Larvicultura de tilápia do Nilo Oreochromis niloticus (Linnaeus, 1758) submetido a dietas com diferentes níveis protéicos com tecnologia de biofloco

Abstract

The objective of this study was to evaluate the use of diets with different protein levels during Nile tilapia larviculture cultivated with biofloc technology. The experiment with larviculture was carried out at the Laboratory of Experimentation of Aquatic Organisms of the Serra Talhada Academic Unit (UFRPE / UAST), during 28 days. A completely randomized design with five treatments with diets containing different concentrations of 30PD digestible protein was adopted; 34PD; 38 PD; 42PD and 46PD, with four repetitions. Twenty circular fiberglass experimental tanks with a useful volume of 1000 L of water were used, and 200 L of water were used in the experiment for the cultivation of Nile tilapia larva (O. niloticus) in biofloc technology. The larvae were fed 6 times a day. To maintain the C: N ratio, 15: 1 was fertilized daily with molasses. Physical and chemical variables of water quality were monitored throughout the cultivation. The zootechnical performance of the larvae was evaluated through the variables final weight (g), survival (%), apparent feed conversion factor (FCA), TBI (%. day-1), and daily weight gain (mg day -1). Based on the study results, the zootechnical performance variables did not present significant differences (p> 0.05), however, it was observed that in a biofloc system a protein level below that required by the larvae of 38% of digestible protein presented favorable data for the. cultivation of nile tilapia larva. The results by the water quality analysis showed that the treatments with the different protein levels did not present significant difference in the water quality (p> 0,05). Given the study it was possible to realize that it is possible to cultivate Nile tilapia larvae (oreochromes niloticus) using 30% digestible protein diets in a culture system using biofloc technology.