Amblyceps accari Dahanukar, Raghavan, Ali & Britz, 2016, sp. nov.

Amblyceps accari sp. nov.

(Figure 1, 2 a)

Type material. Holotype: BNHS FWF 201, 37.0mm SL, India: Karnataka, Kudremukh (13.206°N, 75.283°E, 788m a.s.l.), Tunga River, Krishna River System, coll. N. Sood, 15 June 2015.

Paratype: WILD-15-PIS-249, 47.0mm SL, same data as holotype.

Diagnosis. Amblyceps accari differs from all its congeners by having 12 branched anal-fin rays (vs. 7–10 in other Amblyceps, rarely 11 in A. tuberculatum). It also differs from all other species of the genus except A.

murraystuarti and A. torrentis in having the adipose fin confluent with the dorsal procurrent part of the caudal fin. It can be further distinguished from its congeners by the following combination of characters: jaws unequal with lower jaw weakly-projecting; pectoral spine smooth; adipose fin origin at vertical through anal fin origin; dorsal fin to adipose fin distance 29.2–30.2 %SL; adipose-fin base long, 28.1–33.2%SL; and deeply forked caudal fin with poorly developed projections on the proximal lepidotrichia of the central caudal-fin rays.

Description. Morphometric data are provided in Table 1. General body shape as in Figs. 1 and 2.

Body elongate, sub-cylindrical anterior to pelvic fins, slightly laterally compressed posterior to pelvic fins to strongly compressed posterior to anal fin. Predorsal profile convex at head region; sharply increasing from tip of snout to nape, then gradually increasing to dorsal fin origin; almost straight from dorsal-fin origin to adipose-fin origin, then gently sloping ventrally to end of caudal peduncle. Ventral body profile almost straight. Skin on head densely covered with small tubercles, that of lateral side of body with vertical rows of small keratinized tubercles, clearly visible at 40× magnification, from just behind opercle to anal-fin origin. Lateral line complete, lateral-line pores (25*or 27) at end of short tubes, consecutive tubes separated by short distance.

Head depressed, roundish in lateral view, widest at opercle. Snout long, about ¼ HL, acutely triangular in lateral view, rounded in dorsal view. Both anterior and posterior nostrils situated in front of or behind base of nasal barbel, respectively. Anterior nostril rim extended as short tube. Anterior margin of posterior nostril confluent with posterior base of nasal barbel; posterior margin surrounded by short rim of skin. Sensory pores on head: Two on lower jaw anterior to outer mandibular barbel; one on lower jaw between outer and inner mandibular barbel; one on lower jaw posterior to inner mandibular barbel; laterally, one on dorsal side of base of inner mandibular barbel; three on preoperculum (one at base, one about one fourth of distance from upper margin, one at upper margin of preoperculum); one behind eye; dorsally, one next to anterior nostril and one next to posterior nostril, both towards middle of head. Eye ovoid, small, its diameter about 5% of HL, subcutaneous, dorsolateral in position, situated posterolateral to base of nasal barbel. Interorbital area concave, slightly less than one third of HL. Mouth terminal, jaws unequal, lower jaw weakly projecting beyond upper. Lips thick, papillate, with double folds. Upper jaw teeth smaller than lower jaw teeth, arranged in large broad crescentric band. Lower jaw teeth in crescentic band. Gill membranes joined at isthmus. Branchiostegals 11 on each side.

Barbels in four pairs. Nasal barbel long, reaching beyond base of pectoral fin. Maxillary barbel long, reaching to vertical through middle of dorsal-fin base. Outer mandibular barbel reaching to vertical through dorsal fin origin. Inner mandibular barbel reaching beyond base of pectoral fin.

Dorsal fin with one short smooth spine, one unbranched ray and 6 (2) branched rays, origin at vertical through middle of adpressed pectoral fin. Pectoral fin with a smooth spine, one simple ray and 6 (2) branched rays. Pelvic fin with one simple ray and 5 (2) branched rays, located approximately at vertical through posterior one fourth of adpressed dorsal fin. Anal fin with three simple and 12 (2) branched rays, its margin rounded, origin vertical from adipose-fin origin. Caudal fin with xi-8- 8-x * or x-8- 9 -ix rays; deeply forked; upper lobe longer than lower, terminating in pointed filament formed by uppermost branched caudal-fin ray joined by uppermost and unbranched principal caudal-fin ray. Two central caudal-fin rays with poorly developed hooks on proximal lepidotrichia, appearing as small nubbins. Feather-like extensions along anterior aspect of posteriormost dorsal procurrent caudal-fin rays. Adipose fin long, origin at vertical through anal fin origin, upper margin slightly convex, posteriorly continuous with dorsal procurrent part of caudal fin.

Coloration. In life (Fig. 2), dorsum light brown with pinkish tinge. Flanks pinkish brown, becoming lighter ventrally. Ventrally cream. All barbels whitish, but light brown with pinkish tinge at base. Fins hyaline. Base of dorsal, pectoral and anal fins light brown with creamy distal margins. Adipose-fin base light brown becoming lighter along distal margins. Pelvic fin uniform cream. Caudal-fin base light brown becoming lighter along distal margins with golden hue along some principle rays. In alcohol preservation (Fig. 1), dorsum and upper flanks light olive brown to beige. Lower flanks beige to cream. Ventrally white. Barbels white with brown pigment at base. Dorsal, anal and pectoral fins light olive brown at base; distal margins white. Pelvic fin uniformly white. Adipose fin olive brown to beige at base; margin white. Caudal fin light brown at base; margins white.

Etymology. The specific epithet derives from ಅಚud, accari (pronounced achchari), the Kannada word for ‘surprise’ highlighting our excitement over the discovery of a new Amblyceps species in the Western Ghats.

Common name. Nikhil’s Torrent Catfish (after Nikhil Sood who collected specimens of the new species and made them available for the present study).

Distribution and habitat. Currently the species is only known from its type locality, the Tunga River at Kudremukh (13.206°N, 75.283°E, 788m a.s.l.), a tributary of the Krishna River System in Karnataka State, India (Fig. 3). Habitat at the type locality consisted mostly of sand and stones of various sizes. The fish was collected from among the stones, not the sandy portions, of the moderately flowing river. The habitat was relatively undisturbed, with plants like such as Eriocaulon sp., Utricularia sp. and various ferns and mosses growing along the banks of the river. Amblyceps accari seems to be uncommon as fishing during both day and night resulted in only two specimens. Co-occurring organisms included shrimps of the genera Caridina and Macrobrachium and freshwater fish species, Schistura cf. nagodiensis Sreekantha, Gururaja, Rema Devi, Indra & Ramachandra, Schistura cf. semiarmata (Day), Nemachilichthys rueppelli (Sykes), Nemacheilus anguilla Annandale, Garra sp., Puntius sp., Osteochilichthys nashii (Day), Hypselobarbus kurali Menon & Rema Devi, Hypselobarbus dobsoni (Day), Tor khudree (Sykes), Rasbora daniconius (Hamilton), Glyptothorax sp., Pterocryptis wynaadensis (Day) and Mastacembelus armatus (Lacepède).