I got one from a local reefer and kept in a 200g that was swarming with asterina, after about 4 mos you couldn't see almost any asterina and then I rehomed it. If you want to feed it you should keep the cc in a sump or another tank and chop off its leg every week or so to feed to the harlequin. The CC will regenerate but the chopping parts takes some stomach so I didn't want to keep it. The harlequin will most likely kill the the cc if you throw it in the tank, although sometimes they don't and can do all sorts of weird things like force feeding stars and keeping them just barely alive for food... Some people try to grow asterina in a separate tank and then feed some every few days. Gorgeous little monsters