 'var. millanensis': Waters, 1909 : 168, pl. 17, figs. 2-4. Schizoporella nivea 'var. wasinensis': Waters, 1913 : 504, pl. 70, figs. 1,2. Calyptotheca wasinensis (Waters), Harmer, 1957 : 1017, pl. 68, figs. 15, 20, 21, 24, 32, 33.

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630 J . P . C . Dumont

Waters (1909) described a var ie ty of C. wasinensis found in the Red Sea with a "broad spathulate avicular ium" in the proximal corner of some zooids. A number of specimens with these avicularia have been found. The size of the spathula te avicularia varied. The largest extended from one of the proximal corners to the edge of the raised proximal lip of the orifice, which is larger than any previously recorded. Waters (1909) s ta ted tha t it was not necessary to make new var ie ty for this form, though at one t ime it was decided to call it ' va r millanensis'. One specimen also illustrates the ontogeny of the ovicell, which appears to develop from an uncalcified area of the frontal wall of the distal zooid.

Escharoides Milne Edwards Escharoides Milne Edwards: Hayward and Ryland, 1979 : 78.

Escharo ides longirostr is sp. nov. (Fig. 1, A)

Ho L O T Y P E : Sudanese Red Sea, BMNH 1980.2.14.1.

Description Colony enerusting, usually small, c. 0"5cm across. Zooids broad, convex,

separated by deep grooves (Lz 0-49-0-59mm, lz 0-37-0 '43mm). Fronta l wall originally smooth and imperforate with a single row of large marginal pores; rapidly becoming nodular due to secondary calcification. Orifice irregular, no calcification of p r imary orifice. A broad shelf extends from the distal r im below the level of the operculum. There are six tubular spines in a disto-lateral arc, reduced to four in fertile zooids. Proximal rim of orifice raised into a proximo-distal ly f lat tened mucro from which a dentiele projects running the whole length of the muero. There are also two smaller lateral dentieles. Avieularia very long (Lm 0'22-0"33 mm), t r iangular and very acute. Ros t rum dentieulate, upturned at the tip, a l though this is often missing due to damage. Subrostral chamber initially p ro tuberan t but becoming largely immersed and nodular due to secondary calcification. The chamber has a row of marginal pores. Fertile zooids develop three zooid generations from the ancestrula. Ovicell prominent , originally smooth with a single row of marginal pores; developing tubercles similar to the zooids, and becoming par t ia l ly immersed, with a double row of small pores. Ancestrula tat i form, circular, with a narrow cryptoeys t and 12 spines.

Remarks This is the first record of Escharoides f rom the Red Sea. E. longirostris differs from

other species in this genus in its small zooids and very long, acute, laterally directed avieularia. The form of the orifice is quite characteristic. These features distinguish this species from E. distincta H a y w a r d and Cook (1979) which is South African, E. angela (Hutton) which is synonymous with E. praestans (Hineks), and E. excavata (MacGillivray), which is synonymous with E. sauroglossa Levinsen, both of which are Australasian species (see Brown 1952). Boreal and Arctic species of Escharoides are discussed by H a y w a r d and Ryland (1979).

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Cheilostome B~\yozoa of the Sudanese Red Sea 631

D i s t r i b u t i o n Four problems arose in the a t t e m p t to measure populat ion density:

(1) There is the theoretical problem of how to assess a populat ion of 'any colonial organism. The populat ion of such species may be es t imated by number of' colonies, number of zooids, area covered by the colonies or biomass. I chose the first of these methods for purely practical reasons. This method does tend to emphasize the sexual, ra ther than the asexual reproduction which is a drawback as some species tend to reproduce asexually to a much greater extent than others.

(2) There is also the practical problem of a t t empt ing to measure populat ion density, i.e. the number of" colonies per unit area. I t is vel T difficult to measure the available surface area because of the irregulari ty of the surfaces involved. There is also the problem of which surfaces suit the se t t lement requirements of the larvae, which may not be the same in all species (see Eggleston 1972). Samples were collected to give the m a x i m u m number of colonies, so they were not representat ive of the true situation. I t was therefore only possible to measure species density as a percentage of the number of colonies found in each sample. While this has its drawbacks, it does have the advantage of removing the problem of a part icularly favourable environment at one collection point, leading to a high bryozoan population, and therefore to a spuriously high populat ion density for any species found at tha t point.

(3) A third problem is tha t microenvironmentM varia t ion may tend to confuse the situation. For example, a well protected but shallow locality may present a similar environment in m a n y respects, part icularly in s trength of' water current, to a deeper but less well protected spot.

(4) Another problem which might obscure distribution trends is tha t of colonies growing on a piece of rock or coral a t one depth and being t ranspor ted to a greater depth if the subs t ra tum is broken away.

These problems make it impossible to give absolute figures for populat ion density. However, for the purpose of measuring distribution of species, a relative measure is adequate.

The colonies were, for the most part , small (c. 90~o under 1 em across) but quite closely spaced, possibly suggesting a rapid turnover of colonies. While it was not possible to obtain truly representat ive figures for the populat ion density, est imates of the upper limit could be made on the flatter, more densely popula ted samples. The m a x i m u m populat ion density appeared to be abou t 5000 colonies per square metre, and did not seem to vary with depth.

A s tudy of individual species dis t r ibut ion-pat terns provided more definite information. Only nineteen species were present in sufficient numtJer to make it feasible to s tudy their vertical distributions. The lower limit for inclusion in this s tudy was set arbitrarily at 25 colonies found and the data from 20-30m were combined. The results of this section are shown in figs. 3 5 . Some species (e.g. Trematooecia turrita) appear to show a random distribution, but this is not true for many other species. A Chi-squared test showed tha t the differences in the distribution between the species is stat ist ically significant. I t is difficult to test the significance of the distribution of any single species, as the only information as to what form tha t distribution might take comes from these figures, and such an

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632 J . P . C . Dumont

A

0 I0 20-3O

Depth(~) C

I0 20l]0

Depth(m)

E

0 i0 20-50

Depth(m)

G m

6

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Depth(m)

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20

/ i0 20-30

Depth(m)

0 I0 20-30

Depth(~) F

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i

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Depth(m)

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Depth(m)

FIG. 3. Plots of vertical distribution of species of Bryozoa on Baraja, plotted as a percentage of colonies in a sample against depth. (A) Arthropoma ciroinatum (n=37); (B) Chorizopora brongniartii (n=25); (C) Escharoides longirostris (n=46); (D) Escharina pesanseris (n=53); (E) Exechonella antillea (n--51); (F) Exechonella discoidea (n=52); (G) Labioporella crenulata (n = 30); (H) Microloorella orientalis (n = 61).

argument would be circular. However, the results may be tested for possible linear or quadratic trend. To do this a measure of the contrast of the species distribution with an invariant distribution is obtained. This is then compared with the normal distribution. In this case a linear trend would represent a steady increase or decrease in population density with depth, and a quadratic t rend would represent a distribution pat tern with a maximum approximately in the centre of the depth

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Cheilostome Bryozoa of the Sudanese Red Sea 633

E

%

0 i0 20-30

Depth(m) C

0 lO 2 0 - 3 0

Depth(m)

0 0 10 2 0 - 3 0

Oepth(m)

I0 20-30

Depth(m)

15

%

D

B

0 0 10 2O-3O

0 l 0 2 0 - 3 0

Depth(m) F

4

~ 0 0 i0 ?o-3o

De~th(m)

H B

12

10 2 0 - 3 0

D e p ~ ( m )

FIG. 4. Plots of vertical distribution of species of Bryozoa on Baraja, plotted as a percentage of colonies in a sample against depth. (A) Parasmittina glomerata (n=49); (B) P. parsevalii (n=95); (C) P. raigii (n=26); (D) P. tropica (n=177); (E) Rhynchozoon detectum (n=55); (F) R. qlobosum (n=27); (G) R. larreyi (n=52); (H) Thalamoporella rozieri (n=77).

range. These trends therefore provide a mathematical model for the simplest forms tha t a hypothetical distribution pat tern might be expected to take. By testing the actual patterns against the hypothetical ones, we can obtain a measure of the confidence with which it can be said that the patterns found are not due to chance errors in sampling of a random distribution pattern. Using this test, Exechonella antillea, E. discoidea, Parasmittina parsevalii and P. raigii all show a significant

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634 J . P . C . Dumont

A

8 16

0 0 ' io ~o-?o o lo ~o-~o

C Depth(m) Depth(m)

16

0

0 10 2 0 - 3 0

Depth(m)

FIGS. 5. Plots of vertical distribution of species of Bryozoa on Baraj& plotted as a percentage of colonies in a sample against depth. (A) Trematooe<:ia turrita (n =48); (B) Water~vipora subovoidea (n = 77); (C) Cribrilina radiata (n = 97).

linear trend (5% confidence limits), and Arthropoma (:ircinatum, Escharoides longirostris, Escharina pesanseris and Cribrilaria radiata show a significant quadratic trend (5% confidence limits). Therefore, while the da ta basis is ra ther tenuous, there are apparent ly definite depth-related distribution pa t te rns to be found over a depth range of only 30 m.

Summary Eighty-six species of bryozoa are listed from collections from reels in the

Sudanese Red Sea, increasing the known fauna list by 30 species. The abundance, in terms of numbers of colonies, and the distribution of nineteen species has been analysed over a range of 30 metres depth. The character of the genera Calyptotheca Harmer and Emballothe(;a Levinsen are briefly discussed. C. thornelyae is introduced for Lepralia subimmersa Thornely not MacGillivray, and E. harmeri for E. acutirostris H a r m e r not Canu and Bassler. In addition, three new species of Calyptotheca, C. heteroavicularia, C. nigra and C. 8udanensis, and one of Escharoides, E. lonffirostris, are described.

Acknowledgments I am grateful to Dr. C. Roads (Cambridge Coral Starfish Research Group), Dr. S.

Head (Depar tment of Zoology, Oxford Universi ty) and Prof. Schroeder (Inst i tute of Oceanography, Por t Sudan). I would like to thank Miss P. L. Cook and Mr. P. J . Chimonides (Depar tment of Zoology, British Museum (Natural History)), for their invaluable help and advice.

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Cheilostome Bryozoa of the Sudanese Red Sea 635

Appendix: Species of Bryozoa found ((~lassifi(,ation after Harmer 1926. 1957. FR= First record from Red Sea.)

Order: Cheilostomata Suborder: Anasea Division: Malacostega Superfamily: Membraniporidae

Family: Setosellinidae Division: Coelostega Family: Onyehoeellidae Family: Labioporellidae Family: Thalamoporellidae Family: Steganoporellidae Division: Cellularina Family: Scrupocellaridae

Family: Bicellariellidae

Division: Cribrimorpha Family: Cribrilinidae

Suborder: Aseophora Division: Ascophora Imperfeeta Family: Exochellidae Family: Adeonidae Family: Exechonellidae

Family: Arachnopodiidae

Other Ascophora Family: Celleporariidae

Family: Petralliellidae

Antropora granulifera (Hincks) (FR) ,4. marginella (Hincks) Nellia tenuis Harmer Setosellina coronata (Hincks) (FR)

Smittipora cordiformi8 Harmer (FR) Labioporella erenulata (Levinsen) (FR) Thalamoporella rozieri (Audouin) Steganoporella simplex Harmer

Serupocellaria diadema Busk S. longispinosa Harmer (FR) Canda arachnoides Lamouroux Beania cupuIa~'ien~'is Osburn (FI~) B. mirabilis Johnstone (FI~) B. diseodermiae (Ortmann) Bungula robusta MacGillivray

M embraniporella aragoi (Audouin) Cribrilina radiata (Moll) Reginella floridana (Smitt)(FR)

Escharoides longirostris sp. nov. (FR). Reptadeonella sp. ? Exechonella tubereulata (MacGillivray) E. discoidea Canu and Bassler (FI~) E. antiIlea (Osburn) Tremogasterina robusta (Hincks) T. spathulata (Canu and Bassler)

Celleporaria aperta (Hineks) C. eolumnaris (Busk) C. granulosa (Haswell) C. labelligera Harmer C. pilaefera (Canu and Bassler) Ciglisula occlusa Busk Trematooecia turrita (Smitt) (FR) Mucropetralliella thenardii (Audouin) M. echinata (Canu and Bassler)'(FR) M. philippinensis (Canu and Bassler) (FR) M. robusta (Canu and Bassler) (Fl~) H ippopet,raU iella magna (D'Orbigny)

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636

Family: Savigayellidae Family: Margarettidae

Family: Hippopodinidae

Family: Gigantoporidae

Family: Celleporinidae Family: Smittinidae

Family: Chorizoporidae Family: Hippothoidae Family: Microporellidae Family: Sehizoporellidae

Family: Cleidochasmatidae

Family: Watersiporidae

Family: Sertellidae

J. P, C. Dumont

Savignyella otophora (Kirkpatrick) Margaretta gracilior (Ortmann) M. tenuis Harmer H ippopodina f eegeensis (Busk) Robertsonidra argentea (Hincks) Crepidacantha poissonii (Audouin) Hippopodinella adpressa Powell not Busk Gigantopora pupa (Jullien) G. fenestrata (Smitt) Cetleporina costazii (Audouin) Smittina nitidissima (Hineks) Smittoidea levis (Kirkpatrick) (FR) Parasmittina egyptiaca (Waters) P. glomerata (Thornely) P. parsevalii (Audouin) P. raigii (Audouin) P. tropica (Waters) Codonellina montferrandii (Audouin) Chorizopora brongniartii (Audouin) Trypostega venusta (Norman) (FR) Microporella orientalis Harmer Escharina pesanseris (Smitt) Arthropoma cecilii (Audouin) A. circinatum (MacGillivray) (FR) Calyptotheca wasinensis Waters C. heteroavicularia sp. nov. (FR) C. nigra sp. nov. (FR) C. sudanensis sp. nov. (Fg) Schizobrachiella convergens (Audouin) (FR) Stylopoma duboisii (Audouin) S. viride (Thornely) Scorpionidipora bernardii (Audouin) Cribellopora trichotoma (Waters) (FR) Schizomavella sinapiformis Harmer (FR) Cleidochasma laterale Harmer C. porcellanum (Busk) C. protrnsum (Thornely) Watersipora subovoidea (D'Orbigny) Cosciniopsis globosa Harmer (FR) C. lonchaea (Busk) Rhynchozoon detectum Harmer (FR) R. globosum Harmer (FR) R. larreyi (A adouin) R. tubulosum (Hincks) Drepanophora incisor (Thornely) (FR) D. longiuscula Harmer Hippoporella multidentata (Thornely) (FR) H. spinigera (Phillipps) (FR) Thorneyla ceylonica (Thornely) (FR)

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Cheilostome Bryozoa of the Sudanese Red Sea 637

For other species found in the Red Sea see Audouin and Savigny (1826), Waters (1909, 1910), Hastings (1927), Harmer (1926, 1934, 1957), Powell (1967, 1969), Balavoine (1959) and Redier (1970).

R e f e r e n c e s

AUDOUIN, J. V., and SAVIGNY; J. C., 1826, Explication sommaire des Planches de Polypes de l'Egypte et de la Syrie, in: Description de l'Egypte, Histoire Naturelle, l, Pt. 4, (Paris), pp. 225-244.

BALAVOINE, P., 1959, Rgsultats scientifiques Mission Robert Ph. Dollfus en Egypte, Pt. 3, xxxiv--Bryozoa, (Paris: Centre national de la Recherche Scientifique), pp. 257-282.

BROWN, D. A., 1952, The tertiary cheilostomatous Polyzoa of New Zealand, British Museum (Natural History), London, i-xii, 1-405.

BUSK, G., 1884, Report on the Polyzoa, Pt. 1, The Cheilostomata, Reports of scientific results of the voyage of the Challenger, Zoology, 10, 30, i-xxiii, 1-216.

CANU, F., and BASSLER, R. S., 1929, Bryozoa of the Philippine region, Bulletin of the United States National Muse,am, 9, 100, ii-xi, 1-685.

EGGLESTON, D., 1972, Factors influencing the distribution of sublittoral ectoprocts off the South of the Isle of Man (Irish Sea), Journal of Natural History, 6, 247 260.

ESPER, E. J. C., 1794-7, Fortsetzungen der Pflanzenthiere in Abbildungen nach der Natur mit Farbenerleuehtet nebst Beschreibungen, Theil 1:1-230 (pp. 117-163 were published in 1796) (Niirnberg).

HARMER, S. F., 1926, The Polyzoa of the Siboga Expedition, Pt. 2, Cheilostomata Anasca, Siboga Expedition Report, 28b, 181-501.

- - 1934, The Polyzoa of the Siboga Expedition, Pt. 3, Cheilostomata Ascophora 1, Family Reteporidae, Siboga Expedition Report, 28c, 502-640.

- - 1957 , The Polyzoa of the Siboga Expedition, Pt. 4, Cheilostomata Ascophora . . . , Siboga Expedition Report, 28d, 641-1147.

HASTINGS, A. B., 1927, Zoological results of the Cambridge Expedition to the Suez Canal, 1924, 20, Report on the Polyzoa, Transactions of the Zoological Society of London, 23, 3, 321-354.

- - 1932, The Polyzoa, with a note on an associated Hydroid, Reports of the Great Barrier Reef Expedition, 4, 12, 399-458.

HAYWARD, P. J., and CooK, P. L., 1979, The South African Museum's Meiring Naude Cruises, Pt. 9, Bryozoa, Annals of the South African Museum, 79, 4, 43 130.

HAYWARD, P. J., and RYLAND, J. S., 1979, British Aseophoran Bryozoans, Synopses of the British Fauna (New Series), No. 14, (Academic Press), pp. 1-312.

LEVI~SEN, G. M. R., 1909, Morphological and Systematic Studies on the Cheilostomatous Bryozoa (Copenhagen).

MACG~LLIVRAY, P. H., 1879, Polyzoa, in: F. McCoy, Prodromus of the Zoology of Victoria, (Melbourne, Decade III), edited by F. McCoy pp. 15-35.

O'DoNoGHUE, C. H., and DE WATTEVILLE, D., 1937, Notes on South African Bryozoa, ZooIogischer Anzeiger, Leipzig, 117, 12-22.

POWELL, N. A., 1967, Bryozoa (Polyzoa) from the South Red Sea, Cahiers de Biologie Marine, 8 , 161-183. 1969, A check-list of Indo-Pacific Bryozoa in the Red Sea, Israel Journal of Zoology, 18, 357-362.

REDIER, L., 1970, R6sultats scientifique de campague de la Calypso en Mer Rouge (1951- 1952), 24, 12, Bryozoaires, Annales de l'Institut Ocganographique, Monaco, 47, 9, 3-16.

ROGICK, M. D., 1955, Genus Emballotheca Levinsen 1909, Transactions of the American microscopical Society, 74, 2, 103-112.

THORbTELY, L. R., 1905, Report on the Polyzoa, in: Report on the Pearl Oyster Fisheries, Gulf of Manaar, 4, edited by W. A. Herdman, Supplementary Report, 26, pp. 107-130.

WATERS, A. W., 1909, Reports on the marine biology of the Sudanese Red Sea, 12, The Bryozoa, Pt. 1, Cheilostomata, Journal of the Linnean Soc, iety, Zoology, 31,123-181. 1910, Reports on the marine biology of the Sudanese Red Sea, 12, The Bryozoa, Pt. 2, Cyclostomata, Ctenostomata and Endoprocta, Journal of the Linnean Society, Zoology, 31,231-256. 1913, The marine fauna of the British East Africa and Zanzibar..., Proceedings of the Zoological Society London, 1913, 458-537.

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