The catfish has a prominent lower jaw. The interdental teeth are fine and fuzzy, the jaw teeth and pearly teeth are arranged in a curved band, the pearly teeth band is continuous and the posterior margin is slightly concave in the middle. Eyes small, periostracum. Adults have 2 pairs of 4 whiskers, the maxillary whiskers reaching the end of the pectoral fins, the mandibular whiskers shorter. Steelhead have a short snout and 4 pairs of whiskers. The maxillary whiskers are long, ending beyond the middle of the pectoral fins, and the body is scale-free, with the posterior margin of the dorsal fin spines serrated. The pectoral spines are as long as the dorsal spines, with serrated anterior and posterior margins, short adipose fins, and y forked caudal fin.

Catfish, also called earth catfish, is the most widely distributed fish in the catfish family. It is distributed all over the world. The steelhead is widely distributed in all Pacific Ocean waterways in eastern China, in the Yangtze, Yellow and Pearl rivers and in the Heilongjiang and Liaoning basins.