Catfish (or catfishes; order Siluriformes / s ɪ ˈ lj ʊər ɪ f ɔːr m iː z / or Nematognathi) are a diverse group of ray-finned fish.Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, the Mekong giant catfish from Southeast Asia, the wels catfish of Eurasia, and the piraíba of South America, to