Phragmatopoma californica

Phragmatopoma californica
Sandcastle worm in captivity, building its tube out of sand and white ceramic beads
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Annelida
Clade: Pleistoannelida
Clade: Sedentaria
Family: Sabellariidae
Genus: Phragmatopoma
Species:
P. californica
Binomial name
Phragmatopoma californica
Kinberg, 1867

Phragmatopoma californica, commonly known as the sandcastle worm, the honeycomb worm[1] or the honeycomb tube worm,[2] is a reef-forming marine polychaete worm belonging to the family Sabellarididae. It is dark brown in color with a crown of lavender tentacles and has a length of up to about 7.5 centimeters (3.0 in).[3] The worm inhabits the Californian coast, from Sonoma County to northern Baja California.[4]

Sandcastle worms live in colonies, building tube reefs somewhat similar to sandcastles (hence the name), which are often seen on rocky beaches at medium and low tide. The sandcastles, which have a honeycomb-like outward appearance, can cover an area of up to 2 meters (6.6 ft) on a side.[3] They may share areas with mussel beds and are found in any place that provides some shelter, such as rock faces, overhanging ledges and concave shorelines.[4]

The worms remain in their tubes and are almost never seen. At low tide, when above the water, they close the entrance to their tubes with a shield-like operculum made of dark setae. When submerged, they extend their tentacles out of the tube to catch food particles and sand grains. The grains are sorted, with the best ones used to keep the tube in repair,[3] and the rest ejected. The colonies are formed by the gregarious settlement of larvae, which require contact with an existing colony to metamorphose into adult worms.[4] Gregarious settlement of this species has been linked to specific free fatty acids associated with the tubes of adult worms.[5] On rocky beaches, settlement is dependent on larval behavior in the water column and perception of chemical cues when the larvae contact the tubes.[6]

Sandcastle worms should not be confused with the similar, but more northern Sabellaria cementarium which are found from Alaska to southern California and have an amber-colored operculum.[4] Unlike P. californica, S. cementarium rarely forms colonies, does not settle gregariously, and its larvae do not respond to free fatty acids.[7]

  1. ^ Hinton, Sam (1987). Seashore life of southern California: an introduction to the animal life of California beaches south of Santa Barbara. California natural history guides. Vol. 26. University of California Press. p. 48. ISBN 978-0-520-05924-5.
  2. ^ "Honeycomb Tube Worm". LiMPETS. Archived from the original on 2011-03-13. Retrieved 2009-10-31.
  3. ^ a b c Hinton, Sam (1988-01-26). Seashore Life of Southern California: An Introduction to the Animal Life of California Beaches South of Santa Barbara. ISBN 9780520059245. Page 31.
  4. ^ a b c d Between Pacific Tides (5th ed.). Stanford University Press. 1992. p. 233. ISBN 978-0-8047-2068-7.
  5. ^ Pawlik, J. R. (1986). "Chemical induction of larval settlement and metamorphosis in the reef-building tube worm Phragmatopoma californica (Sabellariidae: Polychaeta)". Marine Biology. 91: 59–68. doi:10.1007/BF00397571. S2CID 87087873.
  6. ^ Pawlik, JR; Butman, CA; Starczak, VR (1991). "Hydrodynamic Facilitation of Gregarious Settlement of a Reef-Building Tube Worm". Science. 251 (4992): 421–424. Bibcode:1991Sci...251..421P. doi:10.1126/science.251.4992.421. PMID 17775107. S2CID 981815.
  7. ^ Pawlik, JR; Chia, F-S (1991). "Larval settlement of Sabellaria cementarium Moore, and comparisons with other species of sabellariid polychaetes". Canadian Journal of Zoology. 69 (3): 765–770. doi:10.1139/z91-110.