Koi fish Endangered in West Bengal, India

A research team from Calcutta University have found that Sumidon – 40, an organophosphate pesticide, excessively used in paddy fields of West Bengal hampers the reproductive performance of Koi (Anabus testudenius) fish, which prefers to breed in shallow water-logged paddy field during rainy season.

The adverse effects of the pesticide went to the extent that this fish was dubbed as endangered species, the study reveals. The reproductive performance of the fish significantly deteriorated with increase of the period of the exposure of pesticide. The team found that the hatchlings died instantly due to pesticide exposure. Scanning electron microscope showed that the pesticide affected the outer thick layer of mature eggs.