Invasion History

First Non-native North American Tidal Record: 2000
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 2000

General Invasion History:

Janua heterostropha was initially described from France (Appeltans et al. 2015) and later found in waters through much of the world, including the Northeast Atlantic, the Mediterranean and Black Seas, the Caribbean, the coast of Brazil, the Red Sea, sites on the coast of India, Australia, New Zealand, the Pacific coast of Russia (a single collection), the Galapagos Islands, Mexico, and British Columbia (Knight-Jones and Knight-Jones 1975; Ben-Eliahu 1976; Rzhavsky 1991; Wehe and Fiege 2002; Atlas of Living Australia 2015; U.S. National Museum of Natural History 2015). Spirorbin polychaetes have a great potential both for natural dispersal on floating seaweeds, driftwood, and other debris, and for anthropogenic distribution on ships’ hulls (Knight-Jones and Knight-Jones 1975; Knight-Jones and Knight-Jones 1979). Janua heterostropha was found on the hulls of ships in Massachusetts (Woods Hole Oceanographic Institution, United States Navy Dept. Bureau of Ships 1952).

The native range of J. heterostropha is difficult to determine, owing to its potential for natural dispersal on floating wood and algae, and its likely early dispersal on wooden ships. Knight-Jones and Knight-Jones (1975) suggest an origin in the Northeast Atlantic, where it shows its greatest range of climate, depth, and habitat. They also note the scarcity of records on the western sides of temperate oceans. Until recently, despite its worldwide distribution, J. heterostropha had not been found in the Northwest Atlantic (Knight-Jones and Knight-Jones 1977). During a Rapid Assessment Survey in 2000, this polychaete was found at several sites in Massachusetts and Rhode Island (MIT Sea Grant 2003-2008; Museum of Comparative Zoology 2015). It has also been reported as an introduction in South Africa (Mead et al. 2011b) and the Hawaiian Islands (Carlton and Eldredge 2009).

North American Invasion History:

Invasion History on the East Coast:

In 2000, Janua heterostropha was collected at Newport, Rhode Island; and Buzzards Bay, Westport, Woods Hole, Plymouth, Duxbury and Gloucester, Massachusetts (MIT Sea Grant 2003; Museum of Comparative Zoology 2015). We presume that it is still established on the coast of New England, but may not have been identified, owing to the taxonomic difficulty of this group of polychaetes.

Invasion History in Hawaii:

In the Hawaiian Islands, it was first found in Kaneohe Bay, Oahu before 1970 (Vine et al. 1972, cited by Carlton and Eldredge 2009), and later found in Hilo, on the island of Hawaii (Coles et al. 2004; Carlton and Eldredge 2009).

Invasion History Elsewhere in the World:

Knight-Jones and Knight-Jones (1975) suggested that J. heterostropha was native to the Northeast Atlantic, where it ranges as far north as Norway, and was introduced, mostly by shipping, to the rest of the world. It was first found in Cape Town and Durban, South Africa in 1971 (Mead et al. 2011b) and was also collected in Namibia and Angola (Knight-Jones and Knight Jones 1975). If Knight-Jones and Knight-Jones (1975) are correct about the native range of J. heterostropha, then its introduced range includes ports and coasts in all the world's temperate and tropical oceans.


Worms of the Spirorbinae (currently considered a subfamily of Serpulidae) are small tubeworms, usually growing in tightly coiled, calcareous shells (Blake and Ruff 2007; ten Hove and Kupriyanova 2009). They have a branchial crown of feather-like radioles, as in the other serpulids. The radioles can be folded and withdrawn into the tube. One of the radioles is modified to form an operculum, which acts as a plug when the animal contracts. The peristomium (segment behind the mouth) is folded back to form a collar, which bears uniramous parapodia, with a distinctive set of collar chaetae, with spines or serrations. The collar is the first of three or four asymmetrical thoracic chaetigers.

The tube of Janua heterostropha is coiled dextrally (counter-clockwise when seen from above), and is usually chalky white. The shell is usually tightly coiled, but may become irregular when heavily fouled by algae. Tubes of juveniles may have a median ridge, while adults may have up to three ridges or none at all. The outer edge of the tube often has a sloping flange. Embryos are brooded in the operculum, which has transparent walls. When not brooding embryos, the funnel-shaped operculum contains a pin-shaped talon. The operculum is covered by a distal plate. During brooding, the embryos are visible, and the distal plate becomes flat or convex (sometimes asymmetrical). Early embryos are dark brown, but they later become pale and develop two pairs of red eyespots. As the embryos develop, a second distal plate develops beneath the embryos, and a new brood chamber is formed.

The thoracic membrane of J. heterostropha is not fused dorsally and resembles an open cape. There are three chaetigers in the thoracic region, each with paired bundles of chaetae. Some collar chaetae have a knee-like swelling, with a finely toothed edge; there are capillary chaetae mixed among them, comprising about 11 chaetae in each bundle. The third chaetiger contains sickle-like chaetae, again with a knee-like swelling, but with the fine teeth on the curved blade. The longest abdominal chaetae are sickle-like and longer than the collar chaetae. The animal forms a coil, usually less than 2 mm in diameter. The body color varies – a bright orange form is found in high rock pools in Europe, while a paler form is found in deeper water. Description based on Knight-Jones and Knight-Jones 1974 and 1977, Hayward and Ryland 1990, MarLin 2015.

Notes on the potentially misidentified species: Polychaetes of the subfamily Spirorbinae are diverse. For example, at least 7 genera and 13 species are known from the central region of the West Coast (Blake and Ruff 2007). Only the most closely related species are listed below. They are easily overlooked as a result of their small size, and because many key characters are concealed by the tube-shell. Consequently, records are dependent on specialists, and frequently sporadic.


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Annelida
Class:   Polychaeta
Subclass:   Palpata
Order:   Canalipalpata
Suborder:   Sabellida
Family:   Serpulidae
SubFamily:   Spirorbinae
Genus:   Janua
Species:   heterostropha


Janua pusilloides (Bush, 1904)
Janua unicornis (Bailey, 1969)
Mera pusilla (T. Joseph, 1894)
Spirorbis epichysis (Bailey, 1969)
Spirorbis gnomonicus (Bailey, 1969)
Spirorbis pagenstecheri (Quatrefages, 1865)
Spirorbis pusilloides (Bush, 1904)
Spirorbis unicornis (Bailey, 1969)
Janua pagenstecheri (Quatrefages, 1866)

Potentially Misidentified Species

Neodexiospira brasilensis
This spirorbin polychaete is of unknown origin (possibly Indo-Pacific), but appears to be introduced in the Northeast Atlantic, Northeast Pacific (Knight-Jones et al. 1975; 1979), and Northwest Atlantic (Wells et al. 2014).

Neodexiospira foraminosa
Neodexiospira foraminosa is widespread in tropical and subtropical waters. It has been found in the Gulf of Mexico (Knight-Jones et al. 1975), where we consider it cryptogenic.

Neodexiospira pseudocorrugata
Neodexiospira pseudocorrugata is widespread in temperate and tropical waters (Knight-Jones et al. 1975).



Janua heterostropha is a small, tube-dwelling, epifaunal polychaete. The worms are hermaphroditic, with male and female gonads. Fertilization occurs outside the body but inside the tube, where the larvae are brooded in an opercular chamber. Self-fertilization can occur but is rare. Larvae are lecithotrophic and can probably begin metamorphosis soon after hatching (Knight-Jones and Knight Jones 1977). Janua heterostropha is a wide-ranging, occurring from the lower intertidal to at least 120m depth, and from cold-temperate regions to the tropics (Knight-Jones and Knight-Jones 1977; Rzhavsky 1991). Spirorbin polychaetes are filter-feeders, feeding on phytoplankton and other suspended particles (Fauchald and Jumars 1979). 


Phytoplankton, detritus



Other spirorbin polychaetes

Trophic Status:

Suspension feeder


General HabitatCoarse Woody DebrisNone
General HabitatRockyNone
General HabitatMarinas & DocksNone
General HabitatVessel HullNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Tidal RangeLow IntertidalNone
Vertical HabitatEpibenthicNone

Life History

Tolerances and Life History Parameters

General Impacts

Impacts are unknown. 

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NA-ET2 Bay of Fundy to Cape Cod 2000 Def Estab
NA-ET3 Cape Cod to Cape Hatteras 2000 Def Estab
NEA-III None 0 Crypto Estab
NEA-IV None 1897 Crypto Estab
AR-V None 1953 Crypto Estab
B-I None 1953 Crypto Estab
NEA-II None 0 Crypto Estab
NEA-V None 1923 Crypto Estab
MED-II None 1968 Crypto Estab
MED-III None 1968 Crypto Estab
MED-VII None 1910 Crypto Estab
MED-IV None 1968 Crypto Estab
MED-VI None 1969 Crypto Estab
WA-I None 1880 Crypto Estab
WA-VI None 1959 Crypto Estab
NEA-VI None 0 Crypto Estab
WA-IV None 1971 Def Estab
WA-V None 1971 Def Estab
AG-3 None 1975 Crypto Estab
CIO-II None 1926 Crypto Estab
AUS-VII None 1973 Crypto Estab
NZ-IV None 1973 Crypto Estab
SP-XXI None 1972 Def Estab
NEP-III Alaskan panhandle to N. of Puget Sound 1912 Crypto Estab
NEP-VIII None 1942 Crypto Estab
SEP-Z None 1968 Def Estab
SP-XVIII None 1912 Crypto Estab
SA-III None 1872 Crypto Estab
CAR-III None 1972 Crypto Estab
CAR-IV None 1970 Crypto Estab
MED-IX None 0 Crypto Estab
MED-X None 1949 Crypto Estab
NWP-4a None 1991 Crypto Unk
MED-V None 0 Crypto Estab
RS-3 None 1976 Crypto Estab
M020 Narragansett Bay 2000 Def Estab
M010 Buzzards Bay 2000 Def Estab
N180 Cape Cod Bay 2000 Def Estab
RS-2 None 0 Crypto Estab
RS-1 None 0 Crypto Estab
N170 Massachusetts Bay 2000 Def Estab
SEP-H None 1971 Crypto Estab
AUS-VIII None 1983 Crypto Estab
AUS-IV None 2008 Crypto Estab
PAN_PAC Panama Pacific Coast 1971 Crypto Estab
PAN_CAR Panama Caribbean Coast 1972 Crypto Estab
B-II None 0 Native Estab
M026 _CDA_M026 (Pawcatuck-Wood) 2022 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Appeltans, W. et al. 2011-2015 World Registry of Marine Species. <missing URL>

Atlas of Living Australia 2013-2016 Atlas of Living Australia. <missing URL>

Ben-Eliahu, M. N. (1976) Polychaeta cryptofauna from rims of similar intertidal vermetid reefs on the Mediterranean coast of Israel.and in the Gulf of Elat: Serpulidae (Polychaeta Sedentaria), Israel Journal of Zoology 25: 103-119

Blake, James A.; Ruff, R. Eugene (2007) The Light and Smith Manual: Intertidal invertebrates from Central California to Oregon (4th edition), University of California, Berkeley CA. Pp. 309-410

Carlton, James T.; Eldredge, Lucius (2009) Marine bioinvasions of Hawaii: The introduced and cryptogenic marine and estuarine animals and plants of the Hawaiian archipelago., Bishop Museum Bulletin in Cultural and Environmental Studies 4: 1-202

Coles, S. L.; Reath, P. R.; Longenecker, K.; Bolick, Holly; Eldredge, L. G. (2004) <missing title>, Hawai‘i Community Foundation and the U. S. Fish and Wildlife Service, Honolulu. Pp. 1-187

Gee, J. M.; Williams, G. Brinley (1964) Self- and cross-fertilization in Spirorbis borealis and S. pagenstecheri, Journal of the Marine Biological Association of the United Kingdom 45: 275-285

Hayward, P.J.; Ryland, J. S. (1990) The Marine Fauna of the British Isles and North-West Europe, 1 Clarendon Press, Oxford. Pp. <missing location>

Knight- Jones, Phyllis; Knight- Jones, E. Wyn (1995) Spirorbidae (Polychaeta) from Madeira including a new species and subgenus of Spirorbis, Mitteilungen aus dem Hamburgishen Zoologischen Museum und Institut 92: 89-101

Knight-Jones, E. W.; Knight-Jones, Phyllis (1974) Spirorbinae (Polychaeta: Serpulidae) from Southeastern Australia., Records of the Australian Museum 29: 101-151

Knight-Jones, Phyllis, Knight-Jones, E.W., Dales, R. Phillips (1979) Spirorbidae (Polychaeta Sedentaria) from Alaska to Panama, Journal of Zoology, London 189: 419-458

Knight-Jones, Phyllis, Knight-Jones, E.W., Kawahara, Tatuo (1975) A review of the genus Janua, including Dexiospira (Polychaeta: Spirorbinae), Zoological Journal of the Linnean Society 56: 91-129

Knight-Jones, Phyllis; Knight-Jones, E. W. (1977) Taxonomy and ecology of British Spirorbidae (Polychaeta)., Journal of the Marine Biological Association of the United Kingdom 57: 453-499

MarLin- Marine Life Information Network 2006-2024 MarLin- Marine Life Information Network. <missing URL>

Mead, A.; Carlton, J. T.; Griffiths, C. L. Rius, M. (2011b) Introduced and cryptogenic marine and estuarine species of South Africa, Journal of Natural History 39-40: 2463-2524

MIT Sea Grant 2003-2008 Introduced and cryptogenic species of the North Atlantic. <missing URL>

MIT Sea Grant 2009-2012 Marine Invader Tracking and Information System (MITIS). <missing URL>

Museum of Comparative Zoology 2008-2015 Invertebrate Zoology Collections Database <missing URL>

Quintanilla, Elena; Thomas Wilke; Ramırez-Portilla, Catalina; Sarmiento, Adriana; Sanchez, Juan A.2017 (2017) Taking a detour: invasion of an octocoral into the Tropical Eastern Pacific, Biological Invasions <missing volume>(17): 2583–2597
DOI 10.1007/s10530-017-1469-2

Ruiz, Gregory M.; Geller, Jonathan (2018) Spatial and temporal analysis of marine invasions in California, Part II: Humboldt Bay, Marina del Re, Port Hueneme, and San Francisco Bay, Smithsonian Environmental Research Center & Moss Landing Laboratories, Edgewater MD, Moss Landing CA. Pp. <missing location>

Rzhavsky, A. V. (1991) Revision of Januinae (Polychaeta, Spirorbidae) in the Seas of the USSR, Zoologichaeskii Zhurrnal 70(8): 37-44

Rzhhasky, A. V. (1991) Revision of Januinae (Polychaeta, Spirorbidae) in the seas of the USSR., Zoologicheskii Zhurnal 70(8): 37-45

ten Hove, Harry A.; Kupriyanova, Elena (2009) Taxonomy of Serpulidae (Annelida, Polychaeta): The state of affairs, Zootaxa 2036: 1-126

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database.

Wehe, Thomas; Fiege, Dieter (2002) Annotated checklist of the polychaete species of the seas surrounding the Arabian Peninsula: Red Sea, Gulf of Aden, Arabian Sea, Gulf of Oman, Arabian Gulf., Fauna of Arabia 19: 7-238

Wells, Christopher D. and 23 authors (2014) Report on the 2013 rapid assessment survey of marine species at New England bays and harbors, Massachusetts Office of Coastal Zone Management, Boston MA. Pp. 32

Woods Hole Oceanographic Institution, United States Navy Dept. Bureau of Ships (1952) Marine fouling and its prevention., United States Naval Institute., Washington, D.C.. Pp. 165-206

Zibrowius, Helmut, Thorp, Clifford H. (1989) A review of the alien serpulid and spirorbid polychaetes in the British Isles, Cahiers de Biologie Marine 30(3): 271-285