ASSESSMENT OF TOXICOLOGICAL EFFECTS OF GUAVA (PSIDIUM GUAJAVA) LEAF EXTRACT ON THE HISTOPATHOLOGY OF GILLS AND LIVER OF CLARIAS GARIEPINUS FINGERLINGS

This study evaluates the toxicological effects of ethanolic extract from Psidium guajava (guava) leaves on fish with the aim of understanding the toxic effects of the plants. The experiment involved exposure of the test organism (C. gariepinus) to varying concentrations of the extract, with a control group to compare in two batches. Prior to commencement of actual toxicity studies, a preliminary finding test for safe concentration was conducted. Ten (10) experimental aquarium were used with ten (10) fingerlings stocked in each aquarium both batches A and B. Fingerlings of C. gariepinus was exposed to varying concentrations of (0, 8, 12, 16 and 20) mg/l concentrations of the extract. Mortality was monitored on 24 hours basis. The results of preliminary showed lethal effects of the extract, hence the concentrations for the final bioassay were reduced to (4, 6, 8 and 10) mg/1 concentrations of the extract. Results showed a concentration-dependent increase in fish mortality, with no effect observed in the control group. Statistical analysis using one-way Anova showed no significant difference between the two batches. Water quality parameters, including pH, dissolved oxygen (DO), and temperature, exhibited significant variations across treatment groups at different time intervals (24, 48, 72, and 96 hours). Histopathological examination revealed moderate to severe pathological changes in gill and liver tissues as concentrations increased. Behavioral abnormalities, such as attempts to jump out, gasping for air, and erratic swimming, were observed in the exposed fish. The study underscores the importance of proper dosage assessment when considering plant extracts for aquaculture applications.