Species profile
Bigeye Thresher Shark
Alopias superciliosus
At a glance
Bigeye Thresher Shark (Alopias superciliosus) is an IUCN Vulnerable invertebrate regulated in 4 of 66 jurisdictions tracked by CatchRules across the U.S. and Canada.
Listed under MSA and CITES — verify protected-species rules with the issuing agency before retaining or handling.
Notable details
- Has eyes up to 4 inches across — the largest relative to body size of any shark.
- Can dive to depths exceeding 1,600 feet to hunt in cold, dark water.
- Uses its long scythe-like tail fin to stun schooling prey before eating.
- A groove along the top of its head lets it tilt its head sharply downward.
- Can reach about 15 feet in total length, including the elongated tail.
Jurisdictions with rules for Bigeye Thresher Shark
Protected status
- Atlantic HMS prohibited — must release unharmed.
- CITES Appendix II (Alopiidae — all thresher sharks, CoP17 2017).
Always verify protected-species rules with the issuing agency before retaining or handling.
Background
The bigeye thresher (Alopias superciliosus) is a species of thresher shark, family Alopiidae, found in temperate and tropical oceans worldwide. Like other thresher sharks, nearly half its total length consists of the elongated upper lobe of the tail fin. Its common name comes from its enormous eyes, which are placed in keyhole-shaped sockets that allow them to be rotated upward. This species can…
Background excerpt adapted from Wikipedia's Bigeye Thresher Shark article (CC BY-SA). Visit Wikipedia for the full entry.
Photo credit: iNaturalist / Wikipedia. Identification reference only — verify regulations with the issuing wildlife agency before retaining a catch.