Dietary protein requirement for armoured catfish juveniles (Hypostomus commersoni - Loricariidae)

The objective of this study was to determine crude protein (CP) requirement for armoured catfish juveniles. Seventy two juveniles of Hypostomus commersoni were used with average weight of 2.44 ± 0.14g, distributed in nine tanks, totalizing eight fish per experimental unit. In a completely randomized design, with three treatments and three replications. Three experimental diets were prepared with protein levels of 25, 30 and 40% and isocaloric (3.500 kcal. kg -1 ). The fish were fed daily with at the rate of 5% of body weight for 10 weeks.  Evaluated variables were final average weight, weight gain, specific growth rate (SGR), survival and body composition. Dietary levels of protein did not affect weight gain, specific growth rate and survival. Crude protein higher levels in the diet increased the deposition of protein and reduced body fat (P ≤ 0.05). For an adequate performance of armoured catfish juveniles, a diet with at least 30% crude protein is recommended.