The caespitose tube coral or Cladocora caespitosa is a species belonging to the phylum of cnidarians, and is classified within the class Anthozoa, the order Scleractinia, and temporarily in family Scleractinia until there is greater agreement among taxonomists. This coral species is endemic to the Mediterranean Sea, where it is found in the infralittoral zone on rocky bottoms or in Posidonia oceanica meadows. As for the bathymetric range of this species, we can find it from a few meters deep to depths of up to 50 meters.
Cladocora caespitosa is a coral with a compact brownish calcareous skeleton that forms colonies with globular or spherical shapes that can reach between 50 cm and 1 meter in diameter, and up to 10 cm in height. The polyps that make up the colony are greenish in color, and at the slightest danger they retract completely into their tubular skeletons of rounded section of approximately 6 mm in diameter and have numerous radial protuberances.
The growth of Cladocora caespitosa is relatively slow, and it is a species with extremely long-lived specimens, with records of specimens that exceed 300 years of life.
In relation to the feeding of Cladocora caespitosa, we can distinguish two different sources. On the one hand, the polyps that make up the colony, through their tentacles capture the zooplankton circulating in the water around them. The fact that this active feeding is carried out both during the day and at night makes it relatively easy to observe the polyps of this species fully extended. The other method of feeding is indirect and is due to the presence of zooxanthellae algae in a symbiotic relationship within its tissues. Through photosynthesis, these algae generate organic compounds from CO2 and light. Part of these organic compounds are shared by the zooxanthellae algae with their host, the Cladocora caespitosa specimen.Photos: