The crappie spawn
Both black and white crappie spawn when the water temperature is 60 to 68 degrees. The male crappie clears a small area - usually less than 1 foot in diameter - on the bottom. Unlike the "craters" excavated by bass or sunfish, the cleared areas are shallow depressions or just flat bottom. The nests are usually built in shallow water and associated with vegetation, cypress knees or brush; lacking such cover, crappie will spawn under undercut banks or even in shallow open water. Some observations suggest that black crappie select nesting sites on sand or gravel bottom, whereas white crappie will spawn on any hard bottom.
The male attracts the female who releases only part of her egg mass before leaving. The male guards the fertilized eggs for four or five days until they hatch.
A large female may contain as many 150,000 eggs and often spawns in several nests.
Although the peak spawn may only last a couple weeks, the entire spawn usually persists for a month or more. The variation in when crappie spawn is likely related to the temperature characteristics in different parts of the waterbody, such as shallow lakes or coves warming faster than deeper lakes or coves, and differences among individuals in the population.
In a year with steadily warming and stable weather, the early-spawned crappie have better food resources, and the later-spawned fish get what's left over. However, if abrupt cold spells or flood conditions threaten the success of early-spawned crappie nests, survival and growth may be better for the later-spawned young. Perpetuating the population requires successful spawning year after year, regardless of the environmental conditions; different spawning times among different fish in the crappie population ensure the long-term fitness of the population.
What biologists don't know
Biologists learn what they need to know to manage sportfish, and crappie are no exception. Information about spawning and rearing habitat, water-quality requirements, and food are essential to ensure sustaining populations. Information about growth and mortality rates are used to establish harvest regulations.
A black box for crappie, as well as many of Mississippi's game fish, is what happens between fall and the spawn the following spring. Indeed, anglers do much more "sampling" than biologists during the winter and early spring, so most of what biologists "know" about winter and pre-spawn crappie is what is referred to as "anecdotal" information. Anecdotal information may be accurate, but it lacks scientific validation.
The anecdotal information indicates crappie go through an annual cycle, moving to deep water in the winter, and then moving toward shallow-water spawning areas in the spring. There are certainly plenty of examples of deep-water winter crappie fisheries, but why would crappie move to deep water? It's not temperature - southern lakes are essentially the same temperature top to bottom in the winter.
Like all warm-water fishes, food intake and activity are reduced in cold water. They eat less, but they still eat. Evidence in support of winter activity and feeding is the excellent winter crappie fishing in the ice-covered lakes in the northern states, especially during the last one or two months of ice cover.
Food probably has much to do with the distribution of crappie, and in southern waters that translates into the location of the preceding summer's shad spawn. Vertical cover, when available, is a crappie magnet. Often, the same cover that attracts crappie in the summer is equally attractive in the winter. Lacking cover, the game is all about food.
The movement to shallow water beginning about a month before the spawn is probably instinctive but fine tuned by water temperature. Regardless of what factors control their winter distribution, the crappie are back in the shallow spawning areas when the water temperature starts approaching 60 degrees.