Carcharhinus signatus

Common Name

Night Shark

Year Described

Poey, 1868

Identification

Anteroposterior tooth rows: 15-16/14-16 on each side; 31-34/29-32 total
Vertebrae: 101-104 precaudal, 184-192 total

A fairly large and stout shark with a very long and pointed snout. Eye large. Distance between nostrils 1.7-1.9 times in pre-oral distance. Nasal flaps narrow and short. Upper labial furrows very short. A low interdorsal ridge is present. Long preanal ridge absent. No keels on caudal peduncle. Gill slits short (2.7-3.3% TL). Teeth in upper jaws low and wide, with an oblique, serrated cusp and up to several basal cusplets. Lower jaw teeth thick-based, with slender, smooth, and erect cusps (no cusplets). First dorsal fin small (6.4-8.4% TL) with a convex anterior margin, a rounded tip, and inserted just posterior to free tips of pectoral fin. Second dorsal fin much smaller (1.6-1.9% TL) and inserted almost directly above anal fin. Both dorsal fins with extended free posterior tips (second dorsal free tip around twice height of second dorsal). Anal fin similar in size to second dorsal fin. Pelvic fin origin well behind free tip of first dorsal. Pectoral fin long and falcate, with a pointed or rounded tip.

Color

Gray-brown to bluish-gray above, grading to whitish or grayish below. Fins unmarked. There are often small dark spots on the dorsum. Eye is green in life.

Size

Mature adults from 160-194cm TL. Newborns from 60-72cm. Maximum size to 280cm TL.

Habitat

Deepwater outer shelf waters or semi-pelagic from 160-366m (usually deeper than 275m during the day and shallower at night)

Range

Delaware to Argentina, including the Gulf of Mexico and the Caribbean islands. Poorly known from the continental Caribbean.

References

Castro, J.I. 2011. The Sharks of North America. Oxford University Press, 640 pp.

Compagno, L.J.V. 2002. Sharks. In: Carpenter, K.E. (Editor) FAO Identification Guide for Fishery Purposes. The Living Marine Resources of The Western Central Atlantic. Volume 1: Introduction, mollusks, crustaceans, hagfishes, sharks, batoid fishes, and chimaeras. ASIH Special Publication No. 5. FAO, Rome.

Compagno, L., M. Dando, and S. Fowler. 2005. Sharks of the World. Princeton University Press, 480 pp.