Science Main Index
There are about 10,000 different species of crab. The crab is native to all of the world's oceans. There are also freshwater crabs, and even some crabs that live on land. Crabs have a large, hard shell. Extending from the front of its shell are the eyes, mouth and two pairs of antennae. The crab has 5 pairs of legs extending from the side of its shell. The first pair of legs have claws or pincers used to catch and hold food. The other pairs of legs are used for walking. Most crabs don't swim, they use their legs to walk. However, some crabs such as the Blue Crab can use their legs as paddles to swim. Play the following videos to learn more about the crab.