Fish Iowa - Fish Species - Central Stoneroller

Characteristics

Body form varies from slender to moderately stout. They are slightly compressed laterally with an arch in the back. The horizontal mouth is sub-terminal and lacks a barbel. A cartilaginous and chisel-shaped lower jaw is a distinct characteristic of stonerollers. Slender arches support the slightly hooked pharyngeal teeth, which are arranged in a 4-4 pattern. The lateral line is complete, with 49 to 55 scales, and the circumferential scale counts (around the body frontal of the dorsal fin) range from 39 to 55. Dorsal and pelvic fins ray count are 8, while the pectoral fins have 15 rays and the anal fins 7 rays. The long intestine is usually wrapped around the air bladder, and it is covered by a black peritoneum. The body is brownish-olive with a brassy luster above and silvery to white beneath. Body sides are marked with scattered dark scales, giving the fish a mottled look. Spawning males develop a dark bar across the anal fin and have tubercles on their back, top of the head, and between the nostrils.

Foods

Stonerollers feed by scraping the algae and bottom ooze from submerged objects.

Expert Tip

Spawning males develop a dark bar across the anal fin and have tubercles on their back, top of the head, and between the nostrils, as shown in the photo above.

Details

The Central Stoneroller lives in many habitats from very small streams to large rivers. Some researchers have found that the largest populations were found where a combination of habitats was available such as small streams with moderate to high gradients with sandy-gravel bottoms in which to spawn, moderate-sized streams with moderate gradients in which to summer, and larger streams of lower gradients in which to winter. In Iowa, the Central Stoneroller lives in small creeks, reaching its highest abundance in coolwater streams. The Central Stoneroller prefers clear water, but can tolerate turbidity if the bottom is free of silt, stays reasonably cool and is well oxygenated.

Spawning peaks during April, when males built nests by moving gravel with their mouths or nudging it away with their snouts, giving rise to their common name. Adults may reach 7-inches long.

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

Sources:

Harlan, J.R., E.B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Conservation Commission, Des Moines, Iowa. 323pp.

Loan-Wilsey, A. K., C. L. Pierce, K. L. Kane, P. D. Brown and R. L. McNeely. 2005. The Iowa Aquatic Gap Analysis Project Final Report. Iowa Cooperative Fish and Wildlife Research Unit, Iowa State University, Ames.

Photo credit: Photo courtesy of Garold W. Sneegas, copyright Garold W. Sneegas

State Record(s)

Master Angler Catches