Baros Underwater

The Colourful World of Christmas Tree Worms

Many marine lives reside between corals, hidden in the corners of the reefs, and go unnoticed by the visitors. But when we have the patience to stop - breathe and observe - the ocean allows us to appreciate the beauty and explosion of life.

Worms are a piece of art that has successfully evolved during the millennia and continues to be one of the most adapted creatures spread wide around the world on land and in the sea. Christmas Tree Worms, or Spirobranchus Giganteus, are sedentary and immobile, much like the most abundant Polychaetes. While these segmented worms have a name derived from their appearance, the anatomical feature of each segment of the body is aligned perfectly with a specific and vital function.

Only a part of their colourful body is usually visible as the rest is hidden inside calcareous tubelike buildings encrusted in coral blocks. One of the preferred coral habitats for these worms is the stony Porites, which are abundant at the Baros House Reef. The vividly beautiful feathery structure that is exposed is not only responsible for capturing and filtering food particles such as plankton and detritus but also acts as the worm’s respiratory organ. Though these tiny creatures are only four centimetres long, their unique spiral body shape and the bright colours of the feathers make them difficult to ignore. Living in colonies of up to 50 individuals, they are delicate and sensitive. Some divers even describe them as “shy” as they disappear into their homes when approached closely for a macro photo or a simple deep observation.

As stony corals can be found in shallow and deep waters, Christmas Tree Worms can be encountered on the top reef as well as deep down up to 30 meters, making their observation by divers and snorkellers easy - especially during early evening and night when the number of predators lessens, and the availability of food is higher.