Freshwater Sunfish

The freshwater sunfish is a family of freshwater fish, also known as Centrarchidae, that belongs to the order of Perciformes and is one of the most popular angling species in North America. This family includes 38 different freshwater species that fall into three subdivisions. The most distinctive feature of the freshwater sunfish is its rough scales and two spiny dorsal fins.

These fish can be found in warm, diverse habitats and have been introduced out of their native waters in North America, and now can be found in lakes, ponds, and streams throughout Africa and Europe.

3 Facts About Freshwater Sunfish

• Four out of the 38 identified species of freshwater sunfish have gone extinct.
• All species of freshwater sunfish are carnivorous, feeding primarily on insects, crustaceans, and other invertebrates, and some also prey on smaller fish.
• Freshwater sunfish can reach 18 inches in length.

Classification and Scientific Name

There are 44 different species of freshwater sunfish. Four of these have gone extinct. They belong to the Centrarchidae family, which is a family of nest-building fish. One of the largest groups of centrarchids is the true sunfish, or Lepomis, which is a small species.

Here are some of the most popular freshwater sunfish species:

• Bass (Micropterus salmoides)
• Crappies (Pomoxis)
• Bluegill (Lepomis macrochirus)
• Redear sunfish (Lepomis microlophus)
• Longer sunfish (Lepomis megalotis)
• Pumpkinseed sunfish (Lepomis gibbosus)
• Warmouth sunfish (Lepomis gulosus)
• Redbreast sunfish (Lepomis auritus)
• Green sunfish (Lepomis cyanellus)
• Orange-spotted sunfish (Lepomis humilis)
• Black-banded sunfish (Enneacanthus chaetodon)

Evolution

The oldest Centrarchidae fossils were discovered in Montana and South Dakota and were dated to be around 28 million years old. These specimens belonged to species of freshwater sunfish that are now extinct, but scientists believe they belonged to the subfamily Centrarchinae, a distinction they would share with such modern-day freshwater sunfishes as crappies and rock basses, making these fish, in turn, likely to be some of the oldest living members of the  Centrarchidae family.

Appearance

All freshwater sunfish have a pancake-like body structure that makes them look flat. They have two dorsal fin rays, one that has sharp spines and the second that has soft rays. Each species has between three and nine anal fins and two dorsal fins that are fused but can have a different appearance.

They have six to 13 dorsal spines on the fins, and the smallest species of sunfish, the black-banded sunfish, grows as small as 3.1 inches in length, whereas the largemouth bass grows up to 3.3 feet in some instances. Most freshwater sunfish have an average length of 18 inches.

Some species of freshwater sunfish have rounder bodies that are not as flat as the others, as well as smaller mouths. Other species, usually from the Micropterus genus, have streamlined bodies and much larger mouths. The size of the mouths determines how the freshwater sunfish feeds, as large-mouthed sunfish use ram-feeding (a method of feeding in which the sunfish swims into its prey with an open mouth), whereas small-mouthed species use suction feeding (a method of feeding in which the sunfish sucks in its prey).

The coloration of freshwater sunfish varies by species, but is generally green, blue, yellow, or silvery.

Distribution, Population, and Habitat

Distribution

Freshwater sunfish are native to parts of North America, but they have now populated waters in Europe and Africa. You can find freshwater sunfish in New Jersey, where they inhabit some of the state’s largest reservoirs and lakes, along with small farm ponds. The main species found in New Jersey are the redbreast, pumpkinseed, and bluegill freshwater sunfish. The redbreast species of freshwater sunfish is distributed throughout Ohio, Tennessee, Missouri, South Dakota, and Arkansas.

Population

There are thirty-eight identified species of freshwater sunfish; four of these species are now extinct. They can be found throughout North America, Europe, and Africa. A few species of freshwater sunfish are considered threatened or endangered in certain regions, and local regulations may restrict their harvest to protect populations.

Habitat

The freshwater sunfish inhabits a variety of different water systems, from small lakes and ponds to large creeks and rivers. They prefer warm, clear bodies of water. Some species of freshwater sunfish can also be found in low-flow streams and swamps. The Bluegill freshwater sunfish can be found east of the Rockies, whereas others, such as the popular Redbreast, inhabit river systems of eastern Canada and the United States.

Diet

Young freshwater sunfish start off by eating fish larvae, either through suction or ram feeding. Sunfish are considered to be carnivores, and they primarily eat small invertebrates like insects, mollusks, crustaceans, snails, and smaller fish. Small species of freshwater sunfish that uses suction feeding eats fish larvae and very tiny fish. The Micropterus species are ram feeders, and they eat in limnetic zones, which are open areas.

Reproduction and Lifespan

Freshwater sunfish are nest builders and dig round nests along the shorelines of lakes and streams during late spring in preparation for reproduction. The nest will contain mud, sand, and gravel, and is usually dug by the male. Sunfish can become quite territorial and aggressive when they make their nests and are very protective of their eggs.

While the females are egg layers, the males will build and guard the nest until the larvae develop into fry and are large enough to swim. The female freshwater sunfish will lay eggs in the nest after the male has performed a dancing courtship ritual, and the larger the male freshwater sunfish is, the more likely he is to attract a female.

Freshwater sunfish have an average lifespan of four to six years, but some species can live for up to 10 years, like the bluegill sunfish.

Freshwater Sunfish in Fishing and Cooking

Freshwater sunfish have been caught in still, baitcasting, drift, and fly fishing. They can be baited with worms and make a popular angler fish. They are better for seasoned anglers, and you will need to find the right location, use the right equipment, and try different techniques to successfully catch freshwater sunfish. Lake sunfish are the most popular fish to fish for in the United States, but make sure it is legal to fish for this species in your area, as some species are endangered.

You can eat freshwater sunfish, and many people say they taste like black sea bass or tuna. They are a good source of essential minerals and can be baked, grilled, or fried in preparation.