They can grow from 7 to about 15 ft. in length. They dont have any natural enemies.
Sharks have great sense of hearing.
They can also smell blood in water from a great distance. But for the final attack on their prey they use their eyes. If there is little food, but plenty of sharks when they are feeding, they can work themseleves into a feeding frenzy. They swallow their prey whole. They can grow from 6 in.