Order of the class Crustacea. They are small, bilateral compressed, scavenging crustaceans. It is a large order with 100 families. There is no carapace. Only the first two segments are fused to the head. The abdomen is not distinctly demarcated from the thorax, and there are seven pairs of legs. Their compound eyes are sessile. Example: gammarids.

Alternative form for amphipod : amphipods.