The Pygmy or Cherub angelfish is the only dwarf angel that comes from the Caribbean region. They are almost always imported out of Haiti, as they are uncommon in the Keys. They are considered reef safe, although they may occasionally nip at LPS polyps or clam mantles. As with most other angelfish, there should only be one per tank. Exceptions would be to purchase 3 young specimens, and place them into the tank at the same time. That way as they mature, you'll end up with a harem, one male and 2 females.