The thresher shark (Alopias vulpinus) is easily recognized by its large upper caudal fin, which can often be more than half of the total length of its body! Thresher sharks are strong swimmers and with the help of their powerful tail, they can breach clear out of the water. There is evidence that thresher sharks use their huge tail to swat and stun their prey.
Here are some quick facts about thresher sharks:
- Circumglobal: found throughout warm and temperate waters of world’s oceans.
- Summer visitor to the Canadian Atlantic region.
- Sometimes seen inshore, in shallow waters, but mostly seen in the open ocean over continental shelves.
- Can be brownish, purplish or bluish grey coloured and are about 10-18ft.
- Maximum lifespan is about 45 to 50 years.
- Eat schooling fish like mackerel, juvenile tuna, bluefish, squid and cuttlefish.
- Major threat to thresher sharks in Canadian waters is bycatch: caught in longline and recreational fisheries.
- Listed as Vulnerable by the IUCN.
Thresher sharks are occasionally sighted in the Bay of Fundy, usually when they are breaching out of the water. On September 3, 2012, the New England Aquarium spotted a thresher shark swimming steadily through the water and managed to snap a few photos of it before it submerged.