Carcharhinus porosus

Common Name

Smalltail Shark

Year Described

Ranzani, 1839


Anteroposterior tooth rows: 13-15/12-15 on each side; 29-32/26-32 total
Vertebrae: 41-61 precaudal, 96-135 total

A small and slender shark with a long and pointed snout. Eye large. Distance between nostrils 1.2-1.8 times in pre-oral distance. Nasal flaps narrow with a pointed tip. Upper labial furrows short. Interdorsal ridge is absent. Long preanal ridge absent. No keels on caudal peduncle. Gill slits short (2.8-3.4% TL). Teeth in upper jaws broad-based, narrow and low, with oblique and serrated cusps. Lower jaw teeth thick-based, with narrow cusps that range from straight to oblique. First dorsal fin fairly high (6.9-9.9% TL) with a convex anterior margin, a rounded tip, and inserted over inner margin of pectoral fin. Second dorsal fin much smaller (2.2-2.8% TL) and inserted above middle or rear of anal fin base. Both dorsal fins with extended free posterior tips (second dorsal free tip much shorter than 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 small and slightly falcate, with an angular tip.


Grayish blue to gray above, grading to whitish below. Fins unmarked or with darkish edges and tips.


Mature adults from 72-90cm TL. Newborns from 31-40cm. Maximum size to 134cm TL.


Coastal and continental shelf waters from 16-32m over mud bottoms. Common in high salinity parts of estuaries.


Northern Gulf of Mexico to the Yucatan Peninsula, and Panama to southern Brazil. Appears to be absent from the east coast of the U.S.A. and the Caribbean islands.


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.