HomeFish encyclopediaRay-finned fishesCatfishNorth American freshwater catfishesSlender madtom Slender madtom (Noturus exilis) Scientific name: Noturus exilis Nelson, 1876 The Slender madtom (Noturus exilis) is a freshwater fish of the family Ictaluridae. BiologyInhabits rocky riffles, runs, and flowing pools of clear creeks and small rivers. Rarely found in springs and along wave-swept margins of large impoundments. Feeds on aquatic insect immatures (midges, mayflies, caddisflies) and small crustacea (isopods, amphipods, copepods).Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameNoturus exilisFamilyIctaluridae (North American freshwater catfishes)OrderSiluriformes (Catfish)ClassActinopterygii (Ray-finned fishes)Maximum length15.0Common length10.2EnvironmentFreshwater; demersalClimateTemperateDistributionNorth America: Green, Cumberland and Tennessee River drainages in central Kentucky to northern Alabama, USA; upper Mississippi River basin from southern Wisconsin and southern Minnesota to Ozark and Ouachita Highlands of Arkansas, Kansas and Oklahoma in USA.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessResilienceMedium, minimum population doubling time 1.4 - 4.4 years (tmax=4) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026