They are Sanctithomae, from the Discosoma genus. I've own at least 10 different colors with 8 different colors presently. They will adapt to most any type of lighting if acclimated properly. In the past when I first purchased them, I used no specialized feeding at all and they did exceptionally well. So much so that I had to frag the football size rock in half and remove half of them. When they're happy, they can expand at maturity at least 4 to 5 inches across. Low to medium current is best. Very high current will cause them to retract severely or peel right off of the rock at the base.
Mucho Reef