Centrarchidae

Centrarchidae, better known as sunfishes, is a family of freshwater ray-finned fish belonging to the order Perciformes (formerly belonging to the deprecated order Centrarchiformes), native only to North America. There are eight universally included genera within the centrarchid family: Lepomis (true sunfishes), Micropterus (black basses), Pomoxis (crappies), Enneacanthus (banded sunfishes), Centrarchus (type genus, consisting solely of the flier C. macropterus), Archoplites (Sacramento perch), Ambloplites (rock basses), and Acantharchus (mud sunfish). A genetic study in 2012 suggests that the highly distinct pygmy sunfishes of the genus Elassoma are also centrarchids.

The centrarchid family comprises 38 identified species, 34 of which are extant. It includes many popular game fishes familiar to North American anglers, such as the rock bass, largemouth bass, bluegill, pumpkinseed, green sunfish and crappies. Most sunfish are highly valued panfish for sport fishing, and have been introduced in many areas outside their native ranges, sometimes becoming invasive species. While edible, they are not commercially marketed as food fish.

Centrarchids prefer clear, warm, and slower-moving water, and are commonly found in habitats such as lakes, ponds, medium to low flow streams and rivers, and swamps. They also prefer to live in and around aquatic vegetation so they can get adequate coverage from predators. While few species in the family diverge from the aforementioned habitat list, the Sacramento perch can survive in habitats with unusually high alkalinity, salinity, and temperatures. Centrarchids can be found in various locations within the water column and their exact preference is species specific. For instance, bluegill (Lepomis macrochirus) mainly inhabit the deeper littoral zones, while green sunfish (Lepomis cyanellus) prefer habitats near the shoreline and shallower areas. Suction feeders within the family (i.e. Lepomis) generally feed off the bottom of their habitat, while ram feeders (i.e. Micropterus) generally feed in more open areas known as the limnetic zone. Centrarchids diet consists of macro-invertebrates (e.g. insects, snails and crayfish) and other fish found in their habitat.

The native range of Centrarchidae is confined within North America, covering most of the United States and stopping in southern Canada. The northern edge of the native range is heavily bound by temperature due to reduced foraging ability and growth in cold weather and subsequent starvation in winter months. As a result, centrarchid distributions and range in any place they are found will be restricted by cold temperatures.

While centrarchids are native to only North America, they can be found worldwide due to introductions on multiple continents, including Europe, South America, Africa, and Asia. At least 18 species of Centrarchidae are North American exports. Its multi-continental spread is mostly due to the high popularity of the family (especially from the genera Micropterus) as freshwater game fish that are frequently stocked for recreational fishing all around Europe.

Across the globe, invasive and introduced centrarchids pose a great threat to native species in the areas they invade. There are multiple confirmed instances of largemouth bass (Micropterus salmoides) severely altering and reducing native fish populations in Italy, South Africa, Japan, and Madagascar and even causing the local extinction of any species of the family Cyprinodontidae within the waterbodies they have invaded in Mexico.