A small crustacean that grows to approximately 6-8 mm in length. Its body is laterally compressed with two pairs of antennae and seven pairs of thoracic limbs. Antenna 1 is shorter than antenna 2, and holds an accessory flagellum. The basal segment of antenna 1 is very large, and rectangular in shape. The remaining segments of antenna 1 are smaller and arise at right angles to the basal segment, a feature known as geniculate, and characteristic of the genus. The body appears semi-transparent to white, with varying degrees of red pigment associated with the abdomen. The eyes are red in colour and easily visible.The Gammaridea are difficult to identify and reference should be made to Lincoln (1979) for guidance.