Ok here is what iIhave gotten from a couple of fisheries biologist over the few years I been around:D .Crappie spawn down so to speak.The spawning down term given me means that the largest fish start spawning first and the smaller they are the later so I guess they mean spawning down from the largest to the smallest that are mature enough to spawn.They do not all spawn at the same time but start at the 64- 65 ° water temp for the black crappie(although I think the blacks spawn at even cooler temps) and at 68-70° for the white crappie and will continue to spawn until the water gets too hot which is usually 75°.The reason given that they all do not spawn at the same time is to assure that some will get a spawn in because as we have seen this year they havent had to much of a time frame to spawn in ideal conditions...in other words nature doesn't want them to put all their eggs in one basket so to speak:D.If they have a good year and the water temp stays in the 65 to 73 range for a good 2 to 3 weeks then there will be a majority of them spawn but even then there will be a few straglers spawning late.If they do not get the spawn in once the eggs are ready to be laid because of sudden low water temps the fish will not lay them.They simply keep them in their body and the blood flow is stopped to them and they are eventually reasorbed back into the body and this process can take several weeks .If the eggs are still live they will be a bright yellow color but if they have died they will be a pale yellow to even beige color.I do not know how long they can hold the eggs alive to be laid ,i would guess a week or so.This years spawn may be a very low one given the high water and non- steady water temps from mid-March thru all of April!! I know i have caught them a few times still with active yellow eggs in May too.As to them having a second spawn its pretty certain they dont at least not like Gills but seem to because they dont all spawn at the same time.Also if the eggs get laid and there is a sharp temperature decrease or a big water fluctuation up or down it can cause them to not hatch .Good thing they can each lay thousands of eggs!!!