Vol. 9 No. (1): 50- 669 (2018): BIOCHEMICAL AND PHYSIOLOGICAL RESPONSES OF HETEROCLARIAS AND RAT FED ON CONTAMINATED HETEROCLARIAS TO DIESEL OIL-INDUCED STRESS

Impacts of sub-lethal concentrations of water soluble fraction of diesel-oil (WSFD) on
biochemical and physiological responses of hybrid catfish, Heteroclarias and rats fed on
contaminated-Heteroclarias-were investigated. Heteroclarias was assessed in a static
renewal bioassay for 28 days using varying concentrations (0.00, 15.63, 31.25, 62.50,
125.00, and 250.00 ppm) of WSFD, while rats were fed with diet compounded with WSFDcontaminated-Heteroclarias for 30 days. The WSFD-exposed fish and the WSFDcontaminated-Hetroclarias-fed rats were sacrificed, blood samples were collected and the
gill and liver of the fish as well as the liver and kidney of the rat were removed for assay. In
both animals, red blood cell, haemoglobin, packed cell volume, protein and glucose
decreased, while the white blood cell increased compared to the control. Serum activities of
alanine aminotransferase, aspartate aminotransferase and superoxide dismutase
significantly increased in WSFD-exposed Heteroclarias and WSFD-contaminatedHeteroclarias-fed rat, while the enzymes’ activities were inhibited in the gill and liver of the
fish and liver and kidney of the rat. Lactate dehydrogenase activity decreased in the serum
of both WSFD-exposed Heteroclarias and WSFD-contaminated-Heteroclarias-fed rat but
increased in the gill and liver of WSFD-exposed Heteroclarias and liver and kidney of
WSFD-contaminated-Heteroclarias-fed rat. There was a significant (P < 0.05) reduction in
the specific growth rate of WSFD-exposed Heteroclarias and rat fed WSFD-contaminatedHeteroclarias as the concentrations increased. Therefore, toxic effects of diesel-oil on
aquatic organisms should be monitored, so as to ensure safety, survival and sustainable
exploitation of healthy fish as well as prevent risk of health disorder in fish consumers.