Mooneye

Characteristics

Mooneyes have deep bodies that are strongly compressed laterally. Color varies from steel blue on the back to silver sides and a white belly. The eye has a silvery iris. The belly has a fleshy keel, but lacks scutes. The head is blunt and rounded with a slightly oblique mouth. Teeth are in both jaws, as well as on the roof of the mouth and on the tongue. There are 15 to 17 gill rakers along the lower limb of the first gill arch. The fish has adipose eyelids. Scales are cycloid and the lateral line has 52 to 57 scales. The dorsal fin has 10 to 14 rays and inserts in front of the anal fin, which has 26 to 29 rays. Males have a sickle-shaped anal fin, and in females it is bowl-shaped. An axillary process is found near the base of the pelvic fin. Anglers often mistaken this fish as a Gizzard Shad.

Distribution

Restricted to the large rivers in Iowa; found in many of the larger, interior rivers such as the Cedar, Des Moines and Upper Iowa Rivers, but most abundant in the Mississippi River. It has been documented in the Big Sioux and Missouri River, but its distribution spreads along the southern and eastern borders of the state.

Foods

Plankton during the young stages of life switching to insects, mollusks, crayfish, and small fish at later stages.

State Record

1.52 lbs - Pool 9, Mississippi River Allamakee County, October 2016 - Tricia Steines. Springbrook, Iowa

Expert Tip

Mooneye eat minnows; fish for them like you would for White Bass or crappies.

Details

Mooneye live in the clearest rivers, lakes and large reservoirs. It is often found in backwaters and other quiet areas, but feed in swift current over firm bottoms, such as dam outflows. It is a surface-feeder and needs an abundant supply of small fish. Mooneye do not tolerate excessive turbidity and high gradients.

Little is known of the spawning ritual of this fish, but it probably occurs at random in April and May in shallow areas of cleaner streams. Each female produces about 10,000 to 20,000 eggs, and no care is given to the young. Mooneye commonly reach 9- to 11-inches long, with a maximum size of about 10- to 12-inches. 

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 William L. Pflieger, Missouri Department of Conservation