[Amber's Arches, 42 fsw., Photo © 1995, A. Kimo Morris.]

The domino damselfish (Dascyllus albisella ) is endemic to Hawaii and is almost always found in small schools on heads of Pocillopora coral. Work done by David Booth (as part of his PhD thesis at Oregon State University) showed that these fish will only school with other damselfish of the same size. If a fish grows too fast, or not fast enough, they are kicked out of the school and presumably wander to a more "size friendly" coral head. My favorite name for these fish is "the oreo cookie fish".