This unit contains information about the biology and ecology of crabs. It includes sections on crab anatomy, how crabs breathe, how they defend themselves, what they eat and what eats them, lfe cycles and more.

The information is mainly presented using Flash movies, there are also games, music and cartoons about crabs.

Crabs are the most commonly recognised crustaceans. Although crabs come in a variety of shapes and sizes they all have the same general body plan. They are found in a variety of coastal and marine environments from the coastal fringe to the depths of the oceans. There are more than 100 known species in southern Australia.

Crabs perform a number of roles in ecosystems. Some are scavengers or detritovores, others herbivores (eating seaweeds), others filter feeders (eating plankton), many are predators.

Many crabs have been accidentally introduced into Australian waters and now threaten native crab species either through competition or predation. Some of these introduced species of crab threaten important commercial shellfish fisheries as well as native shellfish..

Crabs are relatively easy for primary students to find and study in the field. They can withstand some handling by students if they are handled with care and respect.