Both species of crappie as adults feed predominantly on smaller species, including the young of their own predators (which include the northern pike, muskellunge, and walleye). They have diverse diets, however, including zooplankton, insects, and crustaceans. By day, crappie tend to be less active and to concentrate around weed beds or submerged objects, such as logs and boulders; they feed especially at dawn and dusk, moving then into open water or approaching the shore.
The Pomoxis species are highly regarded game fishes and are often considered to be among the best tasting freshwater fish. Because of their diverse diets, crappie may be caught in many ways, including casting light jigs, trolling with minnows or artificial lures, using small spinnerbaits, or using bobbers. Crappies are also popular with ice-fishers, as they are active in winter.
The genus name Pomoxis derives from the Greek πώμα (cover, plug, operculum) and οξύς (sharp). The common name (also spelled croppie or crappé), derives from the Canadian French crapet, which refers to many different fishes of the family Centrarchidae. Note that the plural form of the name, crappies, tends not to be used, by analogy with fishes, except to refer to types of crappie. Other names for crappies are papermouths, calico bass, strawberry bass, white perch, specks, speckled perch, sac-a-lait (in southern Louisiana), rock bass and Oswego bass.
The dorsal fin of the white crappie has six spines. The maximum recorded length for a white crappie is 53.0 cm (21 in), with a maximum weight of almost 2.35 kg (more than 5.18 lb); it can live as long as ten years.
These species prefers slower-moving water, often turbid, whether a backwater of a small creek or a large lake.
When spawning, the white crappie deposits its eggs on plant surfaces or in poorly-defined nests in shallow water.
This very prolific fish may overpopulate small bodies of water under 40 ha (100 acres) in area.
The black crappie's range is uncertain, since it has been so widely transplanted, but it is presumed to be similar to the white crappie's; as of 2005, populations existed in all of the lower 48 states.
The black crappie tends to prefer clearer water than the white crappie does. Its diet, as an adult, also tends to be less dominated by other fish than that of the white crappie.
The breeding season varies by location, due to the species’ great range; breeding temperature is 14‒20 °C (58‒68 °F) and spawning occurs between April and June. Spawning occurs in a nest built by the male, who guards the eggs and young.
Like P. annularis, P. nigromaculatus is very prolific and can tend to overpopulate its environment, with negative consequences both for the crappie and for other fish species. A commercial supplier of the fish, however, claims that it can be safely stocked in ponds as small as one acre (0.4 ha) in area.