Six hundred lambari tambiú (Astyanax bimaculatus) averaging initial weight of 1.30 ± 0.01 g, placed in 40 aquariums (100 L) with water renewal, controlled temperature and individual aeration, were used to determine the digestible energy (DE) requirements, according to the dietary crude protein (CP) levels. The experiment was analyzed as a 5 x 2 factorial scheme (five levels of DE: 2,900, 3,000, 3,100, 3,200, and 3,300 kcal/kg, combined with two levels of CP: 32 and 38%), in a completely randomized design with four replicates and fifteen fishes per experimental unit. The fish were submitted to the feeding controlled based on the average daily intake of the treatments with the highest energy level (3,300 kcal/kg) for each daily corrected protein level, during 49 days. Weight gain, specific growth rate, feed intake, crude protein intake, digestible energy intake, apparent feed:gain ratio, protein efficiency rate, carcass yield, nitrogen retention efficiency, and contents of body humidity, fat and protein were evaluated. Fishes fed diets with 32% of CP showed smaller specific growth rate and protein efficiency rate and higher feed:gain ratio. Fishes fed diets with 38% of CP showed greater carcass yield. The requirement of digestible energy for lambari tambiú is of 2,900 kcal/kg for diets with 32 and 38% of CP.
Astyanax bimaculatus; diets; nutrition
