Influência da densidade de estocagem no desempenho zootécnico de Litopenaeus vannamei durante a fase de berçário em sistema de bioflocos

This study evaluated the zootechnical performance of the marine shrimp Litopenaeus vannamei reared at different stocking densities during the nursery phase in a biofloc culture system. The experiment consisted of four treatments with three replicates, corresponding to the densities of 1,500, 3,000, 4,500 and 6,000 shrimp m-². Twelve 300 L circular plastic tanks (microcosms) with a bottom area of 0.5 m2 were randomly stocked with shrimp (0.004 g) according to the treatments and maintained for 35 days. These tanks were supplied by biofloc water from a 200 m2 matrix tank (macrocosm), where L. vannamei was reared with the stocking density of 300 shrimp m-2. The water quality parameters remained within acceptable limits throughout the experiment. The zootechnical performance results showed significant differences (P<0.05) among treatments. The values of final weight were higher in shrimp reared at the densities of 1,500, 3,000 and 4,500 m-², whereas survival was significantly reduced at 4,500 and 6,000 shrimp m-². The density of 3,000 shrimp m-2 was considered the most appropriate considering the zootechnical performance for the nursery phase of L. vannamei in a biofloc technology system in northeastern Brazil.