The species confined to a particular region and not found elsewhere is termed as :
Alien
Endemic
Rare
Keystone
Endemism -
Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type;
- wherein
organisms that are indigenous to a place are not endemic to it if they are also found elsewhere.
Option 1)
Alien
Incorrect option
Option 2)
Endemic
correct option
Option 3)
Rare
Incorrect option
Option 4)
Keystone
Incorrect option