Tissue analysis of <i> Clarias gariepinus</i> juveniles injected with different concentrations of crude oil

Abstract

Aspects of tissue analysis of Clarias gariepinus juveniles (90.60 ± 0.24g) were studied following injection of different concentrations of Bonny light crude oil (BLCO). Experimental fish were injected at concentrations: 0.00, 25.00, 50.00 and 75.00 μlg^-1 to test fish responses during 4 days toxicity and 42 days recovery periods. A control experiment was left with fish not injected with BLCO. A 38% crude protein diet was fed to the fish at 3% body weight per day (p.w.d^-1) during the toxicity and 5% during the recovery period. The protein value (PV) increased as the BLCO concentration increased up to 75 μlg^-1 at recovery phase and vis-versa at toxicity phase. This could be due to immune response mechanism which eventually dropped at recovery phase. The starch value (SV) and unsaponification values (USPV) were not affected, the saponification value (SPV) only increased between 25.00 and 0.0 μlg^-1 and declined at 75 μlg^-1. The decrease in values of SPV in treated fish tissues has implication on energy metabolism. Of the four tissues values (PV, SV, SPV and USPV) of fish tested, only the USPV was not significantly different (P > 0.05) among the fish injected with the different concentrations of BLCO. The 0 and 25 μlg-1 has the same effect on mortality rate. Similar mortality values of the fish recorded with the 25 μlg-1 BLCO and the control suggests that this oil dosage was probably inadequate to alter the mortality rates of C. gariepinus juveniles. The survival rates increased with decreasing concentration.

Keywords: Tissue Analysis, Bonny Light Crude Oil, Mortality, Survival

Animal Research International (2012) 9(2): 1567 – 1571