Stylaster
Stylaster is a genus of colonial, athecate hydrocorals in the family Stylasteridae. These small, branching corals are commonly found in tropical and subtropical waters worldwide. They are characterized by their distinctive, star-shaped calices (individual polyp openings) and the presence of “stylets,” small, pointed structures that project from the central part of the calice. These stylets are believed to be involved in prey capture and defense.
Common Names
Stylaster species are often referred to as "stylasterid corals" or simply "stylasterids." Some species may have specific common names, but these are not widely used.
Characteristics
Stylaster corals exhibit a variety of growth forms, ranging from small, encrusting colonies to larger, branching structures. They are typically white or pale yellow in color, but some species may have reddish or purplish tints. The polyps are small and retractile, with a single tentacle ring surrounding the mouth. The calices are typically arranged in a radial pattern around the branches, giving the colonies a distinctive, star-shaped appearance.
A key characteristic of Stylaster is the presence of stylets, which are small, pointed structures projecting from the center of each calice. These stylets are thought to play a role in prey capture and defense. They may also be involved in the dispersal of larvae.
Environments
Stylaster corals are primarily found in shallow, tropical and subtropical waters. They are often found attached to hard substrates, such as rocks, coral reefs, and shipwrecks. Some species may also occur in deeper waters, down to depths of several hundred meters. These corals are often found in areas with strong currents and clear water.
References
For more information on Stylaster, please refer to the following resources: