The festivity of this holiday season is not only felt, it is more seen through Christmas trees around us! And while we have this season every December, its counterpart underwater seems to have it year-round!
In today’s #WildlifeWednesday, let us introduce you to one of the most beautiful creatures under the sea – the Christmas tree worms! They may not have those light bulbs that twinkle, but they are seen showing off their crowns in a vast array of color hues of blue, red, bright pink, violet, orange, brown, white, green, or yellow!
Did you know that for several years, the iconic Christmas tree worms in the Philippines were believed to be known as Spirobranchus giganteus which is found only in the Caribbean? This only proves the diverse specificity of the genus. For sure, Christmas tree worms on our shores are members of the highly variable species Spirobranchus corniculatus!
Christmas tree worms of the genus Spirobranchus belong to a group of segmented worms known as polychaetes. They are often associated with coral reefs wherein more than half of their body is covered in coral and only the crowns are shown outside of their calcareous tubes. Each worm’s colorful crown has a spiny covering (operculum) that plugs the worm burrow’s hole to defend itself from butterflyfishes, crabs, sea urchins, or shrimps that make a tasty meal out of them.
While Christmas tree worms do not have many threats, the coral reefs where they anchor themselves are prone to both natural and man-made disasters which, in a way, will severely affect them. While enjoying the shelter provided by the corals, Christmas tree worms, in turn, defend their host from the crown-of-thorns starfish by irritating their tube feet as the predator walks across their coral home keeping the living corallites undamaged around the worm’s tube opening. Aside from this task, they are known to facilitate the revival of the damaged areas during bleaching events and turf algae overgrowth.
What an amazing creature!
Text and photo by the NMP Zoology Division and by Chrissy Piotrowski, California Academy of Sciences
