Effects of nicosulfuron herbicide on the haematological profile and behaviour of juvenile <i>Clarias gariepinus<i/> (Burchell, 1822)

Abstract

The challenges faced by Freshwater fish are enormous especially those that occur as a result of Agricultural intensification, through constant discharge of wastes into aquatic environment which led to accumulation of heavy chemicals and other variety of pollutants. Herbicides present in these wastes are washed down, carried by rains and flood to nearby aquatic environment. This study has determined the hematological effect of exposure of the juvenile African Catfish (Clarias gariepinus) to varying acute concentrations of Nicosulfuron herbicide for 96hr using static bioassay. Healthy180 pieces active fish of mean weight 13.6-46.1g and11.00-20.00 cm length were randomly distributed into five concentrations of Nicosulfuron herbicide and control (0.0, 1.5, 1.625, 1.75, 1.875 and 2.0 ml) in triplicates of ten fish per tank. Data obtained were analyzed for descriptive statistics (mean and standard error of means) and further subjected to analysis of variance (ANOVA) at P< 0.05 using Minitab. There was an increase in WBC (6.00 ± 2.83 - 8.55 ± 7.78 (10³/mm³), PCV (27.00 ± 2.00 - 36.67 ± 1.53 %), Hb (9.03 ± 0.75 - 12.23 ± 0.60 g/d), MCV (108.57 ± 3.39 - 128.47 ± 6.00 FL) and MCH (42.53 ± 1.11 - 48.83 ± 4.91 pg) with increase in concentration while MCHC decreased with increase in concentration. The result shows no significant difference in RBC and MCHC. The study therefore, concluded that toxicity could be of low impact when compared to other toxicants but the bioaccumulation effect can be hazardous and this finding can serve as baseline information to develop models on effects of Nicosulfuron herbicides on ecological characteristics of aquatic environment. It can also be as an index of toxicity in water to determine the health of an aquatic organism.