A deep, slab-sided sunfish with a small mouth similar in appearance to Bluegill and Pumpkinseed. The upper jaw does not reach past the front of the eye when the mouth is closed. The dorsal fin has 10 spines and is connected to the soft dorsal fin without the presence of a notch. The pectoral fins are pointed and long. The earflap is rounded and has a thin and flexible margin. The dorsal fin is without spots, and the sides of the head do not have bluish lines as in Pumpkinseed. The back and sides are golden or light olive-green, usually marked by several dark vertical bars. But these disappear in large fish. The ear flap has a whitish border and has a prominent red or orange spot in adults, hence the name redear. The fins are greenish without spots.
Introduced into man-made recreational lakes in the 1960's; common to occasional in the southern two thirds of the state, mostly in the lakes that are steep-sided. Recorded in the interior streams, the origin of these fish is thought to be man-made lakes or ponds that overflow during periods of high runoff. It is very rare in the Missouri River and oxbows, as well as the Mississippi River.
Young redear feed exclusively on zooplankton, but as they approach adulthood they eat more aquatic insect larvae, snails and cladocerans. Snails are a major food item in adults, which they crush with pharyngeal teeth, giving rise to the vernacular name shellcracker. In some small ponds, redear practically eliminate snails.
2.31 pounds, 12.8 in - farm pond, Van Buren County, Oct. 2018 - Elijah Parrett,
Redear Sunfish are native from North Carolina to Florida, west into Texas, southern Missouri and Ohio. They are a recently introduced sunfish in Iowa waters. It was first propagated and stocked into the man-made recreational lakes in the early 1960's.
Redear spawn in late May and June when the water temperatures are 68 to 75 degrees. The males build a nest, usually grouped into colonies near submerged aquatic plants. Males usually release a "popping" sound when courting females. Females have an average of about 20,000 eggs, but as with other sunfish, it is unlikely that a female deposits all of her eggs in one nest. The eggs hatch in 6 to 10 days, and the fry stay in the nest guarded by the male. Redear growth is more rapid than Bluegill. They reach up to 2-inches in their first year, 4-inches the second, 6-inches in the third and 7-inches in the fourth year. Most redear mature in the second year of life.
Recent stream sampling information is available from Iowa DNR's biological monitoring and assessment program.