Picture credit : Simon Dowling
Sabellidae, also known as the Fan Worm or Feather Duster Worm, are often overlooked by divers. Their beautiful spray of feathery tentacles sprout from a protective tube buried in coral or rock. If you get too close they will retract into their tube and come out slowly when they feel safe. They can see danger because their tentacles have eyes, very simple ones that detect light or dark. Insect eyes work in a very similar fashion.
When young and they are ready to settle, they burrow into the host rock or coral assisted by secretions of acid. Their tube homes are built from a variety of materials. They can build tubes out of parchment, sand, and bits of shell. Some species make theirs from Calcium Carbonate (a key element in many species of coral) They tend to be common in the intertidal zones around the world. Their oldest fossils are known from the Early Jurassic, and their feathery tentacles can vary in colours throughout the spectrum.
They feed by collecting passing floating particles of food from the water never moving from their chosen spot. Water movement also provides them oxygen and helps shed mucus deposits.
These guys are great for taking photos of, but your buoyancy must be tip top, or the worm will retract and spoil your photo.
Take the PADI Peak Performance Buoyancy Course and fine tune your diving buoyancy skills so you can get closer to these amazing critters.