Editing Lepomis cyanellus

|sexing=:Males are slightly larger than females of the same age.

|tank_compatibility=:The Green Sunfish (''Lepomis cyanellus'') is an aggressive [[Centrarchidae|centrarchid]], and although smaller than its cousins the [[Bluegill]] (''[[Lepomis macrochirus]]'') and the [[Pumpkinseed]] (''[[Lepomis gibbosus]]''), it can dominate them behaviourally. In the wild, green sunfish inhabit the weeded [[littoral zone]], excluding Bluegill and Pumpkinseed. In captivity, the green sunfish is a powerful fish, capable of overpowering many other species, even fish larger than itself. This species may be stocked in species tanks, where they form loose schools in which no one is [[hyperdominant]], although breeding behaviour may necessitate removing some individuals. Green sunfish may also be kept with similarly sized [[catfish]], such as the [[Brown Bullhead]] (''[[Ameiurus nebulosus]]''). It is not advisable to house green sunfish with other [[Sunfish]], because the green sunfish are likely to injure the less aggressive species. It is possible to keep Green Sunfish with [[Neotropical]] [[Cichlidae|Cichlids]] of similar size and temperament, such as the [[Convict Cichlid]] (''[[Archocentrus nigrofasciatus]]''), [[Texas cichlid]] (''[[Herichthys cyanoguttatus]]''), or [[Jack Dempsey]] (''[[Cichlasoma octofasciatum]]''). However, given the subtle differences in their behavioural repertoires, it is more prudent not to mix them.

|diet=:Green Sunfish are the most predatory species of the genus ''[[Lepomis]]'', preying on insects, crustaceans, and smaller fish. In captivity, however, they easily adapt to thawed frozen items, such as [[brine shrimp]] or [[blood worms]], and pelleted foods marketed for Cichlids. They can also be given live foods like [[earthworm]]s or [[feeder fish|"feeder" fish]], but this is not necessary.

|feeding_regime=:Once or twice a day for adults, four to six times a day for [[fry]] (babies).

|environment_specifics=:Green sunfish come from the quiet, cool to warm waters of [[North America|North America's]] Midwest, but have been introduced elsewhere. They prefer thickly vegetated, slow-moving water near the edges of ponds or lakes where they can stalk smaller fish, and feel secure from larger predators, such as [[Largemouth Bass]] (''[[Micropterus salmoides]]'') or wading birds. Their aggressive behaviour allows them to occupy this favoured habitat to the exclusion of other fishes. Green sunfish can also be found in the deeper, calmer parts of streams and creeks, or schooling in open water when food is available and it is safe to do so. In the aquarium, they should have ample plant cover, as well as open areas for free swimming. The [[Substrate|gravel]] should be dark to tan in colour, and of fine grain in the event that the male Green Sunfish attempts to excavate a spawning pit or [[nest]] with his caudal fin (unlike Cichlids, which use their mouths to dig).

|behaviour=:Like other [[Perciformes|perciform]] fish (Cichlids, [[anabantoid]]s), Green Sunfish appear to make themselves look larger during [[agonistic]] bouts with rivals. To intimidate another fish from the side, green sunfish extend their [[fins]] and wave their tail in their opponent's face. To look more intimidating from the front, Green Sunfish expand or flare their gill covers (opercula). If these tactics don't work, actual fighting with bodily contact may take place, in which the green sunfish will bite the other fish. Green Sunfish are considered a good "[[wet pet]]", though, because they interact with people through their aquarium glass, appearing to get excited at feeding times.

|identification=:True to their name, Green Sunfish have a yellowish-green base colour all over their body. They have iridescent, wavy blue lines on their cheeks, as well as iridescent blue flecks on their flanks. Their [[pectoral fin]]s are a clear to faint yellow colour, their [[pelvic fin]]s white to yellow, and their belly a pale yellow. Their [[unpaired fins]] have clear to white, yellow, or orange edges along the edges. As in other Sunfish, there is a black "ear flap" where the operculum meets the head. When excited or breeding, ten to twelve dark green to black vertical [[bars]] appear on the head, flanks, and [[caudal peduncle]] (base of the [[caudal fin]], or tail). The most visible bar connects the single black spots found at the base of the [[dorsal fin|dorsal]] and [[anal fin|anal]] fins. Given adequate room and nutrition, green sunfish may reach {{cm|20|25}} [[standard length]], but commonly reach about {{cm|15}} standard length.

:Green Sunfish are a sport fish in North America, so obtain a fishing license prior to collection. Green Sunfish may be captured using conventional hook-and-line angling, but this may injure their mouths. Thus, baiting a minnow trap is a safer way to catch smaller fish, and using a net is a safer way to catch larger individuals.