Not sure how many. I try to count and the little buggers keep playing the shell game with me, switching places all the time. If I had to guess a range, it would be 600-1000. But it may be more.
Mama and Papa have slowed down to every 12 days spawning for the last 2 spawns. Perhaps it is not Spring anymore, or perhaps it is the effect of having turned on the air conditioning, so they are not as warm by one degree. I've moved some things around in their tank and doing more water changes than previously, trying to get a handle on the constant algae--inevitable result of the saturation feeding necessary for spawning. (Don't do what I do if you care about the esthetics of your reef tank.) These and other small changes may be affecting the spawning cycle.
I have decided not to take the next couple of nests as my system is only 5 tanks, and I am full up now. I should maybe only take one nest a month, if I can repeat my recent good success harvesting them and raising them, I should have more than enough clownfish to grow.