Free-living vs. Attached
Corals that are not attached to the bottom are described as free-living. Corals may change between the two states as they grow.
Corals that are not attached to the sea floor are termed free-living - the genus Zoopilus.
A selection of free-living corals on soft sediment. Clockwise from top: Heteropsammia, Heterocyathus, Cycloseris x2 & Heteropsammia.
Some corals are attached as juveniles and become free-living as adults - the genus Fungia.
Corals may live as a solitary polyp or clone to form a colony of many polyps. Solitary corals can be as large, or larger, than colonies. The genus Ctenactis (left) and Moseleya (right). Note: both of the corals illustrated are also free-living.
Free-living corals can be solitary or colonial - the genus Fungia (left) & Halomitra (right).
A selection of hard and soft corals. The majority of corals live attached to the seafloor.