Alien species are highly invasive and are a threat to indigenous species. Substantiate
this statement with any three examples.
Alien (exotic) species invasions are:
(i) Some alien species when introduced unintentionally or deliberately, become invasive
and cause harmful impact resulting in extinction of the indigenous species.
(ii) Nile perch, a large predator fish when introduced in lake Victoria in East Africa
caused the extinction of an ecologically unique species of Cichild fish in the lake.
(iii) Invasive weed species like Parthenium, Lantana and Eicchornia caused
environmental damage and posed threat to our native species.
(iv) Introduction of African catfish for aquaculture purposes is posing a threat to the
indigenous cat fishes of Indian rivers.