Bluegill are an important species when it comes to fisheries management. Bluegill provide an excellent forage for bass due to their ability to reproduce at incredible rates. During one summer, a female bluegill can spawn three times releasing 2,300 to 81,100 eggs per spawn. This rate of reproduction is necessary to maintain adequate bass forage in a balanced bluegill/largemouth bass fishery and is why bluegill are preferred over other sunfish species.
The bluegill (Lepomis macrochirus) is a member of the sunfish family. This family of fish contains many species, including bass and crappie. Bluegill and other sunfish, sometimes called bream, are often incorrectly referred to as perch. Perch, however, are very different. Perch belong to a separate family of fish not related to bluegill or other sunfish. Common species from the perch family include walleye, sauger, yellow perch and darters. Many people mistake any small sunfish they see or catch, such as a redear or shellcracker, green sunfish, longear, coppernose or hybrid sunfish, for a bluegill. Therefore, when stocking a pond or making fisheries management decisions, it is important to be able to properly identify bluegill.
The bluegill is mostly known by its small mouth, black or dark navy opercular (gill) flap, flat compressed body and faint dark spot at the rear base of the dorsal fin (fin on the back). Vertical bars are normally visible on their side, while body color varies, depending on water quality, sex and age. The dorsal fin usually has 10 spines, but may range from nine to 11, whereas the anal fin has just three spines.
Bluegill become sexually mature when they are approximately three inches long and spawn when water temperatures are 67° F to 89° F, but prefer 72° F to 79° F. Spawning beds are usually found in water 1 to 5 feet deep. To construct the nest, the male sweeps away debris creating a shallow circular depression about 2 to 6 inches deep and 4 to 24 inches wide. Substrates such as sand or gravel are chosen as preferred nest sites. Bluegill are considered colony spawners, meaning 50 or more males may construct their nests in one location.
Once the nest is complete, the male begins searching for a female. To attract a female, the brightly colored males will circle the nest making a series of grunt-like sounds. After the male finds a female, the two circle the nest. Females usually release only a portion of their eggs in the first spawn and the remaining eggs in one or more successive spawns. A female may release her eggs into multiple nests and more than one female may deposit her eggs into a single nest. After fertilizing the eggs, the male will defend the nest from predators and aerate the eggs by periodically fanning the nest. Incubation takes one to six days depending on water temperature.
Fry (newly hatched fish) feed on the yolk sac of the egg for the first few days. Once the yolk sac has been depleted, the fry begin feeding on zooplankton (microscopic animals). The young grow rapidly at this stage, and as their mouth size increases, so does their prey size.
Most experienced anglers might say they prefer to pursue largemouth bass or crappie, but many of them probably learned to fish while waiting patiently for a bluegill to pull their bobber under the water. Bluegill fishing is a great way to introduce a newcomer to the sport.