Portuguese dogfish

Portuguese dogfish
Conservation status
Near Threatened  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Subdivision:	Selachimorpha
Order:	Squaliformes
Family:	Somniosidae
Genus:	Centroscymnus
Species:	C. coelolepis
Binomial name
Centroscymnus coelolepis (Barbosa du Bocage & Brito Capello, 1864)
Range of the Portuguese dogfish
Synonyms
Centroscymnus macrops* Hu & Li, 1982 Scymnodon melas Bigelow, Schroeder & Springer, 1953 * ambiguous synonym

The Portuguese dogfish (Centroscymnus coelolepis) or Portuguese shark, is a species of sleeper shark of the family Somniosidae. This globally distributed species has been reported down to a depth of 3,675 m (12,057 ft), making it the deepest-living shark known. It inhabits lower continental slopes and abyssal plains, usually staying near the bottom. Stocky and dark brown in color, the Portuguese dogfish can be distinguished from similar-looking species (such as the kitefin shark, Dalatias licha) by the small spines in front of its dorsal fins. Its dermal denticles are also unusual, resembling the scales of a bony fish. This species typically reaches 0.9–1 m (3.0–3.3 ft) in length; sharks in the Mediterranean Sea are much smaller and have distinct depth and food preferences.

Relatively common, the Portuguese dogfish is an active hunter capable of tackling fast, large prey. It feeds mainly on cephalopods and fishes, though it also consumes invertebrates and cetacean carrion. This shark has acute vision optimized for detecting the bioluminescence of its prey, as sunlight does not reach the depths at which it lives. The Portuguese dogfish is aplacental viviparous, with the young provisioned by yolk and perhaps uterine fluid. The females give birth to up to 29 young after a gestation period of over one year. Valued for its liver oil and to a lesser extent meat, Portuguese dogfish are important to deepwater commercial fisheries operating off Portugal, the British Isles, Japan, and Australia. These fishing pressures and the low reproductive rate of this species have led the International Union for Conservation of Nature (IUCN) to assess it as Near Threatened.