HISTOLOGY OF GONADS IN Tilapia zillii (GERVAIS) FED
NEEM (Azadirachta indica) LEAF MEAL DIETS
Temitope JEGEDE1 and Oyedapo FAGBENRO2
1Department of Forestry, Wildlife & Fisheries, University of Ado Ekiti, Ado Ekiti, Nigeria.
2Department of Fisheries & Aquaculture Technology, Federal University of Technology, Akure, Nigeria.
Neem (Azadirachta indica) leaf meal (NLM) was added to a basal diet at 0, 5, 10, 15 or 20 g/kg diets and fed to mixed-sex Tilapia zillii for 60 days to evaluate the effects on histology of the testes and ovaries. Male T. zillii fed 0g NLM/kg diet showed normal testicular tissues; and no pathological lesions occurred. Fish fed 5g NLM/kg diet showed alteration in testicular architecture and cystic seminiferous tubules. Fish fed 10g NLM/kg diet showed severe testicular atrophy. Fish fed 15g NLM/kg diet exhibited cystic seminiferous tubule and atrophy of tissue. Fish fed 20g NLM/kg diet showed severe tissue atrophy, sperm cells disintegration and necrosis. Female T. zillii fed with control diet (0g NLM/kg diet) showed normal ovary histology and no pathological lesions were observed. Typical bilateral lobes of the ovaries were evident and with normal olive green colour of ovaries. Fish fed 20g NLM/kg diet revealed ovarian colour change. There was evidence of hydropic degeneration, ruptured follicle, granulomatous inflammation in the insterstitium and necrosis. Histological observations of testes and ovaries in T. zillii fed high dietary NLM levels revealed that neem leaves may be effective as sterility-inducing agents as they were destructive to tissues of testes and ovaries.
Medicinal plants have successfully been used to induce sterility in laboratory animals (Gary & Garg, 1971; Bodharker et al., 1974; Das, 1980). Neem tree (Azadirachta indica A. Juss) is a large evergreen tree with edible fruits and aromatic leaves. A mature tree can produce 350 kg of leaves a year. Neem has been used worldwide in traditional