American Oceans

What’s the Difference Between Sunfish and Bluegill?

Freshwater sunfish are a diverse group of fish found in North America that belong to the family Centrarchidae.

a bluegill swimming underwater

One of the most well-known members of this family is the bluegill sunfish (Lepomis macrochirus), which is a popular game fish and a common sight in many freshwater habitats.

While bluegill sunfish are often used interchangeably with the term “sunfish,” there are many other species of sunfish that differ in appearance, behavior, and habitat.

By understanding the differences between these species, anglers and fish enthusiasts can better appreciate the diversity of freshwater sunfish and the important role they play in their ecosystems.

Key Takeaways

  • Freshwater sunfish are a diverse group of fish found in North America that belong to the family Centrarchidae.
  • Bluegill sunfish are small, aggressive, and adaptable fish with distinctive blue-green coloration on their backs and sides.
  • Comparing the size and appearance of bluegill sunfish to other sunfish species can help identify them in their natural habitats.

Understanding Sunfish

a pumpkinseed sunfish on a white background

Freshwater sunfish are a diverse group of fish species that belong to the sunfish family, which is part of the Centrarchidae family.

They are small fish that are commonly found in freshwater bodies such as rivers, lakes, and ponds. They are known for their distinctive body shape, which is round and flattened, with a small mouth and a single dorsal fin.

There are several different species of freshwater sunfish, each with its own unique characteristics.

Some of the most common species include the green sunfish, longear sunfish, pumpkinseed sunfish, redbreast sunfish, spotted sunfish, and redear sunfish. These species vary in size, color, and habitat preferences.

The green sunfish, for example, is a small, aggressive species that is often found in shallow, weedy areas of lakes and ponds. It is known for its bright green coloration and its ability to adapt to a wide range of environmental conditions.

The longear sunfish, on the other hand, is a more colorful species that is often found in clear, rocky streams and rivers. It has long, pointed fins and a distinctive orange-red spot behind each eye.

One of the most common and well-known species of freshwater sunfish is the bluegill. The bluegill is a member of the Lepomis genus and is known for its blue-green coloration and its distinctive black spot on the back of its gill cover.

It is a popular game fish that is often targeted by anglers due to its abundance and willingness to bite.

Characteristics of Bluegill

a bluegill swimming in the water

Bluegill (Lepomis macrochirus) is a species of freshwater sunfish native to North America.

It is a small fish, typically measuring 4-12 inches in length and weighing 0.2-1.0 pounds. The common name “bluegill” comes from the blue coloration on the gill cover of the fish.

One of the most distinctive characteristics of bluegill is their body shape. They have a deep, compressed body with a rounded profile.

The head is relatively small, and the mouth is relatively large, with a slightly protruding lower jaw.

Bluegill are known for their foraging behavior, which is highly variable and can be influenced by a variety of factors, including water temperature, water clarity, and food availability.

They are opportunistic feeders and will eat a wide range of prey items, including insects, crustaceans, and small fish.

In terms of their coloration, bluegill are typically olive-green or brown on the back and sides, with a yellow or orange belly. The blue coloration on the gill cover is most prominent in males during the breeding season.

Comparative Size and Appearance

a pumpkinseed sunfish swimming underwater

Freshwater sunfish and bluegill are two of the most common and well-known species of fish found in North America’s freshwater bodies.

While they belong to the same family, they have distinct differences in size and appearance.


Bluegills are generally smaller than other sunfish species, growing up to 12 inches in length and weighing up to 4.5 pounds.

In contrast, freshwater sunfish can grow up to 16 inches in length and weigh up to 5 pounds.


Both species have a round and flattened body shape, but bluegills have a more oval shape compared to the more circular shape of freshwater sunfish.

Bluegills are typically greenish-blue in color with yellow and white underbellies. In contrast, freshwater sunfish have a more diverse range of coloration, including green, blue, yellow, and white.

They also have distinctive markings such as vertical bars and dark spots on their dorsal fins and gill covers.

Dorsal Fin

The dorsal fin of bluegills is relatively small and triangular-shaped, while the dorsal fin of freshwater sunfish is more elongated and pointed.


The gills of bluegills are typically a bright red color, while the gills of freshwater sunfish are often a lighter pink or orange color.

Anal Fin

Both species have an anal fin, but the anal fin of bluegills is generally shorter and more rounded compared to the longer and more pointed anal fin of freshwater sunfish.

Black Spot

One of the most distinctive features of bluegills is the black spot that is present on the base of their dorsal fin. Freshwater sunfish, on the other hand, do not have this feature.

Habitat and Location

a school of bluegill swimming in a quarry

Freshwater sunfish and bluegill are both found in North American freshwater habitats, including ponds, rivers, and lakes.

They are typically found in shallow waters with vegetation, but can also be found in open-water habitats.

Bluegill sunfish are known to be generalists in their habitat selection, meaning they can adapt to a variety of environments.

They are commonly found in both open-water and littoral zones, and are known to forage in areas where prey are absent.

Freshwater sunfish, on the other hand, are more commonly found in slow-moving streams and rivers with clear water and gravel or sand bottoms.

They are also known to inhabit ponds and lakes with vegetation, and can be found in saltwater environments in some regions.

Behavior and Social Structure

a sunfish swimming in clear water

Sunfish and bluegill are both known for their aggressive behavior, especially during the breeding season. However, there are some differences in their social structure that set them apart.

Sunfish are generally solitary fish, preferring to live alone or in small groups. They are territorial and defend their space aggressively, especially during the breeding season.

They are known to attack other fish that enter their territory, even fish that are much larger than them.

They also tend to be more active during the day, spending much of their time swimming around in search of food.

Bluegill, on the other hand, are more social fish and are often found in larger groups. They tend to form schools, especially during the breeding season when they gather in large numbers to spawn.

They are less territorial than sunfish, but will still defend their nests aggressively. They are also more active during the early morning and late afternoon, spending much of their time near the surface of the water in search of food.

Both sunfish and bluegill are known to build beds, which are circular depressions in the sand or mud at the bottom of the water.

These beds are used for spawning and can be used year after year. Sunfish tend to build their beds in shallower water, while bluegill tend to build their beds in deeper water.

Diet and Predation

a close up of the face of a bluegill

Bluegill sunfish are known for their diverse diet, which includes a wide range of prey items such as insects, worms, crustaceans, and small fish.

They are opportunistic feeders and will consume whatever prey is available at the time. Bluegill sunfish have been observed to prefer insects and crustaceans over fish, but they will also consume small minnows when they are abundant.

Predation is a major factor in the life of bluegill sunfish. They are preyed upon by a variety of predators, including larger fish, birds, and mammals.

In order to avoid predation, bluegill sunfish have developed a number of defensive mechanisms, such as schooling behavior, rapid swimming, and hiding in cover.

Studies have shown that the diet and distribution of bluegill sunfish are influenced by factors such as macrophytes and predation.

For example, the presence of macrophytes can provide cover for bluegill sunfish and increase their foraging efficiency.

On the other hand, the presence of large predators can change bluegill foraging behavior, leading to a narrower diet and more selective feeding.

In terms of growth and age at maturity, there is variation in bluegill sunfish that may be attributed to genetic or environmental effects.

For instance, predation on juveniles can affect growth rates, while increased predation on adults can affect age at maturity.

In a study examining bluegills, a block design was used with two food levels, three strains of bluegills, and 10 replicates to determine if genetic or environmental factors play a role in growth and age at maturity.

Common Confusions and Identification

a bluegill on a white background

Sunfish and bluegill are often confused with each other due to their similar physical appearance. However, there are some distinguishing characteristics that can help identify them.

Physical Characteristics

Sunfish and bluegill have a similar shape, with a round body and a small mouth. However, bluegill have a distinctive blue or black spot on their gill cover, while sunfish do not. Additionally, bluegill have a yellow belly, while sunfish have a white or cream-colored belly.

Age and Size

Bluegill are typically smaller than sunfish, with an average length of 6-10 inches, while sunfish can reach up to 16 inches in length. Bluegill also tend to live shorter lives, with an average lifespan of 5-6 years, while sunfish can live up to 10 years.

Family and Species

Sunfish and bluegill both belong to the Centrarchidae family, which includes other popular game fish like largemouth bass and crappie. However, there are several different species of sunfish, including the pumpkinseed, green sunfish, and longear sunfish, each with their own unique characteristics.

Smallmouth vs Largemouth

Another common confusion is between smallmouth and largemouth bass, which are both members of the sunfish family.

Smallmouth bass have a brownish-green color with dark vertical bars on their sides, while largemouth bass have a greenish color with a dark horizontal stripe along their sides.

Other Sunfish

Other sunfish species, like the ocean sunfish, have distinct physical characteristics that set them apart from freshwater sunfish and bluegill. For example, the ocean sunfish has a distinctive ear flap and lacks the black spots found on other sunfish species.

Frequently Asked Questions

What are the different types of sunfish found in Minnesota?

Minnesota is home to several species of sunfish, including bluegill, pumpkinseed, green sunfish, and rock bass.

These species are commonly found in freshwater lakes and rivers throughout the state.

What are the differences between bluegill, sunfish, and pumpkinseed?

Bluegill, sunfish, and pumpkinseed are all types of sunfish, but they have some distinct differences. Bluegill have a blue-green color on their upper body and a yellow-orange color on their lower body.

Sunfish are typically larger than bluegill and have a more oval shape. Pumpkinseed have a distinctive orange-red spot on their ear flap and a more rounded body shape.

How does the taste of bluegill compare to that of sunfish?

Bluegill and sunfish have a similar taste, but some people prefer the taste of bluegill over sunfish.

Bluegill has a mild, sweet flavor with a firm texture, while sunfish has a slightly stronger flavor with a softer texture.

What is the difference between panfish, sunfish, and bluegill?

Panfish is a term used to describe small, freshwater fish that are typically caught for food. Sunfish and bluegill are both types of panfish, but not all panfish are sunfish or bluegill. Other types of panfish include crappie, perch, and trout.

Can you eat freshwater sunfish?

Yes, freshwater sunfish are safe to eat and are a popular food fish in many parts of the world. However, it is important to follow local fishing regulations and guidelines to ensure that the fish are safe to eat.

Why are bluegill sometimes called bream?

Bluegill are sometimes called bream because the term bream is often used to describe a group of freshwater fish that includes bluegill, pumpkinseed, and other sunfish species.

However, in some regions, the term bream is used specifically to refer to a different type of fish altogether.

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