What is an "exotic" fish?
One not native to an area, but introduced either by accident or design. Some such species can cause problems. Often their natural predators are absent from the new area, permitting more rapid reproduction rates than those of natural inhabitants, sometimes at the expense of more desirable native fish. The "walking catfish" in Florida is an example. Thought to have escaped from a private aquarium, the catfish have shown a remarkable ability to avoid eradication efforts by man. An aggressive and voracious fish, it poses a threat to other forms of aquatic life. Population is now estimated in the millions.