Two new species of damselfishes (Pomacentridae: Chromis) from Indonesian seas

Transcription

1 aqua, Journal of Ichthyology and Aquatic Biology Two new species of damselfishes (Pomacentridae: Chromis) from Indonesian seas Gerald R. Allen 1 and John E. Randall 2 1) Department of Aquatic Zoology, Western Australian Museum, Francis Street, Perth, Western Australia 6000 and Conservation International, 1919 M. Street N.W. Suite 600, Washington, DC 20036, U.S.A. 2) Bishop Museum, 1525 Bernice Street, Honolulu, HI , U.S.A. Accepted: Keywords Taxonomy, marine fishes, Indonesia, Pomacentridae, Chromis, new species Abstract Two new species of pomacentrid fishes are described from coral reefs of Indonesia. Chromis monochroma is described from five specimens, mm SL, collected at Flores in depths between 42 and 53 m. It has XIII,10-11 (usually 11) dorsal rays; II,11 anal rays; (usually 17) pectoral rays; 3 spiniform caudal rays; (usually 14) tubed lateral line scales; body depth in SL, and lacks any distinctive colour markings. Chromis alpha is the closest relative, having the same meristic and morphometric data except usually 12 instead of 11 dorsal and anal soft rays, and 15 rather than 14 lateral line scales. It differs in colour, notably in having a black spot at the upper base of the pectoral fin and blackish posterior margins of the preopercle and opercle. The second new species, C. pura, is described from five specimens, mm SL, collected at Pura, near Alor in the Lesser Sunda Islands, Indonesia in 18 m. It has XIII,12-13 (usually 12) dorsal rays; II,11 anal rays; pectoral rays; 2 spiniform caudal rays; tubed lateral line scales; and a colour pattern similar to C. flavomaculata from which it differs in having instead of gill rakers. Zusammenfassung Zwei neue Riffbarsch-Arten ( Schwalbenschwänze ) werden von den Korallenriffen Indonesiens beschrieben. Chromis monochroma wird nach fünf Exemplaren mit einer Länge von 41,0 bis 51,3 mm SL beschrieben, die bei Flores in einer Tiefe zwischen 42 und 53 m gesammelt wurden. Folgende Merkmale kennzeichnen diese Art: Flossenstrahlen: XIII, (meist 11) in der Rückenflosse; II, 11 in der Afterflosse; (meist 17) in den Brustflossen; 3 stachelförmige in der Schwanzflosse; weiterhin (meist 14) mit Röhrchen durchzogene Schuppen auf der Seitenlinie; Körpertiefe 1,79-2,0 mm SL; keine auffälligen Farbkennzeichen. Am nächsten verwandt ist Chromis alpha mit denselben morphometrischen Daten abweichend jedoch mit 12 statt 11 Weichflossenstrahlen in der Rückenflosse und in der Analflosse und 15 statt 14 Seitenlinienschuppen. Bestes Unterscheidungsmerkmal ist die Farbgebung: vor allem ein schwarzer Fleck am oberen Ende der Brustflossen und schwärzliche hintere Ränder an Vorkiemendeckel und Kiemendeckel. Die zweite neue Art: C. pura, wird auf der Grundlage von fünf Exemplaren mit 54,7-76,3 mm SL beschrieben, die bei Pura, nahe Alor, an den Kleinen Sundainseln in Indonesien in 18 m Tiefe gefangen wurden. Flossenstrahlen: XIII, (meist 12) dorsal; II, 11 anal; pectoral; 2 stachelförmige Flossenstrahlen caudal; Schuppen mit Röhrchen auf der Seitenlinie; Farbmuster ähnlich wie bei C. flavomaculatus; deren Unterscheidungsmerkmal ist eine Anzahl von statt Kiemenblättchen-Reihen. Résumé On décrit ici deux nouvelles espèces de Pomacentridés des récifs coralliens indonésiens. Chromis monochroma est décrit sur base de cinq spécimens, 41,0-51,3 mm de LS, collectés à Flores, à des profondeurs de 42 à 53 m. Ses rayons dorsaux: XIII, (généralement, 11); rayons de l'anale: II,11; rayons pectoraux: (généralement, 17); trois rayons spiniformes à la caudale; (généralement, 14) écailles canaliculées sur la ligne latérale; hauteur du corps: 1,79-2,0 en LS; toute couleur distinctive faisant défaut. Chromis alpha est l'espèce la plus proche: elle partage les mêmes données méristiques et morphométriques, sauf 12 rayons mous, habituellement, au lieu de 11 à la dorsale et à l'anale, et 15 plutôt que 14 rangées latérales d'écailles. Elle se distingue surtout par la couleur, notammant par une tache noire sur la base supérieure de la pectorale et des liserés noirs postérieurs au préopercule et à l'opercule. La seconde nouvelle espèce, C. pura, est décrite sur base de cinq spécimens, 54,7-76,3 mm de LS, collectés à Pura, près d'alor, dans les petites îles de la Sonde, Indonésie, par 18 m de fond. Il compte XIII, (généralement,12) rayons à la dorsale; II,11 rayons à l'anale; à la pectorale; 2 rayons spiniformes à la caudale; aqua vol. 9 no

2 Two new species of damselfishes (Pomacentridae: Chromis) from Indonesian seas écailles canaliculées sur la ligne latérale; et un patron de coloration analogue à celui de C. flavomaculata dont il diffère par la présence de branchiospines au lieu de Sommario Due nuove specie di pomacentridi sono descritte dalla barriera corallina indonesiana. Chromis monochroma è descritta sulla base di 5 esemplari, mm SL, raccolti a Flores a profondità di m. Possiede XIII,10-11 (di solito 11) raggi dorsali; II,11 raggi anali; (di solito 17) raggi pettorali; 3 raggi caudali spiniformi; linea laterale con (di solito 14) scaglie; altezza del corpo in SL; assenza di qualsiasi segno distintivo di colore. Chromis alpha è un suo parente stretto, avendo le stesse caratteristiche morfometriche e gli stessi valori meristici, tranne per una maggiore frequenza di 12 anziché 11 raggi anali e dorsali e una linea laterale con 15 anziché 14 scaglie. Si differenzia per il colore, principalmente per la macchia nera alla base superiore della pinna pettorale e per il contorno nerastro del margine posteriore dell opercolo e del preopercolo. La seconda specie nuova, C. pura, è descritta sulla base di cinque esemplari, mm SL, raccolti a Pura, presso Alor, nell Arcipelago Minore della Sonda, Indonesia, entro 18 m di profondità. Possiede XIII,12-13 (di solito 12) raggi dorsali; II,11 raggi anali; raggi pettorali; 2 raggi caudali spiniformi; linea laterale con scaglie; colorazione simile C. flavomaculata da cui differisce per avere anziché rastrelli branchiali. Introduction The pomacentrid genus Chromis Cuvier is common on coral and rocky reefs throughout tropical and warm temperate seas. The genus, which contains 82 species, is the largest in the family. Allen (1991) provided photos and a brief diagnosis for 75 of the 76 described species (C. dispilus from New Zealand unintentionally omitted). An additional seven species have been described in recent years (Randall and McCosker, 1992; Moura, 1995; Randall, 2001). In addition, Allen (1993) showed that C. megalopsis, which he described (1976) from Western Australia is a junior synonym of C. mirationis Tanaka of southern Japan. The present paper describes two new species that were collected by the second author during visits to the islands of Flores and Pura (near Alor) in the Lesser Sunda Group, Indonesia in 1988 and Methods Measurements were taken with a digital calliper to a hundredth decimal place. Lengths of specimens are given as standard length (SL) measured from the anterior end of the upper lip to the base of the caudal fin (posterior edge of hypural plate); head length is measured from the same anterior point to the posterior edge of the opercle flap; body depth is the maximum depth taken vertically between the belly and base of the dorsal spines; body width is the maximum width just posterior to the gill opening; snout length is measured from the anterior end of the upper lip to the anterior edge of the eye; orbit diameter is the horizontal fleshy diameter, and interorbital width the least fleshy width; upper jaw length is taken from the front of the upper lip to the posterior end of the maxilla; caudal peduncle depth is the least depth, and caudal peduncle length is the horizontal distance between verticals at the rear base of the anal fin and the caudal fin base; lengths of fin spines and rays are measured to their extreme bases (i.e., not from the point where the ray or spine emerges from the basal scaly sheath); caudal fin length is the horizontal length from the posterior edge of the hypural plate to a vertical at the tip of the longest ray; caudal concavity is the horizontal distance between verticals through the tips of the shortest and longest rays; pectoral fin length is the length of the longest ray; pelvic fin length is measured from the base of the pelvic spine to the filamentous tip of the longest soft ray; pectoral ray counts include the small splint-like, uppermost rudimentary ray; only the tube-bearing anterior lateral line scales are counted; a separate count is given for the deeply-pitted scales occurring in a continuous series midlaterally on the caudal peduncle; the decimal figure.5 appearing in the scale row count above and below the lateral line refers to a small truncated scale at the respective bases of the dorsal and anal fins; gill raker counts include all rudiments and are presented as separate counts for the upper and lower limbs as well as a combined count; the last fin ray element of the dorsal and anal fins is usually branched near the base and is counted as a single ray. Counts and proportions appearing in parentheses apply to the range for the paratypes if different from the holotype. Proportional measurements expressed as percentage of the standard length are recorded in Table I and Table II. Type specimens are deposited at the Bernice P. Bishop Museum, Honolulu (BPBM), California Academy of Sciences, San Francisco (CAS), Muséum National d Histoire Naturelle, Paris (MNHN), United States National Museum of Natural History, Washington, D. C. (USNM), and the Western Australian Museum, Perth (WAM). Chromis monochroma n. sp. (Fig. 1; Table I) Holotype: BPBM 34070, 40.9 mm SL, Maumere, Flores, Indonesia (approximately 8 39 S, E): reef off Pertamina dock; at depth of 53 m, collected with quinaldine, by J. E. Randall, 13 September Paratypes (same locality as holotype): CAS , 45.9 mm SL, 52 m, collected with spear, J. E. Randall, 12 September 1988; MNHN , 48.3 mm SL, m, spear, J. E. Randall, 13 September, 1988; aqua vol. 9 no

3 Gerald R. Allen and John E. Randall USNM , 48.9 mm SL, m, spear, J. E. Randall, 13 September 1988; WAM P , 51.3 mm SL, 50 m, quinaldine, J. E. Randall, 15 September Diagnosis Dorsal rays XIII-XIV,10-11 (usually XIII,11); anal rays II,11; pectoral rays (usually 17); spiniform caudal rays 3; tubed lateral line scales (usually 14); gill rakers (total, 28-29); body depth in SL; colour olive-brown dorsally, shading to pale iridescent blue-green ventrally; top of head and tip of chin blackish; spinous dorsal fin and scaled basal part of soft dorsal fin yellowish grey; rest of soft dorsal fin hyaline with pale yellow rays; anal fin yellowish, scaled basal part slightly dusky brownish; lobes of caudal fin broadly dusky yellow, tips blackish, posterocentral half of fin hyaline; pelvic and pectoral fins pale yellowish; colour in alcohol nearly uniform brown. Fig. 1. Chromis monochroma n. sp., holotype, 41.0 mm SL, Flores, Indonesia. Photo by J. E. Randall. 19 Description Dorsal rays XIII,11 (one paratype with XIV,10); anal rays II,11; all dorsal and anal soft rays branched, the last to base; pectoral rays 17 (one paratype with 16), the upper 2 and lowermost unbranched; pelvic rays I,5; principal caudal rays 15, the upper and lowermost unbranched; spiniform caudal rays 3, followed by 2 accessory segmented rays; scales in longitudinal series 27; tubed lateral line scales 15 (14); posterior midlateral scales with a pore or deep pit (in continuous series) 7 (7-9); scales above lateral line to origin of dorsal fin 2.5; scales above lateral line to base of middle dorsal spine 1.5; scales below lateral line to origin of anal fin 8; gill rakers = 28 ( = 28-29); branchiostegal rays 6; supraneural (predorsal) bones 3; vertebrae Body moderately deep, depth 1.93 ( ) in SL, and compressed, the width 3.26 ( ) in body depth; head length 3.02 ( ) in SL; dorsal profile of head with a slight convexity anterior to eye; snout shorter than orbit diameter, its length 3.80 ( ) in head length; orbit diameter 2.51 ( ) in head; interorbital space convex, its width 2.95 ( ) in head; caudal peduncle depth 2.21 ( ) in head; caudal-peduncle length 2.28 ( ) in head. Mouth terminal, small, and oblique, forming an angle of about 42 to horizontal axis of head and body; posterior edge of maxilla reaching a vertical at anterior edge of pupil or slightly behind this point, the upper jaw length 3.02 ( ) in head; teeth multi-serial, an outer row of conical teeth in each jaw, largest anteriorly; 20 (22-25) upper and 19 (20-24) lower teeth on each side of jaw; a narrow band of villiform teeth lingual to outer row, in 2-3 irregular rows anteriorly, narrowing to a single row on side of jaws; tongue triangular with rounded tip; gill rakers long and slender, the longest on lower limb near angle about three-fourths length of longest gill filaments; nostril with a fleshy rim, more elevated on posterior edge and located at level of middle of pupil, slightly less than one-third distance from front of snout to base of upper lip. Opercle ending posteriorly in a flat spine, the tip relaaqua vol. 9 no

4 Two new species of damselfishes (Pomacentridae: Chromis) from Indonesian seas Table I. Proportional measurements of selected type specimens of Chromis monochroma n. sp. as percentage of the standard length. Holotype Paratype Paratype Paratype Paratype BPBM USNM MNHN CAS WAM P Standard length (mm) Body depth Body width Head length Snout length Orbit diameter Interorbital width Depth of caudal peduncle Length of caudal peduncle Upper jaw length Predorsal distance Preanal distance Prepelvic distance Length of dorsal fin base Length of anal fin base Pectoral fin length Pelvic fin length Pelvic fin spine length st dorsal spine th dorsal spine Last dorsal spine Longest soft dorsal ray st anal spine nd anal spine Longest soft anal ray Caudal fin length Caudal concavity tively obtuse and obscured by a large scale; margin of preopercle smooth, the posterior margin extending dorsally to level of upper edge of pupil, the anterior margin extending to level of anterior edge of pupil; suborbital with free lower margin extending nearly to a vertical at posterior edge of pupil. Scales finely ctenoid; anterior lateral line ending beneath rear portion of spinous dorsal fin; head scaled except lips, tip of snout, and a narrow zone from orbit to edge of snout containing nostrils; a scaly sheath at base of dorsal and anal fins, about two-thirds pupil diameter at base of middle of spinous portion of dorsal fin, progressively narrower on soft portion; a column of scales on each membrane of dorsal and anal fins, narrowing distally, those on spinous portion of dorsal progressively longer, reaching about two-thirds distance to spine tips on posterior membranes, then progressively shorter on soft portion; small scales on caudal fin extending slightly more than two-thirds distance to posterior margin; small scales on basal one-fifth of pectoral fins; a median scaly process extending posteriorly from between base of pelvic fins, its length about half that of pelvic spine; axillary scale above base of pelvic spine slightly more than one-third length of spine. Origin of dorsal fin over third lateral line scale, the predorsal distance 2.33 ( ) in SL; base of soft portion of dorsal fin contained 3.1 times in base of spinous portion; first dorsal spine 3.51 ( ) in head; second dorsal spine 2.34 ( ) in head; fifth to eighth dorsal spines subequal, the longest 1.59 ( ) in head; last dorsal spine 2.14 ( ); membranes of spinous portion of dorsal fin moderately incised; thirdfifth dorsal soft ray subequal, 1.44 ( ) in SL; first anal spine 4.62 ( ) in head; second anal spine 1.58 ( ) in head; first three anal soft rays subequal, the longest 1.36 ( ) in head; caudal fin forked, its length 2.97 ( ) in SL, the caudal concavity 2.08 ( ) in head; fourth pectoral ray longest, 0.95 ( ) in head; pelvic spine 1.72 ( ) in head; first soft ray of pelvic fin filamentous, usually reaching to origin of anal fin if not damaged, 1.04 ( ) in head. Colour of holotype when fresh (from field notes): olive-brown dorsally, shading to pale iridescent bluegreen ventrally; top of head and tip of chin blackish; spinous dorsal fin and scaled basal part of soft dorsal fin yellowish grey; rest of soft dorsal fin hyaline with pale yellow rays; anal fin yellowish, the scaled basal part slightly dusky; lobes of caudal fin broadly dusky yellow, the tips blackish, posterocentral half of fin hyaaqua vol. 9 no

5 Gerald R. Allen and John E. Randall line; pelvic and pectoral fins pale yellowish. Colour of holotype in alcohol: entirely brown, slightly darker on uppermost portion of head and back; dorsal and anal fins brown with fine dark brown margin on spinous portion of dorsal; broad brown dorsal and ventral margins on caudal fin with central portion of fin translucent; pelvic fins translucent with dusky anterior margin; pectoral fins translucent yellowish brown. Paratypes are generally similar, although the largest (51.3 mm SL) is slightly darker. Etymology This species is named monochroma from the Greek meaning one colour, with reference to its uniform coloration. Remarks Only three species of Chromis share the combination of XIII dorsal spines and relatively low number (14-15) of tubed lateral line scales: C. alpha, C. caudalis, and C. delta, all described by Randall (1988) from the western Pacific Ocean and illustrated in colour by Allen (1991). The three species are sympatric with C. monochroma, frequenting outer reef slopes, often at considerable depths (e.g m). Chromis caudalis and C. delta are easily separated by having 2 instead of 3 spiniform caudal rays and their dark brown colour with abruptly white caudal peduncle and fin. Chromis alpha is the closest relative, having the same body depth and the same meristic data except usually 12 instead of 11 dorsal and anal soft rays, and usually 15 rather than 14 lateral line scales. It differs in colour, notably in having a black spot at the upper base of the pectoral fin and blackish posterior margins of the preopercle and opercle. The type locality and only known collection site consists of a steep drop-off near shore off the town of Maumere on the Indonesian island of Flores in the Lesser Sunda Group. The species was observed at depths between 42 and 53 m. Chromis pura n. sp. (Figs. 2-3; Table II) Holotype: BPBM 37348, 67.6 mm SL, Pura, Alor Islands, Indonesia ( S, E); collected at depth of 18 m, by spear, J. E. Randall, 22 November Paratypes (same data as holotype): CAS , 54.7 mm SL; MNHN , 72.4 mm SL; USNM , 67.0 mm SL; WAM P , 76.3 mm SL. Diagnosis Dorsal rays XIII,12-13 (usually XIII,12); anal rays II,11; pectoral rays 19-20); spiniform caudal rays 2; tubed lateral line scales 16-18; gill rakers (total, 25-27); body depth in SL; colour bluegrey, grading to dusky yellowish on caudal peduncle; scale margins darker grey; dorsal portion of head and nape greenish grey; suborbital blue and similar blue shade on opercular scales; dorsal fin mainly blue-grey, darker on anterior half of soft portion, abruptly yellowish on posterior half; anal fin mainly black except last few rays hyaline and thin blue anterior margin; caudal fin dusky yellow; pelvic fins hyaline with prominent black triangular marking at base. Fig. 2. Chromis pura n. sp., holotype, 67.6 mm SL, Pura, Indonesia. Photo by J. E. Randall. 21 aqua vol. 9 no

6 Two new species of damselfishes (Pomacentridae: Chromis) from Indonesian seas Table II. Proportional measurements of selected type specimens of Chromis pura as percentage of the standard length. Holotype Paratype Paratype Paratype Paratype BPBM WAM MNHN USNM CAS P Standard length (mm) Body depth Body width Head length Snout length Orbit diameter Interorbital width Depth of caudal peduncle Length of caudal peduncle Upper jaw length Predorsal distance Preanal distance Prepelvic distance Length of dorsal fin base Length of anal fin base Pectoral fin length Pelvic fin length Pelvic fin spine length st dorsal spine th dorsal spine Last dorsal spine Longest soft dorsal ray st anal spine nd anal spine Longest soft anal ray Caudal fin length Caudal concavity Fig. 3. Underwater photo of Chromis pura n. sp., ca. 60 mm SL, Pura, Indonesia, depth 18 m. Photo by J. E. Randall. aqua vol. 9 no

7 Gerald R. Allen and John E. Randall Description Dorsal rays XIII,12 (one paratype with XIII,13); anal rays II,11; all dorsal and anal soft rays branched, the last to base; pectoral rays 19 (19-20), the upper and lowermost pair unbranched; pelvic rays I,5; principal caudal rays 15, the upper and lowermost unbranched; spiniform caudal rays 2, followed by 2 accessory segmented rays; scales in longitudinal series 27; tubed lateral line scales 17 (16-18); posterior midlateral scales with a pore or deep pit (in continuous series) 7 (7-9); scales above lateral line to origin of dorsal fin 2.5; scales above lateral line to base of middle dorsal spine 1.5; scales below lateral line to origin of anal fin 9; gill rakers = 27 ( = 25-27); branchiostegal rays 6; supraneural (predorsal) bones 3; vertebrae Body moderately deep, depth 2.02 ( ) in SL, and compressed, the width 2.41 ( ) in body depth; head length 3.19 ( ) in SL; dorsal profile of head slightly convex; snout shorter than orbit diameter, its length 3.94 ( ) in head length; orbit diameter 2.52 ( ) in head; interorbital space convex, its width 2.55 ( ) in head; caudalpeduncle depth 2.02 ( ) in head; caudal peduncle length 2.11 ( ) in head. Mouth terminal, small, and oblique, forming an angle of about to horizontal axis of head and body; posterior edge of maxilla reaching a vertical at anterior edge of pupil or slightly behind this point, the upper jaw length 2.69 ( ) in head; teeth multiserial, an outer row of conical teeth in each jaw, largest anteriorly; 21 (18-20) upper and 18 (15-21) lower teeth on each side of jaw; a narrow band of villiform teeth lingual to outer row, in 2-3 irregular rows anteriorly, narrowing to a single row on side of jaws; tongue triangular with rounded tip; gill rakers long and slender, the longest on lower limb near angle about three-fourths length of longest gill filaments; nostril with a fleshy rim, more elevated on posterior edge and located at level of middle of pupil, nearly half the distance from front of snout to base of upper lip. Opercle ending posteriorly in a flat spine, the tip relatively acute, projecting from beneath a large scale; margin of preopercle smooth, the posterior margin extending dorsally to level of upper edge of pupil, the anterior margin extending to level of anterior edge of pupil; suborbital with free lower margin extending nearly to a vertical at posterior edge of pupil. Scales finely ctenoid; anterior lateral line ending beneath rear portion of spinous dorsal fin or beginning of soft portion; head scaled except lips, tip of snout, and a narrow zone from orbit to edge of snout containing nostrils; a scaly sheath at base of dorsal and anal fins, about one-half pupil diameter at base of middle of spinous portion of dorsal fin, progressively narrower on soft portion; a column of scales on each membrane of dorsal and anal fins, narrowing distally, those on spinous portion of dorsal progressively longer, reaching about two-thirds distance to spine tips on posterior membranes, then progressively shorter on rear half of soft portion; small scales nearly covering entire caudal fin; small scales on basal one-fifth of pectoral fins; a Fig. 4. Underwater photograph of Chromis flavomaculata, about 60 mm SL, Ogasawara Islands, depth 15 m. Photo by J. E. Randall. 23 aqua vol. 9 no

8 Two new species of damselfishes (Pomacentridae: Chromis) from Indonesian seas median scaly process extending posteriorly from between base of pelvic fins, its length about half that of pelvic spine; axillary scale above base of pelvic spine slightly more than one-third length of spine. Origin of dorsal fin over second lateral line scale, the predorsal distance 2.52 ( ) in SL; base of soft portion of dorsal fin contained 3.2 times in base of spinous portion; first dorsal spine 4.09 ( ) in head; second dorsal spine 2.73 ( ) in head; fifth to eighth dorsal spines subequal, the longest 1.75 ( ) in head; last dorsal spine 2.22 ( ); membranes of spinous portion of dorsal fin moderately incised; 4th and 5th dorsal soft rays longest, 1.39 ( ) in SL; first anal spine 4.17 ( ) in head; second anal spine 1.51 ( ) in head; fourth to sixth anal soft rays longest, 1.39 ( ) in head; caudal fin forked, its length 2.53 ( ) in SL, the caudal concavity 1.51 ( ) in head; third pectoral ray longest, 1.08 ( ) in head; pelvic spine 1.76 ( ) in head; first soft ray of pelvic fin filamentous, usually reaching to tip of urogenital papilla if not damaged, 1.11 ( ) in head. Colour in life (from colour transparency): overall blue-grey, grading to dusky yellowish on caudal peduncle; scale margins darker grey; dorsal portion of head and nape greenish grey; suborbital blue and similar blue shade on opercular scales; dorsal fin mainly bluegrey, darker on anterior half of soft portion, abruptly yellowish on posterior half; anal fin mainly black except last few rays hyaline and thin blue anterior margin; caudal fin dusky yellow; pelvic fins hyaline with prominent black triangular marking at base. Colour of holotype in alcohol: overall brown with darker brown scale margins; spinous portion of dorsal fin mainly brown with broad semitranslucent margin; soft portion of dorsal fin dark brown to nearly blackish on anterior half, translucent on posterior half; anal fin dark brown to blackish except last few rays yellowish brown; caudal fin with broad brown dorsal and ventral margins, central portion of fin translucent; pelvic fins dusky brown, darker on anterior margin; pectoral fins translucent with triangular dark brown marking on upper base and invading upper portion of axil. Paratypes have similar coloration. Etymology This species is named Chromis pura with reference to the type locality and only known collection site. The name is treated as a noun in apposition. Remarks Chromis pura is most similar to C. flavomaculata Kamohara (1960), which has an apparent anti-equatorial distribution consisting of Japan to the Batan Islands (Philippines) in the north and Coral Sea, New Caledonia, Loyalty Islands and Lord Howe Island in the south. The general coloration of the two species is very similar (compare Figs. 3 and 4), but there are important differences. The dark spot on the pectoral fin base is much smaller in C. pura, which also has a much stronger yellow hue on the caudal peduncle and caudal fin. Moreover, C. flavomaculata, as the specific name suggests, possesses a small yellow spot at the base of the posteriormost dorsal rays, a feature that is lacking in C. pura. Although the two species share most meristic and morphometric characters, there is a difference in the number of total gill rakers, for C. pura and for C. flavomaculata. Chromis pura is known only from the type locality, which is situated about 1.6 km west of the island of Alor, between the mouth of Kalabahi Bay on Alor and the island of Pantar. Pura is a small circular, steepsided volcanic island which rises abruptly from the sea, amplifying the already strong, deep currents in the passage. It is one of the last volcanic islands in the Lesser Sunda chain as one progresses eastward into a region of uplifted karst. The habitat of C. pura consists of a sloping, rocky bottom exposed to strong currents. Acknowledgements We thank Jeff Clayton (USNM), Glenn Moore (WAM), Patrice Pruvost (MNHN) and David Catania (CAS) for providing registration numbers. Special thanks are due to Loreen O Hara (BPBM) for sending loan material to the first author. References Allen, G. R Two new species of damselfishes (Pomacentridae) from Western Australia. Records of the Western Australian Museum, 4 (2): Allen G. R Damselfishes of the World. Aquarium Systems, Mentor, Ohio, 271 pp. Allen, G. R Two new species of damselfishes (Pomacentrus), with comments on the validity of two additional pomacentrid fishes. Revue Française Aquariologie, 20 (1): Kamohara, T On the fishes of the genus Chromis (family Amphiprionidae, Chromides, Pisces), found in the waters of Japan. Reports of Usa Marine Biological Station, 7 (1): Moura, R. L. de A new species of Chromis (Perciformes: Pomacentridae) from the southeastern coast of Brazil, with comments on other species of the genus. Revue Française Aquariologie, 21 (3-4): Randall, J. E Three new Indo-Pacific damselfishes of the genus Chromis (Pomacentridae). Memoirs of the Museum of Victoria, 49 (1): Randall, J. E. & J. M. McCosker Two new damselfishes of the genus Chromis (Perciformes: Pomacentridae) from the South Pacific. Proceedings of the California Academy of Sciences, 47 (12): aqua vol. 9 no