Ostorhinchus: Apogonidae) from the Solomon Islands

aqua, International Journal of Ichthyology

A new species of cardinalfish (Ostorhinchus: Apogonidae) from the Solomon Islands

Gerald R. Allen1 and Mark V. Erdmann2, 3

1) Department of Aquatic Zoology, Western Australian Museum, Locked Bag 49, Welshpool DC, Perth, Western Australia 6986. E-mail: [email protected] 2) Conservation International Indonesia Marine Program, Jl. Dr. Muwardi No. 17, Renon, Denpasar 80235 Indonesia. E-mail: [email protected] 3) California Academy of Sciences, 55 Museum Concourse Drive, San Francisco, CA 94118, USA.

Received: 24 December 2016 – Accepted: 30 December 2016

Keywords Reihe schwacher, schmaler dunkler Streifen in der unteren Taxonomy, cardinalfish, new species, reef fish, Solomon Hälfte, sowie ein schwarzer Außenrand der ersten Rücken- Islands. flosse. Das neue Taxon ähnelt O. lineomaculatus von den Kleinen Sundainseln Indonesiens, unterscheidet sich aber Abstract durch das Farbmuster, einen breiteren Interorbitalraum, A new species of apogonid, Ostorhinchus pallidus, is de- einen tieferen Schwanzstiel und einen längeren ersten After- scribed from 13 specimens, 41.2-51.8 mm SL, collected in flossenstrahl. 18-30 m at Guadalcanal and Makira in the Solomon Is- lands. Diagnostic features include dorsal rays VII-I,9; anal Résumé rays II,8; pectoral rays 14-15; lateral-line scales 24; predorsal Une nouvelle espèce d’Apogonidé, Ostorinchus pallidus est scales 3-4; developed gill rakers 4-5 + 18-19; preopercular décrite sur base de 13 spécimens, 41,2-51,8 mm LS, collec- margin and ridge serrate; body depth 2.9-3.4 in SL; third tés à une profondeur de 18-30 m à Guadalcanal et Makira and fourth dorsal spines longest; colour in life pale pinkish, dans les îles Salomon. Les caractéristiques diagnostiques grading to pale yellow ventrally with faint grey stripe on comprennent les rayons de la dorsale VII-I,9, les rayons de head at eye level, large black spot at base of caudal fin, series l’anale II,8, les rayons de la pectorale 14-15, les écailles de la of faint narrow dark bars on the lower side, and black outer ligne latérale 24, les écailles prédorsales 3-4, les branchio - edge on first dorsal fin. The new taxon is similar to O. lineo- spines développées 4-5 + 18-19, la marge préoperculaire et maculatus from the Lesser Sunda Islands of Indonesia but l’excroissance en dents de scie, la hauteur du corps 2,9-3,4 differs with regards to colour pattern, a wider interorbital, LS, les troisième et quatrième rayons durs de la dorsale les deeper caudal peduncle, and longer first anal spine. plus longues, la couleur in vivo rose pâle, passant au jaune pâle ventralement avec une ligne grise peu marquée sur la Zusammenfassung tête au niveau de l’oeil, une grande tache noire à la base de Auf der Grundlage von 13 Exemplaren, 41,2-51,8 mm SL, la caudale, des séries de légères barres sombres et étroites sur die in 18 bis 30 m Tiefe bei Guadalcanal und Makira an den la partie inférieure, et un bord externe noir sur la première Salomoninseln gesammelt worden waren, wird eine neue dorsale. Le nouveau taxon est proche de O. lineomaculatus Art der Apogoniden, Ostorhinchus pallidus, beschrieben. Zu des Petites Iles de la Sonde en Indonésie, mais se distingue den Bestimmungsmerkmalen gehören: Rückenflossen- par le patron de coloration,, un espace interorbital plus strahlen VII-1,9; Afterflossenstrahlen II,8; Brustflossen- large, un pédoncule caudal plus large et un premier rayon strahlen 14-15; Seitenlinienschuppen 24; prädorsale Schup- dur anal plus long. pen 3-4; voll entwickelte Kiemenreusen 4-5 +18-19; Rand und Grat vor dem Kiemendeckel (präopercular) gesägt; Sommario Rumpftiefe 2,9-3,4 in SL; dritter und vierter Rückenstachel Una nuova specie di apogonide, Ostorhinchus pallidus, è am längsten; Farbgebung bei lebenden Tieren: blasser descritta sulla base di 13 esemplari, di 41,2-51,8 mm SL, Rosaton, der bauchwärts in ein blasses Gelb übergeht, mit raccolti in 18-30 metri di profondità a Guadalcanal e einem schwachen grauen Streifen am Kopf auf Augenhöhe, Makira nelle Isole Salomone. Le caratteristiche diagno- großer schwarzer Fleck an der Basis der Schwanzflosse, eine stiche includono: VII-I, 9 raggi dorsali; II, 8 raggi anali;

33 aqua vol. 23 no. 1 - 18 January 2017 A new species of cardinalfish (Ostorhinchus: Apogonidae) from the Solomon Islands

14-15 raggi pettorali; 24 scaglie della linea laterale; 3-4 sured to their extreme bases; caudal concavity is the scaglie predorsali; 4-5 + 18-19 rastrelli branchiali svilup- horizontal distance between verticals at the tips of pati; margine preopercolare e cresta seghettati; altezza del the shortest and longest caudal-fin rays. corpo 2,9-3,4 in SL; terza e quarta spina dorsale più lunga; Pectoral-ray counts include the upper rudimentary colorazione vitale rosa pallido, tendente al giallo pallido ventralmente con una debole striscia grigia sulla testa all'al- ray; lateral-line scale counts are made to the base of tezza degli occhi, una grande macchia nera alla base della the caudal fin (not including the pored scales poste- pinna caudale, una serie di sottili e tenui barre scure sul lato rior to the hypural plate); gill-raker counts are made inferiore e la prima pinna dorsale con bordo esterno nero. on the first gill arch and include developed rakers Il nuovo taxon è simile a O. lineomaculatus presente nelle only (those which are higher than the width of their Piccole Isole della Sonda in Indonesia, ma si differenzia per base); the count of the upper-limb rakers is given la colorazione, un interorbitale più ampio, un peduncolo first, followed by the lower-limb count; the raker at caudale più alto e una prima spina anale più lunga. the angle is contained in the lower-limb count. Proportional measurements of type specimens are INTRODUCTION given in Table I as percentages of the standard Cardinalfishes, family Apogonidae, are an impor- length. Data in parentheses in the description refer tant component of the global coral-reef fish com- to paratypes. Type specimens have been deposited munity. Although not entirely confined to this at the U.S. National Museum of Natural History, habitat, the majority of the estimated 358 species Washington, D.C. (USNM) and the Western Aus- (Mabuchi et al. 2014) inhabit Indo-Pacific reefs or tralian Museum, Perth (WAM). Other museum adjacent soft-bottom areas where they are among abbreviations as follows: Bishop Museum, Hon- the most abundant nocturnally active fishes. Simi- olulu (BPBM) and Muséum National d’Histoire lar to numerous other reef-fish families, the highest Naturelle, Paris (MNHN). number of genera and species occur in the East In- Comparative material examined: Ostorhinchus li- dian Archipelago, extending from the Andaman neomaculatus (all paratypes from Indonesia): Sea to the Solomon Islands. Allen & Erdmann BPBM 32233, 2 specimens, 44.3-48.5 mm SL, (2012) included coverage of the 149 reef species in Maumere, Flores; BPBM 34081, 43.2 mm SL, 24 genera from this region. The present paper de- Japanese shipwreck east of Maumere, Flores; scribes a new species of Ostorhinchus Lacépède BPBM 34159, 2 specimens, 38.7-46.4 mm SL, 1802 collected by the authors at the Solomon Is- Maumere Bay, Flores; MNHN 1998–1380, 2 lands. It was initially identified as O. lineomacula- specimens, 37.6-42.6 mm SL, Maumere Bay, Flo- tus Allen & Randall (2002), originally described res; USNM 351559, 2 specimens, 37.7-38.7 mm from Indonesia. However, closer examination SL, Maumere Bay, Flores; WAM30514-002, 2 prompted by the collection of additional speci- specimens, 45.0-47.2 mm SL, Tulamben, Bali. mens in 2016, revealed the two species are distinct, but obvious close relatives. Ostorhinchus pallidus, n. sp. MATERIALS AND METHODS Pale Cardinalfish Lengths given for specimens are standard length (Figs 1-3 & 5A; Table I) (SL), measured from the front of the upper lip to the base of the caudal fin (posterior end of hypural Holotype: WAM P.32546-001, 49.0 mm SL, Star plate); body depth is the maximum depth from the Harbour, 10°47.308’S, 162°16.112’E, southeast- base of the dorsal spines; body width is measured ern end of Makira Island, Solomon Islands, 30 m, just posterior to the gill opening; head length (HL) rotenone, G. R. Allen, 7 June 2004. is taken from the front of the upper lip to the end Paratypes: USNM 432538, 4 specimens, 45.1- of the opercular membrane, and snout length from 51.8 mm SL, collected with holotype; WAM the same anterior point to the fleshy edge of the or- P.32546-002, 6 specimens, 45.9–50.9 mm SL, col- bit; orbit diameter is the greatest fleshy diameter, lected with holotype; WAM P.34617-009, 2 speci- and interorbital width the least bony width; caudal mens, 41.2-44.7 mm SL, Aruhilo, 09°17.222’S, peduncle depth is the least depth, and caudal pe- 159°46.078’E, Guadalcanal, Solomon Islands, 18 duncle length the horizontal distance between ver- m, clove oil, M. Erdmann, 12 October 2016. ticals at the rear base of the anal fin and the caudal- Diagnosis: Dorsal rays VII-I,9; anal rays II,8; fin base; lengths of fin spines and soft rays are mea- pectoral rays 15 (occasionally 14); lateral-line scales

aqua vol. 23 no. 1 - 18 January 2017 34 Gerald R. Allen and Mark V. Erdmann

24; predorsal scales 3-4; developed gill rakers 4-5 + dorsal fin (more pronounced in male); peritoneum 18-19; preopercular margin serrate; preopercular pale with scattered melanophores; outer surface of ridge finely serrate; body depth 2.9–3.4 in SL; intestinal tract black. third and fourth dorsal spines longest; colour in life Description: Dorsal rays VII-I,9; anal rays II,8; pinkish, grading to pale yellow ventrally with faint all dorsal and anal soft rays branched, the last to grey stripe on head at eye level, large black spot at base; pectoral rays 15 (except 2 paratypes with 14), base of caudal fin, series of faint narrow dark bars the lowermost and uppermost pair unbranched; on the lower side, and black outer edge on first pelvic rays I,5, all rays branched; principal caudal

Fig. 1. Ostorhinchus pallidus, approximately 45–50 mm SL, underwater photo, Guadalcanal, Solomon Islands. Photo by G. R. Allen.

Fig. 2. Ostorhinchus pallidus, freshly collected holotype, WAM 32546-001, 49.0 mm SL, Makira, Solomon Islands. Photo by G. R. Allen.

35 aqua vol. 23 no. 1 - 18 January 2017 A new species of cardinalfish (Ostorhinchus: Apogonidae) from the Solomon Islands rays 17, the upper and lower rays unbranched; up- row on each palatine. Tongue broad-based with per and lower procurrent caudal rays 8, the most rounded tip. posterior (and occasionally the one preceding it) Anterior nostril a small, low-rimmed, membra- segmented; lateral-line scales 24, plus 3-4 pored nous tube directly in front of center of eye about scales posterior to hypural plate, the last long, and half distance from edge of orbit to front of upper narrow; scales above lateral line to origin of dorsal lip; posterior nostril ovate without elevated rim, fin 2; scales below lateral line to origin of anal fin more than twice as large as anterior nostril. 6; median predorsal scales 3 (3-4); circumpedun- Cephalic lateralis pores numerous, especially on in- cular scales 12; developed gill rakers 4 + 18 (4-5 + terorbital, around eye, and on ventral surface of 18 or 19), and 1-3 low rudiments at beginning of lower jaw. Preopercular margin finely serrate (46 upper limb; branchiostegal rays 7; pseudobranchs serrae on left side of holotype and 46-70 on 15 (15-20); supraneural (predorsal) bones 3; verte- paratypes); preopercular ridge finely serrate, partic- brae 10 + 14. ularly around angle and on lower edge. Body depth 3.1 (2.9-3.4) in SL; body width 2.2 Scales weakly ctenoid. Lateral line conspicuous, (1.8-2.4) in depth; head length 2.8 (2.5-2.8) in SL; nearly paralleling dorsal contour of body, and end- dorsal profile of head straight, snout pointed; ing at caudal-fin base (three pored scales posterior to snout length 3.7 (3.9-4.7) in HL; orbit diameter hypural, the last pointed). No scales on dorsal and 2.6 (2.8-3.2) in HL; interorbital width 4.6 (4.4- anal fins except a low sheath at base of second dorsal 5.0) in HL; caudal peduncle depth 2.7 (2.6-2.9) in and anal fins; small scales on basal one-fourth of HL; caudal peduncle length 1.6 (1.4-1.6) in HL. caudal fin; no scales on paired fins except a pair of Mouth large, maxilla reaching vertical slightly pos- large midventral scales at base of pelvic fins. terior to middle of eye, upper jaw length 2.1 (2.1- Origin of first dorsal fin above third lateral-line 2.4) in head; mouth oblique, gape forming an angle scale; first dorsal spine very short, 12.4 (12.9-20.8) of about 33 (34-40) degrees to horizontal axis of in HL; third and fourth dorsal spines longest, 2.4 head and body; posterior edge of maxilla slightly (2.3-2.6) in HL; spine of second dorsal 3.0 (2.8- concave; no supramaxilla present; lower jaw slightly 3.1) in HL; anterior soft dorsal rays longest, 1.7 protruding; jaws with dense band of small villiform (1.6-1.8) in HL; origin of anal fin below base of teeth arranged in irregular rows, the bands decreas- second dorsal soft ray; first anal spine very short, ing in width posteriorly; an irregular row of small 15.0 (14.6-17.7) in HL; second anal spine 3.3 teeth forming a V on vomer and a straight, narrow (3.0-3.9) in HL; anterior anal soft rays longest, 2.0

Fig. 3. Ostorhinchus pallidus, preserved holotype, WAM 32546-001, 49.0 mm SL, Makira, Solomon Islands. Photo by G. R. Allen.

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Table I. Proportional measurements of selected type specimens of Ostorhinchus pallidus expressed as percentage of the standard length. Asterisk (*) indicates damaged spines.

Character Holotype Paratype Paratype Paratype Paratype Paratype Paratype Paratype Paratype Paratype WAM USNM WAM WAM USNM WAM USNM USNM WAM WAM P.32546 432538 P.32546 P.32546 432538 P.32546 432538 432538 P.34617 P.34617

Standard length (mm) 49.0 51.8 51.1 50.9 49.7 48.8 46.2 45.1 44.7 41.2 Body depth 31.8 31.6 34.6 32.7 31.5 33.6 31.4 29.1 30.7 30.7 Body width 14.4 15.4 14.2 16.0 15.8 16.9 14.9 13.9 15.2 16.6 Head length 35.5 36.7 39.0 39.5 39.7 39.8 37.7 37.2 37.2 37.5 Snout length 9.6 9.2 9.3 9.0 9.5 9.7 8.0 8.3 8.2 9.2 Orbit diameter 13.5 12.8 12.8 13.5 13.7 13.6 12.7 12.5 11.7 12.4 Interorbital width 7.6 7.9 8.2 8.1 8.2 7.9 7.6 7.9 7.6 7.5 Upper jaw length 16.7 17.1 17.7 18.1 17.0 17.5 17.2 16.5 15.6 17.1 Caudal peduncle depth 13.0 13.1 13.4 13.5 14.4 13.9 13.1 13.5 14.0 13.3 Caudal peduncle length 21.7 22.5 25.0 24.8 24.1 25.7 25.4 25.1 27.5 25.5 Predorsal length 38.8 38.9 40.1 40.8 40.1 40.8 39.3 36.7 37.3 38.5 Preanal length 64.0 65.4 64.8 64.9 65.1 62.3 64.2 63.0 60.1 63.2 Prepelvic length 36.2 36.1 40.5 37.1 37.2 40.2 36.5 36.7 36.1 39.2 Length 1st dorsal spine 2.9 1.9 2.5 2.7 2.5 2.5 2.9 2.6 2.6 2.7 Length 2nd dorsal spine 11.4 9.8 10.7 12.2 11.7 11.8 11.8 13.3 9.6 * Longest dorsal spine 14.8 14.5 16.7 17.2 15.3 15.5 15.6 16.0 16.4 * Spine of 2nd dorsal fin 11.9 12.4 13.1 12.7 12.7 12.9 13.1 13.4 12.8 13.6 Longest soft dorsal ray 20.8 21.1 23.1 21.8 22.4 22.7 22.2 22.9 20.4 21.5 Length 1st anal spine 2.4 2.4 2.5 2.3 2.7 2.4 2.6 2.5 2.3 2.1 Length second anal spine 10.7 11.1 11.2 10.2 11.8 11.8 11.8 12.1 11.8 11.2 Longest anal soft ray 17.5 18.6 17.9 17.2 18.6 18.4 18.2 18.2 17.9 18.6 Caudal fin length 27.3 26.4 29.5 29.1 28.6 27.0 27.7 30.1 28.3 27.4 Caudal concavity 9.5 9.7 9.8 9.6 10.4 10.2 9.6 11.9 11.4 9.1 Pectoral fin length 24.0 22.7 24.4 24.7 23.8 22.9 21.9 22.1 23.0 23.6 Pelvic spine length 14.3 15.0 15.5 15.0 15.5 15.4 15.0 15.2 15.1 14.6 Pelvic fin length 18.5 21.0 21.0 22.5 21.7 21.2 21.1 20.3 20.2 20.2

Fig. 4. Distribution of Ostorhinchus pallidus and O. lineomaculatus.

37 aqua vol. 23 no. 1 - 18 January 2017 A new species of cardinalfish (Ostorhinchus: Apogonidae) from the Solomon Islands

(2.0-2.3) in HL; caudal fin forked, its length 1.3 diffuse whitish margin; narrow brown band from (1.2-1.5) in HL; caudal concavity 3.7 (3.1-4.2) in side of nape, converging with corresponding band HL; upper pectoral rays longest, 1.5 (1.5-1.7) in from opposite side at snout tip, its anterior portion HL; origin of pelvic fins below pectoral-fin base; (from level of front of eye) often with whitish mar- first pelvic soft ray longest, reaching about midway gins; narrow brown stripe mid-dorsally from dor- between anus and origin of anal fin, its length 1.9 sal-fin origin to interorbital; tip of lower jaw no- (1.8-1.9) in HL. ticeably dusky brown; inconspicuous, diffuse Colour in life (Figs 1 & 5A): generally pink- blackish patch sometimes evident immediately ish, semi-translucent on back, grading to pale yel- above first few anal rays; fins translucent except lowish on lower head, breast, and abdomen; dusky outer part of first dorsal fin blackish, also faint, brown stripe from snout to front of eye, continued narrow brownish stripe sometimes evident near faintly behind eye to rear edge of upper opercle; base of second dorsal fin; iris brownish with nar- lower sides with series of about 14-16 short, brown row whitish ring around pupil and pair of narrow bars; black spot, slightly smaller than pupil at mid- whitish stripes across eye at level of upper and low- dle of caudal-fin base, anterior half of spot with er edges of pupil.

Fig. 5. Comparison of colour patterns: A) Ostorhinchus pallidus, approximately 45 mm SL, Guadalcanal, Solomon Islands, and B) O. lineomaculatus, approximately 45 mm SL, Bali, Indonesia. Photos by G. R. Allen.

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Colour of freshly collected holotype neither species has been observed or collected in (Fig. 2): markings similar to those described above, the vast intermediate region that separates their but lateral head and spaces between narrow dark distributional ranges. bars on ventral half of body silvery and remainder Distribution and habitat: Ostorhinchus pallidus is of body and caudal fin pink. currently known only from two locations at the is- Colour in alcohol (Fig. 3): preserved spec- lands of Guadalcanal and Makira in the Solomon imens overall tan, except operculum silvery, with Islands (Fig 4). It occurs in aggregations, usually dark grey spot at middle of caudal-fin base; tip of mixed with other apogonids, which hover about lower jaw dusky grey; fins translucent whitish ex- 1-2 m above the bottom at depths of 18-30 m. It cept outer part of first dorsal fin blackish. Peri- was encountered on a World War II shipwreck toneum pale with scattered melanophores; outer at Guadalcanal and above a boulder bottom at surface of intestinal tract black. Makira. Comparisons: The new species is an obvious Etymology: The species is named pallidus (Latin: close relative of O. lineomaculatus (Fig. 5B) from pale) with reference to the overall colour pattern, Bali and Flores in the Lesser Sunda Islands of In- particularly in comparison to its similar, but more donesia. The two species share similar counts and vividly-patterned relative O. lineomaculatus (Fig. 5). measurements as well as colour pattern features, including most of the dark markings on the head, ACKNOWLEDGEMENTS body, and fins described above for O. pallidus. The We are indebted to The Nature Conservancy colour patterns are compared in Fig. 5. The overall (TNC), and especially Alison Green of that organi- colouration, particularly on the dorsal half of the zation, for making possible the first author’s parti - body is much paler in O. pallidus and it usually cipation in the month-long TNC marine biologi- lacks the dark mid-lateral stripe, although this fea- cal survey of the Solomon Islands in 2004. Similar- ture is sometimes faintly evident. The numerous ly, we thank Brian Bailey for logistic support aboard bars on the ventral half of the body and dark mark- MV Wyuna during our 2016 visit to the islands. ing adjacent to the anal-fin base are also much The latter trip was generously funded by the Paine fainter in O. pallidus. A final difference involves the Family Trust and supported by Conservation Inter- black spot at the caudal-fin base, which is slightly national. Museum registration numbers and cura- horizontally elongate with a vivid white anterior torial assistance were provided by Mark Allen and rim in O. lineomaculatus compared to the more Glenn Moore (WAM) and Jeff Clayton (USNM). rounded spot with a diffuse whitish margin in O. pallidus. Although, there are some slight overlap- REFERENCES ping of ranges, proportional differences between ALLEN, G. R. & ERDMANN, M. V. 2012. Reef fishes of the the two species include a slightly wider interorbital, East Indies. Volume 1. Tropical Reef Research, Perth, Aus- deeper caudal peduncle, and longer first anal spine tralia, pp. 1-424. in O. pallidus (7.5-8.2, 13.0-14.4, and 2.1-2.7% ALLEN, G. . & RANDALL, J. E. 2002. Four new Indo-Pacif- SL respectively) compared to O. lineomaculatus ic species of cardinalfishes (Apogonidae). aqua, Journal of (6.5-7.6, 11.3-13.2, and 1.5-2.1% SL respective- Ichthyology and Aquatic Biology 5 (3): 115-126. MABUCHI, K., FRASER, T. H., SONG, H., AZUMA, Y. & ly). Additionally, there appears to be a genuine ge- NISHIDA, M. 2014. Revision of the systematics of the car- ographic gap between the two species (Fig. 4). De- dinalfishes (Percomorpha: Apogonidae) based on molec- spite considerable diving effort by the authors, in- ular analyses and comparative reevaluation of morpho- cluding hundreds of hours around New Guinea, logical characters. Zootaxa 3846 (2): 151-203.

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