Scavenger fish is an exotic species, preferring to move in the bottom of the water body, with strong adaptability, easy to feed, omnivorous, low oxygen resistance, the lack of natural enemies in the domestic rivers and lakes lead to a large number of breeding, will bring a serious impact on the local fisheries, so can not be released. Scavenger for eating aquarium debris, dirt and play a role in purifying the water quality, so named, also known as sucker fish, sucker catfish, scientific name of a catfish, native to the rivers of South America, can often be seen in Central America. The fish body is semi-cylindrical, the caudal fin is shallow forked, preferring weakly acidic soft water, suitable for water temperatures above 2 0 ℃, the adult fish body length reaches 3 0 centimeters, can not naturally overwintering, activities in the bottom of the water body, with adaptability, easy to feed, omnivorous, low oxygen resistance, starting rate of high characteristics, welcomed by consumers and breeders. When dealing with scavenger fish, burying them alive is one of the best options and they should not be released. If they are released in rivers, streams or other waters then they will have no natural predators. Coupled with their own hardiness, they will reproduce rapidly and their numbers can easily exceed the limit, upsetting the balance. They also eat the eggs of other fish, and the amount they eat is very large, easily endangering other fish. Moreover, the garbage they produce may also pollute the waters. So, releasing them is not a wise choice.