Hexanchus nakamurai Teng, 1962
Bigeyed sixgill shark
Pating
photo by Murch, A.

Family:  Hexanchidae (Cow sharks)
Max. size:  180 cm TL (male/unsexed); 142 cm TL (female)
Environment:  bathydemersal; marine; depth range 0 - 700 m
Distribution:  Indo-West Pacific: patchily distributed in most warm-temperate and tropical seas.
Diagnosis:  Vertebrae: 155-155. This slender-bodied shark is readily distinguished from its larger congener (H. griseus) by having a narrower head, relatively larger eyes, 5 large lower comb-shaped anterolateral teeth, a long slender dorsal-caudal space, with distance from the dorsal origin to the upper caudal origin being at least twice the length of the dorsal fin base; with the upper and lower caudal postventral margins forming a strong arch. In life, Color of dorsum a uniform pale brown without a light line extending along the lateral body trunk, the trailing fin edges are white in some specimens and the ventral surface is lighter (Ref. 94780).
Biology:  Found on continental and island shelves and slopes, occasionally near surface or inshore from 0 to 700 m depth. Feeds on small to medium-sized bony fishes and occassionally on crustaceans. Viviparous, with 13-26 young in a litter (Ref. 125614). Size at birth measures to about 40-43 cm TL (Ref. 94780). It is taken as bycatch within its range, but is not commercially important (Ref. 125614). Utilized for its fins, meat and liver oil but of little value due to its relatively small size (Ref. 58048).
IUCN Red List Status: Near Threatened (NT); Date assessed: 21 November 2019 (A2d) Ref. (130435)
Threat to humans: 
Country info:  Misidentified by Herre (Ref. 280) as Hexanchus griseus; two Dumaguete specimens SU 30642. Also collected from Dipolog City market and Isla Verde, Pulu, Dapitan City (Ref. 47737). Occurrence based on map distribution (Ref. 125614). Also Ref. 247, 13573.


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