Mississippi waters provide homes to some good populations of sunfish. And there is a cadre of anglers that would rather fish for — and eat — bream than any other fish on an anglers’ most-wanted list.
Here’s a summary of the biology of the most-common and probably the most-popular sunfish in the Magnolia state: the bluegill.
I’ll fill you in on the other species in the next couple months.
First, I’ll confess some confusion about the name “bream.” My confusion is rooted in the many uses of the term.
Many anglers I’ve met refer to bluegill and redear sunfish collectively as “bream.” OK, I’m good with that; the two often occur together, and are caught using similar methods and baits.
To others, a bream is any sunfish — as in bluegill bream and redear bream.
And yet other anglers fish for bream and redear, so apparently “bream” is synonymous with bluegill for these anglers.
And here’s a true story.
My students and I were sorting through a large sample of fish collected by rotenone sampling from a Florida lake. Rotenone sampling is a method of sampling fish that involves blocking off an area and applying a very low concentration of rotenone that kills the fish.
A fishing guide and his two clients for the day sauntered up and watched us pushing fish into piles of different species. The guide picked up a bluegill about 5 inches long, displayed it for his clients, and said, “This is a bluegill bream.”
He then picked up a redear sunfish about the same size, showed it to his clients, and said, “This is a redear bream. We call them shellcrackers.”
He then picked up an exceptionally dark and colorful bluegill about 8 inches long. As he displayed it to his clients, he proclaimed, “Now, this is a true bream.”
So forgive me for using the names biologists agree to be accepted for these fish. Call them what you want: On these pages, I’m talking about bluegill.
Bluegill are common in lakes and reservoirs, and are a popular fish for stocking in private ponds. This sunfish commonly grows to up to 9 inches long, with the males growing faster and larger than females.
Adults and juveniles feed on zooplankton and invertebrates living on the bottom or attached to aquatic plants or woody substrates like brush piles.
Although bluegill can thrive in a wide range of habitats, populations seem to benefit from the presence of aquatic vegetation, possibly because of the rich buffet of aquatic insects that live in association with the plants.
Also, plucking meals from the vegetation matches their preference for feeding up in the water column.
Bluegill are suctorial feeders, meaning they approach individual prey and, by creating negative pressure in their mouth cavity, suck in their food.
Their fine teeth at the front edges of their jaws also help nip prey from plants and brush.
Many food-habit studies of bluegills list plant material in their diet. Bluegills, like all but a few herbivorous fish, are unable to digest plant material. I’ve always interpreted the presence of plant material in their stomaches to result from snapping up a plant-dwelling insect larvae and getting the leaf, too.
Bluegill also have long gill rakers — comblike bony structures that extend from the gill arches that help them strain microscopic zooplankton from the water.
Bluegill live in a world of trade-offs, seeking habitats where food is abundant while at the same time avoiding habitats where they become food for larger predators like largemouth bass and pike. That makes vegetation a good place to feed because it provides abundant food and good cover.
In this regard, it is interesting that bluegill consume zooplankton in open water where they are vulnerable to predation. Zooplankton feeding is most prevalent among larger bluegill, the individuals that would be least vulnerable to predation.
Bluegill feed most heavily in the spring and fall, with food intake declining in summer and winter. Nevertheless, bluegill can be caught year round and, in temperate climates, anglers score large catches of bluegill when ice fishing.
Certainly, winter temperatures in Mississippi should not deter good catches. You just have to find them.
Spawning begins in the spring when water temperatures climb into the 70s. While the greatest spawning effort occurs in late spring in southern waters, many bluegill will spawn again during the summer.
Bluegills build nests or beds in shallow, flat areas with hard bottom. The male cleans a small area of the bottom, creating a shallow depression. A female is courted, and eggs are deposited and fertilized in the depression. The male then guards the developing eggs, and the larvae and fry after they hatch.
Bluegills are colonial nesters, with many nests built by multiple bluegills in a confined area. These are the “bream beds” anglers seek.
The largest males tend to nest in the center of the colony.
Bluegills grow quickly in southern waters, often reaching 3 to 4 inches by age 1, 5 inches by age 2 and 6 inches by age 3. Faster growth can be expected in well-managed ponds and more-fertile waters. Males tend to grow slightly faster than females.
Bluegills typically reach sexual maturity by age 2, although fast-growing bluegill in new ponds will spawn at age 1.
A 5- to 6-inch female bluegill can spawn 10,000 to 12,000 eggs, and larger females will spawn more eggs.
With multiple spawns in a growing season, a single female can add a lot of bluegill fry to the population. So the management paradigm in southern waters has been maintaining high predation on bluegill populations to reduce the population and allow fast growth of the survivors.
Yet recent research from northern waters has demonstrated that greatly reduced harvest limits produce higher-quality bluegill for anglers.
Much work remains to be done on this fish that “seems to require little management.”