My name is Daniel Sasse, a marine conservationist, the owner of Poseidon Dive Center Ao Nang Thailand and an award-winning underwater photo and videographer. I have 25 years of experience in scuba diving, teaching and photographing wildlife. Protecting our oceans must be our priority since every second breath we take is produced by our oceans.

Spirobranchus giganteus, commonly known as Christmas tree worms, are tube-building polychaete worms.

The worms' most distinct features are two "crowns" shaped like Christmas trees. These are highly modified prostomial palps, which are specialized mouth appendages. Each spiral is composed of feather-like tentacles called radioles, which are heavily ciliated and cause any prey trapped in them to be transported to the worm's mouth. While they are primarily feeding structures, S. giganteus also uses its radioles for respiration; hence, the structures commonly are called "gills". The worm can retreat into its tube the opening is shut using an operculum, which is further protected by sharp, antler shaped spines.

More info: poseidon-krabi.com