Bioenergetic budget of juveniles of fat snook Centropomus parallelus (Perciformes, Centropomidae) as a function of salinity acclimation

The energy allocation from food consumption (C) to fecal losses (F), routine oxygen consumption (Rr), ammonia excretion (U) and body mass production (P) was assessed in juveniles of Centropomus parallelus acclimated for 15 and 30 days to 5, 20 and 30 salinities, and temperature of 21o C. Oxygen consumption and ammonia excretion were linear related to fish wet weight and differences were significant either between salinities and acclimation periods. The body mass production suggests this salinity range as better conditions for rearing C. parallelus at this stage of life cycle. The energy balance as food consumption ranged from: 101.86 to 105.43%; 79.85 to 92.90%; 91.16 to 111.66%, at salinities 5, 20 and 30, respectively. This energy balance was comprised with metabolic maintenance that expended from 40 to 70% and with 20 to 42% saved as body mass production, in accordance to the salinity and period of acclimation. The energy lost as feces and ammonia excretion represented ca. of 8.70 - 11.90% and 0.50 1.30%, respectively from the general balance. Suitable environmental conditions for the fat snook aquaculture are discussed in accordance to the present results.