Skip to main content

Thresher Shark

Alopias vulpinus

Distinguishing Characteristics

Illustration of a thresher shark showing important characteristics
  • Huge caudal fin upper lobe, nearly equal to length of body
  • White patches extending from abdomen above pectoral fin bases
  • No interdorsal ridge

Similar Species: Bigeye thresher shark, A. superciliosus (has larger eyes and V-groove on top of head)


Maximum size about 20 feet in length and a maximum recorded weight of 750 pounds. Matures at approximately 7-9 years of age (about 10-15 feet) and is estimated to live 28+ years.


Adults are observed offshore and in oceanic waters, sometimes wandering close to coastal areas in search of food.  Juveniles inhabit coastal bays and nearshore areas. 


Feeds on a variety of schooling fishes such as menhaden, herring, bluefish, and mackerel. Also feed on bonito, squid, and sea birds. Known to hunt in groups and/or pairs, using their large tails to herd and stun their prey.


Gives birth to live young after approximately 9 months of gestation. Embryos known to consume other embryos within the uterus (known as oophagy) but are not cannibalistic. Broods contain 2-7 pups. Size at birth about 4-5 feet.

Additional Information

Considered harmless to humans, this is a shy species and difficult to approach. Valuable commercial species with marketable flesh, hide, fins, and liver. A popular game fish species, often hooked on the upper lobe of their tail as they try to stun the live bait with their tail.

Recreational Regulations


Image Credit: © Diane Rome Peebles