Scavengers, whose scientific name is Silurus leopard, are the common names of Silurus polymorpha and Silurinae, commonly known as strong-backed dragon, strong-backed fish, waist-protected fish and so on. In some areas, it is also called anglerfish and trash fish.

Because the scavenger likes to eat the bait and dirt left in the aquarium, it plays a role in purifying the water quality, so it is named, also known as sucking fish and sucking catfish, and its scientific name is Silurus asotus, which is native to rivers in South America and can often be seen in Central America. The fish body is semi-cylindrical, the tail fin is shallow and forked, and it likes weak acid and soft water. The suitable water temperature is above 20℃. Adult fish can't overwinter naturally and move at the bottom of water. At first, it was welcomed by consumers and farmers because of its strong adaptability, easy feeding, omnivorousness, hypoxia tolerance and high catch. Because the skin is hard, the meat is rough, it is not delicious, and it is easy to survive and multiply, which occupies the living space of native fish. Experts call for strict control of artificial introduction and spread, to prevent it from spreading to the natural water system, and not to release it at will.

Morphological characteristics: scavenger fish fish is streamlined, with small eyes, low mouth, prominent kiss and thick forehead. The upper and lower lips have left and right teeth respectively. Teeth are brush-like. There are 1 whiskers on the left and right. A comb as dense as a gill rake. The whole body is covered with black patterns with clear black stripes. The base of pectoral fin can make a sound similar to that of Pelteobagrus fulvidraco. There are 2 dorsal fins, no lateral line scales, and only 4 rows of large scales on the side.

Male and female identification: the female sweeping mouse has a wide back, soft and smooth barbs, light body color and short and round pectoral fins; The male sweeper has a narrow back, hard and rough barbs, black body color, long and pointed pectoral fins and idolatry.