I went to look at my tank shortly after my lights came on and my water is cloudy. I saw a stream float of what looked like that temporary alk precipitate you see when dosing 2 part. I followed it back to a banded trochus. I found several doing this simultaneously.
These are awesome! Free cleanup crew! Love when this happens. Seems to follow moon cycles (or I could be making that up!). Mine spawn from the very top of the water.
Mine spawned last week. I have hundreds of tiny babies everywhere. In a 20 gallon. Send help.
*edit*
They also spawned a few months ago. The surviving babies are maybe penny sized by now. My royal gramma was very happy with all the snail eggs he had to enjoy. I didn't need to feed him that day, he was so fat.