Isurus paucus

Common Name

Longfin Mako

Year Described

Guitart Manday, 1966

Identification

Upper jaw: 24-26 rows
Lower jaw: 22-26 rows

A large, slender yet robust shark. Snout relatively long and bluntly pointed. Eye large. Nostrils closer to tip of snout than mouth. Mouth wide and strongly curved. Labial furrows distinct. Teeth slender, straight and asymmetrical without serrations. Gill slits number five and are very long (3/4 of body depth). Posterior two slits compressed together before pectoral fin base. Body tapering posteriorly. Caudal peduncle much wider than tall with a high lateral keel and no secondary keel. First dorsal fin origin posterior to free rear tip of pectoral fin. D1 straight to convex on rear edge. Second dorsal fin tiny. Pectoral fin very large and paddle shaped with a rounded tip. Pelvic fin much larger than D2 and far behind level of D1. Anal fin about the size of D2 and originates behind D2. Caudal fin with precaudal pits above and below. Caudal fin lunate with a long lower lobe and a well developed notch on upper lobe.

Color

Dorsum gray-blue, blue-black, or blue-purple, becoming abruptly gray on flanks and white on belly. No markings on body or fins. Fins body colored. Eye black.

Size

Mature adults from 190-250cm TL. Maximum size possibly over 400cm TL. Juveniles at least 90cm TL. Females average larger than males.

Habitat

An open water pelagic species occurring from the surface to over 1700m. A fish feeder.

Range

Maine to S. Brazil, including the Caribbean Sea. Most common in the Gulf Stream, off Cuba, and Brazil.

References

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

Ebert, D. A., & M. Dando. 2020. Field Guide to Sharks, Rays & Chimaeras of Europe and the Mediterranean. Princeton University Press. 2020.