Spirobranchus giganteus, AKA Christmas Tree Worms, are an intriguing specimen among Earth’s creatures. These little guys are not  uncommon in tropical waters, but they certainly are unique!

The tube-dwelling worms are found living in and on coral, eating plankton and tiny microorganisms as they pass by carried on the currents. The twin, spiral appendages are actually a breathing apparatus, and tiny hairs on them allow the worm to feed.  At the slightest disturbance in the water, they retract their feathery plumes, becoming almost invisible, expanding again slowly when they feel safe. Brilliant colors range from yellows and oranges, to reds to blues and white.

The photo above was taken while snorkeling in Aruba.

Cool video of the Christmas Tree Worm retracting and reappearing by California Academy of Sciences.

This post inspired by the theme “Unique” presented by the WordPress Weekly Photo Challenge.