UTILIZAÇÃO DE Spirulina platensis COMO SUPLEMENTO ALIMENTAR DURANTE A REVERSÃO SEXUAL DE TILÁPIA DO NILO

Abstract

This study aimed to evaluate the influence of S. platensis as a food supplement for Nile tilapia post-larvae. Two trials was running. In the first, was used two treatments, one offered freshwater microalgae (green water) and other offered microalga S. platensis. In the second trial, were evaluated the effect of without copepods, administration of copepods alone and copepods enriched with S. platensis. Throughout the study, all animals were fed diets with masculinizing hormone 17-K-methyl-testosterone. It was evaluated the growth in weight and length, the survival rate and the rate of sex reversal of tilapia (mean +,- SD). In the first trial, the fish that received the S. platensis and receiving freshwater microalgae showed as result, 0.21 +,- 0.042 g; 2.50 +,- 0.091 cm; 97.5 ± 1,00% and 0.11 +,- 0.022 g; 1.91 +,- 0.419 cm; 98.33 +,- 0.70%, respectively. In the second trial, when the copepods were utilized, with and without S. platensis, the post-larvae as result, 0.221 ± 0.008 g; 2.70 ± 0.070 cm; 86.67 +,- 1.03% and 0.211 +,- 0.014 g; 2.56 ± 0.121 cm; 77.50 +,- 1.33%, respectively. The animals that received only commercial had as result, 0.190 +,- 0.008 g; 2.22 +,- 0.215 cm and 79.17 +,-0.21%. Using S. platensis resulted in better growth in weight and length, but did not affect survival and rates of sex reversal Nile tilapia post-larvae of exposed to natural food.