Shark
Bigeye Thresher
Alopias superciliosus
A deep-water shark with huge upward eyes and an enormous scythe-like tail, found offshore of KwaZulu-Natal.
Also known as thresher shark, thresher(bigeye)
- Typical size
- Commonly 3-4 m including tail
- Habitat
- Deep offshore and mid-water
- Depth
- Surface to several hundred metres
The bigeye thresher is instantly known by its greatly enlarged, upward-facing eyes and the immense upper tail lobe that is nearly as long as its body, which it uses like a whip to stun schooling fish. It is dark purplish-grey to brown above and paler below, with a grooved head, and lives mainly in deep offshore and mid-water zones off the KwaZulu-Natal coast.
Threshers make daily vertical migrations, dropping into cool deep water by day and rising toward the surface at night to feed on fish and squid. They are shy and rarely seen by divers, and their populations are slow to recover from fishing pressure, so they are a species of conservation concern. Hooked fish should be handled quickly and released whenever possible.