Coco Tube Worm
The coco worm or feather duster is probably one of the largest of calcareous tube worms, lives inside a hard white tube and is a suspension feeder. It has a double-headed set of gills, but lacks an operculum (trap door) to seal off the top entrance of the tube. Its tentacle crown approaches 3 inches (7.5 cm) in diameter, and its tube can be almost 1 inch (2.5 cm) in diameter and up to 8 inches (20 cm) in length. Specimens are better placed near the bottom of the aquarium in shaded areas where gentle to moderate currents will help bring various foods.