this shark is one three found in the family Alopiidae. It is widespread in tropical waters and, although it lives at considerable depths, it is commonly observed swimming at the surface in coastal waters. It frightens it's prey and herds it into tight groups by slapping the water surface with it's large, strong tail. It has also been seen using it's tail to stun prey. Numbers of this shark have drop significantly due to overfishing.

The Thresher shark has a husky, spindle shaped body with large pelvic fins, two dorsal fins, and broad, curved pectoral fins. It's caudal fin is it's most striking feature, the upper lobe being equal in length to the rest of it's body. The body is pale to dark blue grey above, with a sharp, ragged line marking the edge of it's underside, which is pale grey or white.

Reproduction: Females give birth to a ltter of two to four pups after a gestation period estimated at nine months.

It is not aggresive towards humans, but it's powerful tail can pose a danger.