Channel catfish. According to the query Baidu encyclopedia information shows that catfish is a freshwater fish of the genus Shad in the family of Luridae, the water quality conditions are relatively high, only in a clean body of water in order to survive, while the catfish is a catfish family of fish collectively, the water quality requirements are not high, and even in the stinking gutter, sewers and other extremely poor environment to survive, so the catfish is clean.