The river chub (Nocomis micropogon) is a minnow in the family Cyprinidae. It is one of the most common fishes in North American streams. The river chub is a robust minnow, dark olivaceous above to dusky yellow below, with orange-red fins, large scales, a large slightly subterminal mouth, and a small barbel (whisker-like organ) at the corners of the jaw. During the breeding season, sexually mature males develop pinkish-purple coloration, and swollen heads with tubercles between the eyes and snout tip (they are sometimes called hornyheads). The river chub grows to a maximum of about 33 centimetres (13 in), with males larger than females. Common length is about 14 centimetres (5.5 in). Distribution The river chub is among the most common fishes in North American streams. Its range extends primarily through most of the Great Lakes and Appalachian regions. The river chub is found in clear, medium to large creeks and rivers with moderate to swift current over rock and gravel substrate, from southeast Ontario and southern New York to Michigan and Indiana, south to northwest South Carolina to northwest Alabama. This includes the Susquehanna River system, James River system, Great Lakes basin (except Lake Superior), Ohio River basin, Santee River, Savannah River, and Coosa River. It has been introduced into the Ottawa River system in Ontario, and may owe its presence in the Santee, Savannah and Coosa Rivers to introduction by fishermen emptying bait buckets. The river chub is generally considered widespread and abundant with no apparent major threats. Exceptions are Illinois, where it is considered Critically Imperiled in its very limited range on the Wabash River; Alabama, where it is considered Imperiled; and in Georgia it is ranked as Vulnerable (NatureServe conservation status). Populations in Ohio have been extirpated by turbidity and siltation in western regions and are threatened by acid mine drainage in the coal region. Also, dams have inundated areas that were once habitat for the river chub eliminating bits of its range.
