Faviidae Family of Brain Corals
Two Brain Corals of the Faviidae Family can be found in this website:
Phylogeny: The Faviid Corals of the Faviidae Family, like hydroids, jellyfish and sea anemones are in the phylum Cnidaria. They are in the subphylum Anthozoa, the class Hexacorallia, the order Scleractinia, and the suborder Vacatina. The Faviidae Family is one of twenty-five families in this suborder. The Faviidae Family contains two subfamilies, ten genera, and around twenty-three species. The name Faviidae comes from the Latin word for “honeycomb” and refers to the honeycomb-like cell structure of these corals. Most brain coral species are in this family, but not every member of this family is a brain coral. Until fairly recently this family was considered to be a subfamily in the Mussidae Family.
Morphology: Faviid Corals are stony, reef-building, corals that may be solitary or colonial. The colonies may be encrusting or massive. Massive structures may be dome-shaped or flat. They are characterized by having large corallites (cups where polyps reside) with thickened septal walls. They polyps have radial symmetry, a hollow digestive cavity, and specialized stinging structures in tentacles surrounding the mouth. Their polyps have a flower-like appearance that produce a hard, calcareous skeleton. Many species in this family have a sinuous maze-like surface, but some have circular or hexagonal calices. Many species are fluorescent. Dome-shaped colonies of species in this family can range in size from a golf ball to large colonies exceeding 2.0 m (6 feet 6 inches) in diameter.
Distribution: Faviid Corals are found in shallow water, with ample access to sunlight, attached to hard substrates such as buoy chains, pilings, rocks, and wreckage. Only a few species are found in deeper water, but they can be found at depths up to 100 m (330 feet). They may be found in tightly packed colonies with multiple generations building upon the skeletons of previous generations, which forms coral reefs. Faviid Corals are a subtropical to tropical Atlantic Ocean species. At least four species from this family are found in Mexican waters.
Reproduction: Faviid Corals are hermaphroditic (having male a female reproductive organs). Reproduction can be asexual, through budding, or sexual. Sexual reproduction involves broadcast spawning, with internal fertilization. The eggs hatch into planktonic planulae larvae, which settle on an appropriate substrate, where asexual reproduction begins. Secondary polyps are formed, which develop to adult polyps.
Ecosystem Roles: Faviid Corals are zooxanthellate that have a symbiotic relationship with single-cell dinoflagellates, the zooxanthellae. Zooxanthellae live within certain coral polyps, jellyfish, nudibranchs and sea anemones and produce energy, by means of photosynthesis during daylight hours. This energy is passed along to their hosts, sometimes providing up to 90% of the host’s total energy needs. In return, the host provides nutrients, carbon dioxide, and a secure, sunlit, platform for the zooxanthellae. During periods of chemical or thermal stress the corals can eject the zooxanthellae to reduce metabolic stress, a process known as bleaching, as the coral appear white. Coral bleaching can be an indicator of an unhealthy environment, or a natural response to a short-term condition such as El Niño. The coral can replace the zooxanthellae after the stress has dissipated, or they can acquire a different species of zooxanthellae that are better accommodated to the new environment. In either case, the polyp risks starvation if it is unable to replace the zooxanthellae. Faviid Corals supplement the energy provided by zooxanthellae by using their tentacles to capture amphipods and other plankton from the surrounding water. The tentacles then pass the food to the mouth. Because these polyps are rigid, they are found in areas with moving water, caused by wave action or current, that has an abundance of food. In turn Faviid Corals are preyed upon by crabs, fish, gastropods, starfish, and polychaete worms.