The fingerlings of Clarias gariepinus of 2.620 ± 0.370g and 6.480 ± 0.598cm weight and length were exposed to a Cypermethrin, Deltamethrin and Cyhalothrin insecticide at 0.0045, 0.0085, 0.0110, 0.0125 and 0.015ml/L in triplicates with a control (0ml/L) for 96hours. Some haematological parameters and blood performance (BP) were assessed to determine the ‘health status’ of the fish. The growth performance of the survivor fish from the exposure concentrations two weeks after exposure were also evaluated based on some growth parameters- mean weight gain (WG), specific growth rate (SGR%), relative growth rate (RGR%), and condition factor (K). The means ± SD of data obtained were determined and analyzed using One-way ANOVA. Results showed that the variations (at p<0.05) in the values of the parameters analyzed were concentration-dependent. The red blood cells, haemocrit, haemoglobin, mean corposular haemoglobin counts reduced with increase in concentration while the white blood cells, lymphocytes, eosinophils counts, and mean corposular haemoglobin concentration reduced with increased concentration, the basophils and monocytes counts were also affected. The BP values reflected the negatively impacted physiological condition and ‘health status’ of the fish. The growth performance premised on the WG (1.20±2.580 – 6.02±4.820g), SGR (11.06 – 22.68%), and RGR (54.9 – 217.46%) gave values that were comparatively better with increased concentration, than the control (2.29±2.772g, 14.96% and 109.56% respectively) which implied good recovery of the survivor fish. The K value, indication of the state of well-being of the fish had values from 0.69 – 1.60 from the concentrations while the control was 0.50, indicative of better well-being in the survivors with the removal of the toxicant.
Keywords: Clarias Gariepinus, Pyrethroid insecticide, blood parameters
