Whale-louse (Cymus), a genus of Crustacea, of the order Amphipoda and sub-order Læmodipoda, parasitic on the skin of Cetaceans. The body is broad and flat, the abdomen is rudimentary, the appendages are short, stout, and for the most part clawed. By means of these claws they attach themselves to whales, sometimes almost covering the skin, so that the animal appears whitish. See PARASITIC ANIMALS.
