A study was carried out at the National Aquaculture Research and Development Centre (NARDC) Fish Farm (12°49’0” South and 28°12’0” East), in Kitwe district of Zambia , to evaluate the effect of 17α-Methyltestosterone on the growth performance of fry of Oreochromis andersonii , Oreochromis macrochir and Oreochromis niloticus raised for a period of ninety days. The first 21 days, the fry (0.04g± 0.001) across all treatments were fed on commercial feed incorporated with 17α-Methyltestosterone for the purpose of achieving sex reversal to all males and were held in 1m x 1m x 1.3 m hapas installed in a 400 m2 semi concrete pond, at a stocking density of 250 fry per hapa and replicated three times in a completely randomized design. There were no significant differences (P>0.05 ) between the growths (weight gain) of sex reversed fingerlings treated with 17 α Methyltestosterone for 28 days and later fed on a commercial feed for a period of 60 days as indicated in Table 1
Note: IW – Initial weight; FBW – Final body weight; BWG – Body weight gain; FSL – Final standard length; SGR – Specific growth rate; AFCR – Apparent feed conversion ratio; SR – Survival.
These results indicate that the effect of 17α-Methyltestosterone on the growth of fry of the three species produce similar results. Therefore, the study has demonstrated that these species can substitute the other and still produce similar results, hence a farmer having a wider choice to select from and as well as for the hatchery managers information.
Key words: Aquaculture; 17α Methyltestosterone ; Oreochromis species; Feed conversion ratio