Growth and diurnal variations in metabolic parameters in the starved bass, Dicentrarchus Labrax, after experimental feeding .

Abstract

-I. Young bass (Dicentrarchus lahrax) were fed either a natural diet (filleted bogue) or a commercial diet for 107 days and studied after fasting for 7 days. 2. The food consumption index and daily caloric intake was lower in the bass on the natural than on the commercial diet but the growth related parameters were much greater in the first group. 3. Plasma acetoacetate levels showed daily rhythmicity in the bass on a bogue diet and these changes showed a trend similar to that of glucose. 4. Plasma glycerol levels were greater in the bass on a commercial than on a natural diet probably as a result of enhanced lipolysis due to the limited efficiency of energy utilization in the first group. 5. Some individual plasma amino acids showed significant daily rhythms in the bass on either diet. The compiled values of plasma amino acids were very similar in fish on either diet, indicating that in both groups lipid and carbohydrate metabolisms are more sensitive than those of protein-amino acids to the differences in the efficiency of energy utilization.