The green sunfish (''Lepomis cyanellus'') is a species of aggressive freshwater fish in the sunfish

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

( Centrarchidae) of order Centrarchiformes. The green sunfish does not always grow large enough to be an appealing target for anglers, but it is kept as an

aquarium An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

fish by hobbyists. They grow to be long on average, but can achieve a length of .

Geographic distribution

The green sunfish is native to a wide area of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, from the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

in the west to the

Appalachian Mountains The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain ...

in the east and from the

Hudson Bay Hudson Bay, sometimes called Hudson's Bay (usually historically), is a large body of Saline water, saltwater in northeastern Canada with a surface area of . It is located north of Ontario, west of Quebec, northeast of Manitoba, and southeast o ...

basin in

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

to the Gulf Coast in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

and northern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. They are specifically indigenous to a number of lakes and rivers, such as the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes spanning the Canada–United States border. The five lakes are Lake Superior, Superior, Lake Michigan, Michigan, Lake Huron, H ...

and some of the basins of the

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

. Green sunfish have been introduced to many bodies of water all across the United States. The green sunfish is considered an

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

by the states of

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

and

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

, with unconfirmed presence in

Vermont Vermont () is a U.S. state, state in the New England region of the Northeastern United States. It borders Massachusetts to the south, New Hampshire to the east, New York (state), New York to the west, and the Provinces and territories of Ca ...

and

New Hampshire New Hampshire ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Massachusetts to the south, Vermont to the west, Maine and the Gulf of Maine to the east, and the Canadian province of Quebec t ...

, namely the

Connecticut River The Connecticut River is the longest river in the New England region of the United States, flowing roughly southward for through four states. It rises 300 yards (270 m) south of the U.S. border with Quebec, Canada, and discharges into Long Isl ...

and its tributaries. Their invasive potential is due in part to their penchant for chasing other sunfish away from mutually preferred habitat of submerged vegetation, a form of interference competition, their relatively large mouth, high fecundity and ability to tolerate sediment pollution. In the state of

, as of 2021, anglers must destroy green sunfish when caught and should report their catch to a state fisheries biologist. In the state of

, a permit is required in order to possess green sunfish as it is listed as a prohibited non-native species there. ''L. cyanellus'' has been transplanted to countries in

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

, and

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

, where it has become established in some.

Description

The green sunfish is blue-green in color on its back and sides with yellow-flecked bony-ridged (

ctenoid A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as w ...

) scales, as well as yellow coloration on the

ventral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

sides. The gill covers and sides of head have broken bright blue stripes, causing some to mistakenly confuse them with bluegill. They also have a dark spot located near the back end of the

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

, the base of the

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

and on the opercular flap. The margins of the soft-rayed portion of the dorsal fin, the caudal fin, the ventral fins and the anal fin are orange or yellow, most pronounced in individuals during breeding periods. ''L. cyanellus'' has a relatively big mouth and long snout that extends to beneath the middle of the eye. Its

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s are short with rounded edges containing 13 to 15 pectoral fin rays, a dorsal fin with about 10 dorsal spines followed by 10 to 12 rays and a homocercal tail. The typical length ranges from about 3–7 in and the fish usually weighs less than a pound. The green sunfish reaches a maximum recorded length of about , with a maximum recorded weight of . Identification of sunfish species from one another can sometimes be difficult as these species frequently hybridize.

Habitat

The species prefers areas in sluggish backwaters, lakes, and ponds with gravel, sand, or bedrock bottoms. They also can be found in very muddy waters and are able to tolerate poor water conditions. Green sunfish tend to spend their time hiding around rocks, submerged logs, plants, and other things that provide cover.

Diet

Its diet can include aquatic

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s and

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

, insects that fall into the water,

crayfish Crayfish are freshwater crustaceans belonging to the infraorder Astacidea, which also contains lobsters. Taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some spe ...

snail A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...

s, other

molluscs Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

, turtle food, frogs, some small fish, fish eggs,

bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic animal, aquatic invertebrate animals, nearly all living in sedentary Colony (biology), colonies. Typically about long, they have a spe ...

ns,

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

, other small

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s, and sometimes plant material. They are omnivores.

Reproduction

Green sunfish begin

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

in the summer with the exact time varying with location and water temperature. When they do spawn, the males create nests in shallow water by clearing depressions in the bottom, often near a type of shelter such as rocks or submerged logs.(Paulson 2004). The male defends his nest from other males using visual displays and physical force when necessary. On occasion, simply constructing a nest is sufficient for the male to attract a mate, but when it is not he will court a female with grunts and lead her to his nest. They continue their courtship dance, swimming with each other around the nest until the female descends to deposit her eggs in the nest. The female will lay 2,000 to 26,000 eggs and leave them for the male to guard. He keeps watch over them until they hatch in three to five days, while protecting them and fanning them with his fins, keeping them clean and providing them with oxygenated water. When they hatch, the fry remain near the nest for a few days, then leave to feed and fend for themselves. After the eggs have hatched, the male will often seek to attract another female to lay her eggs in his nest. ''Lepomis cyanellus'' typically live between 4 and 6 years in the wild. Green sunfish tend to nest in areas close to other green sunfish, as well as other species of sunfish. Due to the close proximity of multiple nests, a green sunfish female may deposit some of her eggs into the nest of a male of a different species. This in turn leads to the next generation containing some amount of hybrids. These green sunfish hybrids will often look like a combination of their parents, often making it difficult to distinguish one species from another.

Anatomy and physiology

The

retina The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional ...

of the green sunfish includes a mosaic of

cone cell Cone cells or cones are photoreceptor cells in the retina of the vertebrate eye. Cones are active in daylight conditions and enable photopic vision, as opposed to rod cells, which are active in dim light and enable scotopic vision. Most v ...

s and double cone cells in a regular arrangement. The green sunfish has been theorized to have vision that is sensitive to the polarization of light, which could enhance visibility of targets in scattering media if a processing technique called polarization difference imaging is employed by the fish. Experimental evidence, however, suggests that green sunfish are not able to visually discriminate on the basis of light polarization. Thus, the function of the green sunfish's retinal patterning is not known, although the two different types of cone cell present in green sunfish do facilitate color discrimination.

IGFA records

The

International Game Fish Association The International Game Fish Association (''IGFA'') is the leading authority on angling pursuits and the keeper of the most current world record fishing catches by fish categories. Fishermen who are sport fishers and anglers are careful to follow ...

(IGFA) all-tackle world record for the species stands at , caught from

Stockton Lake Stockton Lake is a reservoir located in southeastern Cedar County, northeastern Dade County, and southwestern Polk County, Missouri. The lake is V-shaped, and covers , with of shoreline. It has three marinas, and 10 public-use areas. It has a ...

, Missouri in 1971.

Etymology

The generic name ''Lepomis'' derives from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

λεπίς (scale) and πώμα (cover, plug, operculum). The specific epithet, ''cyanellus,'' derives from the Greek ''κυανός'' (blue).

Aquaria

An aggressive sunfish, it is difficult to keep with other green sunfishes, other sunfishes, or even other perciform fishes in general unless kept in very spacious aquaria or ponds. Like many fishes, it is more tolerant of distantly related species (i.e., catfishes and minnows), if they are too large to be eaten. The green sunfish accepts a variety of foods, including flakes, pellets, krill, brine shrimp, bloodworms, and live prey.

References

General References

* * * * * * *Axelrod, Herbert R. ''et al.'' (2007) ''Dr. Axelrod's Atlas of freshwater aquarium fishes'' T.F.H. Publications, Neptune City, New Jersey, *Philips, Gary, Schmid, W., Underhill, J. (1982) "Fishes of the Minnesota Region". University of Minnesota Press, Minneapolis, Minnesota, *Page, Lawrence, Burr, B. (1991) "A Field Guide to Freshwater Fishes". Houghton Mifflin Company, Boston, New York, *"Green Sunfish." Ohio Department of Natural Resources - Camping, Boating, Fishing, Hunting, Biking, Hiking in Ohio. Web. 26 Apr. 2011. . *"Sunfish Biology and Identification: Minnesota DNR." Minnesota Department of Natural Resources: Minnesota DNR. Web. 26 Apr. 2011. . *"Green Sunfish: Identifying Characteristics." Wyoming Game and Fish - Home - 1. Web. 26 Apr. 2011. . *Paulson, Nicole, and Jay T. Hatch. "Fishes of Minnesota-Green Sunfish." Green Sunfish. Minnesota Department of Natural Resources' MinnAqua Aquatic Program, 25 Aug. 2004. Web. 30 Apr. 2011. . {{Authority control Lepomis Freshwater fish of the United States Fauna of the Great Lakes region (North America) Fauna of the Eastern United States Fish described in 1819 Taxa named by Constantine Samuel Rafinesque