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. 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. The genera Trogoglanis, Satan, and Prietella include four species of blind catfishes. They have the ability to inflict painful stings with venomous spines embedded in their fins. One of the largest species is the blue catfish, Ictalurus furcatus, specimens of which have been found to weigh over 50 kg (110 lb). The maximum length is 160 cm (5.2 ft) in the blue catfish and the flathead catfish. The bullheads, though, are small catfish that at maturity often weigh less than 0.5 kg (1 lb), while the madtoms (genus Noturus) are in general much smaller.
