The Shofield Desert Hawk can kill a Tooth Fish in one shot. Using any other weapon on the Tooth Fish is a waste of ammo. Even groups of Tooth Fishes can be killed with ease by using the Desert Hawk.
A Tooth Fish will constantly bite the player if it gets very close to them, which makes them quite annoying. If the player is suddenly taking low but constant damage while underwater, it is always a Tooth Fish nipping at them from behind.