I've been checking several sites, but I can't find very much detailed info on how long the flathead spawn usually lasts. I'm sure there are several of you out there that can give the info that I've been looking for. I've read that they start the spawn at 70 degree water temp, can lay up to 90,000 eggs, and the males guard the nest and fan the eggs. So...do the females lay their eggs then go lay in deeper water and re-coup for a few days? I'd really like to hear from a fish biologist and get all of the details of the flatheads spawning ritual and movements.