Native to North America, the bluegill is most commonly found east of the Rocky Mountains but their range has been extended to much of the North American continent through stocking.  They have also been introduced outside of North America and can now be found in South America, Europe, Asia and the African continent.  In some of these areas they are considered an invasive species wreaking havoc with local fish populations.  Their habitat is diverse, they can be found in ponds, lakes, streams and rivers, in both brackish and freshwater.  In moving water, bluegills show a preference for quiet, slow moving water with plenty of vegetation.  In its more common still water habitat, they can be found shallow or deep but will often relate to structure.  Under water structure such as trees, stumps, rocks and vegetation all attract bluegills.  Bluegills will also relate to shoreline structure such as the shade of a overhead tree.  Found in both shallow and deep water, bluegills will often move between these zones based on time of day or season of the year.  They prefer water in the 60 to 80º F range and will often move or suspend at various depths to find a comfortable temperature.

The most prominent feature of the bluegill is the dark spot located on the posterior edge of its gill plate.  The side of the bluegill’s head are often a dark shade of blue.  The color of the body can vary from light olive green to almost black.  The fish usually displays 5-9 vertical bars on its flank, but these stripes are not always visible.  The breast of the fish is often a yellowish color which sometimes extends into the abdomen area, and in the case of a spawning male, the breast can be bright orange.  A male fish in full spawning colors can be visually striking.  Bluegills have flattened,  laterally compressed bodies with spines on their dorsal and anal fins.  It is often debated whether the the term panfish, which they are often referred to as, comes from their flat pan like shape or the fact that they are perfectly suited to be cooked in one.  Adult fish normally range in size from 4 to 12 inches but specimens in excess of 16” have been caught.  The current IGFA world record is a 4 lbs 12 oz fish caught in Alabama in 1950, but a larger 5 lbs 7oz fish was reported to have been caught in 1998 in South Carolina.

The bluegills are also known as brim, bream or coppernose, depending on what part of the country you are fishing for them

Bluegills feed on a wide range of aquatic and terrestrial food forms.  The diet of adult fish consist of aquatic insects, both larvae and adult, including mayflies, caddis, as well as damsel and dragon flies.  Land based prey consisting of insects that drop or fly into the water are also readily consumed when available to the fish.  Larger specimens will also consume leeches, snails, crayfish and smaller fish.  There are also some reports of the fish occasionally eating vegetation.   Most feeding activity occurs in the morning and evening hours but they will readily feed during daylight hours under most conditions.  They have relatively small mouths and capture their prey by sucking it to their mouths.  Food forms must be small enough to fit in their mouth and the bluegill needs to get very close to it’s prey.  They do on occasion grab larger food items and attempt swim off with them  This usually results in a chase by other bluegills in the area.  Like many other fish, bluegills have a lateral line system and inner ears that allow them to respond to pressure changes and vibrations, but they are primarily sight feeders. Bluegills are highly maneuverable and can change direction quickly, which aids in capturing pray and evading predators.

In return, bluegills are prey to every larger that carnivorous fish that swims in their habitat.  Bass, pike, muskellunge, walleye, yellow perch, catfish even bluegills themselves will feed upon appropriate sized bluegills.  Turtles, herons, and mammals such as mink and otter also eat bluegills when they can catch them.  However, the bluegills flattened plate like shape and sharp spines can make them difficult to swallow.  Larger bluegill seem to be aware of this and will often school with predatory fish seemingly unconcerned that they could be on the next on the menu.  

Bluegills typically begin spawning in the spring, beginning in May and extending through August throughout most of their range.  Spawning usually occurs once water temperatures reach 67-80º.  Male bluegills are the first to arrive on the spawning grounds, which are typically found in shallow water over gravel or sand bottoms.  The male fish will scoop out shallow depressions in the bottom 6-12” in diameter.  The fish tend to spawn in large groups.  Its is not unusual to find fifty or more beds in a relatively small area.  Males become very protective of their nests and will attempt to drive off anything that comes near regardless of size.  This behavior makes them particularly vulnerable to angling.  A male bluegill on guarding a nest will attack any fly that comes near it.  The female bluegill will choose the male it wishes to mate with and after depositing her eggs on the nest she is driven off.   The male will remain to guard the eggs. They will continue to guard the nest until the eggs hatch and the fry are able to swim off under their own power.

Bluegills will take a large variety of flies.  They readily rise to dry flies, including foam bugs, poppers as well as traditional dry fly patterns.  They can also be taken subsurface on wet flies, nymphs and small streamers.  They are voracious feeders and will take any fly they can fit into their mouths and they will try their best to eat flies they have no hope of swallowing!.  Fly size is definitely something to consider as a bluegill’s mouth is quite small although I am often surprised when I catch bluegill while fishing for other species on flies I would have normally considered to large for these fish.