Resumo

CONCHA-FRIAS, Bartolo et al. Dietary protein requirement in common snook (Centropomus undecimalis) juveniles reared in marine and brackish water. Ecosistemas y recur. agropecuarios [online]. 2018, vol.5, n.13, pp.45-54. ISSN 2007-901X.  https://doi.org/10.19136/era.a5n13.1393.

A total of 300 Centropomus undecimalis juveniles, with an average initial weight of 3.16 ± 0.28 g and average total length of 7.17 ± 0.22 cm, were reared for eight weeks using a recirculating system to determine the dietary protein requirement for their growth and survival. The effect of five experimental diets containing 40, 45, 50, 55 and 60% total protein content and two salinities (brackish water, BW at 5 UPS and marine water, MW at 36 UPS) were assessed. Fish were fed five times per day at 2.5% of total biomass. All treatments were performed in triplicate, recording the individual weight and total length every 15 d, while weight gain and daily growth rate were recorded at the end of the experiment. Mean weight increased proportionally as protein content increased, with the greatest growth occurring with a 60% protein diet for fish reared in brackish water, and 55% for fish in marine water. We consider that the protein requirement in C. undecimalis juveniles is high; in addition, it differs depending on the salinity, which may be due to the higher energy expenditure derived from the processes of osmoregulation in fish reared in marine water.

Palavras-chave : marine water; brackish water; growth; protein; common snook.