EFFECT OF PAWPAW SEED (CARICA PAPAYA) AS ANTIFERTILITY AGENT IN FEMALE NILE TILAPIA (OREOCHROMIS NILOTICUS)

摘要

To determine if pawpaw seed (Carica papaya Linn.) could induce sterility in Nile tilapia and whether the sterility so induced was reversible or not, matured female fish of mean weight 40 g were treated for 30 days with a low dose of 4.9 g/kg/day and ahigh dose of 9.8 g/kg/ day of ground pawpaw seeds incorporated into the feed. The pawpaw seed induced permanent sterility in fish that received high dose whereas in the low dose treatment sterility was temporary and reversible. Fish in the control experiment spawned two weeks into the experiment and again the fifth week into the study. Fish in the low dose treatment spawned three weeks after the treatment was discontinued. The number of fry produced in the low dose treatment was less than that in the control experiment. Histological sections of the ovary showed that pawpaw seed acted to produce necrotic and disintegrated cells in the ovary. The study had shown that pawpaw seed, which is affordable and easy to obtain, can be incorporated into feed andused to control prolific breeding in Nile tilapia by fish farmers.