Invasion History

First Non-native North American Tidal Record: 1895
First Non-native West Coast Tidal Record: 1895
First Non-native East/Gulf Coast Tidal Record: 1900

General Invasion History:

The Green Sunfish (Lepomis cyanellus) is a freshwater fish native to the Great Lakes, Hudson Bay and Mississippi Basins from New York and Ontario to Minnesota and South Dakota south to the Gulf Coast (Escambia River, Florida) south to the Rio Grande River. Its typical habitats are small streams, ponds, and backwaters (Lee et al. 1980; Page and Burr 1991; Jenkins and Burkhead 1993). This fish was probably widely introduced by United States Fish Commission and state fish commissions in mixtures recorded as 'Sun-Fish' or 'Bream'. They are introduced in much of United States and Canada, and parts of Europe (Carlander 1977; Dill and Cordone 1997; Hardy 1978; Page and Burr 1991). In the United States they were introduced to Nevada, Utah, and California where they are abundant, frequently displace native fishes. In the east, they were introduced in Chesapeake Bay tributaries, Delaware Bay, and Hudson River (Cohen and Carlton 1995; Fuller et al. 1999; Mills et al. 1997). Altogether, they have been introduced to 32 states, and are established in most (Fuller et al. 1999; USGS Nonindigenous Aquatic Species Program 2018).

North American Invasion History:

Invasion History on the West Coast:

In 1891 to 1895 The US Fish Commission stocked many ponds and streams in Washington and California with mixtures of Green Sunfish and Bluegills (L. macrochirus), and possibly other species. Eighteen fish were stocked in the Bolso Chica River. Additional plantings were made in Lake Elsinore, San Jacinto County, and Cuyamaca Lake (Smith 1895). The early history of 'sunfish' in California is obscure because of the confusion among species. Dill and Cordone (1997) cite recollections of fisheries biologists who saw Green Sunfish and Bluegills in the San Joaquin River between 1908 and 1917. Green Sunfish were probably widely introduced by fishermen transplanting Bluegills from one stream or lake to another and are now widespread in low-elevation waters in California. They are found in watershed streams, including Suisun Creek Walnut-San Ramon Creek (1945), and San Francisquito Creek in 1940-1956 (Leidy 2007), and was present in the Delta by 1963 (Cohen and Carlton 1995). Its habitats include creeks, ponds, ditches, sloughs and reservoirs, such as lower portion of Walnut Creek; Napa River near spillway (Wang 1986). In freshwater portions of the Delta, Green Sunfish, are common to rare, but not abundant (Feyrer and Healy 2003; Brown and Michniuk 2007). Green Sunfish were rare in the brackish Suisun marshes (Matern et al. 2002).

Green Sunfish are especially good at colonizing small bodies of water, including ponds and temporary streams (Moyle 2002). These fish have been found in many small streams in coastal Southern California (Swift et al. 1993), and have been reported from the tidal regions of several coastal streams, including the Santa Clara River, Ventura County (Lafferty and Page 1997), Malibu Creek, San Juan Creek (Orange County), inlets to Carlsbad Lagoon, and the San Diego River (USGS Nonindigenous Aquatic Species Program 2018). The occurrence of Green Sunfish in these small estuaries is likely to be very dependent on rainfall and streamflow.

We have not found reports of Green Sunfish from the tidal Columbia or Willamette Rivers (Hughes and Gammon 1984; Farr and Ward 1994; Systma et al. 2004; Van Dyke et al. 2008). However, it was found in Blue Lake, Portland, a few kilometers from the Columbia River (Wydoski and Whitney 1973, cited USGS Nonindigenous Aquatic Species Program 2018).

Invasion History on the East Coast:

The earliest record of the Green Sunfish (Lepomis cyanellus) on the East Coast is in the tidal Potomac River in 1900 (Jenkins and Burkhead 1993). By 1911, they were found in large numbers in the vicinity of Chain Bridge, at the head of tide in the river (Bean and Weed 1911). It was probably introduced by United States Fish Commission with mixed batches of 'Bream' or 'Sun-Fishes' (Jenkins and Burkhead 1993). There are apparently few recent records from tidal Potomac (Lippson and Moran 1974) but these sunfish are common in the nontidal river (Jenkins and Burkhead 1993), in nontidal waters of Rock Creek and Anacostia River (Lippson et al. 1979), and nontidal creeks at Fort Belvoir, near Gunston Cove (Ernst et al. 1995). In the Susquehanna, 'Bream' were released in the Susquehanna drainage by the United States Fish Commission between 1910-1919 (Bowers 1911; Leach 1919). Green Sunfish were not listed for the Susquehanna in Pennsylvania in 1893 (Bean 1893), 1919 (Fowler 1919), or 1948 (Fowler 1948). However, they were common in the lower Susquehanna (PA) by 1961 (Bielo 1963) and collected below Conowingo Dam after 1972 (McKeown 1984, National Museum of Natural History 1996). They were also found in a creel survey in the Northeast River (Elser 1958) and are apparently common on Susquehanna Flats (Serafy et al. 1995), but rare in the Rhode River (Hines et al. unpublished). They were found in the watersheds of the Severn and Rhode Rivers (Kazyak et al. 1998).

Green Sunfish were not listed for the Delaware River by Fowler (1948) but were collected in Delaware ponds and nontidal streams beginning in 1952 (Raasch and Altemus 1991). Currently, this fish is a stray in tidal freshwater of Delaware River (Horwitz 1986; Weisberg et al. 1996). In the Hudson River drainage in 1936, Green Sunfish were found in a pond near Millwood, New York, and were reported from the main channel of the river in 1976 (Smith and Lake 1990; Mills et al. 1997). They are rare but increasing in the Mohawk River and the lower Hudson (below Troy, Daniels et al. 2005). Green Sunfish were found occasionally in the upper Thames River estuary, near Norfolk, Connecticut, in spring and summer (Jacobson et al. 1980).

Invasion History in Hawaii:

A population of Green Sunfish were discovered in a golf course pond in Kauai in 1990 but was extirpated by 1999 (USGS Nonindigenous Aquatic Species Program 2018).

Invasion History Elsewhere in the World:

Green Sunfish have established populations in Germany, Morocco, South Africa, Brazil, Korea, the Philippines, and Mauritius. Introductions to Japan and Zimbabwe have failed to establish. These introductions were made mainly as forage for introduced 'Black Basses' (Micropterus spp.) (Lever 1996).


Green Sunfish (Lepomis cyanellus) are medium-sized freshwater fish. Fishes of the genus Centrarchidae (Sunfishes and Black Basses) have laterally compressed bodies with a fused spiny and soft dorsal fin. They have 3-8 anal spines, thoracic pelvic fins, and ctenoid scales. The sunfishes of the genus Lepomis have a shallowly forked tail, a smooth edge to the gill cover, and a fleshy 'ear-flap' projecting from the gill-cover. The gill-cover has a stiff rear edge. Green Sunfish have a compressed, somewhat rectangular 'bass-like' body, a large mouth (with the upper jaw extending to the midpoint of the eye), and short, rounded pectoral fins, which do not extend past the eye when bent forward. The dorsal fin has 9-12 spines and 10-12 rays, while the anal fin has three spines and 9-10 rays. There are 41-53 lateral line scales. Their maximum length is 310 mm, but they are usually 150-200 mm long. The back and sides are blue green, with yellow metallic green flecks, and dusky bars on the sides, with a white-to-yellow belly. The earflap is black, with a white margin. There is a large dark spot on the posterior dorsal and anal fins (Hardy 1978; Page and Burr 1991; Jenkins and Burkhead 1993; Moyle 2002).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Chordata
Subphylum:   Vertebrata
Superclass:   Osteichthyes
Class:   Actinopterygii
Subclass:   Neopterygii
Infraclass:   Teleostei
Superorder:   Acanthopterygii
Order:   Perciformes
Suborder:   Percoidei
Family:   Centrarchidae
Genus:   Lepomis
Species:   cyanellus


Apomotis cyanellus ((Rainesque, 1819) 1996-06-13, None)
Chaenobryttus cyanellus ((Rainesque, 1819) 1996-06-13, None)
Icthelus cyanella ((Rainesque, 1819) 1996-06-13, None)
Lepidomus cyannelus ((Rainesque, 1819) 1996-06-13, None)
Telipomis cyannelus ((Rainesque, 1819) 1996-06-13, None)

Potentially Misidentified Species

Lepomis gibbosus
Pumpkinseed (Lepomis gibbosus) differs from the Green Sunfish in having a deeper oval 'typical-sunfish' body, a small mouth, a bright red spot on the earflap, and long, pointed pectoral fins. The Pumpkinseed has thin, wavy lines on the posterior of the anal and dorsal fins (Page and Burr 1991). The Pumpkinseed is native to the Atlantic Slope from New Brunswick to South Carolina, the Great Lakes basin, and the Mississippi-Gulf basins from Manitoba to Missouri (Page and Burr 1991). It is introduced to the San Francisco and Columbia River estuaries (USGS Nonindigenous Aquatic Species Program 2018).

Lepomis gulosus
Warmouth (Lepomis gulosus) resembles the Green Sunfish in having a more rectangular 'bass-like' body, a large mouth. and dark vertical bars running down the body, However, the Warmouth has dark lines radiating from the eyes, and lacks dark spots on the posterior of the anal and dorsal fins (Page and Burr 1991). The Warmouth is native to Atlantic drainages from the James River to Florida, and the southern Great Lakes-Mississippi-Gulf (Page and Burr 1991). It is introduced in the San Francisco and the Columbia river estuaries, and from the Rappahannock River north to the Hudson River (USGS Nonindigenous Aquatic Species Program 2018).

Lepomis macrochirus
Bluegill (Lepomis macrochirus) differs from the Green Sunfish in having a deeper oval 'typical-sunfish' body, a small mouth, a bright red spot on the earflap, and long, pointed pectoral fins. The Bluegill has a black spot on the rear edge of the dorsal fin (Page and Burr 1991). The Bluegill is native to the Atlantic Slope from North Carolina to Florida, the Great Lakes basin, and the Mississippi-Gulf basins from Quebec and Minnesota to Texas (Page and Burr 1991). It is introduced to the San Francisco and Columbia River estuaries, and widely through the western US, and on the Atlantic Slope, from northern North Carolina to Maine (USGS Nonindigenous Aquatic Species Program 2018).

Leponis microlophus
Redear Sunfish (Lepomis microlophus) differs from the Green Sunfish in having a deeper oval 'typical-sunfish' body, a small mouth, longer earflap with a bright red spot, and long, pointed pectoral fins (Page and Burr 1991). Redear Sunfish are native to the Atlantic Slope from Georgia to Florida, and the Mississippi-Gulf basins from Indiana and Illinois and Minnesota to Florida and Texas (Page and Burr 1991). It is introduced to the San Francisco estuary, and on the Atlantic Slope form South Carolina to the Potomac River (USGS Nonindigenous Aquatic Species Program 2018).



Green Sunfish (Lepomis cyanellus) are freshwater fish found in ponds, backwaters, and slow-moving rivers (Page and Burr 1991; Moyle 2002). Males and females are similar in appearance, but males can mature at a smaller size (45 mm) compared to females (65 mm) (Hardy 1978), at ages as early as 6 months, in some populations, but more usually in 2-3 years. Spawning takes place at 16-28 C (Hardy 1978). Males excavate and guard a nesting site, in sand, gravel (or rarely) muck, often near vegetation or logs. Males can produce a grunting sound during mating or courting. Males are territorial and aggressive when defending nesting areas. Females can carry 2000-10000 eggs (Hardy 1978; Jenkins and Burkhead 1994). Eggs hatch in 19-50 hours at 24-28 C. Early maturation and stunting is common in crowded populations, resulting in fish that mature at 100-120 mm (Moyle 2002).

Green Sunfish inhabit a wide range of freshwater habitats, including temporary ponds, streams, and backwaters, and can tolerate a wide range of temperatures, 4-36 C (Hardy 1978; Moyle 2002). They are found mostly in tributaries at the edges of estuaries, with few records from brackish waters (Wang 1986; Peterson 1988), but they have been collected at 10-12 PSU in the Rhode River, a Chesapeake tributary (Hines et al., personal communication). Habitats include 'quiet pools and backwaters of sluggish streams, lakes, and ponds' (Page and Burr 1991) and in shallow 'sunlit waters in creeks, ponds, ditches, sloughs and reservoirs' (Wang 1986). They are generally rare in waters that contain a diverse fish community and are especially abundant in streams disrupted by human activity. They are a pioneer species, good at colonizing streams and pools with depleted fish communities (Moyle 2002). As a relatively small fish with a big mouth, they are opportunistic feeders, feeding on small aquatic insects and crustaceans as a juvenile, and incorporating larger adult insects, crayfishes, and small fishes as they grows (Jenkins and Burkhead 1994; Moyle 2002). Predators of Green Sunfish include larger fishes, such as Largemouth Bass, and humans. However, frequent stunting makes this fish a less desirable catch (Moyle 2002).


micro-crustaceans, aquatic insects, crayfish, fish


fishes (basses), birds, humans


other sunfishes (Lepomis spp.)

Trophic Status:




General HabitatFresh (nontidal) MarshNone
General HabitatNontidal FreshwaterNone
General HabitatSwampNone
General HabitatTidal Fresh MarshNone
General HabitatGrass BedNone
General HabitatUnstructured BottomNone
General HabitatCanalsNone
Salinity RangeLimnetic0-0.5 PSU
Salinity RangeOligohaline0.5-5 PSU
Tidal RangeSubtidalNone
Vertical HabitatNektonicNone

Tolerances and Life History Parameters

Minimum Temperature (ºC)3.9Field, Hardy 1978
Maximum Temperature (ºC)36Moyle 1988
Minimum Salinity (‰)0This is a freshwater species.
Maximum Salinity (‰)12Field, Rhode River, MD, Hines et al. (unpublished data).There is only one published records of Green Sunfish from brackish water (0.7 PSU, Hardy 1978, Peterson 1988).
Minimum Dissolved Oxygen (mg/l)3Moyle 2002
Minimum Reproductive Temperature15.6Field, Hardy 1978
Maximum Reproductive Temperature28None
Minimum Reproductive Salinity0This is a freshwater species.
Minimum Length (mm)45Males, 66 mm for females (Hardy 1978)
Maximum Length (mm)310Page and Burr 1991, but usually less than 200

General Impacts

Green Sunfish (Lepomis cyanellus) were widely intentionally introduced as a 'pan-fish', and unintentionally with stocked Bluegills (Lepomis macrochirus) (Smith 1895; Dill and Cordone 1997). Green Sunfish are often caught by children, but they can be regarded as a pest, because they can produce large populations of stunted fish (Jenkins and Burkhead 1994; Moyle 1992). Some of the more recent introductions of Green Sunfish have been stockings as forage fish for 'Black Basses' (Micropterus spp.) (Dill and Cordone 1997; Lever 1996). They are usually rare and peripheral in estuaries, but in tributaries they have been considered responsible for local extinctions of the California Roach (Hesperoleucus symmetricus) in the Sierra Foothills, and the Tidewater Goby (Eucyclogobius newberryi), in southern California coastal streams through predation (Lafferty and Page 1997; Moyle 2002). They are also potential predators on adults and tadpoles of California Red-Legged (Rana draytoni) and Foothill Yellow-Legged Frogs (R. boylii) (Cohen and Carlton 1995). Hybridization is common among introduced populations of sunfishes, especially in small, turbid bodies of water (Hubbs 1955; Jenkins and Burkhead 1993).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
M060 Hudson River/Raritan Bay 1976 Def Estab
M090 Delaware Bay 1971 Def Estab
M130 Chesapeake Bay 1900 Def Estab
P090 San Francisco Bay 1963 Def Estab
P060 Santa Monica Bay 1971 Def Estab
P050 San Pedro Bay 1895 Def Estab
P027 _CDA_P027 (Aliso-San Onofre) 1972 Def Estab
P030 Mission Bay 1973 Def Estab
P023 _CDA_P023 (San Louis Rey-Escondido) 1975 Def Estab
GL-I Lakes Huron, Superior and Michigan 0 Native Estab
GL-II Lake Erie 0 Native Estab
GL-III Lake Ontario 2002 Def Estab
G330 Lower Laguna Madre 0 Native Estab
G320 Upper Laguna Madre 0 Native Estab
G310 Corpus Christi Bay 0 Native Estab
G300 Aransas Bay 0 Native Estab
G290 San Antonio Bay 0 Native Estab
G280 Matagorda Bay 0 Native Estab
G270 Brazos River 0 Native Estab
G260 Galveston Bay 0 Native Estab
G250 Sabine Lake 0 Native Estab
G240 Calcasieu Lake 0 Native Estab
G230 Mermentau River 0 Native Estab
G220 Atchafalaya/Vermilion Bays 0 Native Estab
G210 Terrebonne/Timbalier Bays 0 Native Estab
G200 Barataria Bay 0 Native Estab
G190 Mississippi River 0 Native Estab
G170 West Mississippi Sound 0 Native Estab
G180 Breton/Chandeleur Sound 0 Native Estab
G160 East Mississippi Sound 0 Native Estab
G150 Mobile Bay 0 Native Estab
G140 Perdido Bay 0 Native Estab
G130 Pensacola Bay 1992 Native Estab
P064 _CDA_P064 (Ventura) 1995 Def Estab
M040 Long Island Sound 1973 Def Estab
P023 _CDA_P023 (San Louis Rey-Escondido) 1974 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


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Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta, U.S. Fish and Wildlife Service and National Sea Grant College Program (Connecticut Sea Grant), Washington DC, Silver Spring MD.. Pp. <missing location>

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Jacobson, Paul M. (1980) Studies of the Ichthyofauna of Connecticut, Storrs Agricultural Experiment Station. Papers 82: 1-39

Jenkins, Robert E.; Burkhead, Noel M. (1993) Freshwater Fishes of Virginia, American Fisheries Society, Bethesda, MD. Pp. <missing location>

Kazyak, Paul (1998) Lower Potomac River Basin: Environmental Assessment of Stream Conditions, Maryland Department of Natural Resources, <missing place>. Pp. <missing location>

Kazyak, Paul F; Randle, Doug A.; Christmas, John F.; Stranko, Scott A. (1998) <missing title>, Maryland Department of Natural Resources, Annapolis. Pp. <missing location>

Lafferty, Kevin; Page, Carl J. (1997) Predation on the endangered Tidewater Goby, Eucyclogobius newberryi, by the introduced African clawed frog, Xenopus laevis, with notes on the frog parasites., Copeia <missing volume>(3): 589-592

Leach, Glenn H. (1921) Report on the propagation and distribution of food fishes., In: (Eds.) Report of the United States Bureau of Fisheries for 1919.. , Washington D.C.. Pp. <missing location>

Lee, David S.; Gilbert, Carter R.; Hocutt, Charles H.; Jenkins, Robert E.; McAllister, Don E.; Stauffer, Jay R. (1980) Atlas of North American freshwater fishes, North Carolina State Museum of Natural History, Raleigh. Pp. <missing location>

Leidy, R. A. (2007) <missing title>, San Francisco Estuary Institute, Oakland. Pp. <missing location>

Lippson, Alice J.; Haire, Michael S.; Holland, A. Frederick; Jacobs, Fred; Jensen, Jorgen; Moran-Johnson, R. Lynn; Polgar, Tibor T.; Richkus, William (1979) Environmental atlas of the Potomac Estuary, Martin Marietta Corp., Baltimore, MD. Pp. <missing location>

Lippson, Alice J.; Moran, R. Lynn (1974) Manual for identification of early developmental stages of fishes of the Potomac River estuary., In: (Eds.) . , Baltimore MD. Pp. <missing location>

Massmann, William H.; Ladd, Ernest C.; McCutcheon, Henry M. (1952) A biological survey of the Rappahannock River, Virginia, Virginia Fisheries Laboratory Special Scientific Report 6: 1-152

Matern, Scott A.; Moyle, Peter; Pierce, Leslie C. (2002) Native and alien fishes in a California estuarine marsh: twenty-one years of changing assemblages, Transactions of the American Fisheries Society 131: 797-816

Matern, Scott; Meng, Lesa; Pierce, Leslie C. (2001) Native and introduced larval fishes of Suisun Marsh, California: the effects of freshwater flow., Transactions of the American Fisheries Society 130: 750-765

Maurakis, Eugene; Woolcott, William S.; Jenkins, Robert E. (1987) Physiographic analyses of the longitudinal distribution of fishes in the Rappahannock River, Virginia, ASB Bulletin 34(1): 1-14

McKeown, Paul E. (1984) Additions to ichthyofauna of the Susquehanna River with a checklist of fishes of the Susquehanna River drainage below Conowingo Dam, Proceedings of the Pennsylvania Academy of Science 58: 187-192

Mills, Edward L.; Scheuerell, Mark D.; Carlton, James T.; Strayer, David (1997) Biological invasions in the Hudson River: an inventory and historical analysis., New York State Museum Circular 57: 1-51

Moyle, Peter B., Light, Theo (1996) Biological invasions of fresh water: empirical rules and assembly theory, Biological Conservation 78: 141-161

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Page, Lawrence M.; Burr, Brooks M. (1991) Freshwater Fishes: North America North of Mexico, Houghton-Mifflin, Boston. Pp. <missing location>

Raasch, Maynard S. (1996) Delaware's Freshwater and Brackish-water Fishes: A Popular Account, T.F.H. Publications, Neptune, NJ. Pp. <missing location>

Raasch, Maynard S.; Altemus, Vaughn L., Sr. (1991) Delaware's freshwater and brackish water fishes, a popular account , Society of Natural History of Delaware, Wilmingotn, Delaware. Pp. <missing location>

Rahel, Frank J. (2000) Homogenization of fish faunas across the United States., Science 288: 854-856

Serafy, J. E.; Harrell, R. M. (1993) Behavioral responses of fishes to increasing pH and dissolved oxygen: field and laboratory observations, Freshwater Biology 30: 53-61

Smith, C. Lavett, Lake, Thomas R. (1990) Documentation of the Hudson River fish fauna, American Museum Novitates 2981: 1-17

Smith, Hugh M. (1895) A review of the history and results of the attempts to acclimatize fish and other water animals in the Pacific states., Bulletin of the U. S. Fish Commission 15: 379-472

Starnes, Wayne C.; Odenkirk, John; Ashton, Matthew J. (2011) Update and analysis of fish occurrences in the lower Potomac River drainage in the vicinity of Plummers Island, Maryland—Contribution XXXI to the natural history of Plummers Island, Maryland, Proceedings of the Biological Society of Washington 124: 280-309

Swift, Camm C., Haglund, Thomas R., Ruiz, Mario, Fisher, Robert N. (1993) The status and distribution of the freshwater fishes of southern California, Bulletin of the Southern California Academy of Sciences 92(3): 101-167

U.S. National Museum of Natural History 1996-2014 NMNH Fish Collection Database.. <missing URL>

USGS Nonindigenous Aquatic Species Program 2003-2024 Nonindigenous Aquatic Species Database.

Waldman, John R.; Lake, Thomas R.; Schmidt, Robert E. (2006) Biodiversity and zoogeography of the fishes of the Hudson River watershed and estuary, American Fisheries Society Symposium 51: 129-150.

Wang, Johnson C. S. (1986) Fishes of the Sacramento - San Joaquin Estuary and Adjacent Waters, California: A Guide to the Early Life Histories, IEP Technical Reports 9: 1-673

Wright, Rosalind; et al. (2022) First direct evidence of adult European eels migrating to their breeding place in the Sargasso Sea, Scientific Reports 3,2(25362): Published online