Adekunle David Micah, John Ameh Adakole, Abdullateef Yusuf, Ndagi Abubakar Mohammed
The toxicity effect of glyphosate on fingerlings of Heteroclarias after series of range finding tests, the fishes were exposed to lethal concentration of 0.00 mg/L, 5.40 mg/L, 7.20 mg/L, 9.00 mg/L, 10.80 mg/L and 12.60 mg/L for 96 hours in a renewal bioassay procedure showed that the 96 hours LC50 was 6.838 mg/L. Respiratory disturbance, erratic swimming, loss of equilibrium, lethargies and sudden fish death were observed in the exposed fish and these varied greatly with differences in concentration of the toxicant and this shows that mortality increases with an increase in concentration. Also, as the concentration of glyphosate increased the beats of the tail and operculum increased in 12 and 24 hours. Also the toxicant led to significant changes (P<0.05) in hematological parameters as the toxicant concentration increased. Mean Red Blood Cells (RBC), Hemoglobin content (Hb), Packed Cell Volume (PCV), reduced as the concentration of toxicant increased while other parameters increased proportional with the toxicant concentration. Others, such as Basophils, Eosinophils and Monocytes were tested but not detected.