Ophichthus johnmccoskeri, Mohapatra & Ray & Mohanty & Mishra, 2018

Mohapatra, Anil, Ray, Dipanjan, Mohanty, Swarup R. & Mishra, Subhrendu Sekhar, 2018, Ophichthus johnmccoskeri sp. nov. (Anguilliformes: Ophichthidae): a new snake eel from Indian waters, Bay of Bengal, Zootaxa 4462 (2), pp. 251-256 : 252

Ophichthus johnmccoskeri sp. nov.

Proposed common name: McCosker’s snake eel

( Figures 1–3 , Table1)

Holotype. ZSI F 12811/2 (365 mm TL), date of collection: 24 February 2016, Collection site: Shankarpur fishing harbor, West Bengal, India.

Paratypes. EBRC/ ZSI/F9971 (342 mm TL), EBRC/ZSI/F9972 (246 mm TL), Collection details same as holotype.

Diagnosis. A moderate-sized species of Ophichthus with a preanal length 2.6 in TL, DFO well behind pectoral-fin tip, pectoral fin well developed and rounded, posterior nostril a hole in the upper lip opening towards the mouth, covered by a flap. A single barbel between the anterior and posterior nostrils. Teeth elongated, conical and sharp. Vomerine teeth biserial anteriorly, multi to triserial and biserial medially, and in a single row posteriorly. Maxillary teeth biserial anteriorly and triserial posteriorly, lower jaw teeth in a single row followed by biserial and triserial teeth posteriorly. Tip of the lower jaw toothless. Predorsal vertebrae 24, preanal vertebrae 51–52, and total vertebrae 156–158.

Description. A moderately elongated eel with DFO well behind the pectoral fin tip. DFO about 3 pectoral-fin lengths behind the tip of the pectoral fin. Dorsal fin medium and anal fin high. Tail tip finless; dorsal and anal fins end shortly before the tail tip. Preanal length is 2.6 times and tail length 1.6 in TL. Depth at gill opening is about 48.7–52.8 times in TL; head about 11.8–12.7 in TL and 3.5–3.8 in trunk. Snout pointed, upper jaw is slightly longer than the lower jaw; lower jaw reaches to below anterior nostril. Anterior nostril small and tubular not reaching the tip of the snout. Posterior nostril a hole in the upper lip, opening towards the mouth and covered by a flap. Upper lip has a barbel between the anterior and posterior nostrils. Upper jaw 3.7–3.9 in head length (HL) and lower jaw 4.1–4.4 in HL. Eye moderate, closer to the rictus than the snout; eye diameter 3.2–3.7 in upper jaw and 12.4–13.7 in HL.

Head pores small ( Fig.2). A single frontal pore; supraorbital pores 1 + 3; infraorbital pores 4 + 2; preopercular pores 2; mandibular pores 6; nine lateral-line pores before gill opening & pectoral fin origin; 25–26 pores before dorsal fin and 53–54 lateral line pores before anus.

Teeth sharp, tall and conical ( Fig. 3). Five teeth in the pre-vomer. Vomerine teeth biserial anteriorly with 4 teeth in each row, followed by 3–4 rows of irregularly placed teeth, followed by triserial teeth with 7–8 in each row, followed by biserial teeth, posteriorly ending in a single row. Maxillary teeth biserial anteriorly, about 12–13 teeth in each row and triserial posteriorly with about 11–12 teeth in each row. Lower jaw teeth in a single row anteriorly followed by biserial teeth in between and tri-serial teeth posteriorly. The anterior-most part of the lower jaw is toothless.

Predorsal vertebrae 24, preanal vertebrae 51–52, and total vertebrae 156–158.

Colour. The colour of the preserved specimens are light brown colour throughout the body, much lighter ventrally. Dorsal, anal and pectoral fins white. Eye rim white. Head pores within white rims.

Distribution. Known only from the northern part of the Bay of Bengal (West Bengal), India.

Etymology. The species is named after John E. McCosker, California Academy of Sciences, San Francisco, California, in honour of his vast contributions to the taxonomy of ophichthid eels.

Figures

FIGURE 1. Ophichthus johnmccoskeri sp. nov. holotype (365 mm TL).