Black crappie adults vary from 130-381 mm in length. The average weight varies from 0.25-0.90 kg. Black crappie are a monomorphic species characterized by 7-8 dorsal spines which are stepped in length, an upturned (S-shaped) snout, symmetrical dorsal and anal fins, a wavy light and dark pattern on non-paired fins, and a mottled (spotty) color pattern.
There are color variances among populations of black crappie. Age, habitat, and breeding are all determinants of the intensity and patterns of mottling: juveniles tend to have less pigment and pattern than adults; those black crappie living in clear, vegetated water have strikingly bolder patterns than those living in turbid, murky water; and breeding males have a darker head and breast than normal populations. (Jenkins et al. 1994, Sigler et al. 1987, Trautman 1981, Becker 1983, Smith 1979, Robison et al. 1988, Mettee et al. 1996)
The native range of Pomoxis nigromaculatus is the freshwaters of central and eastern North America. It has further been introduced to freshwater lakes of the Pacific coast and Canada due to its popularity as a sport-fish and its durability. (Mettee et al. 1996, Sigler et al. 1987)
Pomoxis nigromaculatus favors clear, warm, highly vegetated, moderately acidic, and non-turbid waters of lakes and rivers in its natural range. (Sigler et al. 1987)
Both sexes of Pomoxis nigromaculatus reach their sexual maturity by the age of two and usually live seven years. The spawning temperatures and months vary due to the wide natural range of black crappie, but the temperatures are usually from 58° to 68° Fahrenheit, corresponding to the months of April through June.
Before the spawning period, black crappie form schools that migrate to shallower water to feed. It is during schooling when the male crappie sweeps out the nests and attracts the female. The female black crappie is very fertile. She may spawn several times during the period with several males, bearing 10,000-200,000 eggs (variation related to size and age of female). Once the eggs are in the nest, it is the male's responsibility to guard the nest until the young can freely swim and feed. (Jenkins et al. 1994, Sigler et al.1987, Becker 1983, Robison et al. 1988, Mettee et al. 1996)
Pomoxis nigromaculatus are schooling fish. During the day, they can be found in deep water around fallen trees, weed beds, and other submerged structure. They move toward shore to feed several times a day, mainly at dusk and dawn. During the spawning period, they concentrate in shallow, warm water. In the winter, black crappie do not go into semi-hibernation, however they may move to deeper water.
As fingerlings, P. nigromaculatus are preyed upon by many animals. Perch, walleye, bass, northern pike, and muskellunge are the fish that pose the most threat to black crappie young, but the large anal and dorsal fins allow the adults some protection against these predators. Other animals such as the great blue heron, american merganser, snapping turtles, otter and mink can prey upon black crappie young and sometimes adults as well. There are a few parasites of the black crappie, which include many protozoa, trematodes, cestodes, and nematodes. (Sigler et al. 1987, Becker 1983)
As a juvenile, Pomoxis nigromaculatus feeds mainly on microscopic prey such as Cyclops, Cladocera, and Daphnia.
As an adult, Pomoxis nigromaculatus is a mid-water omnivore that feeds in vegetation and open water. Its numerous gill rakers allow it to consume planktonic crustaceans; however aquatic insects, minnows, and fingerlings of other species comprise its main diet. Dawn, noon, dusk, and midnight are peak times for black crappie feeding.
Much of the success of the black crappie is attributed to its ability to eat foods of all forms, at all times of the year. (Becker 1983)
Since black crappie are omnivorous, they eat the fingerlings of many other fish, including those of its predators: pike, walleye, muskellunge, etc. If there are no predators for smaller fish such as sunfish, perch, and black crappie, the lake will become over populated. This tendency for black crappie to overpopulate its community, not only stunts its species' population growth, but also those of other species due to an increase in competition. (Becker 1983)
Pomoxis nigromaculatus is a popular sport fish: the flesh is white and flaky; due to its wide variety of prey, fisherman are able to use many methods to catch them; they can be caught at all times of the year, which especially benefits fishermen who enjoy ice-fishing; high populations allow for many to be caught; and their aggressiveness allows for a good fight. (Sigler et al. 1987, Becker 1983)
Pomoxis nigromaculatus is not among those species in the endangered species list; however, to avoid over-fishing, daily limits are used.
William Fink (editor), University of Michigan-Ann Arbor.
Robert Adams (author), University of Michigan-Ann Arbor.
Becker, G. 1983. Fishes of Wisconsin. Madison, WI: University of Wisconsin Press.
Jenkins, R., N. Burkhead. 1994. Freshwater Fishes of Virginia. Bethesda, MD: American Fisheries Society.
Mettee, M., P. O'Neil, J. Pierson. 1996. Fishes of Alabama and the Mobile Basin. Birmingham, AL: Oxmoor House, Inc..
Robison, H., T. Buchanan. 1988. Fishes of Arkansas. Fayetteville, AR: Universty of Arkansas Press.
Sigler, W., J. Sigler. 1987. Fishes of the Great Basin. Reno, NV: University of Nevada Press.
Smith, P. 1979. Fishes of Illinois. Urbana, IL: University of Illinois Press.
Trautman, M. 1981. Fishes of Ohio. Columbus, OH: Ohio State University Press.