Common Name
Arrowhead Dogfish
Year Described
Smith & Radcliffe, 1912
Identification
Body moderately slender with a very long, flattened snout and narrow mouth. 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 over the base of the pectoral fin. Snout length is longer than mouth width. Anterior nasal flap is short. Teeth in lower jaw are broader than upper and lack cusplets. Tooth rows: upper: 26-31 rows; lower: 26-30 rows. The five gill slits are equal in size. Pectoral fin small with a rounded free edge. Anal fin is absent. Pelvic fins set far back on body, under second dorsal. The caudal fin is long with a well-developed sub-terminal notch and a poorly developed ventral lobe. Caudal peduncle has a ventral keel (unique among Deania spp.). Eye is large. Skin is fairly smooth with small denticles (tricuspidate, stellate bases, high pedicels).
Color
Body dark gray or dark brown.
Size
Mature adults to 43- 80 cm. Maximum size 97 cm.
Habitat
Benthic on the continental slope from 275-1785 m. Can gather in huge aggregations. Feeds on small fishes, squid, and crustaceans. Ovoviviparous (5-7 young).
Range
Widely scattered in the western Atlantic: off Cape Hatteras, North Carolina and the northern Gulf of Mexico.
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.
Other Notes
Deania hystricosa and D. quadrispinosum are both recorded from the eastern Atlantic. They could be eventually discovered in our area.