Physical Description
Green sunfish have the deep and slender body typical of the bluegill, redear, pumpkinseed and other sunfish, but they are slightly thicker than others. Coloration is dark green to bluish-green with emerald and yellow reflections on the sides, and yellow to white on the belly. In some geographical areas they have vertical bars on the side, while in others they are heavily spotted on the side.
Green sunfish have a large head and mouth with heavy lips, orange eyes and either blue spots or wavy lines on the face. The gill flap is dark, often black, but rimmed with yellow or white. They have a dorsal fin with 10 to 11 spines that is connected to a second dorsal fin with soft rays. The tail is only slightly forked and somewhat shaped like a broom.
Green sunfish can be distinguished from other sunfish by their noticeably larger head and mouth, body thickness, as well as the black and bright yellow or orange trimming on their fins.
Range
Green sunfish have a wide distribution range, and are native to the central plains of North America between the Appalachian and Rocky Mountains, from Ontario, Canada and New York in the north to the Gulf Coast and northern Mexico in the south. They have been so widely introduced that their range now includes virtually every state, though populations are stronger within their native range.
Habitat
Green sunfish are found in warm, slow-moving backwaters and quiet pools of sluggish streams, lakes and ponds. They are often near heavy cover such as brush piles, large rocks or thick aquatic vegetation, especially when predators are present. They are also found near many man-made structures such as boat docks and seawalls built near moderately shallow water.
Green sunfish have a high tolerance for ecological conditions that can prevent other sunfish species from surviving, such as low levels of dissolved oxygen and high levels of turbidity, or muddiness. They have also been found to thrive in polluted waters.
Spawning Habits
Green sunfish spawning season begins in spring or early summer, as water temperatures rise to about 70 F, and may continue all summer in some bodies of water. Males build nests in colonies that are closely packed together. These colonies are built over gravel, rocky or silt bottoms in shallow water near shore. Several females may spawn together in a nest with one male. Females deposit between 2,000 and 10,000 eggs, which hatch three to five days later.
Males aggressively guard the nests for up to one week after the eggs are deposited, or until newly hatched fry can swim freely. Spawning males take on orange to whitish fringes on their dorsal, tail and anal fins.
Green sunfish are such prolific breeders that they often overpopulate small lakes and ponds and become stunted. They also readily hybridize with other species of sunfish.
Food Usage/Selection
Green sunfish are carnivorous, aggressive feeders. They eat both aquatic and terrestrial insects, favoring dragonfly and mayfly nymphs, beetles and caddis fly larvae. They also eat crayfish, mollusks and small fish.
Green sunfish feed most actively around sunrise and sunset. They usually are ambush hunters that readily attach insects on the surface but will also chase prey into shallow open water.
Because it has a larger mouth than other sunfish, it often consumes larger forage than other sunfish, thus reducing the competition between the species.
Sporting Qualities
Green sunfish eagerly take a baited hook or lure and are good table fare, but because they are so small an angler has to catch a lot to provide a good meal. They are not widely sought but rather are often caught while fishing for other species. Their large mouths and aggressive nature often leads to frequent strikes on large lures that would scare away other sunfish.
Green sunfish are scrappy fighters and great sport on light tackle. Most anglers pursue them with ultralight spinning tackle, lines of 6-pound test or less, and a variety of small baits and lures, including worms, crickets and grasshoppers, tiny jigs and small spinners. Green sunfish can also be caught using fly tackle, usually 4-weight rods and lines or lower, with small popping bugs, dry flies and weighted nymphs.
Notes
The world record is 2 pounds, 2 ounces caught from Stockton Lake, Missouri, and an identically weighted fish from a strip pit in Kansas.
Green sunfish are a preferred prey species for largemouth bass and large catfish because of their soft spines and thick bodies for their size. They make excellent bait for flathead catfish
(where legal).
In streams where green sunfish have been introduced in California, they are believed to have helped deplete the California roach.
