How do Crappie spawn?

[CrappiePappy]

In-Fisherman article stated the eggs are all dropped at once, .....

That's not what I read.

(quoted from the article)
"Eggs are adhesive and slightly less than a millimeter in diameter. After spawning the female moves on and can be driven over another nest when she enters the territory of another male. Females might spawn in several nests by the time her eggs are spent. Multi-nest spawning can help ensure continued genetic diversity within populations and that at least some eggs of each female hatch.

Or did you mean "all in one day" when you said "all at once" ??

As for how long it takes to produce the eggs .... it would appear to take something on the order of 8-10 months under normal circumstances.

... cp