Bluegill

Lepomis macrochirus

Type: freshwater

Bluegill

Physical Characteristics

Deep, compressed, oval-shaped body with a small mouth. Color is typically olive-green on the back with a yellowish belly and 5-9 dark vertical bars on the sides. Features a prominent dark blue or black spot on the opercle (ear flap) and a dark blotch at the posterior base of the dorsal fin. Pectoral fins are long and pointed.

Habitat & Distribution

Native to North America, they inhabit lakes, ponds, slow-moving rivers, and creeks. They prefer warm, quiet waters with abundant aquatic vegetation, submerged logs, or structures for cover.

Size & Weight

Typically 6-10 inches in length and weighing 0.5 to 1 pound. Maximum recorded size is 16 inches and weight of 4 pounds 12 ounces.

Similar Looking Species

Green sunfish (larger mouth, white-tipped fins), Pumpkinseed (red spot on ear flap, turquoise facial streaks), and Redear sunfish (larger, cherry-red edge on opercle).

Ecological Role

Acts as both a significant prey source for larger predators like largemouth bass and herons, and as a predator of invertebrates. Helps control insect and crustacean populations.

Diet

Opportunistic omnivore. Diets include aquatic insects, small crustaceans (daphnia, shrimp), small fish, fish eggs, and occasionally plant material. They feed throughout the water column.

Behavior

Highly social fish that often form large schools. They are diurnal, being most active during dawn and dusk. Adults are often territorial, especially during the nesting season.

Reproduction

Spawning occurs in late spring to summer when water temperatures reach 70-75°F. Males construct circular nests in shallow, sandy, or gravelly flats, often in dense colonies. Males guard the eggs and fry aggressively.

Conservation Status

Least Concern (IUCN). Populations are stable and they are widely introduced outside their native range.

Identification Tips

Look for the solid black opercular flap and the distinct dark smudge/blotch on the soft dorsal fin. Their small, 'bream' type mouth does not extend past the eye.

Interesting Facts

Bluegills have been known to live up to 11 years. They are remarkably adapted to see in low light and can move their eyes independently to search for prey and predators simultaneously.

Identified on: 5/26/2026

Mode: Standard