Red-headed Dwarfgoby

description

Description. Dorsal-fin rays VI-I, 8; anal-fin rays I, 7 (26), I, 8 (3); pectoral-fin rays 15 (14 – 16, usually 15), rays not branched; pelvic fin I, 4 (I, 4 + a rudiment to 20 %); branches on 4 th pelvic-fin ray 5 (3 – 5), 2 (2 – 6) segments between branches; 11 branched caudal-fin rays; segmented caudal-fin rays 17; lateral scale rows 24 (21 – 24); transverse scale rows 6; breast and pectoral-fin base scaleless; first three dorsal spines may be filamentous in males, the second spine longest, reaching to end of second dorsal-fin base; depressed pelvic fin always extends beyond analfin origin; cephalic sensory-pore system pattern 2 (only IT missing); male genital papilla non-fimbriate; precaudal vertebrae 10, caudal vertebrae 15, total 25. Measurements (based on holotype and 14 paratypes, 10.1 – 13.5 mm). head length 31.8 (29.5 – 33.3, 31.2); origin of first dorsal fin 33.7 (32.4 – 39.0, 35.9); origin of second dorsal fin 55.5 (54.8 – 59.5, 56.7); origin of anal fin 58.5 (55.2 – 62.7, 59.5); caudal-peduncle length 24.4 (16.9 – 29.0, 23.8); caudal-peduncle depth 11.8 (9.1 – 12.7, 10.9); body depth 22.2 (17.8 – 23.8, 21.7); eye diameter 8.5 (8.5 – 11.3, 10.3); snout length 4.4 (2.8 –

Eviota rubriceps, a new goby from the Southwestern Pacific Ocean, with comments on E. mikiae and E. raja (Teleostei: Gobiidae)

diagnosis

Diagnosis. The following combination of characters distinguish E. rubriceps from congeners: cephalic sensory-pore system pattern 2 (only IT pore missing); dorsal / anal fin-ray formula almost always 8 / 7; pectoral-fin rays unbranched; first three dorsal spines may be filamentous in males; 5 th pelvic-fin ray absent or rudimentary to 20 % maximum of 4 th ray; strong black pigment along scale pockets on ventral two-thirds of sides and peppering of dark chromatophores on nape and upper back when preserved; snout, top and sides of head red in life; dark area of abdomen not crossed by a curved yellow-gold line in life.

Eviota rubriceps, a new goby from the Southwestern Pacific Ocean, with comments on E. mikiae and E. raja (Teleostei: Gobiidae)

discussion

Remarks. While conducting a survey of the fishes at Raja Ampat, Indonesia, Gerald R. Allen and Mark V. Erdmann found a species of Eviota with a distinctive red head and a body that was dark on the lower half, which they referred to as Raja Ampat sp. 1. Subsequently they sent photographs to us and we recognized the similarity to the specimens previously given a manuscript name and awaiting description. Prior to this, Greenfield and Suzuki (2010) described an Eviota species from Japan, E. nigrispina, that also has a dark band on the ventral portion of the body when preserved. Comparison of photographs of live individuals of E. nigrispina and E. rubriceps showed that they were quite different in coloration, however, they are very similar when preserved and have the same counts. As discussed in the Comparisons section, in addition to the live coloration, there also are differences in preserved coloration and caudal-peduncle depth. There also are habitat differences between the two at the Raja Ampat Islands. Erdmann (pers. comm., 20 July 2011) reports that E. rubriceps is a dominant species in shallow waters (mostly 2 – 4 m, maximum 6 m). Two specimens of E. nigrispina (ROM 85168) were

Eviota rubriceps, a new goby from the Southwestern Pacific Ocean, with comments on E. mikiae and E. raja (Teleostei: Gobiidae)

distribution

Distribution. Known from the Raja Ampat Islands, Banda Islands, and Maluka Islands in Indonesia; the Bismark Archipelago, Papua New Guinea; and the Palawan Province, Philippines.

Eviota rubriceps, a new goby from the Southwestern Pacific Ocean, with comments on E. mikiae and E. raja (Teleostei: Gobiidae)