But they also use the long upper section of their tail fin, which can grow up to 10 feet (3 meters) long, to hunt. Related: Do wolves wag their tails? "Thresher sharks feed on schooling prey (i.e ...

These ancient fish, little changed over many millions of years, can reach 16.5 feet long, including the tail. There are reports of giant stingrays weighing up to 1,300 pounds, though such accounts ...