Somniosus rostratus (Risso, 1827)
Little sleeper shark
photo by Cambraia Duarte, P.M.N. (c)ImagDOP

Family:  Somniosidae (Sleeper sharks)
Max. size:  143 cm TL (male/unsexed)
Environment:  bathydemersal; marine; depth range 200 - 1330 m
Distribution:  Northeast Atlantic: Madeira, France, and western Mediterranean.
Diagnosis:  Dorsal spines (total): 0-0; Anal spines: 0-0; Anal soft rays: 0-0. Diagnosis: Somniosus rostratus is distinguished from S. longus in having overall length of second dorsal shorter than first dorsal fin 76-88% (vs. almost equal 91-100%); horizontal diameter of eye less than 37% (mean 33%) of length from snout tip to eye (vs. >37, mean 46%); number of tooth rows in upper jaw 53 (vs. 56-57); and spiral valve counts 23 (vs. 26-27) (Ref. 50224). Description: Grey or brown in color (Ref. 26346). Short, rounded snout; equal-sized dorsal fins, first dorsal fin on back closer to pectorals than pelvic fins; long ventral caudal lobe; short keels on base of caudal fin (Ref. 247).
Biology:  A rare species (Ref. 26346) found on outer continental shelves and upper slopes (Ref. 247). Probably feeds on deepwater bottom fishes and invertebrates (Ref. 247). Ovoviviparous (Ref. 205), length at birth 21-28 cm TL (Ref. 26346). Utilized as fishmeal and possibly as food fish (Ref. 247).
IUCN Red List Status: Least Concern (LC); Date assessed: 21 November 2019 Ref. (130435)
Threat to humans:  harmless


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