The black and white striped Dascyllus aruanus, or whitetail damselfish, commonly reaches a size of around 6 cm, but can grow up to 10 cm in length. Its main habitat are shallow waters, often near stony corals, in the Indo-Pacific region.

The fish occure in large generation-spanning, groups that live in the vicinity of corals Acropora. The corals play a key role in providing shelter and safety. When in danger, the entire group hides among the coral branches.