Exotic species are defined as species that have been introduced from another geographic region to an area outside its natural range.
For example,
i. Parthenium, Lantana and Eichhornia are the exotic species of plants that have invaded the native species of India and caused environmental damage.
ii. Introduction of African catfish Clarias gariepinus for aquaculture purpose is posing threat to many indigenous catfish.
iii. Nile perch introduced into lake Victoria in East Africa led to the extinction of cichlid fish.
