The 17α-methyltestosterone is the most common synthetic hormone used in male mono-sex production of Nile tilapia, Oreochromisniloticus. The current study was aimed at finding out the efficacies of 17α methyl testosterone hormone,Carica papaya (pawpaw) and Moringaoleifera(Moringa) seed extracts and Mangiferaindica (Mango) leaves extracts on the sex reversal of newly hatched oreochromisniloticus(Tilapia) for a period of sixty (60) days.A total of 600 fry were randomly allocated to 24 experimental ponds.The hormonal diets were formulated by adding 17α- methyl-testosterone (Tc), Caricapapayaseeds extracted with methane (T1), Caricapapayaseeds extracted with hexane (T2), Moringaoleifera seeds extracted with methane (T3) Moringaoleifera seeds extracted with hexane (T4) Mangiferaindicaleavesextracted with methane (T5), Mangiferaindicaleaves extracted with hexane (T6) and basal feed with neither hormone nor plant extracts as negative control (T7) at an inclusion of 40ml/ kg diet on the treatments .
The fry were fed at 20% body weight during a 30 day feeding trial and a gradual reduction of feed to 10% during the second months rearing period. Results of the growth parameters showed highest weight value of (7.66±0.00 g) in T2 followed by (7.19±0.00g ) in T1, the lowest mean weight value of (5.06±0.01g) was observed in negative control group T7. The maximum length value was recorded as 10.77±0.01 cm in T1, followed by 10.56±0.01cm in T2, followed by 9.96±0.00 cm in TC (positive control). The lowest length value was recorded as 6.99±0.01cm in T7 (negative control).The highest value of SGR (%) occurred at (11.07) from T2 followed by T1 (10.96) and T7 recorded the lowest SGR with (10.37). The maximum survival rate (97.88±2.25) was observed in the negative control group (T7), survival rate of 95.79±3.29 was observed in TC (positive control) and (96.50±2.26) in T1. However, there were no significant differences (p>0.05) in the survival rates among the treatment groups. The results of the physicochemical parameters showed no significant differences (p>0.05) among all the treatments and the results were within the recommended ranges for the growth and survival of O. niloticus(Table 2).Results from the gonad examination (Table 3) revealed that Nile tilapia fry fed with 17α methyl testosterone hormone diet (Tc) produced the highest phenotypic males of 87%, while T1,T2,T3, T4, T5, T6 gave males of 80%,77%,73%,69%,60%,63% and 27% respectively.
Further studies are required to understand the exact mechanism through which the Pawpaw and Moringa seeds and Mango leaves exert their effect of sex differentiation innewly hatched O. niloticus.
Keywords:Efficacies, growth parameters,Nile tilapia, physicochemical parameters 17α methyl testosterone hormone, Sex reversal.