Effect of Atrazine on Some Immunological Indices of Grass Carp (Ctenopharhyngoden idella), Iran

The chronic toxicity effects of atrazine (herbicide) on some immunological indices of Grass Carp (Ctenopharhyngoden idella Staindancher, 1866) were studied by exposing them to sublethal doses of atrazine such as 0 µg, 10 µg, 100 µg, 1000 µg and 10000 µg per liter of water for a period of a month. Doses of atrazine up to 100 µg/L did not show any significant toxicity. In contrast, atrazine doses of 1000 and 10000 µg/L significantly increased toxicity effects on the studied Grass Carp. The highest mortality rate (100%) was observed at doses of 10000 µg/L and 1000 µg/L on the 10th and 20th days respectively. Cytological analysis showed that the white blood cells (WBC) and red blood cells (RBC) were changed significantly (p < 0.05) in many different treatments. Differential count of Leucocytes showed that lymphocyte cells were significantly decreased with the increase of atrazine doses and days; whereas, neutrophile cells were significantly decreased with the increase of atrazine doses and days. Eosynophle cells were not observed. IgM levels significantly decreased with the increase of doses of atrazine and days and reached to the minimum level at dose of 10000 ?g/L. The present study concluded that exposing Grass Carp to doses of atrazine of 1000 µg/L and 10000 µg/L induced significant effects on some immunological indices on the 20th and 10th days of a month respectively. Hence, the obtained results showed the atrazine had a toxicity effect on the immune system of the Grass Carp.