Some pets when released into the wild can become invasive species. So, if the conditions are right, pets like goldfish, some reptiles, amphibians and invertebrates like snails or crayfish can become invasive species. If someone is dumping an aquarium, then everything in the aquarium goes. It’s not just the fish, but the snails, water plants, and anything else in the tank. All this stuff has the potential to become an invasive species.