Comparative acute toxicity of chlorofet and thiodan to the amphipod Parhyale basrensis (Salman, 1986) from Iraq

Abstract

The pesticides chlorofet (active ingredient chlorpyrifos) and thiodan (active ingredient endosulfan) are widely used and released to surface waters in Iraq. To determine the potential effects of these pesticides on the aquatic fauna of Iraq, we tested the acute toxicity of chlorofet and thiodan using the talitrid amphipod Parhyale basrensis. Our results indicate that P. basrensis is more sensitive to chlorofet than thiodan. When expressed in terms of the active ingredients, P. basrensis is the most sensitive amphipod species that has been tested to date to endosulfan. In contrast, P. basrensis appears to be of average sensitivity to chlorpyrifos.