Fancy sea fan

The beautiful sea fans are home to a variety of fishes, shrimps, feather star, shells and algae

I am a big fan of sea fans! Why won’t anyone be, considering their wonderful shapes and colours? They are found amongst the reefs of the Indo-Pacific oceans, and make some of the most beautiful underwater sights. Sea fans are actually colonies of lots of small, individual polyps, similar to corals. Some form colonies in a single sheet, while others grow their branches in somewhat of a tangle. They particularly like areas where there is strong water current, building colonies in branching formations that are almost always fan-shaped, hence the common name.

While SCUBA diving on the reef, finding a sea fan is not difficult. And once you come closer to these creatures, their beauty is just captivating. They come in an array of colours, due to the tiny algae that live in their skeleton. Apart from giving attractive colourations, these algae also help the sea fan by producing nutrients through photosynthesis. In addition to harbouring these algae, sea fans also provide a home for a variety of fishes, shrimps, feather stars and shells.

Shapes and sizes

Most sea fans grow to only a few inches, but sometimes their flare expands up to a metre in width. When they sway with the current, their beauty is nothing short of seeing a dancing peacock on land.

Not all sea fans form fanciful fan-shaped colonies. Some types have long, slender colonies known as sea whips. They jut out from the bottom of the sea like branches of trees. Divers love to photograph their fragile, gentle swaying.

Leave them in the sea!

Over a hundred kinds of sea fans inhabit our Indian waters. Unfortunately, they are collected and sold in aquarium markets. The value of one piece of sea fan can go upto several dollars. This is a great shame, because their beauty is at its peak when they are alive; after being uprooted they lose their colour and shape. And of course they can’t provide shelter to other reef creatures any more!

From 2001 Indian law has given sea fans the strictest form of legal protection, which means collecting, possessing or handling sea fans can result in a fine of upto Rs 25,000 or three years in prison or in some cases both. With sustained efforts and continuous support from the Government, the trade of sea fans can reduce and these beautiful life forms will be allowed to live in peace, as they have for millennia before us. After all, wouldn’t you like to see a sea fan when you have a chance to visit a coral reef?

 


Sea fans are also called ‘Gorgonians’. In Greek mythology, the Gorgons were three sisters whose hair was made of living snakes.

Within phylum Cnidaria, class Anthozoa, sea fans belong to the order Alcyonacea.

They are closely related to corals, however unlike corals, which have six tentacles (and are therefore called Hexacorals), sea fans are Octocorals, with eight tentacles to a polyp. The tentacles capture suspended micro-organisms in the water column: yummy!

A total of 103 species of sea fans are known to occur in Indian waters. They are divided into four common types: Black, Red, Flower and Monkey-tail sea fans.

 

This article appeared in the Hindu in School on 24 December 2014.

Picture: The colony of sea whip at Nirupum rock dive site in South Andaman. (Right) Sea fan of the genus Verucella.
Credit: Vardhan Patankar