We've got 3 diff types of suncoral, the black, yellow, and orange. Dont worry if they dont come out immediately, or even for a day or so. Like it was stated, put a little food in the water column to get him to open up. What i like to do is throw a little dry cyclopeeze into the tank and wait about 30 mins. After that they are all open and then you can feed some mysis to them. After a while, you wont have to put any food in the water column and they will stay open during your photoperiod and you can feed when you want. Its awesome!
By the way, if anyone happens to see the red/purple strain of tubastrea thats in the pic at CR, LET ME KNOW PLEASE. (sorry, not trying to hijack)