The Ictaluridae, sometimes called ictalurids, are a family of catfish native to North America, where they are an important food source and sometimes fished for sport. The family includes about 51 species, some commonly known as bullheads, madtoms, channel catfish, and blue catfish.
Taxonomy
The family Ictaluridae is strongly supported as a monophyletic group.
Though the family includes three genera of blind, subterranean, and troglobitic catfishes, Trogloglanis, Satan, and Prietella, none of these three genera is closely related. Instead, Satan is closely related to Pylodictis, Prietella to Noturus, and Trogloglanis possibly to Ictalurus, although it may not be closely related to any of the other ictalurids. Ameiurus is sister to a clade formed by Satan, Pylodictis, Noturus, and Prietella.
The oldest fossil member of the family was previously thought to be Astephus from the Eocene Green River Formation of Utah and Wyoming. However, more recent studies consider Astephus to not be closely related to the Ictaluridae, and to instead belong to its own extinct family. Excluding Astephus, the oldest fossil member of the family is †Ictalurus rhaeas <small>Cope, 1891</small> from the latest Eocene-aged Cypress Hills Formation of Saskatchewan.
Distribution and habitat
Ictalurids originate from North America from southern Canada to Guatemala. Both bullheads and madtoms tend to be found in small streams and ponds, but are also known in larger bodies of water. Channel catfish, bullheads, and madtoms are "bottom feeders" with widely varied diets that include scavenging.
Notable species
- Blue catfish Ictalurus furcatus
- Tadpole madtom
- Brown bullhead
- Yellow bullhead
- Black bullhead
- Channel catfish
- Widemouth blindcat
Description
Ictalurid species have four pairs of barbels (commonly referred to as "whiskers" as applied to catfish). Their skin does not have any scales. The dorsal and pectoral fins usually possess a spine. The dorsal fin usually has six soft rays. The palate is toothless except in the fossil genus Astephus.