Abstract: A study was conducted to determine the possible sex inversion effect of lyophilized goat testes meal on hatchlings of `Wesafu`. Eighty-five fish and a control group were treated with the meal for forty days in an indoor facility and subsequently transferred into outdoor cages and monitored for growth, the result of manual sex ratio was not conclusive and gonad examination for sex ratio determination has been suspended until fish are big enough. Some mortalities (35%) were recorded during the treatment periods while the control group was intact (100%). The chemical composition of goat testes meal revealed a useful 47% protein and 1.23% oil and a good complement of mineral elements. After the initial 25day exposure of fish to GTM, there was no noticeable length difference (2.9cm) as compared to the control group (3.5cm). The lengths were also similar at 6.03cm and 6.07cm for GTM and the control group respectively after 25 days in outdoor green water culture. There were some non statistical differences in both weight and length of fish in the two groups with the test group clearly showing improvements in terms of length and weight indicating the influence of male hormone (testosterone in GTM) in maleness of the test group.