Once you've hada pair a while spawning is quite common. They don't need anemonae to do it, mine spawn every couple of weeks on a rock.
They hatch after 6 or 7 days, raising the fry is little bit more compicated than more most fresh fish, inc discus. Typically you need to do it in the dark, and depending on the species will likely to need feeding on rotifers. Some of the larger species can go straight onto fresh artemia, but the fry count will be much lower as only the larger fry will be able to feed.