Bioenergetics of juvenile red claw lobster, Cherax quadricarinatus, fed two artificial diets

Abstract

The metabolic response of juvenile Australian red claw lobster, Cherax quadricarinatus, fed two artificial diets (Rangen with 35% protein and Cherax1 with 32% protein of vegetable substrate), acclimated to the preferred temperature of 28 ° C, was evaluated in a dynamic respirometer, measuring oxygen consumption and ammonia excretion during fasting and feeding. Survival and growth were also determined. The energy consumed by juveniles in the food (C) was (mean ± s): 3614.1 ± 591.3 and 1967 ± 493.8 (J day-1 g-1 ) with Cherax1 and Rangen respectively. Energy eliminated in the feces (F) equivalent to 42.6 Joules by organisms that were fed Cherax1 represented a low energy loss in the percentage distribution, with a higher metabolic efficiency compared to the diet Rangen. The highest percentage of protein supplied through the food was channeled to growth, for all treatments, in which lobsters used a mixture of lipid-protein as the main energy substrate to meet their metabolic requirements. There was no difference in survival, but the juveniles fed Cherax1 had a higher specific growth rate and a 2.2 times higher weight gain than those fed with Rangen. The results show that the experimental diet Cherax1, formulated with plant products, can be considered as a high quality, efficient feed for this species, and that it is a good potential replacement for various commercial diets.