Abstract
This study aimed to investigate the effect of temperature at 35 ° C, but soon after hatching of the larvae, on the effectiveness of sex reversal. For this used two treatments (Group I. Heat Treatment; Group II. Control). The gonads of the fish were examined microscopically for the sex ratio thirty days after water heat treatment. The male ratio was 82.66 and 42.10% for the Group I and II, respectively. Significant differences were found (p <0.0001) between the groups, for both body weight and total body length. Intersex fish was not detected. Significant difference was found in sex ratio, indicating the presence of a "thermo-sensitivity" feature in the species. It was conclude that the application of a high temperature during the initial phase of post larvae can induce offspring monossex males, with a ratio over 80%, which means a potential alternative to the sex reversal of tilapia by means of androgenic hormones.
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