Q.What is the difference between endemic and exotic species?

The key difference lies in where a species is naturally found and how it arrived there.

An endemic species is one that is found only in a specific geographical area and nowhere else on Earth. It is native and restricted to that particular region, often due to geographic isolation or unique ecological conditions — this is exactly the property ('high degree of endemism') that conservationists use, along with species richness, to identify biodiversity hotspots such as the Western Ghats. …

The distinction between endemic and exotic species is a fundamental concept in biogeography and ecology, and it hinges entirely on the natural geographic origin of a species. The NCERT textbook for Class 12 Biology (Chapter 13, Biodiversity and Conservation) discusses both ideas in the context of biodiversity patterns and conservation.

An endemic species is one that is found exclusively in a particular region or habitat and nowhere else on Earth. These species have evolved in isolation, often on islands, in mountain ranges, or in other geographically bounded areas. The textbook uses this very property — a high degree of endemism, meaning species confined to a region and not found anywhere else — as one of the two criteria (along with high species richness) used to identify 'biodiversity hotspots' for conservation. Three such hotspots (Western Ghats and Sri Lanka, Indo-Burma, and the Himalaya) cover India's exceptionally high biodiversity regions. Endemism is therefore a measure of uniqueness — the more endemic species a region has, the more irreplaceable its biodiversity is.

An exotic species (also called an alien, introduced, or non-native species) is one that has been brought into a new area outside its natural range, usually through human activity — either deliberately (for agriculture, horticulture, aquaculture, or pets) or accidentally. The NCERT textbook gives concrete examples: the invasive weed species carrot grass (Parthenium), Lantana, and water hyacinth (Eichhornia), all of which cause real environmental damage in India, and the African catfish Clarias gariepinus, illegally introduced for aquaculture, which now threatens indigenous catfishes in Indian rivers.

Anchor each term to a single axis — geographic origin, not abundance or harm: ask whether the species evolved here or was brought in from elsewhere. Endemic answers 'evolved here, found nowhere else'; exotic answers 'ar …