Shorthead redhorse

Characteristics

A slender, coarse-scaled sucker with a bright red tail fin. Its head is shorter than other redhorse, its dorsal fin is strongly curved inward, with 12-13 or sometimes 14 soft rays. The upper lip often has a "pea-shaped" swelling in the middle. The rear margin of the lower lip is nearly straight with the lip folds divided into prominent papillae. The pharyngeal teeth are thin, comb-like with about 53 per arch. The lateral line is complete with 41 to 45 scales. Scale count around the caudal peduncle is 12.

Distribution

Widely distributed throughout Iowa, but is more abundant in streams in the northern and eastern Iowa. Abundant in the Mississippi River, common in the interior rivers and uncommon to rare in the natural lakes and the Missouri River drainage.

Foods

Aquatic insect larvae, some plant material, mainly algae

State Record

3.65 lbs; 20 in. - Wapsipinicon River (Troy Mills to Oxford Junction) Jones County, April 5, 2020 - Rory Petersen, Olin, Iowa

Expert Tip

None

Details

Formerly named the Northern Redhorse (Moxostoma aureouim), this species was renamed to the present nomenclature in 1973. 

The Shorthead Redhorse prefers moderate to swift current over sand and gravel substrate. This sucker is adaptable to high turbidity, but it lives mostly in clear to slightly turbid water in the deeper stretches of the channel.

Life history characteristics of Shorthead Redhorse are not much different than other redhorses. Adults commonly reach 10- to 22-inches long and weigh 1- to 4-pounds. Maturity is reached at age 3. Upstream spawning movements in large schools is common for male redhorses in early April at water temperatures of 47 to 60 degrees. Males gather and defend spawning territories that have gravel riffles and rubble shoals. The actual spawning ritual occurs when a female moves into the gravel-lined troughs or nests and two males mate with a single female. The semi-adhesive eggs are broadcast, left unattended and hatch in 4 or 5 days. An 18-inch female produces about 22,000 eggs. Growth of the Shorthead Redhorse averages 1.9-inches the first year of life, 16-inches at age 5 and 20.9-inches at 11 years of age in the Mississippi River. 

Recent stream sampling information is available from Iowa DNR's biological monitoring and assessment program.