Integrating Biology, Genetics And Tagging Studies For The
Management And Conservation Of The Highly Vulnerable Bigeye
Thresher Shark In The Atlantic Ocean The bigeye thresher,
Alopias supercilious , is commonly caught in the Atlantic as by-
catch in pelagic long-line fisheries targeting tunas and
swordfish. However, there is still little information available
on the biology of this species. The bigeye thresher shark occurs
circum-globally in tropical and temperate seas, ranging in
habitat from oceanic epipelagic to coastal waters, preferring
more oceanic and warmer waters than its congener Alopias
vulpinus. It is known to usually bear only two embryos per
litter (although cases of up to four embryos may occur),
resulting in an extremely low fecundity and consequently, a very
high vulnerability to fishing pressure. The IUCN Shark
Specialist Group (SSG) considered all members of the genus
Alopias as Vulnerable in global terms (according to the IUCN Red
List Criteria), because of their declining populations. Spec