Christmas Tree Worms

What Are Christmas Tree Worms?

Christmas tree worms are a part of the phylum Annelid. Their scientific name is Spirobranchus giganteus but they are referred to as Christmas tree worms because of their shape. These are very cool little invertebrates and most people wouldn’t know that they are a type of worm by just looking at them. They were first described by scientists in 1766  by Peter Simon Pallas. Christmas tree worms are known for their two christmas tree like spirals that are used for feeding and respiration. Each spiral has “feather-like” tentacles which are heavily ciliated so that they can catch prey and have it be transported to the mouth of the worm. They also have a segmented body that is lined with small structures that are used to help them move, these are called chaeta. These worms also posses a digestive system, a nervous system and a circulatory system.

Where Are They Found?

Christmas tree worms live in coral reefs all around the world but are most commonly found in tropical oceans. They can be found from the Caribbean all the way to the Indo-Pacific. They also prefer to live in shallow waters typically around 100 feet deep or less.

This is a map of the coral reefs around the world. Christmas tree worms can be found on many of these reef’s.
Image result for map of tropical coral reefs“Coral Reefs” By NASA SIM LABS

Different Colors of Christmas Tree Worms

File:Spirobranchus giganteus (Red and white christmas tree worm).jpg

“Spirobranchus giganteus” By Nhobgood Under  GNU Free Documentation License

File:Christmas tree worms.jpg

“Christmas Tree Worms” By Nhobgood Nick Hobgood Under  Creative Commons Attribution-Share Alike 3.0 Unported

Image result for christmas tree worms

“Spirobranchus giganteus” By Nhobgood Under  Creative Commons Attribution-Share Alike 3.0 Unported

Image result for christmas tree worms

“Blue Christmas Tree Worm” By Betty Wills Under Wikimedia Commons, License CC-BY-SA 4.0

Image result for christmas tree worms

“Christmas Tree Worm” By  Aquaimages Under Creative Commons Attribution-Share Alike 2.5 Generic

Image result for christmas tree worms

“Corals Sea Worms” By Brocken Inaglory Under  GNU Free Documentation License

Image result for christmas tree worms

“Christmas Tree Worms Close Up” By Thomas Quine Under  Creative Commons Attribution-Share Alike 2.0 Generic


“Christmas tree worms” By vjacob1 Under CC0 Creative Commons


Photo taken by me in the Turks and Caicos Islands

Threats to Christmas Tree Worms

Christmas Tree worms are pretty stable since they are not commercially harvested and people do not eat them. Their biggest threat is climate change and ocean acidification which are hurting the coral reefs. Anything that harmfully affects the coral reefs and destroys the corals is a threat to Christmas tree worms because that is where they live. A large population of Christmas tree worms can indicate a healthy reef.

Cool Facts

  • Two-thirds of their body is hidden in a calcium carbonate tube, which it uses as a bunker.
  • They usually live between 10-20 years but some have been known to live more than 30 years.
  • They are also referred to by some as “Jewel Stones”.
  • They are very sensitive and small disturbances can make them retreat into their tube until they feel safe again.
  • It has been found that they prefer to live in some coral species over others.

6 thoughts on “Christmas Tree Worms

  1. These are beautiful animals. And what a great photo you took on Provo! Since these critters are primarily filter feeders, how much do they influence (or are influenced by) water clarity? Are there studies that look at the effects of suspended sediment in the water column from human dredging or from natural events such as hurricanes on these sedentary polychaetes?

    Liked by 1 person

    1. I am really glad that you asked this question because I was able to find a really interesting paper on an experiment that was done to test this. It was found that the sites with more sediment had higher densities of Christmas Tree worms than sites that had little concentrations of sediment. This could mean that the more sediment, the more chance of food there is since there is more stuff in the water to filter. Another really cool fact about this website was that it included an article about the lionfish population written by a Keene State student.


    1. They reproduce by casting their eggs and sperm into the water. The eggs are then fertilized in the water and develop into larvae. They eventually grow enough to settle on coral heads and form their burrows. They are also filter feeders so they mostly eat phytoplankton.


  2. Love the post! I know we learned about them last semester and saw them in the turks but this definitely went a lot more in depth about what they actually are and their lives. I remember you said they were your favorites and got excited when I saw you wrote this post! Love the last picture too 🙂

    Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s