The bluegill (Lepomis macrochirus), sometimes referred to as "bream," "brim," "sunny," or "copper nose" as is common in Texas, is a species of North American freshwater fish, native to and commonly found in streams, rivers, lakes, ponds and wetlands east of the Rocky Mountains. It is the type species of the genus Lepomis (true sunfish), from the family Centrarchidae (sunfishes, crappies and black basses) in the order Perciformes (perch-like fish).
Bluegills can grow up to long and about . While their color can vary from population to population, they typically have a very distinctive coloring, with deep blue and purple on the face and gill cover, dark olive-colored bands down the side, and a fiery orange to yellow belly. They are omnivorous and will consume anything they can fit in their mouth, but mostly feed on small aquatic insects and baitfishes. The fish are important prey for bass, other larger sunfish, northern pike and muskellunge, walleye, trout, herons, kingfishers, snapping turtles and otters, and play a key role within the food chain of its freshwater ecosystem.
A popular panfish among anglers, bluegill usually hide around and inside old tree stumps in swamps and other underwater structures (e.g. snags), and can live in either deep or very shallow water. Bluegills also like to find shelter among aquatic plants and in the shade of trees along banks, and will often move from one cover to another depending on the time of day or season.
The bluegill is noted for the black spot (the "ear") that it has on each side of the posterior edge of the gills and base of the dorsal fin. The sides of its head and chin are commonly a dark shade of blue. The precise coloration will vary due to the presence of neurally controlled chromatophores under the skin. The fish usually displays 5–9 vertical bars on the sides of its body immediately after being caught as part of its threat display. It typically has a yellowish breast and abdomen, with the breast of the breeding male being a bright orange.