Neodexiospira brasiliensis - Brazilian spiral tubeworm

The Brazilian spiral tubeworm is a cryptogenic species. It may be naturally found in the tropical waters of the West Atlantic Ocean, along the Brazilian coast, where the species was first described ^[1,2]. However, the genus Neodexiospira exhibits the greatest diversity in the Indo-Pacific region, with occurrences from the Kuril Islands to New Zealand, making this region also a potential natural distribution area ^[3].

First observation in Belgium

In the summer of 2023, the Brazilian spiral tubeworm was first observed in the Sluice Dock in Ostend ^[4].

Distribution in Belgium

The species has not been observed outside the Sluice Dock in Ostend to date.

Distribution in neighbouring countries

The Brazilian spiral tubeworm was first observed along the Atlantic coast of Europe in 1974, specifically in Portsmouth Harbour in southern England ^[2]. In 1982, the species was also found at Goese Sas in the Dutch Eastern Scheldt ^[5]. The worm is now considered established in the Netherlands ^[6], with occurrences not only in the Eastern Scheldt but also in the Wadden Sea (recorded in 2009) ^[7] and the Western Scheldt ^[8].

The primary introduction vector responsible for the species' presence in European waters remains unknown, but international shipping is suspected to be a likely factor ^[3,8]. Secondary spread occurs through attachment to (also non-native) floating Japanese wireweed Sargassum muticum or via attachment to recreational boats ^[5,8].

The Brazilian spiral tubeworm is observed in both polyhaline (18-30 psu) and euhaline (30-40 psu) environments, and in cold-temperate to tropical waters ^[9]. Exact tolerance limits are not yet known.

Active further spread in colonised areas is considered limited due to the species' brief (several hours) motile larval stage ^[10]. However, the worm has been repeatedly found on the thalli of floating Japanese wireweed Sargassum muticum and the leaves of Eelgrass Zostera marina ^[5], which can facilitate secondary spread through passive drift with currents. In addition to settling on vegetation, the worm is also found on pontoons, mussels, and snail shells ^[11], with bacterial films seemingly promoting its attachment ^[12].

The ecological or economic impact of this worm has rarely been reported. In the Goese Sas channel, high concentrations of the worms may have affected the photosynthesis of eelgrass (Zostera marina) or led to the degradation of its leaves. However, these effects may have been very localised, potentially due to increased temperatures in the channel ^[2,5].

Worms of the Spirorbinae are small tube worms that typically grow in tightly coiled, calcareous tubes ^[13,14]. The tube of the Brazilian spiral tubeworm is right-handed (counterclockwise when viewed from above) and measures about 2 mm in diameter. Larger tubes often have four parallel grooves at regular intervals, which are easily visible from above, and are opaque and white ^[9].

They possess a crown of feather-like radioles, with one of the radioles modified into an operculum. The peristomium (the segment behind the mouth) is folded back to form a collar, which bears uniramous parapodia with a characteristic set of collar chaetae, featuring spines or serrations. The collar is the first of three or four asymmetrical thoracic chaetigers ^[13,15]. The worm itself is orange in color ^[13].

The worms are hermaphroditic. Fertilisation occurs outside the body but within the tube, where larvae are brooded in an opercular chamber. Self-fertilisation can occur but is relatively rare ^[16,17]. The larvae settle within 1 to 5 hours after hatching ^[12].

[1]          World Register of Marine Species (WoRMS) (2024). Neodexiospira brasiliensis (Grube, 1872). https://www.marinespecies.org/aphia.php?p=taxdetails&id=131209 (2024-10-18). 

[2]          Eno, N.C.; Clark, R.A.; Sanderson, W.G. (Ed.) (1997). Non-native marine species in British waters: a review and directory. Joint Nature Conservation Committee: Peterborough. ISBN 1-86107-442-5. 152 pp. [https://www.vliz.be/nl/imis?module=ref&refid=24400] 

[3]          Knight-Jones, P.; Knight-Jones, E.W.; Kawahara, T. (1975). A review of the genus Janua, including Dexiospira (Polychaeta: Spirorbinae). Zool. J. Linn. Soc. 56(2): 91-129. [https://www.vliz.be/en/imis?module=ref&refid=393502] 

[4]          Jonckheere, I.; Kerckhof, F. (2024). Waarnemingen gedaan tijdens de SWG-excursie naar de Spuikom van Oostende op 9 juli 2023 met vondsten van verschillende nieuwe geïntroduceerde soorten voor de Belgische fauna. De Strandvlo 44(2): 33-41. [https://www.vliz.be/nl/imis?module=ref&refid=394050]

[5]          Critchley, A.T.; Thorp, C.H. (1985). Janua (Dexiospira) brasilliensis (Grube) (Polychaeta: Spirorbidae): a new record from the south-west Netherlands. Zoologische Bijdragen 31(1): 1-8. [https://www.vliz.be/en/imis?module=ref&refid=393503]  

[6]          Wolff, W.J. (2005). Non-indigenous marine and estuarine species in the Netherlands. Zool. Meded. 79(1): 3-116. [https://www.vliz.be/nl/imis?module=ref&refid=101200] 

[7]          Gittenberger, A.; Rensing, M.; Stegenga, H.; Hoeksema, B. (2010). Native and non-native species of hard substrata in the Dutch Wadden Sea. Ned. Faunist. Meded. 33: 21-76. [https://www.vliz.be/nl/imis?module=ref&refid=206549] 

[8]          Gittenberger, A.; Rensing, M.; Wesdorp, K.H. (2017). Uitheemse mariene soorten in Nederland. GiMaRIS Rapport, 19. GiMaRIS: Leiden. 39 pp. [https://www.vliz.be/en/imis?module=ref&refid=393505] 

[9]          Nemesis. Neodexiospira brasiliensis. https://invasions.si.edu/nemesis/species_summary/-44 (2024-04-24)

[10]        Knight-Jones, E.W.; Knight-Jones, P. (1980). Pacific spirorbids in the East Atlantic. J. Mar. Biol. Ass. U.K. 60(2): 461-464. [https://www.vliz.be/en/imis?module=ref&refid=393501] 

[11]        Critchley, A.T.; Farnham, W.F.; Thorp, C.H. (1997). On the co-occurrence of two exotic, invasive marine organisms: the brown seaweed Sargassum muticum (Yendo) Fensholt and the Spirorbid tube worm Janua (Neodexiospira) brasiliensis (Grube), in association with the indigenous eelgrass, Zostera marina L. and Wrack, Fucus serratus L. in the south-west Netherlands and the Channel Islands, Europe. S. Afr. J. Bot. 63(6): 474-479. [https://www.vliz.be/en/imis?module=ref&refid=393496] 

[12]        Kirchman, D.; Graham, S.; Reish, D.; Mitchell, R. (1981). Bacteria induce settlement and metamorphosis of Janua (Dexiospira) brasiliensis Grube (Polychaeta:Spirorbidae). J. Exp. Mar. Biol. Ecol. 56(2-3): 153-163. [https://www.vliz.be/en/imis?module=ref&refid=393498] 

[13]        Blake, J. A.; Ruff, R. E. (2007). Polychaeta. In: Carlton, J.T. (Ed.) (2007). The Light and Smith Manual. Intertidal Invertebrates from Central California to Oregon, Completely Revised and Expanded. Fourth Edition. University of California Press: Berkeley. ISBN 9780520239395. 309-410. [https://www.vliz.be/nl/imis?module=ref&refid=300117]  

[14]        ten Hove, H.A.; Kupriyanova, E.K. (2009). Taxonomy of Serpulidae (Annelida, Polychaeta): the state of affairs. Zootaxa 2036(2036): 1-126. [https://www.vliz.be/nl/imis?module=ref&refid=144298] 

[15]        Hayward, P.J.; Ryland, J.S. (Ed.) (1990). The marine fauna of the British Isles and North-West Europe: 1. Introduction and protozoans to arthropods. Clarendon Press: Oxford. ISBN 0-19-857356-1. xvi, 1-627 pp. [https://www.vliz.be/nl/imis?module=ref&refid=4889] 

[16]        Beckwitt, R. (1982). Electrophoretic evidence for self-fertilization in two species of spirorbid polychaetes. Bull. South. Calif. Acad. Sci. 81(2): 61–68. [https://www.vliz.be/en/imis?module=ref&refid=393500] 

[17]        Knight-Jones, P.; Knight-Jones, E.W. (1977). Taxonomy and ecology of British Spirorbidae (Polychaeta). J. Mar. Biol. Ass. U.K. 57(2): 453-499. [https://www.vliz.be/nl/imis?module=ref&refid=212504]

VLIZ Alien Species Consortium (2024). Neodexiospira brasiliensis – Brazilian spiral tubeworm. Introduced alien species of the Belgian part of the North Sea and adjacent estuaries anno 2024. Flanders Marine Institute (VLIZ). 5 pp.