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
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
Effects on commercial interests
It is a fouling species which affects ships, buoys and harbour
Control methods used and effectiveness
It is removed from buoys and ships' hulls by scraping.
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
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'
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,
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,
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.
Hiscock, K., & Hoare, R. 1975. The ecology of sublittoral
communities at Abereiddy Quarry, Pembrokeshire. Journal of the
Marine Biological Association of the United Kingdom,
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:
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.
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,
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,
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,
Thorp, C.H. 1987. Ecological studies on the serpulid
polychaete Ficopomatus enigmaticus (Fauvel) in a brackish
water millpond. Porcupine Newsletter,4:
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:
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.