Thresher sharks are large mackerel sharks of the family Alopiidae found in all temperate and tropical oceans of the world; the family contains three extant species, all within the genus Alopias. All three thresher shark species have been listed as vulnerable by the World Conservation Union since 2007 (IUCN). All three are popular big-game sport fish, and additionally they are hunted commercially for their meat, livers (for shark liver oil), skin (for shagreen) and fins (for use in delicacies such as shark-fin soup). Despite being active predatory fish, thresher sharks do not appear to be a threat to humans.