Whiskered, scaleless fish rule mud bottoms and fish farms
Catfish—order Siluriformes—take their name from barbels that look like whiskers, though not every species flaunts them. All lack true scales, wearing naked skin, mucus for cutaneous breathing, or bony scutes instead. Southern U.S. slang piles on mud cats and chuckleheads for regional favorites.
Most are bottom feeders with heavy bony heads and reduced gas bladders that make them sink. Body plans stay mostly cylindrical with flat undersides. Large farmed species such as Pangasius and Clarias feed people; tiny Corydoras delight aquarists. Walking catfish remind observers that air-breathing skin can matter out of water.
Commercial weight and aquarium charm both flow from the same blueprint: sensory barbels in murky water and armor or slime instead of scales.
Wherever rivers run muddy, Siluriformes fill niches other ray-fins leave open—and humans follow with ponds and frying pans.
Many larger catfish carry taste receptors over the whole body, concentrated on the barbels, so they effectively taste whatever they touch and smell chemicals drifting in the water. Nearly all species, electric catfish excepted, have a stout hollow spine at the front of the dorsal and pectoral fins that can be locked outward as a defence. Their eyes lack the double cones found in most teleosts, and many have a reflective tapetum lucidum that may sharpen vision in dim light. Size varies enormously: many never pass 12 centimetres, and some tiny species mature at about 1 centimetre, while the Amazon's piraíba can reach 200 kilograms. A Mekong giant catfish landed in northern Thailand on 1 May 2005 weighed 293 kilograms, the heaviest since Thai officials began records in 1981. Europe has just two native species, the widespread wels and the much smaller Aristotle's catfish of Greece.
Source: Catfish
