THE EFFECT OF EYESTALK ABLATION ON THE ENERGY-BALANCE OF THE PINK SHRIMP, PENAEUS-NOTIALIS

Abstract

1. The effect of eyestalk ablation on the energy balance of male and female pink shrimp Penaeus notialis adults was determined. 2. The effect of ablation on ingested food, assimilation efficiency, assimiliation and oxygen consumption in both sexes was evident. It was reflected in the scope for growth obtained. 3. The ablation of the eyestalks of females caused an increase in respiratory rate and a decrease in metabolic level with respect to intact shrimps. An increase in the respiratory rate could mean an increase in the physiologically useful energy (PUE). The effect of ablation in males produced an increase in the metabolic level without increase in the PUE. 4. Although ablation caused an increase in the amount of ingested food, assimilated energy and the scope for growth in both sexes, it Aas less marked in males (39%) than in females (53%). 5. These results suggest that the ablation does not increase the efficiency of the processes related to maturity in males as has been demonstrated for females of pink shrimp P. notialis. These differences may be related to the reproductive characteristics of males of P. notialis which is highly efficient and accelerated in normal conditions.