Ophichthus chennaiensis, Das & Mohapatra & Rajendar & Bhaskar, 2020

Das, Mrinal Kumar, Mohapatra, Anil, Rajendar, Kumar R. & Bhaskar, Ranjana, 2020, A new species Ophichthus chennaiensis sp. nov. (Anguilliformes: Ophichthidae) from the southeast coast of India, Zootaxa 4895 (2), pp. 291-296 : 292-293

Ophichthus chennaiensis sp. nov

Proposed common name: Chennai snake eel

( Figures 1–3 , Table1 )

Holotype. EBRC/ ZSI/F12029 ( 405 mm TL), gravid female, Kasimedu fishing harbour , Chennai, Tamil Nadu, India, 03 February 2019.

Diagnosis.

A medium-sized dark brown coloured species of Ophichthus with a head length of 9.4 and preanal length 2.4 in TL, dorsal-fin origin 1 pectoral fin behind the pectoral fin tip, pectoral fin well developed, posterior nostril is in a hole above the upper lip covered partially with a flap that extends below the mouth. No barbel in the upper lip. Teeth pointed and sharp with 5 uniserial intermaxillary teeth, biserial maxillary, uniserial mandibular teeth, biserial to uniserial vomerine teeth and all teeth curved anteriorly. Predorsal vertebrae 19, preanal vertebrae 53, and total vertebrae 154.

Description.

A moderately elongated dark brown coloured eel with dorsal-fin origin 1 pectoral fin behind the pectoral-fin tip. Dorsal fin and anal fin medium. Tail tip finless; dorsal and anal fins end shortly before the tail tip. Snout blunt, upper jaw longer than the lower jaw; lower jaw reaches slightly forward of the anterior nostril. Anterior nostril small and tubular, not reaching the snout tip. Posterior nostril is a hole above the upper lip covered with a flap that extends below the mouth. Upper lip without a barbel between the anterior and posterior nostrils. Eye large, closer to the rictus than the snout; eye diameter 7.2 in HL and 2.3 in upper jaw length. Eye and head pores in white rim. The details of proportionate measurements are given in Table–1.

Head pores ( Fig.2 ) are small. Frontal pore 1, supraorbital pores 5; infraorbital pores 4+2; preopercular pores 3; mandibular pores 6; 9 lateral-line pores before gill opening and pectoral-fin origin; 19 pores before dorsal fin and 58 lateral line pores before anus.

Teeth ( Fig.3 ) pointed and sharp with 5 uniserial intermaxillary teeth, biserial maxillary with 27 teeth in the outer row and 22 teeth in the inner row on each side, vomerine teeth biserial anteriorly with 6 biserial (12 teeth in two rows) followed by 11 uniserial teeth. Mandibular teeth uniserial with 30 teeth on each side.

Predorsal vertebrae 19, preanal vertebrae 53, and total vertebrae 154.

Colour. When fresh the specimen was uniform dark brown in colouration. Both dorsal and anal fins with dark edge and pectoral fins black. Preserved specimen is the same colour. Eye and head pores are in white rims.

Distribution. Known only from a single specimen from the Tamilnadu coast of India.

Etymology. The species is named for its collection site.

Figures

FIG. 1 Ophichthus chennaiensis sp. nov. holotype (405 mm TL).

FIG. 2 Pattern of head pores in Ophichthus chennaiensis sp. nov.

FIG. 3 Teeth pattern of Ophichthus chennaiensis sp. nov.