Unusual corals comprise the family Oculinidae. Although
many species are not commonly available to the reef aquarium hobbyist,
corals of the genus Galaxea
can be readily available. The 'Galaxy Coral' (Galaxea Astreata), named
for its star-shaped polyp formations, extends powerful stinging 'sweeper
tentacles' long distances relative to their size, making them a beautiful
but hazardous addition to any reef tank.