In Pulau Kapas, there are Christmas tree worms from phylum Annelida. They comprises of calcareous tube and is usually embedded in the coral skeleton. Their bright-colored crowns (plumes/ tentacles) are composed of radioles, or hair-like appendages radiating from the central spine.
The marine worms usually catch microscopic plants, or phytoplankton, filter feeders, bottom feeder, and deposit feeders. Some are parasitic too. Such as the Christmas tree worms, they help starfish that could otherwise destroy the coral. Most damaged coral reefs recover faster when there is nearby marine worm population and they can be the prey for shrimps, crabs, sea urchins and butterflyfish.