Lepomis microlophus
(Günther, 1859)
Common Name:
Redear Sunfish
Synonyms and Other Names:
shellcracker, stumpknocker, cherry gill, sunny, sun perch
Identification:
Deep-bodied, olive colored, with darker spots and flecks of red, and occasionally vertical bars along the sides. The hind end of the gill flap is black with a white border and has a red spot on the tip (hence its name). The chest color is yellowish to cream colored.The mouth is small and when closed barely reaches only to the front margin of the eye. The pectoral fins are long and more pointed than those of other sunfish; the first dorsal fin contains 10 sharp spines, followed by 10 to 12 rays. Moyle (1976); Hubbs et al. (1991); Page and Burr (1991); Etnier and Starnes (1993). Lepomis microlophus is composed of two unnamed subspecies; one in Florida, Georgia, and southern Alabama, the other throughout the rest of its range. The two subspecies may no longer be distinguishable due to interbreeding caused by stocking programs (Page and Burr 1991).
Size:
25 cm
Native Range:
The native range for this species is Atlantic coast of North America (USEPA 2008). Page and Burr (1991) report the range as Atlantic and Gulf Slope drainages from about the Savannah River, South Carolina, to the Nueces River, Texas; north in the Mississippi River basin to southern Indiana and Illinois. Rohde et al. (2009) also conclude that the native range includes the Savannah River in Georgia and extends south through Florida and west to the Rio Grande River, and north in the Mississippi River Valley to southern Illinois and Indiana. Jenkins and Burkhead (1994) cite Bailey (1938) in reporting that the native range on the Atlantic slope may not be any farther north than Georgia.
Great Lakes Nonindigenous Occurrences:
This species is known from the lower Colorado River, Roosevelt Lake on the Salt River, and other reservoirs in central Arizona (Minckley 1973; Grabowski et al. 1984; Rinne 1995; Miller and Lowe 1967) and the Bill Williams River National Wildlife Refuges (USFWS 2005); many drainages within the Sacramento-San Joaquin, Death Valley, Tulare-Buena Vista , Southern California regions, the Yolo Bypass, Suisun Marsh, and the Colorado River in California (Smith 1982; Douglas 1974; Moyle 1976; Moyle and Daniels 1982; Grabowski et al. 1984; Moyle and Randall 1999; Sommer et al. 2001; Matern et al. 2002); the Platte, Republican, and Arkansas drainages (Walker 1993; Rasmussen 1998), and College Lake in Larimer County in the Cache La Poudre system in Colorado (Horak, personal communication); Wagamons Pond, Sussex County, Delaware (Raasch, personal communication); the northern two-thirds of Illinois, including the Lake Michigan, Illinois, Kaskaskia, Sangamon, Embarras, and Vermilion drainages (Smith 1979; Burr and Page 1986); southern farm ponds and reservoirs and northern Indiana, including the Tippecanoe, White, and lower Wabash drainages, and the Anderson River (Gerking 1945; Nelson and Gerking 1968; Burr and Page 1986; Mills et al. 1993); artificial recreational lakes and interior streams in Iowa (Harlan et al. 1987); the Kansas River drainage and numerous counties in Kansas (Cross 1967; Cross and Collins 1995); locations east of the lower Green River in Kentucky, including the Licking, Kentucky, upper Levisa , Salt and Rolling Fork drainages (Burr and Page 1986; Burr and Warren 1986; Powers and Ceas 2000); The Chesapeake and Ohio Canal National Historical Park, Washington County, and the mainstem Potomac River near Plummers Island, Maryland (Tilmant 1999; Starnes et al. 2011); Branch, Calhoun, Hardin, Jackson, Oakland, Hillsdale, and Washtenaw counties, Michigan (Bailey and Smith 1992; UMMZ specimens; Michigan DNR); the lower Missouri drainage, and reservoirs and ponds outside its native range in Missouri (Pflieger 1971, 1975, 1997; Cross et al. 1986); the Platte-Niobrara drainage, the Elkhorn River in Dodge and Washington counties, and West Oak Lake in Lancaster County, Nebraska (Morris et al. 1974; Cross et al. 1986); lower Colorado River and Ft. Churchill ponds, Lyon County, Nevada (Deacon and Williams 1984; Insider Viewpoint 2001; Vinyard 2001); the Pecos drainage in New Mexico (Koster 1957; Lee et al. 1980 et seq.); the Susquehanna and Allegheny drainages in New York (Hocutt et al. 1986); Tennessee, Roanoke, French Broad-Holston, and Dan drainages, probably introduced in the Neuse and Tar drainages, and regarded as native but possibly introduced in the Catawba, Yadkin, Lumber, and Waccamaw drainages in North Carolina (Hocutt et al. 1986; Menhinick 1991); Honey Creek at Buckeye Lake, Greter's Lake in Richland County, Pippen Lake in Portage County, the Scioto and Great Miami drainages, and other locations in Ohio (Lee et al. 1980 et seq.; Trautman 1981; Burr and Page 1986; Hocutt et al. 1986; Underhill 1986); non-specific, widely distributed in Oklahoma (Hall 1956; Miller and Robison 1973; Douglas 1974); parts of western Oregon including ponds in the Willamette Valley (Bond 1994) and Benton and Marion Counties (Logan 1994; Anonymous 2001); at least eight lakes in Pennsylvania, seven in the Susquehanna drainage and one in the Allegheny drainage; and the Monongahela drainge (Denoncourt et al. 1975a; Cooper 1983; Hocutt et al. 1986), Lee et al. (1980 et seq.) also mapped collections in eastern Pennsylvania in the Delaware drainage; in the Garzas, Guajataca, and Loiza Reservoirs and at non-specific locations in Puerto Rico (Erdsman 1984; Lee et al. 1983); all drainages of South Carolina except the Savannah River. Introductions have occured throughout the state in the Pee Dee, Santee-Cooper, Edisto, Combahee, Broad, and Saluda drainages (Loyacano 1975; Hocutt et al. 1986; Rohde, personal communication; Rohde et al. 2009); non-specific localized populations in Tennessee (Etnier and Starnes 1993); western Texas (Lee et al. 1980 et seq.; Red River Authority 2001); Holmes Creek Reservoir, Davis County, Utah (Sigler and Miller 1963); two lakes in Caledonia County, northeastern Vermont (Whittier and Hartel 1997); Appomattox, Potomac, Rappahannock, York, James, Dan, Banister, Chowan, Roanoke, and Big Sandy drainages and the Occoquan Reservoir in Virginia (Hocutt et al. 1986; Jenkins and Burkhead 1994; Starnes et al. 2011); and although Stauffer et al. (1995) listed the redear as native, collections in the Ohio River in West Virginia would be based on introductions according to Lee et al. (1980 et seq.) and Jenkins and Burkhead (1994). Established in Ohio River Islands National Wildlife Refuge (USFWS 2005).
Table 1. Great Lakes region nonindigenous occurrences, the earliest and latest observations in each state/province, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Lepomis microlophus are found here.
Full list of USGS occurrences
Table last updated 4/27/2024
† Populations may not be currently present.
Ecology:
The redear sunfish is a molluscivorous species of the Centrarchid family. It lives in vegetated littoral zones of small to large lakes, marshes, and reservoirs, and streams or rivers with sluggish to slow-moving flow (French and Morgan 1995). It prefers the deeper waters of warm ponds, lakes, reservoirs, and swamps, and favors clear water with abundant vegetation and other cover with a substrate of mud or sand (IUCN Redlist, 2013). This species often nests in colonies on the bottom of shallow areas (IUCN Redlist, 2013).
Means of Introduction:
Intentional stocking for sportfishing. In Iowa, fish found in interior streams are believed to be escapes from stocked lakes (Harlan et al. 1987). The species' recent (1991) discovery in Vermont is somewhat of a mystery. It appears the most likely means of introduction there is stock contamination of privately stocked Micropterus (Whittier and Hartel 1997).
Status:
Established in most locations, but extirpated in New Mexico (Sublette et al. 1990) and Utah (Sigler and Sigler 1996). The Delaware population at Wagamons Pond was discovered in October 1994 (Raasch, personal communication). Not established in Missouri (Pflieger 1997). Established in at least one of the two lakes in Vermont (Whittier and Hartel 1997). Results of a 1995 survey show that redear natural reproduction has been highly successful in Clear Lake in Jackson County, MI (Herman 1996).
Great Lakes Impacts:
Summary of species impacts derived from literature review. Click on an icon to find out more...
Lepomis micropholus has a moderate environmental impact in the Great Lakes. Realized:
Redear sunfish is highly molluscivorous. In inland lakes of southern Michigan, introduced redear is associated with ecological changes in populations of pumpkinseed (L. gibbosus), a native molluscivore. Effects of introduced redear sunfish on pumpkinseed include reduced consumption of snails and reduced population densities (Huckins 1997). The effects appear to be driven by differences in pharyngeal morphology and competitive ability; redear sunfish exert greater crushing forces and consume more snails than sympatric pumpkinseeds (Huckins 1997). When introduced into a waterbody, Huckins et al. (2000) found that competition between the two species resulted in a 56% reduction in pumpkinseed abundance and a 69% reduction in average snail biomass when compared with lakes without redear sunfish.
Potential:
Studies involving redear sunfish and gastropods (outside of the Great Lakes) indicated that redear sunfish has the potential to cause changes to the ecosystem via pressure on the mollusk community. Direct impacts on invertebrates and indirect impacts on vegetation are associated with L. microlophus in Tennessee (Ruiz et al. 1999). Mollusk predation by L. micropholus, particularly on gastropods, can result in reduced grazing activity, changes in periphyton abundance and community structure, and a shift toward phytoplankton-dominated (rather than macrophyte) communities (Martin et al. 1992, McCollum et al. 1998).
Kolar and Lodge (2002) predicted that due to species characteristics, redear sunfish introduced intentionally as a sport or recreational species would be slow to spread throughout the Great Lakes, but would attain the status of “nuisance” species due to its relatively high impact potential. The accuracy of this prediction has yet to be fully tested.
There is little or no evidence to support that Lepomis micropholus has significant socio-economic impacts in the Great Lakes.
Lepomis micropholus has a moderate beneficial effect in the Great Lakes.
Realized:
Redear sunfish was intentionally introduced into inland lakes of Michigan to enhance recreational fisheries (Huckins et al. 2000).
Redear sunfish has been used as a research organism to measure uptake levels of chemicals and toxins in other parts of the U.S. (e.g., Bettoli and Clark 1992, Campbell 1994, Eller 1969, Ghent and Grinstead 1965, Melwani et al. 2009, Pickhardt et al. 2006, Saiki et al. 2005, Sorensen 1988).
Although redear sunfish is molluscivorous, it is not suitable as a biocontrol agent for zebra mussels; experimentally, it significantly prefers gastropods over zebra mussel (French and Morgan 1995).
Management:
Regulations (pertaining to the Great Lakes)
The Redear Sunfish is listed as an approved species for aquaculture production in Michigan (MCL § 286.875, Aquaculture Development Act). In Wisconsin, the Redear Sunfish is listed as a restricted species under the definition “nonnative fish in the aquaculture industry” (Wis. Admin. Code § NR 40.02, 40.05). Note: Check federal, state/provincial, and local regulations for the most up-to-date information.
Control
Biological
There are no known biological control methods for this species.
Physical
Removal of catch limits for anglers and public information campaigns could aid control of this species.
Chemical
Of the four chemical piscicides registered for use in the United States, antimycin A and rotenone are considered “general” piscicides, but no studies have been found of their effects on Lepomis microlophus (GLMRIS 2012).
Increasing CO2 concentrations, either by bubbling pressurized gas directly into water or by the addition of sodium bicarbonate (NaHCO3) has been used to sedate fish with minimal residual toxicity, and is a potential method of harvesting fish for removal, though maintaining adequate CO2 concentrations may be difficult in large/natural water bodies (Clearwater et al. 2008). CO2 is approved only for use as an anesthetic for cold, cool, and warm water fishes the US, not for use as euthanasia, and exposure to NaHCO3 concentration of 142-642 mg/L for 5 min. is sufficient to anaesthetize most fish (Clearwater et al. 2008).
It should be noted that chemical treatment will often lead to non-target kills, and so all options for management of a species should be adequately studied before a decision is made to use piscicides or other chemicals. Potential effects on non-target plants and organisms, including macroinvertebrates and other fishes, should always be deliberately evaluated and analyzed. The effects of combinations of management chemicals and other toxicants, whether intentional or unintentional, should be understood prior to chemical treatment. Other non-selective alterations of water quality, such as reducing dissolved oxygen levels or altering pH, could also have a deleterious impact on native fish, invertebrates, and other fauna or flora, and their potential harmful effects should therefore be evaluated thoroughly.
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.
Remarks:
Robison and Buchanan (1988) reported redear sunfish as widely stocked in Arkansas in ponds and reservoirs, presumably in native waters. Menhinick (1991) listed this species as "regarded as native but possibly introduced" and "introduced" into the Catawba, Yadkin, Lumber, and Waccamaw drainages. Stauffer et al. (1995) differed with other authors (Lee et al. 1980 et seq. and Jenkins and Burkhead 1994) in reporting this species as native to the Potomac, Big Sandy, Kanawha, and Little Kanawha drainages, and Ohio basin. No records exist for New York (Whittier and Hartel 1997).
Redear, and to a lesser extent pumpkinseed, are the only known morphologically and behaviorally specialized molluscivores in the sunfish family (Huckins et al. 2000). The ability of these sunfish to crush hard-shelled organisms provides a set of food resources that are less effectively used by other sunfishes, facilitating cohabitation with other sport fish such as bluegill and bass (VanderKooy et al. 2000).
References
(click for full reference list)
Author:
Fuller, P., G. Jacobs, M. Cannister, J. Larson, A. Fusaro, T.H. Makled, and M. Neilson
Contributing Agencies:
Revision Date:
9/12/2019
Peer Review Date:
4/12/2013
Citation for this information:
Fuller, P., G. Jacobs, M. Cannister, J. Larson, A. Fusaro, T.H. Makled, and M. Neilson, 2024, Lepomis microlophus (Günther, 1859): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, https://nas.er.usgs.gov/queries/GreatLakes/FactSheet.aspx?Species_ID=390, Revision Date: 9/12/2019, Peer Review Date: 4/12/2013, Access Date: 4/27/2024
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.