What is Fan Coral?

Fan coral is a type of coral which develops a highly branched flexible skeleton which often comes to closely resemble a fan, albeit a rather inefficient one. These corals belong to the order Gorgonacea, named for the mythical Gorgon, a figure in Greek mythology closely associated with snakes. Fan corals can resemble tangled clusters of snakes in some cases, which explains the scientific name.

You may hear fan coral referred to as a sea fan or a gorgonian, in a reference to its biological order. As is the case with other corals, a sea fan isn't a single organism. It is, in fact, a colony of organisms known as polyps which band together and develop a supportive skeleton. In the case of sea fans, the polyps use bromine, iodine, and tyrosine to create a flexible substance known as gorgonin. The surface of the coral tends to be rough and slightly horny, and it is resilient in addition to flexible, ensuring that sea fans can withstand heavy currents.

The color of this coral varies, depending on the species and whether or not symbiotic algae are living inside the sea fan. Colors typically range from yellow to red, with the polyps located along the branching arms of the fan. The polyps have eight tentacles which they use to filter free-floating organisms from the water to eat. They may also feed on the symbiotic algae, if it is present. Because fan coral cannot actively hunt its prey, it requires strong currents to provide enough nutrition.

Fan coral is primarily nocturnal, with the polyps pulling their tentacles in during the day to protect themselves from predators and the potential for sun burn. These corals reproduce by mass-spawning eggs and sperm, which fuse in the water to become gametes. The gametes free-float until they find an area of sand or mud to settle in.

There are over 500 species of fan coral, most of which are found in the Atlantic. These corals can live to be hundreds of years old, and they are very slow growing. This type of coral is also extremely vulnerable to human interference, as careless divers can break off arms, destroying decades of growth, and trawlers routinely rip out the coral as they dredge the bottom of the ocean for fish. Fan corals are also vulnerable to deliberate harvest for commercial profit, and to nutrient runoff, which can trigger algae blooms which cloud the water, making it difficult for fan coral to live.

Fan coral, a type of gorgonian, is a soft coral distinguished by its tree-like structure that spreads out in a fan shape. These corals are sessile marine animals that anchor themselves to the ocean floor and can be found in a variety of colors, often inhabiting shallow waters where sunlight is abundant for photosynthesis.

Fan coral is part of the soft coral group, which means it lacks the rigid calcium carbonate skeleton that hard corals possess. Instead, fan corals have a flexible, internal skeleton composed of a substance called gorgonin, allowing them to sway with ocean currents, unlike their hard coral counterparts that form rigid, immobile structures.

Fan corals are typically found in tropical and subtropical ocean waters around the world. They thrive in areas with strong currents which facilitate feeding, such as reef slopes and drop-offs. The Caribbean Sea, the Red Sea, and the Indo-Pacific region are known hotspots for these visually striking organisms.

Fan coral plays a crucial role in marine ecosystems by providing habitat and shelter for a myriad of marine species. Its intricate structure offers a safe haven for small fish and invertebrates. Additionally, fan corals contribute to the biodiversity and health of coral reef systems, which are vital to oceanic environmental balance.

Fan coral feeds by capturing plankton and other small particles from the water column using their tiny, hair-like tentacles. They are filter feeders and rely on the flow of water to bring food to them. At night, their polyps extend to maximize their feeding efficiency.

Fan coral, like many marine species, faces threats from climate change, ocean acidification, pollution, and destructive fishing practices. Protecting fan coral involves enforcing sustainable fishing, reducing carbon emissions, and establishing marine protected areas. Efforts to combat climate change and promote coral reef conservation are essential for their survival.