Ficopomatus enigmaticus

Phylum: Annelida
Class: Polychaeta
Order: Sabellida (Serpulidae; serpulid)
Species name: Ficopomatus enigmaticus (Fauvel 1923)
Synonyms: Mercierella enigmatica Fauvel 1923
Common name: A tubeworm
Date of introduction and origin
Ficopomatus enigmaticus was first noticed in northern France in 1921 (Fauvel 1923). It was first recorded from London docks in 1922 (Monro 1924). This origin of this species is not clear, it occurs in waters of variable salinity in temperate or warm temperate areas of both northern and southern hemispheres, and it was possibly introduced from Australia (Zibrowius & Thorp 1989). However, recent Australian literature lists Ficopomatus enigmaticus as introduced, and the best conclusion is that it is clearly southern hemisphere in origin (L. McCann & J. Carlton pers. comm.).
Method of introduction
Its preferred habitat within brackish waters, including estuaries, results in this species being ideal for transport on ships hulls (most major ports are sited on estuaries) and commercial mollusc shells.
Reasons for success
Within relatively confined waters of variable salinity it suffers little competition from other serpulids. Many estuaries are characteristically areas of high productivity and so filter-feeders such as Ficopomatus enigmaticus, which are able to stand considerable variations in salinity are well placed to reap the benefit. High fecundity, possibly allied with larval retention within semi-enclosed waters, facilitates a rapid build up of numbers and initially there might be an absence of predators.
Rate of spread and methods involved
Its disjunct distribution suggests spread by remote dispersal of mobile adults (on ships' hulls).
Ficopomatus enigmaticus has been found in all ports from north Pembrokeshire to the Thames estuary (see reference list). Its distribution is, however, confined to coastal brackish waters and therefore disjunct. It has also been found in Barrow-in-Furness, Cumbria (Markowski 1962). This species is known to be widespread throughout Europe, including Ireland. Thorp (1994) reported how the Emsworth population, West Sussex experienced a catastrophic decline in 1986 and suggested that high density populations are liable to suffer periodic decline.
Factors likely to influence spread and distribution
It is thought to be at, or close to, its temperature minimum for maintaining populations and successful reproduction along southern coasts of Britain (Zibrowius & Thorp 1989; Thorp 1994). More northerly populations survive owing to artificially raised water temperatures. In addition, successful reproduction is considered to be limited to waters of variable salinity. In Britain, therefore, any future invasions or spread would be expected to be confined to brackish waters on southern coasts.
Effects on the environment
Its effects on native species are more likely to be beneficial than problematic (see below). This species favours waters which present some degree of stress to most open-shore marine organisms. Its requirement for variable-salinity water in which to spawn ensures that the major populations do not interfere with most indigenous species.
Effects on commercial interests
It is a fouling species which affects ships, buoys and harbour structures.
Control methods used and effectiveness
It is removed from buoys and ships' hulls by scraping.
Beneficial effects
While F. enigmaticus can be a fouling nuisance it can also benefit the waters it invades. As Keene (1980) and Davies, Stuart & Villiers (1989) have shown, the presence of large numbers in enclosed waters including marinas, where they would be considered a fouling nuisance, has had very beneficial effects on water quality, reducing suspended particulate loads and improving both the oxygen and nutrient status. Thomas & Thorp (1994) have also shown that a large population of F. enigmaticus can remove material from suspension and thus have a very beneficial effect on other benthic species within enclosed or semi-enclosed waters. However, abundant filter-feeders can also deplete phytoplanktonic resources and suspended particulate organic material which might otherwise be utilised by other, native, filter-feeders. Through production of faeces and psuedofaeces in large quanities they also concentrate contaminants from the water column and pass them into the sediment and hence up the food chain.
Recorded initially in 1937 from Weymouth Harbour, Dorset, and within adjacent Radipole Lake in 1952 (Tebble 1953, 1956), this species has been noted there on a number of widely separated occasions over subsequent years. Lack of data render it impossible to determine whether the population in 1937 had survived through many generations for more than 50 years, or whether its observed presence represents a series of discrete invasions, each of which lasted a finite period.
References and selected bibliography on species' distribution
Bianchi, C.N. 1981. Guide per il riconoscimento delle specie animali delle acque lagunari e costiere Itliane. No. 5 Series: Policheti, Serpuloidei. Rome, Consigleo Nazionale delle Ricerche.
Bullimore, B., Dyrynda, P.E.F., & Bowden, N. 1978. The effects of falling temperatures on the fauna of Swansea Dock. Progress in Underwater Science, 2: 135-146.
Davies, B.R., Stuart, V., & Villiers, M. de. 1989. The filtration activity of a serpulid polychaete population (Ficopomatus enigmaticus (Fauvel)) and its effects on water quality in a coastal marina. Estuarine, Coastal and Shelf Science, 29: 613-620.
Dixon, D.R. 1981. Reproductive biology of the serpulid Ficopomatus (Mercierella) enigmatica in the Thames estuary, S.E. England. Journal of the Marine Biological Association of the United Kingdom, 61: 805-815.
Fauvel, P. 1923. Un nouveau serpulien d'eau saumâtre, Mercierella n.g. enigmatica n.sp. Bulletin Société Zoologique de France, 47: 424-430.
Gee, J.M. 1963. On the taxonomy and distribution in South Wales of Filograna, Hydroides and Mercierella (Polychaeta: Serpulidae). Annals and Magazine of Natural History, 6: 705-715.
Harris, T. 1970. The occurrence of Manayunkia aestuarina (Bourne) and Mercierella enigmaticus Fauvel (Polychaeta) in non-brackish localities in Britain. Journal of Experimental Marine Biology and Ecology, 5: 105-112.
Himmelman, J.H. 1980. Synchronisation of spawning in marine invertebrates by phytoplankton. In: Invertebrate reproduction, ed. by W.H. Clarke Jnr & T.S. Adams, 3-19. Amsterdam, Elsevier.
Hiscock, K., & Hoare, R. 1975. The ecology of sublittoral communities at Abereiddy Quarry, Pembrokeshire. Journal of the Marine Biological Association of the United Kingdom, 55: 833-864.
Keene Jnr, W.C. 1980. The importance of a reef-forming polychaete Mercierella enigmatica Fauvel, in the oxygen and nutrient dynamics of a hypereutrophic subtropical lagoon. Estuarine, Coastal and Shelf Science, 11: 167-178.
Kilty, G.M., & Guiry, M.D. 1973. Mercierella enigmatica Fauvel (Polychaeta: Serpulidae) from Cork Harbour. Irish Naturalist, 17: 379-381.
Marine Biological Association of the United Kingdom. 1957. Plymouth marine fauna. 3rd ed. Plymouth.
Markowski, S. 1962. Faunistic and ecological investigations in Cavendish Dock, Barrow-in-Furness. Journal of Animal Ecology, 31: 42-52.
Monro, C.C.A. 1924. A serpulid polychaete from London docks (Mercierella enigmatica Fauvel). Annals and Magazine of Natural History, 13: 155-159.
Naylor, E. 1957. Immigrant marine animals in Great Britain. New Scientist, 2(50): 21-23.
Naylor, E. 1959. The fauna of a warm dock. In: Proceedings of the XVth International Congress of Zoology, 259-262. London.
Naylor, E. 1965a. Biological effects of heated effluents in docks at Swansea, S. Wales. Proceedings of the Zoological Society of London, 144: 253-268.
Naylor, E. 1965b. Effects of heated effluents upon marine and estuarine organisms. Advances in Marine Biology, 3: 63-103.
Nelson-Smith, A., & Gee, J.M. 1966. Serpulid tubeworms (Polychaeta: Serpulidae) around Dale, Pembrokeshire. Field Studies, 2: 331-357.
Ryland, J.S. 1960. The British species of Bugula (Polyzoa). Proceedings of the Zzoological Society of London, 134: 65-105.
Tebble, N. 1953. A source of danger to harbour structures - encrustation by a tubed marine worm. Journal of the Institution of Municipal Engineers, 80: 259-265.
Tebble, N.B. 1956. The control of Mercierella enigmatica Fauvel (Polychaeta) in Radipole Lake, Weymouth in England. In:Proceedings of the XIVth International Congress of Zoology, Copenhagen, 444-446.
Thomas, N.S., & Thorp, C.H. 1994. Cyclical changes in the fauna associated with tube aggregates of Ficopomatus enigmaticus (Fauvel). Memoires de Museum National d'Histoire Naturelle, 162: 575-584.
Thorp, C.H. 1980. The benthos of the Solent. In: The Solent estuarine system: an assessment of present knowledge. London, National Environment Research Council Publications, 76-85.
Thorp, C.H. 1987. Ecological studies on the serpulid polychaete Ficopomatus enigmaticus (Fauvel) in a brackish water millpond. Porcupine Newsletter,4: 14-19.
Thorp, C.H. 1994 . Population variation in Ficopomatus enigmaticus (Fauvel) (Polychaeta: Serpulidae) in a brackish water millpond at Emsworth, West Sussex, UK. Memoires de Museum National d'Histoire Naturelle, 162: 585-591.
Thorp, C.H., Pyne, S., & West, S.A. 1987. Hydroides ezoensis Okuda, a fouling serpulid new to British coastal waters. Journal of Natural History, 21: 863-877.
Zibrowius, H., & Thorp, C.H. 1989. A review of the alien serpulid and spirorbid solychaetes in the British Isles. Cahiers de Biologie Marine,30: 271-285.
Acknowledgements (contributions from questionnaire)
Dr C.H. Thorp, University of Portsmouth.