Question

a species of fish is introduced into a lake. the fish is better at hunting for food than the old fish. the old fish die off, and the new fish population increases. which is the best way to describe these fish in the new ecosystem?
a. keystone species
b. native species
c. invasive species
d. cyclical species

Explanation:

An invasive species is a non - native (introduced) species that causes harm to the environment, economy, or human health. In this case, the new fish species is introduced into the lake (non - native) and causes the old fish to die off (harm to the ecosystem). A keystone species is one that has a disproportionately large effect on its environment relative to its abundance. A native species is one that naturally occurs in an area. There is no common ecological term "cyclical species" in the context of species introduction and impact as described here.

Answer:

C. Invasive species