Studies on the Injection of Heterobranchus bidorsalis Adults with Different Concentrations of Bonny-Light Crude Oil and its Effects on Total Bilirubin Enzyme Concentration

Abstract

The activity of birlirubin enzyme in Heterobranchus bidorsalis adults ( mean weight , 130.80±0.36g), when injected with different concentrations of  Bonny-light crude oil (BLCO) was studied within 4 days  toxicity and 42 days recovery periods. Significant decreases (P <0.05; P <0.01) in the values of total bilirubin enzymes concentrations (BEC)(mg/100ml) were recorded in the fish liver serum  as the BLCO concentrations increased from 10.00 to 50.00μl.g^-1. Fish  samples injected with 10.000 μl.g^-1 BLCO recorded  the highest values of BEC than those injected with 20.00-50.00 μl.g^-1BLCO. Increases in BEC values during the recovery period at day 14(23%), day 28 (15%) and day 42(5%) suggested some measure of relief on the liver tissues from  oil toxicity and were a reflection of the tremendous effects of the oil injections on the activities of the bilirubin enzymes within the liver. This result is consistent with the suggestions by other workers on the necessity for a comparative monitoring of biomarkers and pathological changes in liver tissues in order to use good enzymatic markers as indicators of organ dysfunction. The BEC values in this study: whether on decreases due to increasing BLCO concentrations or on increases due to fish recovery from oil injections point to the fact that bilirubin enzyme activity in the fish livers was dose dependent. This result shows that bilirubin enzymes has the potential of a biomarker for monitoring pollution levels.