Species: Somniosus rostratus, Little Sleeper Shark

Somniosus rostratus (Risso, 1827)

Little Sleeper Shark

Body cylindrical, relatively slender; head short (snout to pectorals 20-23% TL); snout short, rounded, without barbels; eyes on side of head, without nictitating membranes; spiracles large, just behind eyes; mouth short, nearly transverse; top teeth narrow, needle-like, with a single cusp, non-overlapping, 57-63 rows; bottom teeth blades, overlapping, with high oblique cusps, 31-36 rows; gill slits 5, all before pectoral fin; 2 dorsal fins without spines; 1st dorsal higher & slightly larger than 2nd dorsal; origin of 1st dorsal in middle of back, insertion closer to pectorals than pelvics; no anal fin; pelvic fins ~equal to or larger than 2nd dorsal; tail base short (distance between 2nd dorsal base and upper tail fin origin </= 2X 2nd dorsal fin base); tail fin strongly asymmetrical, paddle shaped, lower lobe long, moderately large; short keels before base of tail fin; skin smooth, flank denticles with flat, wide crowns and horizontal points.

Uniform blackish.

Reaches 143 cm.

Depth range 180-2200 m.

Benthopelagic

North Atlantic and Mediterranean; Cuba and NE Yucatan.