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Number 3082, 7 pp., 3 figures.

10024 December 27, 1993

Pseudochromis kolythrus, a New Species of Dottyback from New Caledonia, with Comments on its Relationships (Teleostei: Perciformes: Pseudochromidae)

ANTHONY C. GILL' AND RICHARD WINTERBOTTOM2

ABSTRACT

Pseudochromis kolythrus is described from the 37.7 mm SL male holotype collected at Récif Mbere, New Caledonia. It is distinguished from other pseudochromines in having the following combination of characters: segmented dorsal-fin rays 25, with all rays branched; segmented anal- fin rays 14; fin spines slender and weakly pungent; circumpeduncular scales 16; and anterior lateral line with 25 or 26 scales, terminating beneath seg- mented dorsal-fin ray 15 or 16. It also has a dis- tinctive live coloration, with the anterior four-fifths

of the body olive-gray and the posterior one-fifth bright purple. Pseudochromis kolythrus belongs to the P. tapeinosoma complex, a clade that includes P. coccinicauda, P. cyanotaenia, P. flammicauda, P. jamesi, P. luteus, P. tapeinosoma, and P. wil- soni. This complex is diagnosed by a unique, syn- apomorphic modification of the cleithrum. The new species further shares apomorphic elongation of the pleural rib on the terminal precaudal ver- tebra with P. flammicauda, P. jamesi, P. luteus, and P. wilsoni.

INTRODUCTION

The Indo-Pacific Pseudochromidae in- cludes about 115 species classified in four subfamilies: Anisochrominae, Congrogadi-

nae, Pseudochrominae, and Pseudoplesiop- inae (Godkin and Winterbottom, 1985; Gill, 1990). The nearly 70 species in the Pseu-

' Lerner-Gray Research Fellow, Department of Herpetology and Ichthyology, American Museum of Natural His-

tory.

? Curator, Department of Ichthyology and Herpetology, Royal Ontario Museum, 100 Queen’s Park, Toronto, Ontario, Canada MSS 2C6, and Department of Zoology, University of Toronto, Toronto, Ontario, Canada M5S

1Al.

ISSN 0003-0082 / Price $1.00

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dochrominae are distinguished from other pseudochromids by the symplesiomorphic presence of five segmented pelvic-fin rays (versus 0—4 in the other subfamilies). During recent fieldwork in New Caledonia (Aug/Sept 1991), the second author collected an unde- scribed species of the genus Pseudochromis Rippell. The purposes of the present paper are to describe the new species, to distinguish it from other pseudochromines, and to com- ment on its relationships.

MATERIALS AND METHODS

Methods of counting and measuring follow Gill and Randall (1992). Where counts were recorded bilaterally, both counts are given and separated from each other by a slash; the first value presented is the left count. Oste- ological details were determined from a ra- diograph of the holotype. Comparisons with P. jamesi, P. luteus, and other pseudochro- mines are based on specimens listed in Gill (1990). Institutional acronyms follow Levi- ton et al. (1985).

ACKNOWLEDGMENTS

This study was completed while ACG was a Lerner-Gray Research Fellow in the De- partment of Herpetology and Ichthyology of the American Museum of Natural History. RW gratefully acknowledges financial sup- port from NSERC Grant A 7615, the ROM, and Benjamin Film Laboratories (Ltd.). The assistance of M. Kulbicki, J. Rivaton, the captain, crew, and divers of the ““Dawa” (OR- STOM, New Caledonia), and G. Klassen is much appreciated. We thank R. D. Mooi, G. Nelson, L. R. Parenti, C. L. Smith, and M. L. J. Stiassny for reviewing the manuscript. J. Beckett provided the photograph of the holotype.

Pseudochromis kolythrus, new species Figure 1

HOLOTYPE: ROM 65061, 37.7 mm SL male, New Caledonia, Récif Mbere, north of Passe de Dumbéa (22°19'10’S 167°12'45”E), cave in steep wall of dropoff, heavy Acropora growth, 18.3—30.5 m, rotenone, R. Winter- bottom, G. Klassen, J. Menou, and P. Tirard, 4 Sept 1991.

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D1aGnosis: The following combination of characters distinguishes P. kolythrus from all other pseudochromines: segmented dorsal-fin rays 25, with all rays branched; segmented anal-fin rays 14; fin spines slender and weakly pungent; anterior lateral-line scales 25 or 26, terminating beneath segmented dorsal-fin ray 15 or 16; and circumpeduncular scales 16.

DESCRIPTION: Dorsal-fin rays III,25, all segmented rays branched; anal-fin rays II, 14, all segmented rays branched; pectoral-fin rays 18/18, upper 2/2 and lower 2/2 rays un- branched; pelvic-fin rays I,5, all segmented rays branched; principal caudal-fin rays 9 + 8; branched caudal-fin rays 8 + 7; upper pro- current caudal-fin rays 6; lower procurrent caudal-fin rays 6; scales in lateral series 37/ 37; anterior lateral-line scales 26/25; anterior lateral line terminating beneath segmented dorsal-fin ray 16/15; peduncular lateral-line scales 5/5; caudal-fin lateral-line scales 0/0; horizontal scale rows between anterior and peduncular lateral lines 4/4; horizontal scale rows above anal-fin origin 12 + 1 + 3/13 + 1 + 3; predorsal scales 15; circumpeduncular scales 16; scales behind eye 2; scales to pre- opercular angle 3; circumorbital pores 17/23; preopercular pores 9/8; dentary pores 4/4; posterior interorbital pores 1; gill rakers 3 + 11; pseudobranch lobes 7.

As percentage of SL: head length 26.3; pre- dorsal length 34.5; prepelvic length 34.0; pre- anal length 66.0; dorsal-fin base length 52.8; anal-fin base length 22.5; dorsal-fin origin to pelvic-fin origin 28.4; anal-fin origin to mid- dle dorsal-fin ray (spines included in ray count) 25.2; snout length 5.6; orbit diameter 9.8; body width 13.3; fleshy interorbital width 4.5; bony interorbital width 2.7; snout tip to retroarticular tip 20.4; caudal peduncle length 13.8; caudal peduncle depth 15.4; first dorsal- fin spine length 1.6; second dorsal-fin spine length 4.0; third dorsal-fin spine length 7.2; first segmented dorsal-fin ray length 11.1; fourth last segmented dorsal-fin ray length 15.9; first anal-fin spine length 3.4; second anal-fin spine length 6.1; first segmented anal- fin ray length 10.3; fourth last segmented anal- fin ray length 15.1; third pectoral-fin ray length 17.5; pelvic-fin spine length 11.4; sec- ond segmented pelvic-fin ray length 19.9; caudal-fin length 23.6.

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GILL AND WINTERBOTTOM: DOTTYBACK 3

Fig. 1. Passe de Dumbéa, Récif Mbere, New Caledonia.

Ventral margin of lower lip narrowly in- terrupted at symphysis; scales on head, nape, anterior part of body including pectoral-fin base, preanal contour, and dorsal contour of body beneath anterior part of dorsal fin cy- cloid, the remainder ctenoid; dorsal and anal fins without basal scale sheaths, although with a few intermittent small scales overlapping fin bases; predorsal scales extending anteri- orly to second anterior interorbital pore; operculum with 6 small, irregular bumps; denticles of outer ceratobranchial-1 gill rak- ers well developed only on distal halves or tips of rakers; predorsal formula 0/0/0 + 2/1 + 1/1/1/1/1/1 + 1; dorsal-fin spines slender and weakly pungent; preanal formula 1/1 + 1/1/1 + 1/1; anal-fin spines slender and weakly pungent, the first spine much less stout than the second; pelvic-fin spine slender and weakly pungent; second segmented pelvic-fin ray longest; caudal fin rounded; vertebrae 10 + 16; epipleural ribs 13; epurals 3.

Upper jaw with 5 pairs of curved, enlarged caniniform teeth anteriorly, the medial pair smallest, and 5 or 6 (at symphysis) to 1 or 2 (on sides of jaw) inner rows of small conical teeth; lower jaw with 2 pairs of curved, en- larged caniniform teeth anteriorly, the lateral pair largest, and 4 or 5 (at symphysis) to 1

Holotype of Pseudochromis kolythrus new species, ROM 65061, 37.7 mm SL male, north of

(on sides of jaw) inner rows of small conical teeth, the conical teeth becoming slightly larger and more curved on middle of jaw; vomer with 2 (anteriorly) to 2 or 3 (postero- laterally) rows of small conical teeth, forming a chevron; palatines with 3 or 4 (anteriorly) to | or 2 (posteriorly) irregular rows of small conical teeth, forming a triangle.

PRESERVED COLORATION: Head and body brown, paler on snout, lips, ventral part of head, and abdomen; posteroventral part of orbital rim dusky gray-brown; caudal pedun- cle pale yellowish brown; dorsal fin hyaline with scattered gray-brown melanophores, these densest on basal third to half of fin; anal fin hyaline, narrowly grayish brown on distal and proximal edges of fin; caudal fin pale yellow basally, becoming white centrally; outside white area, caudal fin with broad dusky gray-brown convex mark, this curving from anterodorsal and anteroventral edges of fin to central part of middle rays; behind curved marking, caudal fin hyaline with scat- tered gray-brown melanophores; pelvic fins hyaline with anterior, posterior, and distal margins narrowly gray-brown; pectoral fins hyaline.

LIVE COLORATION (from fieldnotes made immediately after collection): Anterior four-

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fifths of body olive-gray, posterior one-fifth bright purple.

ETYMOLOGY: From the Greek ‘“‘koly- thron,” a ripe fig, an allusion to the olive- gray coloration with the purple representing the split test of the ripe fruit exposing the interior. To be treated as a noun in apposi- tion.

COMPARISONS: Pseudochromis kolythrus closely resembles P. jamesi Schultz from the southwest Pacific (including New Caledonia) and P. luteus Aoyagi from Taiwan, the Ryu- kyu Islands (Japan), and the Batan Islands (Philippines) in most meristic and morpho- metric details. The three species are distin- guished from other pseudochromines in pos- sessing the following combination of characters: segmented dorsal-fin rays 24-26, usually 25, with all or all but first rays branched; segmented anal-fin rays 13 or 14, usually 14; circumpeduncular scales 16; and anal-fin spines weakly pungent to flexible, with the penultimate spine less stout than the ultimate.

Pseudochromis kolythrus differs from P. jJamesi in having fewer anterior lateral-line scales (25 or 26 vs. 27-34, usually 28-31), with the anterior lateral line not extending as far posteriorly beneath the dorsal fin (ter- minating beneath segmented dorsal-fin ray 15 or 16 vs. 19-25); fewer upper procurrent caudal-fin rays (6 vs. 6-8, usually 7); more horizontal scale rows between anterior and peduncular lateral lines (4 vs. 2-4, rarely 2 or 4); more consecutive dorsal-fin pterygio- phores immediately posterior to neural spine 4 with a 1:1 association with interneural spac- es (4 vs. 1 or 2, usually 1); a shorter caudal peduncle (13.8 vs. 15.4-17.4% SL); a longer caudal fin (23.6 vs. 20.7-23.0% SL); and a longer fourth last segmented dorsal-fin ray (15.9 vs. 12.9-15.2% SL). Pseudochromis jamesi also differs from P. kolythrus in usu- ally having a white- or yellow-edged gray to black spot on the dorsoposterior part of the caudal peduncle; however, the spot is occa- sionally absent in females and juveniles, and is usually indistinct or absent in males (see Randall et al., 1990: 128).

Pseudochromis kolythrus differs from P. lu- teus in having fewer anterior lateral-line scales (25 or 26 vs. 26—32, usually 28-31), with the anterior lateral line not extending as far pos-

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teriorly beneath the dorsal fin (terminating beneath segmented dorsal-fin ray 15 or 16 vs. 17-24, usually 20-23); more consecutive dorsal-fin pterygiophores immediately pos- terior to neural spine 4 with a 1:1 association with interneural spaces (4 vs. 2—4, usually 3); a more posteriorly positioned dorsal fin (pre- dorsal length 34.5 vs. 29.4—33.1% SL); anda longer pelvic-fin spine (11.4 vs. 8.2-11.2% SL).

The olive-gray and purple male live col- oration of P. kolythrus further distinguishes it from the male live colorations of P. jamesi (see Randall et al., 1990: 128) and P. luteus (see Aoyagi, 1943: pl. 32, fig. 1, and Burgess and Axelrod, 1974: fig. 263), which are both more or less uniformly bright orange. How- ever, along with many other pseudochro- mids, P. jamesi and P. luteus appear to be protogynous hermaphrodites (e.g., see Springer et al., 1977, for discussion of pro- togynous hermaphroditism in anisochrom- ines); it is therefore possible that the holotype of P. kolythrus may be exhibiting a female or transitional coloration and that the true male coloration of the species is different and un- known. The holotype’s coloration bears some resemblance to the ground coloration of fe- male P. jamesi (see Randall et al., 1990: 128) and P. luteus females: head and body brown to bluish gray, becoming pinkish gray ven- trally, and sometimes pinkish gray to pink on the caudal peduncle.

The presence of two anal-fin spines with only a single supernumerary spine on the first pterygiophore is unique to P. kolythrus among pseudochromines; other pseudochromines have three anal-fin spines, with two super- numerary and one serial spine on the first pterygiophore. Anisochromines and some pseudoplesiopines resemble P. kolythrus in having only a single supernumerary spine on the first anal-fin pterygiophore. However, the anal-fin spines of P. jamesi, P. luteus, and other close relatives of P. kolythrus (see be- low) are slender; the first spine, in particular, is often poorly ossified and minute. It is therefore possible that the absence of a sec- ond supernumerary spine in the holotype of P. kolythrus is the result of damage or de- velopmental anomaly, rather than being typ- ical for the species. Even if the presence of a single supernumerary spine was found to be

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GILL AND WINTERBOTTOM: DOTTY BACK 5

Fig. 2. Lateral views of right cleithra (reversed) of: (A) Pseudochromis flammicauda Lubbock and Goldman, AMS I.19473-101, 38.9 mm SL, (B) P. fuscus Miller and Troschel, AMS I.18469-178, 48.0

mm SL. Arrows indicate lateral wings.

typical for P. kolythrus, it would be of little diagnostic value, as the anterior supernu- merary spine in related species is often easily overlooked (sometimes visible only after dis- section, or on radiographs). For example, Aoyagi (1943) erroneously recorded two in- stead of three anal-fin spines for five nominal species of Pseudochromis, all of which are close relatives of P. kolythrus, and Lubbock and Goldman (1976) erroneously recorded two anal-fin spines for a paratype of P. flam- micauda Lubbock and Goldman. RELATIONSHIPS: Pseudochromis kolythrus belongs to a clade, hereafter termed the “‘P. tapeinosoma complex,” that includes P. coc- cinicauda (Tickell) (from the eastern and cen- tral Indian Ocean), P. cyanotaenia Bleeker (from the eastern Indian Ocean to the Gilbert Islands), P. flammicauda (from the Great Barrier Reef), P. jamesi, P. luteus, P. tapei- nosoma Bleeker (from the eastern Indian Ocean and West Pacific), and P. wilsoni Whitley (from northern Australia). The P. tapeinosoma complex is diagnosed by a single synapomorphy: lateral wing of cleithrum ex- panded anteriorly well past the anterior pro- file of the main cleithral shaft (fig. 2). Species of this complex also share other apomorphic features that have relatively restricted distri-

butions in the Pseudochromidae (including relatively weak [vs. strong] fin spines, and a weakly interrupted to complete [vs. broadly interrupted at symphysis] lower lip). In a par- simony analysis of these and additional char- acters, these apomorphies may prove either to corroborate monophyly of the complex, or to link it with other clades within the family.

The P. tapeinosoma complex is divisible into two smaller clades, one consisting of P. coccinicauda, P. cyanotaenia, and P. tapei- nosoma, and the other consisting of P. flam- micauda, P. jamesi, P. kolythrus, P. luteus, and P. wilsoni. Monophyly of the first of these clades is supported by the synapomorphic presence of two epurals (pseudochromids primitively have three epurals), and mono- phyly of the second clade is supported by the synapomorphic presence of an elongate pleu- ral rib on the last precaudal vertebra (rib greater [usually much greater] than 50% of the length of the pleural rib on the penulti- mate caudal vertebra [fig. 3A], whereas in other pseudochromids it is less [usually much less] than 40% of the length of the preceding pleural rib [fig. 3B]). The two clades also differ in several meristic values. For example, members of the first clade have fewer dorsal- and anal-fin rays (segmented dorsal-fin rays

Fig. 3.

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1mm

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Lateral views of ultimate (10th) and penultimate (9th) precaudal vertebrae of: (A) Pseudochro-

mis luteus Aoyagi, AMNH 57369SW, 42.0 mm SL; (B) P. cyanotaenia Bleeker, AMNH 49636SW, 39.1 mm SL. Abbreviations: EPR epipleural ribs; NSP neural spines; PAP parapophyses; PCV9 9th precaudal vertebra; PCV10 10th precaudal vertebra; PLR pleural ribs.

21-23, usually 22, and segmented anal-fin rays 12-14, usually 13 vs. 23-27, usually 24— 26, and 13-15, usually 14, respectively, for the second clade). Values for these characters vary widely among the remaining Pseudo- chromis species, covering the full diversity seen within the P. tapeinosoma complex, and relationships within the genus are too poorly resolved to apply global parsimony argu- mentation to polarize these characters for the complex. Whatever their polarity, however, these characters must corroborate monophy- ly of one of the two clades.

Pseudochromis flammicauda and P. wil- soni are unique among members of the P. tapeinosoma complex in usually having 20 circumpeduncular scales (vs. 16 in other members of the complex); on that basis they

are hypothesized to be sister species. A sister- group relationship between P. jamesi and P. luteus is also supported by a single synapo- morphy: male coloration more or less uni- formly orange. As noted above, however, the male coloration of P. kolythrus may be un- known; this character may therefore prove to be a synapomorphy linking P. kolythrus with these two species. The testing of this and al- ternative hypotheses (e.g., whether P. koly- thrus is the sister group of either P. flam- micauda + P. wilsoni, P. jamesi + P. luteus, or a clade consisting of all four species) must await the analysis of additional characters. These and other phylogenetic studies of pseu- dochromids are in progress by the first au- thor.

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GILL AND WINTERBOTTOM: DOTTY BACK 7

REFERENCES

Aoyagi, H.

1943. Coral fishes. Tokyo: Maruzen, 224 pp., 37 pls.

Burgess, W., and H. R. Axelrod

1974. Pacific marine fishes. Book 5. Fishes of Taiwan and adjacent waters. Neptune City: T.F.H. Publications, pp. 1111- 1382.

Gill, A. C.

1990. A taxonomic revision of the fish sub- family Pseudochrominae (Perciformes: Pseudochromidae). Ph.D. thesis, Univ. of New England, Armidale, N.S.W., Australia.

Gill, A. C., and J. E. Randall

1992. Pseudochromis steenei, a new sexually dimorphic species of dottyback fish from Indonesia (Perciformes: Pseudochromi- dae). Rev. Franc. Aquariol. 19(1/2): 41- 46.

Godkin, C. M., and R. Winterbottom

1985. Phylogeny of the Congrogadidae (Pi-

sces; Perciformes) and its placement as

a subfamily of the Pseudochromidae. Bull. Mar. Sci. 36(3): 169-219. Leviton, A. E., R. H. Gibbs, Jr., E. Heal, and C. E. Dawson 1985. Standards in herpetology and ichthy- ology: part 1. Standard symbolic codes for institutional resource collections in herpetology and ichthyology. Copeia 1985(3): 802-832. Lubbock, R., and B. Goldman 1976. Two distinctive new Australasian Pseu- dochromis (Teleostei: Perciformes). J. Nat. Hist. 10: 57-64. Randall, J. E., G. R. Allen, and R. C. Steene 1990. Fishes of the Great Barrier Reef and the Coral Sea. Bathurst: Crawford House Press, 507 pp. Springer, V. G., C. L. Smith, and T. H. Fraser 1977. Anisochromis straussi, new species of protogynous hermaphroditic fish, and synonymy of Anisochromidae, Pseu- doplesiopidae, and Pseudochromidae. Smithson. Contrib. Zool. 252: 1-15.