Most catfish species, such as the Brazilian species Phreatobius cisternarum, like clear freshwater habitats, being found from open and shallow waters to caves. Freshwater catfish found in the United States include the blue catfish, the channel catfish and flathead catfish, which prefers deep and turbid waters. Species from the families Akysidae and Amblycipitidae are native to Asia while members of the family Amphiliidae are mainly found in tropical Africa. Doradidae and Cetopsidae catfishes are native to South America while Anchariidae are endemic to Madagascar.
Some species from the families Ariidae and Plotosidae prefer to live in saltwater or brackish environments, including Amissidens hainesi, native to Australia and New Guinea, and the South American Kukwari sea catfish. A few members of the families Bagridae and Aspredinidae, such as Aspredinichthys tibicens, also prefer to live in saltwater.
The majority of catfish species prefer warm waters, from 68 to 80 degrees. However, some species of catfish can live in lower temperatures and generally feel stressed and uncomfortable when temperatures raise above 70 degrees. Low temperature species include several species of cory catfish, such as Corydoras barbatus, Corydoras kronei, Corydoras macropterus and Corydoras paleatus. These species are commonly found in southern South America, where water temperatures are often below 60 degrees. The Atlantic catfish like temperatures as low as 35 degrees.
Although most species of catfish prefer to live in shallow waters, others are found at 60-foot depths. Endemic to Lake Victoria and critically endangered, the Lake Victoria deep-water catfish is found at depths of 66 feet. The Atlantic catfish are found at depths of 250 to 400 feet.