Serpula vermicularis

{{Short description|Species of annelid worm}} {{Speciesbox | image = Serpula vermicularis 2.jpg | image_caption = | genus = Serpula | species = vermicularis | authority = [[Carl Linnaeus|Linnaeus]], [[12th edition of Systema Naturae|1767]]<ref name=WoRMS>[http://www.marinespecies.org/aphia.php?p=taxdetails&id=131051 ''Serpula vermicularis'' Linnaeus, 1767] World Register of Marine Species. Retrieved 2011-10-30.</ref> | synonyms = *''Serpula'' (''Serpula'') ''aspera'' Philippi, 1844 *''S. aspera'' Philippi, 1844 *''S. crater'' Claparède, 1870 *''S. cristata'' Sowerby & Sowerby, 1820–25 *''S. echinata'' Gmelin, 1791 *''S. fascicularis'' Lamarck, 1818 *''S. gervaisii'' Quatrefages, 1866 *''S. interrupta'' Quatrefages, 1866 *''S. montagui'' Quatrefages, 1866 *''S. pallida'' Philippi, 1844 *''S. philippii'' Mörch, 1863 *''S. proboscidea'' (Bruguière, 1789) *''S. rugosa'' Turton, 1819 *''S. venusta'' Philippi, 1844 *''Vermilia vermicularis'' Fleming, 1825 | synonyms_ref = <ref name=WoRMS/> }} [[File:Espirógrafo (Serpula vermicularis), Parque natural de la Arrábida, Portugal, 2020-07-31, DD 02.jpg|thumb|''Serpula vermicularis'' in the Atlantic coast of Portugal]]

'''''Serpula vermicularis''''', known by [[common name]]s including the '''calcareous tubeworm''', '''fan worm''', '''plume worm''' or '''red tube worm''', is a [[species]] of segmented marine [[polychaete]] worm in the [[Family (taxonomy)|family]] [[Serpulidae]]. It is the [[type species]] of the [[genus]] ''[[Serpula]]'' and was first described by [[Carl Linnaeus]] in his 1767 [[12th edition of Systema Naturae|12th edition of ''Systema Naturae'']]. It lives in a tube into which it can retract.<ref name=WallaWalla/>

==Description== ''Serpula vermicularis'' lives in a calcareous tube which is attached to a rock, boulder or other hard surface. The tube is often curved, but is not tightly coiled as in some other related species. It can grow to a length of {{convert|20|cm|in|abbr=on|0|}}, but is usually shorter than this. The anterior part of the worm protrudes from the tube and has a plume of about 40 feather-like radioles projecting from the second segment, or peristomium, which also houses the two eyes and the mouth. The radioles are bi[[pinnate]] and covered with fine [[cilia]]. They are commonly red, orange or pink and are usually banded with white. A funnel-shaped lid or [[Operculum (animal)|operculum]] covers the entrance to the tube when the animal retracts inside. This lid has up to 160 fine creases around its edge and is symmetrical and usually red. It is sometimes divided into two. The yellow-coloured body has seven thoracic segments and up to 190 abdominal segments which are protected by the tube. At least four segments with [[seta]]e (bristles) are found in the thoracic region.<ref name=WallaWalla>[http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Annelida/Serpulidae/Serpula_vermicularis.html ''Serpula vermicularis'' Linnaeus, 1767] {{webarchive|url=https://web.archive.org/web/20111002000012/http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Annelida/Serpulidae/Serpula_vermicularis.html |date=2011-10-02 }} Walla Walla University. Retrieved 2011-10-30.</ref>

==Distribution== ''Serpula vermicularis'' is [[Cosmopolitan distribution|cosmopolitan]] in distribution. It is found in the Pacific and Indian Oceans and the European seaboard of the Atlantic Ocean, but not on the North American coast. It occurs in the intertidal zone and at depths down to {{convert|100|m|ft|abbr=on}}.<ref name=WallaWalla/> Also along Southern African coast from Olifant's River to Maputo.<ref name=" Branch 2010">Branch, G.M., Branch, M.L, Griffiths, C.L. and Beckley, L.E. (2010). ''Two Oceans: a guide to the marine life of Southern Africa'' Struik Nature, Cape Town. {{ISBN|978 1 77007 772 0}}</ref>

==Habitat== ''Serpula vermicularis'' grows on hard substrates. It favours shells of [[Bivalvia|bivalves]], boulders and man-made structures. Around the United Kingdom, juveniles were found to be plentiful growing on the [[bryozoa]]n, ''[[Flustra foliacea]]''. Large colonies sometimes form, but these are seldom on rocks. Larvae may settle on the tubes of other worms and their subsequent development can form reefs. These reefs are very fragile and often break up. This is sometimes due to the activity of certain boring sponges, such as ''[[Cliona celata]]'' (red boring sponge).<ref name=UKMarine>[http://www.ukmarinesac.org.uk/biogenic-reefs.htm Biogenic Reefs] {{Webarchive|url=https://web.archive.org/web/20150102031952/http://www.ukmarinesac.org.uk/biogenic-reefs.htm |date=2015-01-02 }} UK Marine SAC's Project. Retrieved 2011-11-01.</ref>

==Biology== The tube of ''S. vermicularis'' is made from [[calcite]] and [[aragonite]]. [[Calcium]] for its manufacture is stored in two white sacs on the ventral side of the peristomium. The tube is fabricated by the glandular ventral shields on the other thoracic segments, where calcium is mixed with an organic secretion to make a paste. This is formed into shape by a collar found just behind the first segment, the [[prostomium]].<ref name=WallaWalla/>

''Serpula vermicularis'' is a [[filter feeder]] and extends its radioles to catch [[phytoplankton]] and [[detritus]]. The radioles also act as gills. Blood is pumped in and out of these with the flow direction alternating in a single set of vessels. The blood is then pumped through a ventral blood vessel to the tip of the abdomen before returning through a sinus adjoining the gut.<ref name=WallaWalla/>

The blood of ''S. vermicularis'' contains the oxygen-binding pigment [[chlorocruorin]]. As well as transporting oxygen to the tissues, this binds [[carbon monoxide]] much more efficiently than does human [[haemoglobin]]. This may be the reason why the worm may settle and grow on brown seaweeds such as ''[[Fucus]]'', but avoids giant kelp, ''[[Nereocystis]]''. The latter uses carbon monoxide to inflate its pneumocysts, and this would be toxic to the worm.<ref name=WallaWalla/>

==Life cycle== In the United Kingdom, spawning takes place between June and September. The larvae form part of the plankton for up to two months before settling on the seabed. Growth is fairly rapid with tubes extending by {{convert|1|cm|in|frac=16}} in a month. The worms mature in about 10 months and may live for several years.<ref name=UKMarine/>

==Ecology== Coldwater reefs built up by ''S. vermicularis'' take many years to develop and provide a hard substrate which other organisms use. The reefs around the United Kingdom support a diverse community of sessile invertebrates, including [[Porifera|sponges]], [[hydroid (zoology)|hydroids]], [[Ascidiacea|ascidians]], [[bryozoa]]ns, the worm ''[[Pomatoceros triqueter]]'', the sea anemone ''[[Metridium senile]]'' and bivalves such as [[Chlamys (bivalve)|''Chlamys'' spp.]], ''[[Modiolus modiolus]]'' and [[queen scallop]], ''Aequipecten opercularis''. Macrofauna include crabs such as ''[[Cancer pagurus]]'', the sea urchins ''[[Echinus esculentus]]'' and ''[[Psammechinus miliaris]]'', the brittle star ''[[Ophiothrix fragilis]]'', the starfish ''[[Asterias rubens]]'' and the whelk ''[[Buccinum undatum]]''. [[Red algae]] grow on the reef in shallow water. The [[tunicate]] ''[[Pyura microcosmus]]'' occurs on these reefs, but is seldom seen in other habitats. A large number of [[Crypsis|cryptic]] species of [[microfauna]] shelter among the tubes.<ref name=UKMarine/>

[[Predation|Predators]] of the worm include [[sea urchin]]s, [[starfish]], and the [[wrasse]]s ''[[Crenilabrus melops]]'' and ''[[Ctenolabrus rupestris]]''.<ref name=UKMarine/>

==References== {{Reflist}}

==External links== {{Commons category|Serpula vermicularis}} * {{SealifePhotos|131051}}

[[Category:Serpulidae]] [[Category:Animals described in 1767]] [[Category:Cosmopolitan animals]] [[Category:Animal taxa named by Carl Linnaeus]]