Bluegill, Lepomis macrochirus, are deep-bodied laterally compressed fish with a black spot on the end of their opercular flap, or gill cover. They have olive-green backs and usually have a blue or purple tint to their sides. Breeding males have orange on the flank as well. At adulthood, they are 4-12 inches.
They are commonly found East of the Rocky Mountains, but have been introduced almost everywhere in North America as well as parts of South America, Europe, South Africa, and Asia. They live in shallow streams, ponds, lakes, and small rivers. They like to hide out in and around old tree stumps or weed beds.
Bluegill are omnivores, feeding mostly on aquatic insects, crayfish, and small fish. Bluegill are day feeders because they rely heavily on eyesight to hunt. They are a prey species for walleye and bass.
These fish spawn from late May into August, most spawning happening in June, when the water is between 65 and 85 degrees Fahrenheit. Males make nests in groups with 20-50 other males in shallow water that is less than 1 meter deep. The nests are circular and 8-12 inches in diameter. They are sand or fine gravel and males fan all the debris away. When the nest is completed, males will wait in their nest and attract females by grunting.
When a female enters the nest, the pair swims in circles for a while, stop and touch bellies while releasing sperm and eggs, then start swimming in circles again. The male then guards the nest. Females can spawn up to three times each summer, releasing 2,500 to 80,000 eggs each time they spawn.
Learn More About Bluegill
Because of their spawning nature, it is critical that large male bluegill are released back into a waterbody. Chris Seylar shares more on the importance of this in Reasons and Sciences Behind Letting Big Bluegill Go.
