Anotopterus nikparini Kukuev, 1998
North Pacific daggertooth
Anotopterus nikparini
photo by Orlov, A.

Family:  Anotopteridae (Daggertooth)
Max. size:  146 cm TL (male/unsexed); max.weight: 1,650.0 g
Environment:  bathypelagic; marine; depth range 0 - 2750 m
Distribution:  North Pacific: Bering Sea and Gulf of Alaska; south in Pacific waters to about 25°N, south of Baja California and Japan.
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 0-0; Anal spines: 0-0; Anal soft rays: 14-17; Vertebrae: 78-80. Dark brownish, silvery ventrally; paired fins and caudal fin uniformly black. Body extremely elongate. Large adults with a pair of dermal keels midlaterally on each side. Small, flexible projection at tip of lower jaw. Gill membranes joined forward, below anterior edge of eye, and free from isthmus. No rayed dorsal fin. No scales (Ref. 43939). In adults, head depth 29-33% of lower jaw length. Postorbital area 8.1-9.7% SL or 34.4-38.8% (less than 3 times smaller than HL). Rear edge of gill cover overlaps with the vertical of the 5th vertebrae. Postadipose distance 7-8% SL (Ref. 31260).
Biology:  Found in a wide range of depths, sometimes near surface (Ref. 2850) to below 2,000 m. Larger adults inhabit colder water toward the poles, whereas, the young and smaller adults inhabit more temperate regions (Ref. 35956). Feed on mollusks, crustaceans, marine worms, coelenterates, salps, and fishes (Ref. 4525, 6885). Its distensible body wall and large stomach can accommodate prey up to half of its own length. Oviparous, with planktonic larvae (Ref. 35956). Preyed upon by albacore, Pacific lancetfish, halibut, steelhead salmon, blue shark, pomfret, and whales (Ref. 6885).
IUCN Red List Status: Least Concern (LC); Date assessed: 12 October 2018 Ref. (130435)
Threat to humans:  harmless


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