The correct term that scientists use for a species that enters a new region where it has never existed before and begins to thrive at the expense of other species that originally existed there is "C. invasive species."
Explanation:
1. Invasive species are non-native species that are introduced to an ecosystem where they did not evolve naturally.
2. These species have the ability to outcompete native species for resources such as food, habitat, and space.
3. Invasive species can disrupt the balance of the ecosystem, leading to a decline in biodiversity and negative impacts on native species.
4. Examples of invasive species include the zebra mussel in North America and the cane toad in Australia.
5. It is essential to control and manage invasive species to protect the biodiversity and ecological health of an ecosystem.
