Cataracts are described for the first time in a group of aquarium reared Sarotherodon mossambicus. Both eyes of each individual with the condition are affected. Grossly, the entire lens is opaque except for a thin rim of outer cortex. Vision impairment is demonstrated by a decreased ability to avoid swimming into objects but the animals function normally otherwise. Histologic changes are described.

*Supported by special project funds from the Center for Environmental and Natural Resources Programs, Institute of Food and Agricultural Sciences, University of Florida.