Crabs are found in deep water, shallow water, sandy beaches, and on muddy shores.  There are about 4,500 different types of crabs.  Most of these crabs live in salt-water, while a few others live in fresh water.   A crab has five pairs of  legs with very stong claws for digging and holding.  Crabs lay eggs in saltwater.  A newly hatched crab cannot live in freshwater.  Most edible crabs are found on the Pacific coast of countries.