Growth and mortality rates histopathology effects of water soluble fraction of Bonny light crude oil on the African catfish, clarias gariepinus

Abstract

Chronic toxicity test of Water Soluble Fraction (WSF) of crude oil (Bonny Light Crude) was carried out to determine its effect on the African catfish, Clarias gariepinus. Effects such as growth rate, mortality rate histopathology of the fish were investigated. The fish was subjected to graded levels of concentration of WSF of the Bonny Light Crude oil in six different tanks namely 5.0ppm; 10.0ppm; 15.0ppm; 20.0ppm; 25.0ppm and 30.0ppm of toxicant respectively. Tank 7 is the control having 0.0ppm of the toxicant. The results indicated a retarded growth rate when compared to the specific growth rate (SGR) of the control which stands at 38.2% and 48.7% for Total length and Standard length respectively. Where those exposed to 5ppm had (31.2:40.2), 10ppm (28.3:35.1), 15ppm (23.1:29.5), 20ppm (23.8:23.8), 25ppm (20.1:19.4),30ppm (10.8:13.9) respectively. The specific growth rate showed similar trend as that for length. The result shows that those exposed to 5ppm of toxicant (67.8%) weight gain; 10ppm (48.6%) ,15ppm (44.2%) ,20ppm (30.9%), 25ppm (19.7%) ,30ppm (18.8%) respectively. This when compared to the control of (104.2%) gain is a great decrease in growth performance. The summary of the results indicates detrimental effect of the toxicant on the Clarias gariepinus both at low concentrations and at high concentrations of WSF of Bonny Light Crude Oil.