RESPONSE OF PROTEIN-TURNOVER IN THE BROWN TIGER PRAWN PENAEUS-ESCULENTUS TO VARIATION IN DIETARY-PROTEIN CONTENT

1. Diets containing 30, 40 or 50% protein were assessed for their effect on the growth and in vivo protein synthesis and degradation of muscle and hepatopancreas in juvenile Penaeus esculentus. 2. Protein synthesis, degradation and growth of the hepatopancreas was not affected by protein content of the diet. 3. The protein synthetic rate of muscle was significantly higher at 50% protein and the protein degradation rate and RNA activity (K(RNA); g protein synthesized/g RNA/day) was significantly lower at 40% protein. 4. The efficiency of muscle protein retention was 93.1% for prawns fed 40% dietary protein but only 54.4 and 48.5% for those fed 30 and 50% protein, respectively.