Not generally recognized as crustaceans, isopod species occur in both salt and fresh water. They are also the only crustacean to have evolved a purely dry land form; the familiar wood louse or pill bug. The pickle bug (Idotea wosnesenskii) is a common inhabitant of kelp forests and eelgrass beds along the Pacific coast and in Puget Sound. The common name comes from its color and shape, something like a small dill pickle, though its color is dependent on its environment and may vary from olive green to reddish-brown and even black. Up to 1 1/2 inches in length, this crustacean is a good swimmer and a favorite prey of many species of fish. It has seven pairs of fleshy legs along the margins of its dorso-ventrally compressed body and two prominent antennae.