Rose Coral, Manicina areolata
Rose Coral, Manicina areolata. Collected off Tigertail Beach, Marco Island, Florida, January 2019. Size: 9.5 cm (3.7 inches) x 7.8 cm (3.1 inches).
Rose Coral, Manicina areolata. Collected off Whitney Beach, Longboat Key, Florida, January 2018. Size: 8.2 cm (3.2 inches) x 5.5 cm (2.2 inches).
Rose Coral, Manicina areolate. Underwater photograph taken with coastal waters off Cozumel Island, Quintana Roo, March 2021. Photograph and identification courtesy of Marina Sutormina, Stockholm, Sweden.
Phylogeny: The Rose Coral, Manicina areolata (Linnaeus, 1758), is a member of the Faviidae family of Brain Corals. The genus Manicina is one of ten genera in this family. They are the only species in this genus.
Morphology: Rose Corals are a colonial species made up of individual polyps. The polyps have a flower-like appearance, with radial symmetry and specialized stinging structures in tentacles surrounding the mouth. The polyps produce a hard, calcareous skeleton, and when multiple generations of these corals build upon the skeletons of previous generations, coral reefs are formed. Rose Corals can be found as attached heads or unattached cones. The corallites of this species are arranged in a meandroid fashion, meaning that the surface consists of ridges and wide valleys, similar in appearance to a human brain. Some specimens consist of a single, elongate valley, with a few short side lobes. Specimens with many valleys usually have a groove that runs along the top of the ridges. Fine septa run from the ridge walls down to the valley bottoms. Rose Coral may be yellow-brown, tan, or dark brown in color. The heads can reach a maximum of 10 cm (3.9 inches) in diameter.
Habitat and Distribution: Rose Corals live on sand, mud, rubble, cobbles, and rock, as well as in sea grass beds. They are found intertidally, and to a depth of about 60 m (196 feet). They are a tropical Western Atlantic species. In Mexican waters they range from Tampico, Tamaulipas, south to Belize. Free- living Rose Coral colonies have the ability to detach from the substrate and travel short distances. They also have the ability to right themselves if the get turned over by water movement. They do this by filling the stomach,
which is interconnected among all polyps so that it becomes bloated, and alternatively expelling water on one side and then on the other side. This produces a rocking motion until the center of gravity is exceeded and the colony turns right side up again
Diet: Rose Corals feed 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 cannot change location, they are found in areas where moving water, caused by wave action or current, brings them more food. Rose corals are also zooxanthellate. They have a symbiotic relationship with single-cell dinoflagellates, known as zooxanthellae, which live within the polyps. The zooxanthellae produce energy, during daylight, by means of photosynthesis. 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. This causes the coral to appear white. This process is known as coral bleaching. 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 is resolved, or it can acquire a different species of zooxanthellae that is better accommodated to the new environment. In either case, the polyp risks starvation if it is unable to replace the zooxanthellae quickly enough.
Predation: Rose Corals are a poorly studied and understood species. There is very little documentation of predation. Other species in this family are prey for crabs, fish including butterflyfish and parrotfish, gastropods, starfish, and polychaetae worms.
Reproduction: Rose Corals are simultaneous hermaphrodites (having both male and female reproductive organs). While they can reproduce asexually through fragmentation, it is much more common for them to reproduce sexually through broadcast spawning. Fertilization is internal. Spawning takes place around the full moon in May or June. The larvae are brooded for two weeks and then released the following new moon. The larvae may settle immediately to the substrate or drift a few days. Immediate settlement makes for dense colonies. After a short growth period the polyps can detach, move a short distance, and reattach.
Ecosystem interactions: Rose Corals have not been studies and are poorly documented. Beyond their symbiotic relationship with zooxanthellae, there is very little known about their commensalism, mutualism, and parasitism.
Human Interactions: Historically Rose Corals were collected for the souvenir and aquarium trades. This activity is now illegal in most of the Rose Coral’s range. Otherwise, Rose Corals have little impact on human activities. From a conservation perspective they have not been formally evaluated however they are fairly common with a relatively wide distribution and should be consider to be of Least Concern.
Synonyms: Madrepora areola, Madrepora areolata, Maeandra (Manicina) areolata, Maeandra areola, Maeandra areolata, Maeandra areolata var. angusta, Maeandra areolata var. colummelaris, Maeandra areolata var. confertifolia, Maeandra areolata var. hispida, Maeandra areolata var. laxifolia, Maeandra dilatata, Manicina areolata f. areolata, Manicina areolata f. mayori, Manicina areolata var. angusta, Manicina areolata var. gracilis, Manicina areolata var. hispida, Manicina areolat var. laxifolia, Manicina crispata, Manicina danai, Manicina dilatata, Manicina gyrosa, Manicina hispida, Manicina mayori, Manicina praerupta, Manicina sebacana, Manicina strigilis, Manicina valenciennesi, Meandrina areolata, Podasteria gyrosa, and Podasteria mayori.