River Carpsuckers are fairly common throughout the Mississippi basin and other western gulf drainages to Mexico. They are widely distributed in warm prairie streams, rivers, and reservoirs. Preferring large, silty off-colored, slow moving waters, adults are seldom observed in clear water. Carpsuckers gather in large schools, foraging near the bottom in deeper sections of rivers and impoundments. These fish can exceed twenty-four inches and approach 10 pounds in weight. Few fish live over ten years.
Stout bodied, the back of the River Carpsucker is slightly arched sporting a long dorsal fin that much longer in the front that the back. Scales are large, as are their eyes. The mouth is sub-terminal with a nipple-like projection in the middle of the lower lip. Coloration is brown-olive on the upper body, silverish scales along the side that fade to a white underside. Lower fins are white.
Spawning occurs late spring, early summer on most waters when the temperature is 65 to 75 degrees Fahrenheit. Spawning occurs in large fish congregations. The eggs are randomly deposited over sand or gravel bottoms. No parental care is given. Eggs hatch in one to two weeks. No parental protection is provided. Adults become sexually mature in two to three years.
River Carpsuckers are suction and filter feeders, browsing on algae, organic detritus, protozoan, small crustaceans, aquatic insects, aquatic worms and mollusks.
River Carpsucker in Colorado
A deep-bodied sucker with a long, falcate (sickle-shaped) dorsal fin; snout short and rounded; mouth short, wide and wholly inferior (on the ventral side of the head); lower lip with a nipple-like projection in the middle. There are 23-27 rays in the dorsal fins; scales are large. The adults are a slate or olivaceous silvery color. Fins are colorless or pinkish yellow. Length at the end of the first year up to 6 inches. Adults in Colorado reach 18-19 inches in length. The average weight of an adult is in excess of 2 pounds ranging to a maximum of 5 1/2 pounds.
In Colorado, the species is restricted to the lower South Platte River on the eastern plains. Adults are common in Jackson, Jumbo and North Sterling reservoirs. Carpsuckers of all ages, from young to adult, are found in Prewitt Reservoir. Immature fish, 2.5 to 6 inches, are infrequently found in the South Platte mainstem from Fort Morgan downstream to the Nebraska state line (Propst 1982).
In reservoirs, adult carpsuckers are widely distributed through the entire water body and are not restricted to one habitat type. Immature carpsuckers collected in the South Platte are found in quiet backwaters and sloughs over a mud bottom. One reason adult river carpsuckers are found only in reservoirs in Colorado may be that the extremely low flows during fall months leave very few large pools or backwaters required by river dwelling mature fish of this species.
Courtesy of Natural Diversity Informations Source, Colorado Division of Wildlife