Very few anglers in America are unfamiliar with the humble bluegill, and while they don’t receive the fanfare of largemouth bass or crappie, there’s no questioning their popularity.
Abundant across the country, these aggressive predators are fun to catch and delicious to eat.
One testament to their popularity is the abundance of names they've earned, and depending on where you call home, you might know them as “bream,” “brim,” “copper nose,” or “sunny.” In fact, I’ve heard bluegill called “sunfish” more than once as I’ve fished across the country.
And to make matters worse, sunfish are sometimes called “bream” and “perch.”
That can lead to a problem.
Sunfish are a family of fish that includes multiple species, including bluegill, crappie, rock bass, and both large- and smallmouth bass. Many different fish, united by a few taxonomic similarities, comprise the family Centrarchidae or sunfish.
So while bluegill are sunfish, not all sunfish are bluegill.
Table of Contents (clickable)
- 1 The Family Centrarchidae
- 2 Bluegill vs Sunfish: Differentiating bluegill from other true sunfish
- 3 Final Thoughts
The Family Centrarchidae
Centrarchidae is a family of fish genera and species that share some very basic common traits, including their general body shape, the number of their anal spines, and a pair of fused dorsal fins.
These are the sunfish, comprising 8 genera and 34 species (counting only the living members), and they include many of the popular game species common to North America:
- Acantharchus (mud sunfish)
- Ambloplites (rock basses)
- Archoplites (Sacramento perch)
- Centrarchus ( C. macropterus)
- Enneacanthus (banded sunfishes)
- Lepomis (true sunfishes like bluegill)
- Micropterus (black basses like largemouth and smallmouth)
- Pomoxis (crappies)
The genus Lepomis is where you’ll find the bluegill, L. macrochirus, and like all of its close kin, it shares a deep, flat body, a small mouth, and a dark spot just behind the edge of the gills.
You can see these common features across the genus:
The bluegill, Lepomis macrochirus
The orange spotted sunfish, Lepomis humilis
The longear sunfish, Lepomis megalotis
The pumpkinseed, Lepomis gibbosus
Bluegill vs Sunfish: Differentiating bluegill from other true sunfish
Bluegill belong to the genus Lepomis, the true sunfish. And as you’ve seen, members of this genus share quite a few common traits that can make them hard to differentiate.
And to make this even more complicated, the various species of this genus can interbreed, leading to hybridization!
But let's do the best we can.
You can’t tell bluegill apart from other true sunfish by looking for that tell-tale dark spot: they all have one. Ditto on their general size and body shape.
Instead, for the species that most closely resemble one another, you need to look at the details.
The bluegill: L. macrochirus
Bluegill are named for their dark spot behind the gill plate, a feature they share in common with all members of the genus Lepomis. They’ll often sport an orange chest, dark vertical lines on their sides, and a dark spot at the base of the dorsal fin.
Unfortunately, these features also characterize some species of Lepomis, and positive identification is often bedeviled by hybridization.
But if you find that dark dorsal spot, chances are you’ve caught a bluegill. But keep in mind that green sunfish also sport that black dorsal blotch… so things get tricky and you can’t always be 100% sure.
A hybrid of pumpkinseed and bluegill.
The longear sunfish: L. megalotis
The longear sunfish is easy to confuse with the bluegill.
For me, the easiest way to differentiate them is the shape of their tell-tale spot. That elongated operculum flap reaches farther rearward than is common on the bluegill.
The green sunfish: L. cyanellus
The green sunfish isn’t particular about the species within the genus Lepomis with which it breeds, and green sunfish hybrids are almost as common as pure specimens. That can make proper identification impossible at times.
I look for a longer snout than you'd find on bluegill, but I’m never truly sure about this one.
The redear sunfish: L. microlophus
The redear sunfish is virtually identical to the bluegill with one exception.
The males have a cherry-red patch on their ear; the females sport an orange patch.
The pumpkinseed: L. gibbosus
The Pumpkinseed is perhaps the most beautiful of the sunfish. They’ll often - but not always - be characterized by bright blue markings on their cheeks. These can vary in color but are commonly vibrant.
The combination of vibrant cheek markings and an orange patch to the rear of the ear can help you tell them apart from bluegill, but they’re known to hybridize quite a bit.
The redbreast sunfish: L. auritus
I look at the ear shape, in combination with the chest color, to identify this species.
Bluegill will often have a red breast, so that alone isn’t going to help. But if you find a coppery belly combined with a long ear flap, you can be pretty sure you've got a redbreast sunfish and not a bluegill.
Here at USAngler, we love catching bluegill.
And if you want to know more about how to do that, check out these articles:
- Bluegill Fishing Tips: 7 Tricks Guaranteed to Work
- When Do Bluegill Spawn?
- Best Time To Fish For Bluegill
We hope that you've learned something from this article, and we’d love to hear from you if you did.
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