The question deals with two of the most aggressive perennial species known.

It is not a particularly aggressive species and often kept as a pet by hobbyists.

It is an aggressive species, and strongly territorial during the breeding season.

But there are a few exceptions, aggressive species that just take over.

They are an aggressive species that require a large aquarium.

It is an active, aggressive and noisy species, usually seen alone.

It is generally shy, peaceful and should not be kept with aggressive species.

It is not an aggressive species with a biting defense.

Provide cover and hiding places to act as a refuge from aggressive species when fish are first introduced.

These fish are not considered to be an aggressive species in captivity.