Bluegill, Lepomis macrochirus, Lepomis (lehp-OH-miss) is Greek for "scaled gill cover," macrochirus (MACK-row-KY-russ) is Greek meaning "large hand," referring to the shape of the body.
One of the most widespread fish in Minnesota, bluegills are common inhabitants of ponds, lakes and slow-moving rivers across most of the state (they are less common in the Lake Superior watershed of the northeast). Their widespread abundance and relative ease of catching mean bluegills are often the first fish caught by beginning anglers. They are a favorite target species of many shore and pier anglers, and are caught for fun as well as for a flavorful meal.
A member of the very large sunfish family, bluegills frequently interbreed with other members of this family, making hybrids somewhat confusing to identify. Like all members of the sunfish family, bluegills have a very round, pan-shaped profile. True bluegills are the largest of the Minnesota sunfish, growing to 4 to 8 inches in length and a half pound in weight on average.
Perhaps its most distinguishing feature is the dark blue tab or “ear flap” at the rear edge of the gill cover. Bluegills tend to be mostly olive-colored with a powder-blue throat, although their coloration can vary considerably between individuals. Other sunfish members that could be confused with bluegills include pumpkinseeds, green sunfish and orangespotted sunfish. Check out Lesson 2:3 – Fish Families to learn more about fish identification.
Small and toothless, bluegills are easily handled by either smoothing down the sharp dorsal spines before grasping the fish, or by grasping the lower lip and allowing the fish to hang vertically. See Lesson 6:1 – Safety and Fishing at the Water’s Edge for instruction on safe fish handling.
Bluegills have relatively small mouths, and feed mostly on aquatic insects, snails, and other small invertebrates. Young bluegills feed among weeds or beneath the pier for protection, while larger bluegills may feed on plankton in open water.
Bluegills spawn primarily in May, but can also spawn all the way to August if conditions warrant. Male bluegills thrash vigorously in shallow water to hollow out a bowl-shaped “nest” in the sand or gravel bottom. In some locations, several dozen nests may be clustered together. The female lays upwards of 50,000 eggs in the nest and the male fertilizes, then guards, the nest.
Young bluegills have many predators. Both large and small bluegills are wary of larger fish like northern, muskies, walleye, and bass. Bluegills are also eaten by other animals like herons and kingfishers, snapping turtles, otters, and (of course) humans.
Spawning bluegills protect their nests aggressively and attack anything that comes near, often making them easy to catch in the springtime. When not spawning, bluegills can be found among shoreline vegetation or around the pylons of a fishing pier where they spend their time in loosely-knit groups of 20-30 individuals. They can be enticed with a piece of nightcrawler on a small hook with lightweight (6 lb) line. Bluegills seem to be curious, and can sometimes be attracted by lightly “splashing” your bobber on the water’s surface next to the pier. Although they feed all day, the best bluegill fishing is usually in the morning or evening. Because they do not see well in low light, bluegill fishing is poor after dark.
Because they eat mostly invertebrates and are closer to the bottom of the food chain, the accumulation of toxins is largely not a concern in bluegills and they can be eaten frequently. Bluegills are very easy to fillet and can be cooked in a number of ways. See Lesson 6:5 – Eating Fish for more about cooking and eating your catch.