Growth in weight and length, and food conversion efficiencies were compared between similar size control and paired female green sunfish in aquaria. The relationship between hierarchy and growth was noted. Prior residence and size were major factors in hierarchy establishment. Interaction between paired fish stimulated growth and food consumption to an optimal level beyond which a decline was observed. Control and paired fish grew at similar rates but variance was great, Control and dominant fish grew more than subordinate fish. Single control fish converted food more efficiently than paired fish. Death of subordinates because of social interaction was related in part to elevated food maintenance levels and to food consumption. The growth and conversion efficiency of dominant fish after the death of subordinates improved in relation to the length of the recovery period.