Control of Reproduction in Oreochromis niloticus (Linnaeus 1758) Using Hibiscus Rosa-sinensis (Linn.) Leaf Meal as Reproduction Inhibitor

Abstract

Hibiscus rosa-sinensis leaf (HLM) was added to a basal diet (350g crude protein and 18.5MJ gross energy/kg diet) at 0, 1.0, 2.0, 3.0 or 4.0 g/kg diets and fed to mixed-sex Oreochromis niloticus for 60 days to evaluate the effects on growth, feed conversion ratio, reproduction traits, and histology of gonads. There were no variations (p >0.05) in growth parameters and feed conversion ratio. Indices of reproduction traits decreased with increasing dietary HLM levels. Fish fed with the basal diet had higher and better indices of reproduction traits (P<0.05) than the fish fed with HLM diets. Fish fed 0g HLM/kg diet showed normal testicular and ovarian tissues, and no lesions were observed. Fish fed 1.0g HLM/kg diet showed slight increase in interstitial cells in testes. Fish fed 2.0g HLM/kg diet showed swollen spermatids nuclei, increased interstitial cells and focal necrosis in testes; and hydropic degeneration, ruptured follicles, granulomatous inflammation in the insterstitium and necrosis in ovaries. Fish fed 3.0g HLM/kg diet exhibited atrophy of seminiferous tubules in testes. Fish fed 4.0g HLM/kg diet, there was disintegration of spermatids and necrosis in testes and severe atretic follicles in ovaries. Reproduction traits and histological observations of gonads in O. niloticus fed high dietary HLM levels revealed that Hibiscus rosa-sinensis leaves may be effective as a reproduction inhibitor in O. niloticus.