As such Fans of the Sea we wanted to talk a bit about the amazing Sea Fans:
Sea Fans are a form of soft coral that grow in a beautiful and complex ‘fan’ like pattern.
We are proud to say that there are several dive sites that we visit around Tioman island that have a beautiful selection of these delicate corals including ‘Fan Canyon’ on Coral Island, ‘Karang Tohor’ and ‘Ajoy’ in Juara bay and ‘Tg. Api’ on the east coast of Tioman.
Sea Fans are actually coral!
As we said Sea Fans are a species of soft coral, a marine invertebrate under the suborder of Holaxmia. Each sea fan is a unique colony made up of hundreds of polys that grow together in a flat fan-like pattern. Each of these polyps have eight tentacles (unlike hard corals which have multiples of six tentacles per polyp) which they extend to feed.
Sea Fans are unequally identical
As we explained each fan is a unique colony formed from a fertilized egg that forms a gamete and floats around in the water until it finds a suitable site and attaches to a hard substrate. The coral then grows through asexual budding, cloning itself to form the large fan-like colony we have fallen in love with.
The structure of each colony will be decided by the conditions the polyps are living in with the same species growing in large open fans, tight dense fans or longer my tentacle-like fans
Sea Fans are Natural fishing nets
The Sea Fan can be found all across the world with abundance around the coral triangle, Caribbean and Florida. They grow in shallower waters and often areas of stronger current this is so that they can ‘reach out’ from the hard substrate to act like a net catching the floating plankton found in the water column. The sea fan feeds mostly at night when it opens its polyps’ mouth and extends its stinging tentacles to catch, collect and consume tiny plankton that lives in the water. The polyps work together sharing nutrients through the connective tissue
Sea Fans are friendly creatures
Each sea fan has a central structure, or skeleton, which is made up of a flexible wood like core made of protein, known as Gorgonin, which supports the branches of the coral. This is then covered in a living tissue which gives the coral its distinct color and texture. The tissue color is often very vivid and can range across many different colors including yellow, purple, blue, orange, red and white. The coloration and patterns make this species a popular and amazing formation to photograph under water.
The vivid colors of the Sea Fan are made from an algae that lives in the living tissues of the coral. These algae (like in hard coral) has a symbiotic relationship with the sea fan where the algae produce oxygen and nutrients, through photosynthesis, that are used by the sea fan to supplement their own food collection. In exchange the coral gives the algae a stable habitat to thrive in, protection, nutrients from its waste and carbon dioxide.
Sea Fans are loved by Dolphins
Sea Fans have a chemical defense to protect them from other predators giving there tissue a fowl taste to most species.
Interestingly dolphins have become aware of this chemical and can be seen rubbing themselves against the branches of the sea fan to take advantage of the antibacterial qualities of the chemicals the fans use in their tissues.
Sea Fans hold many secrets
With a complex structure sea fans makes an amazing habitat for many smaller species including fish, mollusks, sponges, brittle stars, cowrie shells, basket star and if course the very illusive pygmy seahorse.
Most of these species use the sea fans unique feeding method to their advantages grazing on the collected plankton that gets caught in the sea fans net.
These creatures are often very camouflaged and hard to spot but if you take the time there are some amazing delights to see. However, these structures are very fragile so make sure you keep a safe distance from them, so you don’t end up damaging them.
We hope reading this has made a fan out of you
If you would like to join us on a sea fan dive, we offer a number if different fun dives where we can see these beautiful structures with great guides to point out a variety of species.
If you would like any more information on these courses, fun dives or SEA FANS please do not hesitate to get in touch.