Revision of the fish parasitic genus Richardson, 1910 (Isopoda, Cymothoidae), with the description of a new species and key to the genus.

The cymothoid genus, Richardson, 1910, is revised and a new species from South Africa is recorded. can be distinguished by large eyes covering majority of the cephalon (almost in contact), antennula bases wide apart, antenna extending to middle of pereonite 2, subtruncate pleotelson, pereopod 7 with numerous acute robust setae on the propodus as well as the carpus, and the uropod exopod longer than the endopod. The three known species, Avdeev, 1975; Richardson, 1910; and Richardson, 1911 are also redescribed. differs from these known species in both morphological characters as well as geographical distribution. A key to the species is provided.