Toxicity of unripe Ackee apple (Blighiasapida) fruit extract on Clarias gariepinus fingerlings

The study was conducted to determine the toxicity of unripe Ackee apple (Blighiasapida) fruit extract on catfish, Clarias gariepinus fingerlings using the 96-hour bioassay under laboratory condition. The LC50 was determined graphically as 3.00ppt. Mean mortality was 0, 40, 50, 70 and 80% in the concentrations of 0, 3.33, 3.47,3.60 and 3.73ppt. Statistical analysis of the results showed that there were significant differences (P<0.05) on the effect of concentration. Mortality increased with increase in concentration of toxicant and duration of exposure. Clarias gariepinus showed erratic swimming pattern, loss of reflex which increased with increase in concentration. Histopathological changes were revealed in the gills, skin and heart of the fish. The gill structure was altered and there were moderate mucosal erosion. There were several lymphoid aggregations with fibrous connective tissue at the dermal and epidermal areas in the skin. The heart myofibre were diffusely disintegrated with edema between bundles.