Ophichthus aphotistos McCosker & Chen 2000

E, John, 2010, Deepwater Indo-Pacific species of the snake-eel genus Ophichthus (Anguilliformes: Ophichthidae), with the description of nine new species, Zootaxa 2505, pp. 1-39 : 11

Ophichthus aphotistos McCosker & Chen 2000

Ophichthus aphotistos McCosker & Chen 2000: 354 (Tung-Kong Channel, Taiwan, holotype CAS 209192).

Diagnosis. An elongate species of Ophichthus , subgenus Omochelys , with: tail 59–60%, head 7.7–8.1%, and body depth at gill opening 2.5–2.9% of TL; dorsal-fin origin behind pectoral fin by the pectoral-fin's length; pectoral fin rounded, not elongate and not well-developed; eye moderate, above center of upper jaw, its posterior margin well ahead of rictus; posterior nostril a hole above the upper lip, covered by a flap that extends to or below edge of mouth; upper lip lacks barbels between anterior and posterior nostrils; pores small but conspicuous, SO 1+4, IO 4+2, POM 2+6; teeth small and conical, biserial on anterior vomer and jaws; coloration uniform gray brown to nearly black, pectoral and median-fin margins gray black; mean vertebral formula 17.6/59/160.3, total vertebrae 158–162 (n= 3).

Size. Largest known specimen is 628 mm, a spent female.

Distribution. Known from the type series, from 700–800 m depth, collected off Taiwan.

Remarks. Ophichthus aphotistos is the sole deepwater Indo-Pacific species of the subgenus Omochelys . It would not be mistaken for any other deepwater Indo-Pacific Ophichthus on the basis of its elongation, posterior dorsal-fin origin, biserial jaw dentition and vertebral formula. The holotype of O. aphotistos has 18/ 59/161 vertebrae.

Ophichthus aphotistos is most closely related to the deepwater O. cruentifer ( Goode and Bean 1896) of the northwestern Atlantic Ocean, from which it differs in its coloration and vertebral formula ( McCosker & Chen 2000), and to the eastern Atlantic deepwater O. pullus McCosker (2005) , from which it differs in its dentition, in its head length, dorsal-fin origin, pectoral-fin length, and vertebral number.

Material examined. CAS 209192, the holotype, 580 mm TL, from Tung-Kong Channel, SW Taiwan (22o22'N, 120o19'E), 700–800 m; and USNM 356862, 628 mm, and NSYSU 3657, 480 mm, paratypes, collected with the holotype.