About Lepomis miniatus (Jordan, 1877)
The redspotted sunfish, Lepomis miniatus, reaches a maximum standard length of 160 millimetres (6.3 in). An iridescent crescent is visible inside its eye, underneath its red or dark-colored iris. Unlike the green sunfish, the redspotted sunfish has no dark spot at the rear of its dorsal fin, and also has a smaller mouth than the green sunfish. When breeding, male redspotted sunfish develop red-orange color that starts at the belly and extends upward through pigmented horizontal scale rows to one or two rows below the lateral line. This feature distinguishes them from the paler breeding males of the spotted sunfish Lepomis punctatus. Unlike spotted sunfish, which have dark spots at the base of their scales that form irregular horizontal rows along the body, the redspotted sunfish does not have these dark scale-base spots. Redspotted sunfish have narrow white or cream colored bands on the tips of their dorsal, anal, and caudal fins, and they also have a dark opercular flap. In zones where this species introgresses with spotted sunfish, which include parts of the Florida panhandle, western Georgia’s section of the Tennessee River watershed, and Coosa River tributaries within the Mobile basin, L. miniatus may not be distinguishable from its sister species. The redspotted sunfish is a freshwater fish distributed throughout the Mississippi River Valley. Its range extends north into Illinois and to the Ohio River, west into Texas and to Oklahoma’s Red River, and east to the Chattahoochee River in Georgia. Most populations of L. miniatus across the southern United States are currently considered stable. However, populations have declined sharply in Illinois, which sits at the northernmost edge of the species’ historic range. Once found across the state, the redspotted sunfish’s Illinois range had shrunk to just a few counties in central and southern Illinois by 2004. Mid-2000s surveys found only two confirmed populations in the entire state: one in a tributary of the Illinois River, and another in a tributary of the Ohio River. Multiple possible causes have been proposed for this decline in Illinois. The most common theory is that loss of the species’ natural wetland habitat has caused the species to struggle. Declines may also stem from worsening water quality or competition with invasive species. Lepomis miniatus feeds primarily on benthic organisms. For small redspotted sunfish, zooplankton makes up between 33.3% and 74.6% of their diet. For medium-sized individuals, zooplankton accounts for around 50% of their diet as they start incorporating larger prey. At larger sizes, the redspotted sunfish shifts its diet to primarily benthic macrofauna. Larger carnivorous fish, most often bass, prey on redspotted sunfish. This species is most often found in shallow, heavily vegetated water, and prefers slow-moving water with an average speed of 0.4 cm/s. The redspotted sunfish is salt-tolerant, and can be found in the lower sections of estuaries such as bayous along the Gulf Coast west of Florida. While the redspotted sunfish does compete with other sunfish and some invasive species like the Rio Grande cichlid in Louisiana, this competition is generally thought to have little impact because L. miniatus has a generalist diet. A greater threat comes from invasive species that push redspotted sunfish out of their preferred habitat, which increases the species’ risk of predation.
