Sinularia gibberosa is a species of soft coral, that unlike hard corals, it does not secrete a skeleton of calcium carbonate, but the sustenance is provided by small spicules of calcium carbonate called sclerites that are embedded in its tissue. Taxonomically we find this cnidarian classified within the class AnthozoaAlcyonacea and the family Alcyoniidae. It is widely distributed in the Indian and Pacific Oceans as well as in the Red Sea. They generally live on the edges and lagoons of reefs, attached to hard substrate.
Morphologically and structurally Sinularia gibberosa and in general the species of the genus Sinularia, are similar to Sarcophyton spp. Sinularia gibberosa forms colonies of polyps that have an elongated and often short foot on which is superimposed the surface on which the polyps are, called polyparium or capitulum. Unlike Sarcophyton spp, the capitulum or polyparium of Sinularia gibberosa is branched forming long and relatively thin appendages.
As a peculiar feature of Sinularia gibberosa it is able to shed the outermost layer of its body with a certain periodicity, hence the name skin coral. When molting the skin, the specimen folds all its polyps for several days in which a thin layer of skin is shed. This strategy prevents sediments, bacteria, algae or other organisms from growing on them.
The feeding of Sinularia gibberosa is mainly based on the photosynthetic activity carried out by the zooxanthellae algae it has inside its tissues. The algae obtain protection and a privileged place of access to light, obtaining the coral as a reward the by-products of photosynthesis of zooxanthellae in the form of organic compounds. Not only does it receive this reward of organic compounds, but also as a by-product of photosynthesis, oxygen is generated, which the coral takes advantage of to breathe. This feeding due to the zooxanthellae represents approximately 70-95% of its requirements and is complemented by the capture of phytoplankton and organic particles by means of the tentacles of its polyps. We will find during the night hours, the polyps fully extended in the specimens of Sinularia gibberosa, as this is the time when they take the opportunity to capture their prey that are dragged by the currents.
The reproduction of Sinularia gibberosa can be asexual by means of shoots or cuttings formed from the original specimen; or they can reproduce sexually by external fertilization with a planktonic larval phase that undergoes a metamorphosis to descend to the bottom and generate a new colony.Photos: