River Chub
(Nocomis micropogon)
River chub are often caught hook and line in areas of swift current containing many rocks and boulders. Breeding males (left) get some pink or red coloration and like many minnows have horn like projections on their head called tubercles, young and females (right) lack these features. They and creek chub are the two largest native minnow species found in Ohio.
Description
River chub have a fairly large mouth that ends before it reaches the front of the eye which has a small barbel in the rear corner on each side of the head. They have dark edges to the scales which gives them a crosshatched pattern over much of the body. They have darker brown backs with lighter brown or gold sides and a cream colored belly. They have a dark stripe down the side which is most visible on young and non-breeding adults. The fins are brown or slate gray and do not have a red or orange tinge. They differ from the closely related hornyhead chub in having a longer snout, slightly sub-terminal (ending below tip of snout) mouth, and no dark spot at the base of the tail. Adult breeding males differ from hornyhead chub in having no bright red spot behind the eye and the breeding tubercles (horn like projections) on top of the head extend from the front of the snout to above and not much beyond the eye. River chubs can also be mistaken for creek chubs which have a larger mouth extending just beyond the front edge of the eye, a dark base to the front edge of the dorsal fin, and lack the crosshatched body pattern formed by dark scale edges.
Habitat and Habits
River chub are found in medium to large rivers often in areas of very swift current. They can be found hiding in pockets of deeper water behind large boulder from which they dart out to grab passing food items. They are typically found in larger streams than the closely related hornyhead chub and much larger streams that creek chub. They are found throughout Ohio and some large populations occur in the Scioto, Kokosing, and lower Cuyahoga Rivers.
Reproduction and Care of the Young
River chubs spawn in April and May. The males select spawning sites with gravel substrate in riffles often adjacent to or just behind a large boulder. At these sites, males build a mound by stacking up a pile of pebbles with their mouth. They spawn above this pile of pebbles and continue to add to it between spawning events. As spawning continues this activity creates a round mound of pebbles that can be 2-3 feet across and 8-12 inches high. Many other smaller species of fish will also sneak in and spawn in the nest of the chub taking advantage of the way the male aggressively defends the nest, which insures their eggs are protected as well.