Aquaculture Studies 2019, Vol 19, Num, 1     (Pages: 01-07)

Evaluation of Histopathological Effects of Sub-lethal Concentrations of Chloramphenicol Antibiotic on the Gill of Clarias gariepinus Juvenile (Burchell, 1822)

Jude S. Awoke 1 ,Peter J. Nkwuda 1

1 Ebonyi State University, Department of Fisheries and Aquaculture, P.M.B. 053 Abakaliki, Nigeria DOI : 10.4194/2618-6381-v19_1_01 Viewed : 669 - Downloaded : 334 An investigation on the effect of Chloramphenicol on the gill tissues of Clarias gariepinus juveniles was carried out in the laboratory using static renewal bioassay techniques. Two hundred and seventy fish with length 7.39±39cm and weight 12.37±65g were exposed to sub lethal concentrations of chloramphenicol for 70 days. The gills were removed for histopathological examination. The observed histopathological changes in the gills were occlusion of tubular lumen, congestion of blood vessels, degeneration of primary and secondary gill lamellar, fragmentation of central axis, lamellar fusion and degeneration of epithelial and marginal cells in the test organs. The severity of the lesions along the concentration gradients was observed to be proportional to dosage. The effect was most severe at the highest concentration (12.5 mg/l). The observed abnormalities in the gills of Clarias gariepinus juveniles exposed to chloramphenicol shows the suitability of Clarias gariepinus in the toxicity testing of antibiotics. Keywords : Bioconcentration, Bioaccumulation, Congestion, Bioassay, Edema, Capillary