Family: |
Dalatiidae (Sleeper sharks) |
Max. size: |
182 cm TL (male/unsexed) |
Environment: |
bathydemersal; marine; depth range 37 - 1800 m |
Distribution: |
Western Atlantic: Georges Bank and northern Gulf of Mexico. Eastern Atlantic: Iceland (Ref. 12462), Scotland, and Irish Atlantic slope to Morocco, western Mediterranean, Madeira to Cameroon. Western Indian Ocean: Mozambique and South Africa. Western Pacific: Japan, Australia, and New Zealand. Central Pacific: Hawaii. |
Diagnosis: |
Dorsal spines (total): 0-0; Dorsal soft rays (total): 0-0; Anal spines: 0-0; Anal soft rays: 0-0. Moderately sized, short- and blunt-snouted shark with two almost equal-sized dorsal fins; papillose thick lips; small slender-cusped upper teeth and very large lower teeth with erect triangular serrated cusps and distal blades; first dorsal fin on back with its origin behind the pectoral rear tips and its base closer to the pectoral base than the pelvic fins; and caudal fin with the ventral lobe not expanded (Ref. 247). Dark grey-brown to black; trailing edges of fins translucent (Ref. 26346). |
Biology: |
Found on outer continental and insular shelves and slopes (Ref. 247). Mainly found on or near the bottom but readily occurs well off the substrate (Ref. 247, 58302). Often pelagic (Ref. 58302). Found singly or in small schools (Ref. 6871). Feeds mainly on deepwater bony fish, but also skates, other sharks (etmopterids in Ref. 123656), cephalopods and crustaceans (Ref. 5578). This bioluminescent shark (currently the largest luminous vertebrate) emit light ventrally to counterilluminate which might be used to illuminate the ocean floor while searching/hunting for prey; or to stealthily approach prey, using counterillumination camouflage, before striking fast when it is close enough (Ref. 123656). Ovoviviparous (Ref. 205), with 10-20 young born at 30-42 cm (Ref. 26346). Used for its squalene liver oil, leather and meat, as well as for fishmeal (Ref. 6871). |
IUCN Red List Status: |
Vulnerable (VU); Date assessed: 03 July 2017 (A2bd+3d) Ref. (130435)
|
Threat to humans: |
harmless |
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