Common Name
Black Dogfish
Year Described
Reinhardt, 1825
Identification
Body moderately slender with a broad mouth and blunt snout. There are two dorsal fins with the second larger in size. Both possess a grooved spine on the anterior margin. The second dorsal spine is longer. Origin of the first dorsal is posterior to the rear margin of the pectoral fin. Teeth are numerous and small with a central cusp and two (or four) lateral cusplets. Tooth rows: upper and lower: 68 rows each (equal sized). The five gill slits are equal in size. Pectoral fin small with a squared-off rear edge. Anal fin is absent. Pelvic fins set far back on body, anterior to origin of second dorsal. The caudal fin is long with a well-developed sub-terminal notch and a poorly developed ventral lobe. Caudal peduncle is very short. Eye is large. Skin is fairly smooth with small close-set denticles (stellate bases, hooked cusps). Minute, luminous organs scattered on body.
Color
Body blackish brown with no markings. Juveniles have dark brown upper body with a black belly and white edging on the fins. Dorsal spines are white. Eyes green in life.
Size
Mature adults to 46-66 cm. Maximum size 107 cm. Males mature at a smaller size than females.
Habitat
Continental slopes and shelves from 180-1600 m. Possibly towards surface waters in cooler waters and to over 2000 m. in tropical waters. Forms aggregations in winter and spring. Feeds on small fishes, squid, and crustaceans. Bioluminescent. Ovoviviparous (7-8 young).
Range
Mostly in cooler waters of the Atlantic: from Greenland and eastern Canada to the coast of North Carolina. Also in the southwestern Atlantic from Uruguay to Argentina. Presence in the Gulf of Mexico and the southeastern U.S. is unclear.
References
Castro, J.I. 2011. The Sharks of North America. Oxford University Press, 640 pp.
Compagno, L., M. Dando, and S. Fowler. 2005. Sharks of the World. Princeton University Press, 480 pp.