Total phosphorus contents for feeding silver catfish juveniles reared in net cagesPhosphorous is an essential mineral for fishes, because it acts on various metabolic processes. However, high levels may jeopardize the water quality, and its lack could promote deficiency to animals. The aim of this study was to evaluate the productive performance of silver catfish juveniles reared in net cages and fed with diets containing different total phosphorus contents. A total of 600 silver catfish juveniles, with initial weight of 6.88 ± 0.26 g and 9.28 ± 0.99 cm, were randomly distributed in 20 net cages, in a stocking density of 30 fish per cage. A completely randomized design, with four treatments, different total phosphorus contents (0.65%, 0.80%, 0.95%, and 1.10%), and five replicates were used. These contents affected (p < 0,05) the final weight, length, weight gain, specific growth rate, and condition factor. However, the survival rate and feed conversion did not differ (p > 0,05) among treatments. Thus, it is possible to recommend the commercial use of 0.80% total phosphorus in diets for silver catfish juveniles, providing a good productive performance and, above all, reducing the pollution caused by those diets.
Rhamdia quelen (Quoy & Gaimard, 1824); intensive cultivation; fish nutrition
