Bigeye thresher shark

Alopias superciliosus

 Bigeye thresher

Distribution: An epipelagic and mesopelagic species occurring worldwide and off the U.S. West Coast from the Mexico border north to off cascade Head, Oregon. Ranges deeper than the other thresher species; to 723 meters deep and can reportedly stay in cooler water for longer periods of time than other pelagic sharks. Population off California are predominantly adult males (71% of the observed catch).

Growth and Development: Ovoviviparous. Pups are born 100-140 cm total length (TL; including the elongated upper caudal fin) with 2-4 pups per litter. Bigeye threshers reach maturity at around 300-350 cm for both males and females, and can grow to larger than 460 cm TL. There is no evidence of nursery habitat within the U.S. West Coast EEZ.

 Feeding: The bigeye uses its elongated caudal fin to stun pelagic fish immobile before preying on them. Feeds on small pelagic fish in tropical and temperate oceans.

Conservation Status and Management: In the Eastern Pacific Ocean, bigeye threshers are caught incidentally in some fisheries, however stock assessments are not complete for bigeye thresher sharks in the Pacific Ocean.

Last modified: 12/8/2015