Aqueous extract of neem leaves have been used on fish-farms to control of fish parasites and fish fry predators such as dragon-fly larvae. Generally, neem extract is considered of low toxicity towards non-target aquatic life. Therefore, the effects of Neem leaf (Azadirachta indica) aqueous extract on catfish were investigated using the histology of intestine, gill and liver, haematological and biochemical parameters as indices. Ninety (90) post-juvenile African catfish (Clarias gariepinus) weighing 42.40 ± 2.50g were used. Experimental groups in triplicate were exposed bi-weekly to 3.5% and 7% LC50 of neem leaf aqueous extract infused in commercial floating feed for four weeks while the control group was exposed to untreated feed. At the end of 4 weeks, blood samples were collected for biochemical and haematological analysis and organs (intestine, gills and liver) were harvested.
The tissues from all the groups showed no visible pathological changes. The haematological indices showed that the packed cell volume (PCV), haemoglobin (Hb) and red blood cell counts (RBC) were higher in the control than the treated groups. The mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and mean corpuscular volume (MCV) were not significantly affected by the treatment. The white blood cell counts (WBC) were significantly (p
Key words: Neem Leaf Extract, Clarias gariepinus, Haematological Parameters, Biochemical indices, Tissues
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