Halaelurus immaculatus

Author: Chu and Meng, 1982

Field Marks:
A Halaelurus with rounded snout, long abdomen, short anal base, plain light coloration, large size (see diagnostic features and Femarks, below).

Diagnostic Features:
Snout tip not upturned and knoblike; eyes in adults less than 11 times in distance from snout to first dorsal origin; anterior nasal flaps subtriangular; labial furrows rather short, essentially confined to mouth corners, but lowers extending at least 5 mm onto lower jaw; mouth moderately large, its width 9% of total length, its length 5% of total length; status of papillae in pharynx unknown; gills directed.ventrad, not elevated above level of mouth. Origin of first dorsal about over pelvic midbases; second drosal considerably larger than first, its origin about over anal midbase; abdomen elongated in adults, distance between pectoral and pelvic bases over 2.5 times the pectoral anterior margin; length of anal base about 1.3 times the second dorsal base, slightly longer than distance between dorsal bases. Colour drab yellowish-brown, without markings. Adults moderately large, 71 to 76 cm.

Geographical Distribution:
Western North Pacific: Only known from the South China Sea at about 380 to 400 km east of Hainan Island.

Habitat and Biology:
A recently described benthic catshark of the western Pacific continental slope, at depths of 534 to 1020 m.

Size:
Maximum 76 cm; two females, presumably adult, 75 to 76 cm; adult male 71 cm.

Interest to Fisheries:
None at present.

Remarks:
Generic placement and recognition of this species is provisional and is based on Chu et aL (1982). The species is close to and possibly a synonym of the New Zealand Halaelurus dawsoni but differs in possibly having less lobate nasal flaps, shorter labial furrows, a longer abdomen, and possibly greater size. No material of this shark was available for examination, nor could the writer examined adult specimens of H. dawsoni.

Type material:
Holotype: South China Seas Fisheries Research Institute No. 00094, 708 mm adult male. Type Locality: South China Sea at 19°39.6'N, 114°23.6'E, about 400 km east of Hainan Island; depth 1020 m.

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