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The ichthyofauna diversity of the Jebba Hydroelectric Power (HEP) Dam, Jebba, North-central Nigeria was studied. Fishes were sampled for 24 months using gill net, hook and line, and cast net. Individuals were identified using morphological and molecular (mitochondrial Cytochrome c Oxidase subunit I) data. A total of 9605 freshwater fishes were recorded during the sampling period. The use of an integrative taxonomic approach enabled the identification of 83 species belonging to 42 genera. Additionally, the study recorded three unidentified species – Ctenopoma sp, Malapterurus sp., and Protopterus sp. Analyses showed that individuals belonging to families Cichlidae and Mochokidae dominated the dam. The diversity analyses revealed relatively high fish diversity during the rainy season at the downstream section of Jebba HEP dam compared to the upstream section. The study, therefore, showed the presence of a diverse fish community comprising high species richness and diversity across the Jebba HEP dam. Finally, we recommend proper biodiversity monitoring and assessment of freshwater fish diversity across Nigeria. In addition, the use of an integrated taxonomic approach is recommended for appropriate species’ identification and studies of freshwater fishes from Nigeria.

Pollution of water bodies in most developing countries is of grave concern since toxic pollutants interact with the genetic blueprints of aquatic organisms leading to a variety of illnesses. In this study, histological changes in the gills, liver and kidney as well as the genotoxic effect of water sample from Apodu reservoir, were investigated in the peripheral erythrocytes of cultured catfish (Clarias gariepinus) using micronucleus assay. They were exposed to the water sample for a period of 3, 7 and 14 days. The physico-chemical (pH, temperature, transparency) and heavy metals analysed (Ca>Mg>Fe>Zn>Mn>Cu>Ni=Pb=Cd=Cr) were all within the acceptable limit permissible. However, the micronucleus test shows statistically significant (p<0.05) induction of micronuclei and nuclear abnormalities as compared to the control (borehole water). The histopathological analysis shows some mild alterations in the organs such as distortion and infiltration of lymphocytic cells of the gills. We also reported mild distortion of hepatic tissue of the liver as well as abnormal nephron and glomeruli with congestion and vascular dilation of the kidney. These alterations might be due to anthropogenic activities that pollute the water body. Therefore, the influx of agricultural and domestic waste into the Apodu reservoir should be discouraged as part of remediating efforts.

Drug resistance in malaria infection is a serious public health challenge. Thus, scientific search for alternative treatment measures among the local medicinal plants is exigent. We therefore investigated the anti-plasmodial efficacy and genotoxicity of the methanolic leaf and stem extracts of Alstonia plant at varying concentration (200 mg/kg, 400 mg/kg and 600 mg/kg) in mice infected with chloroquine sensitive Plasmodium berghei. The phytochemical screening of the extract revealed that leaf sample contained significantly higher secondary metabolites, except saponins (p<0.05). Anti-plasmodial activities of the two extracts were duration and dose-dependent. Stem bark extract showed higher curative potential with inhibition rate of 56.71% at 400 mg/kg whereas, leaf extract was efficient at 600mg/kg with 52.15% inhibition rate. Stem bark extract at 400 mg/kg improved the enzymatic activities of the mice; it lowered serum ALT (6.88±4.42) and increased liver ALT (41.07±5.56). Similarly, 400 mg/kg leaf extract showed highest AST (70.65±4.00) and ALT (44.65±7.83) activities in the kidney and liver respectively. Analysis of genotoxicity revealed that micronucleus and abnormal (binucleated, notched and blebbed) were prevalent among the experimental mice which increased significantly (p<0.05) at all concentrations except at 600mg/kg leaf extract. Therefore, this present study indicates that both leaf and stem bark extracts of A. boonei possess anti-plasmodial activity and are less genotoxic when compared with standard drug.