Chestnut Lamprey

Characteristics

The Chestnut Lamprey differs in appearance from the Silver Lamprey by several features. The dorsal fin is continuous without the double lobes. The mouth is a sucking disc, but the circumoral teeth are nearly all bicuspid, or two-pointed. There are 51 to 54, usually more than 52, myomeres or segments in the body between the last gill slit and the anus. This lamprey reaches 8- to 13-inches long.

Distribution

More rarely taken than the Silver Lamprey; reported in the Mississippi River throughout Iowa by the Upper Mississippi River Conservation Committee, but from no other location in the state.

Foods

Adult Chestnut Lamprey are parasitic and live largely by attaching themselves to fish, sucking blood of the host fish.

State Record

State Records are not documented for non-game species.

Expert Tip

Chestnut Lamprey are never taken by hook-and-line; they are of no importance to the anglers, except possibly as bait for other fish.

Details

The Chestnut Lamprey is a threatened species in Iowa (571 IAC 77.2(2) (2015)). It can be found throughout much of the Mississippi River. A single pre-1900 collection in the Des Moines River is the only occurrence of this lamprey from Iowa’s interior waters.

The Chestnut Lamprey moves among different habitats through its life cycle. Adults are common in large streams and reservoirs, where, as parasites, they can find an abundance of fish to eat. Spawning adults can be found in medium creeks to large rivers, and larvae need clear streams with permanent flow, with stable bars of sand, silt, and organic matter. 

The life history of the Chestnut Lamprey is similar to that of the Silver Lamprey. It usually spawns in the spring in small streams. Larvae need several years to reach the adult stage, at which time it returns to the larger streams and stays there until spawning the following spring. The parasitic stage of life continues for one year. 

Recent stream sampling has not resulted in the discovery of any individual Chestnut Lampreys.

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 William L. Pflieger, Missouri Department of Conservation