Mediterranean Stony Corals (Phyllangia americana mouchezii) – Mert Gökalp (2018)

When we talk about corals we always conjure up the iconic image of highly fragile tropical reef-building symbiotic organisms in crystal clear shallow waters. The stony corals living in cold waters are striking in this matter. They show that this symbiotic relationship between the two evolutionarily distant partner organisms can break down (coral bleaching) or never evolve when conditions are less than optimal. The Mediterranean is a rather nutrient poor sea with low productivity. Lacking a photosynthetic partner stony corals cannot compete with other species such as sponges and encrusting algae for space in light exposed hard rocky surfaces. Here as we see in the Phyllangia americana mouchezii (Lacaze-Duthiers, 1897) stony corals are confined to marginal habitats such as cavern walls with currents sufficient enough to bring nutrients. These corals can also be seen inside wrecks that serve as artificial reefs. Nevertheless, stone corals continue to build modest reefs through a single-cell thick tissue layer called calicoblastic epithelium. This cell layer facilitates biomineralization of calcium in the form of aragonite. The geological history of the Mediterranean is quite a thrill ride. As the formal scientific name of this coral indicates the species colonized the Mediterranean from the Atlantic ocean following the end of the Messinian salinity crisis 5.3 million years ago. Here the filmmaker Mert Gökalp has recorded the Mediterranean stone corals in Kaş, Turkey.