I am Suman Mallick, a PhD Scholar pursuing my doctoral degree from Ahmedabad University in the field of ecology. Introduction of exotic species is an age old technique for the purpose of biomonitoring of pests. For example, Gambusia sp. were introduced to control the population of mosquito larvae. But in predator free non-native environments, these exotic species compete for food and space with indigenous species. Exotic species being bolder, proliferative breeder easily conquer large territory pushing the native species on the verge of extinction. My study focuses on various interactions between a native and an exotic species when introduced in a non- native environment. I am working with Sailfin Catfish (Pterigoplichthys sp.), one exotic species native to Amazon basins which has been introduced to India for algae scavenging ability that prevents harmful blooms in pond.