Pharmaceuticals are used extensively in human and veterinary medicine to eradicate or prevent diseases. The residues of these drugs have been detected in aquatic ecosystem; nevertheless, their toxicological effects on Clarias gariepinus have not been critically investigated. In this study, the toxic effects of diclofenac (DCF), a non-steroid anti-inflammatory drug, were studied in C. gariepinus by acute and chronic static renewable bioassay. The 96 h LC50 of DCF to C. gariepinus was 25.12 mg/L. Exposure to acute toxicity resulted in abnormal behavior and mortality of some fish. Compared with the control, chronic exposure of the fish to concentration (1.57, 3.14 and 6.28 mg/L) showed significantly higher mean corpuscular haemoglobin concentration (MCHC), mean corpuscular volume (MCV) and white blood cell (WBC), with significantly lower haemoglobin (Hb), haematocrit, red blood cell (RBC) and mean corpuscular haemoglobin (MCH) with increase in the concentration of the drug. Furthermore, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and glucose values significantly increased while protein levels were reduced (p < 0.05) in serum and gills throughout the 42-day exposure period. The study reports that DCF-induced enzymatic and haematological changes in the fish and recommends that these parameters be used as potential biomarkers for assessing residual pharmaceuticals available in aquatic ecosystem.

The phytochemical and proximate compositions, amino acid profile and characterization of Cannabis sativa leaves, stem and seeds were conducted to provide baseline information on its potent in feed materials for its subsequent utilization in supplementing fish nutrition in aquaculture. Phytochemical analysis of the leaves revealed the presence of alkaloids, flavonoids, cardiac glycosides, resins, terpins and steroids while the proximate composition had elevated levels of 6.87% moisture, 23% crude protein, 19.97% lipid and 11.8% Ash; 18.95% fibre and 39.70% NFE in the stem and 25.36% crude fiber content in seeds. C. sativa leaf contains 9 Essential Amino Acids (EAA), which have good concentration of methionine and lysine. Characterization of the leaf extracts revealed six clearly-pigmented spots with the highest travelled as cannabinol (CBN). The implications of these findings indicate that C. sativa has potential inclusion in fish feeds requirement, ameliorating stress conditions during handling, sampling and transportation as well as possible utilization to anesthetize fish going by the array of the bioactive compounds present in the crude leaf extracts of the plant.

Background: Histopathological changes have been widely used as biomarkers in determining the effects of pollutants on fish. Leaves of Balanites aegyptiaca, a deep-rooted, evergreen or semi-deciduous, multi-branched, spiny tree have been reported to have pesticidal, anaesthetic and ichthyotoxic effects. This study sought to find out the effect of sub-lethal concentrations (5.00, 11.00, 21.00, 43.00, and 86.00 mg/L) of B. aegyptiaca on histopathology of gills, kidney, and liver of mixed-sex Oreochromis niloticus fingerlings Methods: A total of 120 O. niloticus fingerlings (mean weight 23±0.03 g and mean total length 12.50±0.39 cm) were exposed to aqueous crude leaves extract of B. aegyptiaca. The gills, kidney, and liver were excised and processed routinely for the elucidation of histopathological changes Results: Dose-dependent histopathological changes were observed in the three organs (gills, kidney and liver) of O. niloticus exposed to graded concentrations of B. aegyptiaca. Gills showed moderate to severe secondary lamellae fusion, desquamation, and primary lamellae congestion while the kidney displayed mild to severe renal tubular epithelial cell degeneration and necrosis as well as pigmentation of renal tissues. The liver showed varying degrees of histo-architectural alterations such as hepatocellular degeneration and necrosis, cellular infiltrations, kupffer cell proliferation, portal, and sinusoidal congestions Conclusion: Owing to these histological alterations in the gills, kidney, and liver observed in this study, prolonged exposure of fish to B. aegyptiaca should be discouraged to preserve fish diversity

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