What's In a Name?
Bluegill: refers to the blue-ish scales towards the bottom of the gills

Lepomis (leh-pome´-iss) means "scaled gill cover" in Greek
macrochirus (macrow- kai´-russ) means "large hand" in Greek, possibly based on the size and shape of the body

How Big Do They Get?
How Long Do They Live?
The growth of the bluegill in the first 3 years is fast; but once they reach maturity the rate slows down considerably. They can easily grow to a range of 90-130 mm (3.5- 5.1 in) in 3 years and up to 200 mm (8 in) in 7-9 years. In the best possible conditions in Minnesota, they may reach to 250-300 mm (10-12 in). The common weight of this fish is usually less than 0.2 kg (0.5 lbs), but occasionally it may reach 1 kg (2.2 lbs). The hook and line record for Minnesota is 1.37 kg (2 lb 13 oz).

Many bluegills reach the age of 5 to 8 years and in extreme cases may reach 11 years old. In some lakes, bluegills become too numerous and a stunted population results. These fish often do not live beyond 4 years and rarely exceed 90 mm (3.5 in) in length.

What Eats Them?
Mostly larger predatory fish, such as largemouth bass, northern pike, yellow perch, and even bigger bluegill, target the young and small adult bluegills for a food source. Since small bluegills travel in schools in shallow water, animals like herons and otters can easily catch them. The large adults escape most predation because the shape of their bodies makes them hard to swallow. Instead large adults, as well as small ones, end up on many anglers' hooks, and become a favorite treat to breakfast, lunch, or dinner.

How Do They Reproduce?
The spawning season for the bluegill starts in late May and goes into early August, (peak spawning is in June) at water temperatures of 19-27° C (67-80° F). Males arrive first at spawning sites and start to scoop out round depressions in areas of gravel and coarse sand. Bluegills usually form a community of 40-50 these nests in one area. The males are very protective and chase everything away from the nests, especially other male bluegill. Some will even attack snorkelers and divers if they come to the edge of the nest. When a female bluegill approaches, the male starts circling the nest while making grunting noises. The motion and sound appear to attract the female. If the female goes into the nest, both male and female circle around it and finally come to rest in the middle. With the male upright and the female at any angle, the pair touch bellies, quiver and spawn. These actions are repeated at irregular intervals several times. Once the spawning is done, the male then chases the female out of the nest and goes back to protecting the nest. Other females may spawn later in the same nest, and the same female will spawn in other nests.

Sometimes a smaller male hides in the nearby weeds. Just as the spawning act begins, he darts into the nest between the resident male and female and releases sperm. Then he hightails it back to the weeds. These little guys are called "sneakers" and it's easy to tell why.

The size of the female has a large effect on how many eggs she will produce. The number can range from 1,000 in stunted fish to nearly 70,000 in a large, healthy fish. A single nest typically will have 10,000-100,000 eggs (they are really embryos) in it usually from several different females. The male continues to fan the embryos and protect the nest. When the larvae hatch they spend a few days "wriggling" in the nest before they swim up into the water column. At that point, they are on their own.

Conservation and Management
The bluegill is the most sought-after sunfish in Minnesota. All total there are probably more bluegills caught by anglers in Minnesota than any other species of fish. We do little to manage this species, except in some lakes where adult sizes are small. In these lakes we try to reduce the population size by increasing the number of fish caught by anglers. It usually doesn't work.