Desempenho de diferentes linhagens de tilápia do Nilo (Oreochromis niloticus) na fase de reversão sexual

Abstract

This experiment aimed at comparing growth performance and survival of four Nile tilapia (Oreochromis niloticus) strains called CESP, Pernambuco, Santa Catarina and Thailand in sex reversal phase. Thirty Nile tilapia fries were stocked in 4.5Ć aquaria (6.66 fries/Ć) with recirculation system and water temperature control. The fishes were fed with ration containing 60mg/kg of 17 alpha-methyltestosterone, six times a day during 30 days. The experimental design was randomized with four treatments (strains) and seven replications. Total length, weight gain, specific growth rate, survival rate and sexual reversion efficiency were submitted to Anova, means compared by Tukey test and sex reversion by qui-square means. Santa Catarina and Pernambuco strains demonstrated better sex reversion efficiency when compared with CESP and Thailand. Thailand and Santa Catarina strains showed better values of survival, growth performance and specific growth rate than CESP and Pernambuco strains. Thus, Thailand and Santa Catarina strains are more indicated to rear in recirculation system during sex reversal phase.