Kingdom: Animalia
Phylum: Annelida
Class: Polychaeta
Order: Canalipalpata
Suborder: Sabellida
Family: Sabellidae

The Sabellidae family (feather duster worms) are a family of sedentary marine polychaete tube worms where the head is mostly concealed by feathery branchiae. They build tubes out of parchment, sand, and bits of shell. Glomerula secretes a tube of calcium carbonate.

The appendages that give this worm its name are finely divided tentacles that act as plankton filters.  They also wave their tentacles to move the water around them, increasing the odds of catching food. Food is then moved from the tentacles into the worm’s mouth. The tentacles long grooves that get progressively smaller, limiting plankton size which is appropriate to eat when it arrives at its their mouth.  An alternate tube runs upward internally for waste is expelled.

Note: The rock above and to the right is covered by a sponge which differs from the 2 verticle sponges and their symbiotic coral.

Reference: Ryan Schaeffer. California Academy of Sciences Steinhart Aquarium, Hidden Reef 2018

Ron’s flickr