Gorgoniidae - Soft corals
Gorgoniidae belong to the Order Alcyonacea which are corals that lack a hard calcium carbonate skeleton, thus the name soft corals. Instead they have tiny spine-like harden parts in their bodies called sclerites (or spicules) that give them some degree of support. Like hard corals, these animals form colonies of tiny tentacled polyps attached to a harder surface. Colonies may be branch-like, fan-like, bushy or encrusting. Alcyonaceans includes sea whips, sea rods, feather plumes and sea fans.
The family Gorgoniidae includes soft corals whose sclerites are <0.3 mm in length. The colonies are arranged in a branch or stem-like shape with a central core. The core is made of a protein called gorgonin which is exclusive to the gorgonians and contain significant amounts of iodine and bromine. The polyps are embedded in a gelatinous material (called the coenenchyme) which surrounds the core. The material surrounding the openings in the coenenchymes (from which the polyps emerge) are called calyces (singular calyx). They may be flush with the surface or raised. The colonies may be attached to a hard surface by a holdfast or may float freely unattached. The morphology (i.e. shape, branching, attachment method) of the colony and shape of the sclerites are used to distinguish between species.