Latin name

Lepomis macrochirus

Other names

Bream, brim, sun perch, blue perch, blue sunfish, copperbelly, blue bream, copperhead bream, redbreasted bream, bluegill sunfish, roach.

Identification

The bluegill has a considerably compressed oval or rounded body, a small mouth, and a small head, qualities typical of members of the sunfish family. The pectoral fins are pointed. The coloration of the fish varies greatly from lake to lake, from olive, dark blue or bluish purple to spotted yellow and green on the sides with an overall blue cast. Some fish, especially those found in quarry pits, may be transparent and colorless. There are usually six to eight vertical stripes on the flanks, which may or may not be visible. The gill cover extends to form a broad black flap, dull in young individuals, which is not surrounded by a lighter border as in other sunfish. There are dark blue stripes on the lower part of the cheeks between the chin and the gill cover, and there is often a dark mark on the bottom of the anal fin. The breeding male has a brighter coloration: blue head and back, bright orange breast and belly, and black pelvic fins.

Distribution

Native to about the eastern half of the United States, the bluegill range extends south from the St. Lawrence River through the Great Lakes and Mississippi River Basin, east from New York to Minnesota, and drains south from the Cape Fear River in Virginia to the Rio Grande in Texas, including states east to Florida and west to New Mexico. The fish are also found in a small part of northeastern Mexico, but they have been widely distributed in other parts of North America, as well as in Europe, South Africa, Asia, South America, and Oceania.

Habitat

Although primarily lake fish, bluegills inhabit sluggish streams and rivers, vegetated lakes and ponds, marshes, and stream basins. They prefer calm waters and may stay in very shallow areas, especially early in the season and during spawning, although in summer, when surface and shallow water temperatures are warm, they may descend to depths of 30 feet or more. They occupy the same habitat as their larger relative, largemouth bass.

Size

These fish range in length from 4 to 12 inches, averaging 8 inches, with a maximum length of 161⁄4 inches. The largest fish ever caught was a 4-pound, 12-ounce specimen caught in 1950. The growth of bluegill varies so much that age estimates based on size are inaccurate. Bluegills are believed to live 10 years.

Life history and Behavior

The age of sexual maturity varies depending on conditions and terrain, although most fish reach spawning age at 2 to 3 years of age. Spawning occurs from April through September, starting at water temperatures around 70 °F. Males build shallow, round nests in water up to 6 feet deep on sandy or muddy bottoms. These nests are in colonies of up to 500 along the shoreline, densely concentrated and easily detected by anglers. Females can lay anywhere from 2,000 to 63,000 eggs that hatch 30 to 35 hours after fertilization. Usually, fish spawn many times, with one fish laying eggs in several nests and one socket receiving eggs from several females. The males guard the eggs throughout the incubation period and remain to protect the newly hatched young. When they reach 1⁄4 to 1⁄3 inches in length, the young leave the nest and go into deeper water. Bluegills move in small schools, typically consisting of individuals of similar size.

Food and feeding habits

The bluegills eat a variety of small organisms, including insects, crustaceans, fish eggs, minnows, snails, worms, and sometimes even plant material. Juveniles feed mainly on crustaceans, insects, and worms. Adults feed at different depths depending on temperature, so they obtain food both on the bottom and on the surface. Active mostly at dusk and dawn, larger fish move to shore in the morning and evening to feed, and stay in deeper water during the day.

Reproduction

No information