Ecotoxicological assessment of commercial glyphosate-based di-ammonium salt formulation on haematological indices of <i>Clarias gariepinus</i>

Abstract

The study evaluated sub-lethal toxicity of commercial glyphosate-based Di-ammonium formulation commonly known as ‘Touchdown’ on haematological profile of Clarias gariepinus juveniles. A total of two hundred catfish juveniles of mean weight 31.07±1.23g and mean length 19.50 ± 0.50cm were exposed to different  concentrations of Di-ammonium formulation (1.26, 2.52, 5.03 and 0.00 mg/l) for eight (8) weeks. Each concentration was treated in triplicate using a static bioassay system. Physico-chemical parameters of the test water were monitored throughout the study period. Results showed that haematocrit (HCT), red blood cell (RBC), haemoglobin (HGB), Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH), Mean Corpuscular Haemoglobin Concentration (MCHC) and Platelets (PLT) counts decreased significantly (p<0.05) with increase in concentrations of Touchdown. Whereas, white blood cell (WBC) counts increased significantly (p<0.05) with increasing concentrations of the glyphosate-based formulation. Water temperature, pH, Total dissolved solid (TDS) and electrical conductivity (EC) increased linearly with increasing concentration, while dissolved oxygen content decreased significantly (p<0.05). The results from this study indicated that Di-ammonium glyphosate–based formulation had negative consequences on the blood of treated fish. In view of this, the application of Di-ammonium glyphosate-based formulation should be done in a sustainable manner with proper regulations.