Sea Creature Feature of the Week: Christmas Tree Worm

With the holidays quickly approaching, this species receives its name from its similarity to a popular holiday favorite, the Christmas tree worm. This vividly colored worm may be found embedded in the surface of corals by the calcareous tubes in which they dwell. They are frequently seen on coral in the Florida Keys. When frightened, they quickly flee back into their burrows, where they may hide from predators.

This species is classified as a ciliary feeder because it feeds with its cilia, which are small hair-like bristles. As food passes, their decorative hats or appendages grab the floating supper. These appendages not only help them catch their food, of tiny plants or phytoplankton, but they also aid in respiration. Food is driven down a groove by the ciliary tracks, which produce a water circulation that directs digestion. The worms consume sand while eating and then store it in a separate sac to aid in the construction of the tubes that connect them to the corals.

The Christmas tree worm, which belongs to the phylum Annelid and the family Serpulidae, is only about an inch and a half long. They are seen in several hues ranging from orange to blue. Females release eggs and males release sperm into the sea to reproduce; after fertilization, the larvae settle on the coral. The IUCN Red List has not assessed the Christmas tree worm, and conservation efforts appear to be unknown.

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