Nile perch introduced into lake Victoria East Africa led to the extinction of Cichlid fish.
Parthenium / Lantana / Eichharnia invasive plants and pose a threat to indigenous species.
Introduction of African catfish (Clarias gariepinus) to aquaculture is threat to Indian catfishes.
Detailed Answer :
The Nile perch introduced into Lake Victoria in east Africa led eventually to the extinction of an ecologically unique assemblage of more than 200 species of cichlid fish in the lake.
Since, cichlid fish became extinct and so the Nile perch, not finding any food for itself, died too.
The environmental damage caused and threat posed to our native species by invasive weed species like carrot grass (Parthenium), Lantana and water hyacinth (Eichhornia). The recent illegal introduction of the African catfish Clarias gariepinus for aquaculture purposes is posing a threat to the indigenous catfishes in our rivers.
