The Amur catfish, or Japanese common catfish, Silurus asotus, is a species of catfish (sheatfish), family Siluridae. It is a large freshwater fish found in continental East Asia and in Japan. It prefers slow-flowing rivers, lakes, and irrigation canals. Its appearance is typical of a large silurid catfish. Larval S. asotus specimens have three pairs of barbels (one maxillary, two mandibular), while adult fish have only two pairs (one maxillary, one mandibular); second pair of mandibular barbels degenerates. This species grows to 130 cm (51 in) in total length.