Azinphos-methyl causes in Planorbarius corneus toxic effects on reproduction, offspring survival and B-esterases depending on the exposure time.

This work aimed to study in the freshwater gastropod Planorbarius corneus the effects of acute (2 days) and subchronic (14 days) exposures to an environmental concentration of the organophosphate azinphos-methyl on different reproductive parameters, offspring survival and B-esterase activities in gonads and in the whole organism soft tissue. The acute exposure inhibited only carboxylesterase activity in both tissues while the subchronic exposure also inhibited cholinesterase activity, decreased the number of hatched-eggs and increased offspring lethality (92%). On the other hand, B-esterases in gonads were more effective biomarkers than B-esterases in the whole organism due their inhibition appeared earlier in time (cholinesterase activity) and their activity remained inhibited for a longer time (carboxylesterase activity) when recovery studies were performed.

Different effects of subchronic exposure to low concentrations of the organophosphate insecticide chlorpyrifos in a freshwater gastropod.

Chlorpyrifos is an organophosphate insecticide used for pest control on a number of food crops in many parts of the world. In recent years, there has been an important decrease in the number of organisms of Planorbarius corneus. Since the presence of pesticides in the water can be one of the reasons for this decrease, it is very important to study the effect of subchronic exposure to environmental concentrations of pesticides on these organisms.