Habitat
Sharks are found in all seas. They generally do not live in fresh water, with a few exceptions such as the bull shark and the river shark which can swim both in seawater and freshwater.
Diet
Almost all sharks are "carnivores" or meat eaters. They live on a diet of fish and sea mammals (like dolphins and seals) and even such prey as turtles and seagulls. Sharks even eat other sharks. Not all sharks are fierce carnivores. Some are harmless. These sharks eat plankton, a tiny shrimp-like creature found in the ocean. To do this, they swim forward with their mouths wide open. "Gill rakers" at the back of their throat strain the tiny food from the water.
Movement
Sharks move mainly by moving a swishing their tail fins back and forth. Sharks have to move in order to stay alive, so they even move slowly while sleeping.
Description
The one thing that sets sharks apart from other fish is the large fin on its back. Sharks can range in length from six inches to at least forty feet.
Enemies
There are many types of small sharks that are no doubt part of the diet of other predatory animals in the ocean. Also sharks have been observed eating other sharks. The shark's predators are dolphins, other sharks and people!