NOBANIS - Marine invasive species in Nordic waters - Fact Sheet

Elminius modestus

Author of this species fact sheet: Kathe R. Jensen, Zoological Museum, Natural History Museum of Denmark, Universiteteparken 15, 2100 København Ø, Denmark. Phone: +45 353-21083, E-mail: [email protected]

Bibliographical reference – how to cite this fact sheet: Jensen, Kathe R. (2010): NOBANIS – Invasive Alien Species Fact Sheet – Elminius modestus – From: Identification key to marine invasive species in Nordic waters – NOBANIS www.nobanis.org, Date of access x/x/201x.

Species description

Species name Elminius modestus, Darwin, 1854 – Australasian barnacle

Synonyms Austrominius modestus

Common names Firepladet rur (DK); Australasian barnacle, New Zealand barnacle (UK); Australische Seepocke; Australseepocke (DE); Nieuw-Zeelandse zeepok, Kruisridderpok, Sterretje (NL)

Identification Elminius modestus has only 4 calcareous plates surrounding the body. These plates are usually folded to give a scalloped appearance of the base. The base is not calcified; only a membraneous surface separates the body from the substrate. It is a small species, usually only about 5-6 mm in diameter. The only native shallow water species with folded shell plates in Nordic waters is Semibalanus balanoides (Linnaeus, 1767). However, this species has 6 shell plates, as most species of barnacles. Other species of Elminius have been introduced to other parts of the world, e.g., E. kingii J.E. Gray, 1831, from South America to eastern Canada (Gollasch, 2002) For further information see: http://www.jncc.gov.uk/page-1704 and http://www.marlin.ac.uk/speciesfullreview.php?speciesID=3252 For information on Semibalnus balanoides see: http://www.marlin.ac.uk/speciesfullreview.php?speciesID=4328

Pictures of Elminius modestus with the 4 plates

Pictures of Elminius modestus with the 4 plates Taxonomic note The genus name has recently been changed from Elminius to Austrominius, originally proposed only as a sub-genus (Buckeridge & Newman, 2010). However, this has not yet entered the literature, and the database used in this project, World Register of Marine Species (WoRMS; see http://www.marinespecies.org/ ) still uses Elminius, which will also be used here. Buckeridge & Newman (2010) also transferred the subfamily Elminiinae to a new family, Austrobalanidae from the Archaeobalanidae, which is the family given in WoRMS. Future revisions may support this or require further changes.

Distribution

Native area Australia and New Zealand

Introduced area Elminius modestus was first found in Chichester Harbour on the southern coast of the U.K. in 1945 and soon after in several other places along the southern coast of England (Bishop & Crisp, 1958), so it must be concluded that it probably arrived there between 1940 and 1943 (Crisp, 1958; Eno et al., 1997). Presently it is found on all coasts of the U.K., including the Shetland Islands, and it seems to be increasing in abundance (O’Riordan et al., 2009). In Ireland it was first found in 1956, and here it also seems to be still expanding (Lawson et al., 2004; Allen et al., 2006). In the Netherlands it was first found in 1946 and it had spread along the entire coast by 1951 (den Hartog, 1953; Wolff, 2005). In Belgium the first find was on a ship's hull in 1950 (Leloup & Lefevere, 1952; Kerckhoff, 2002). In France the first record was in 1950 near the Belgian border, and over the following years it was found in several localities along the northern coast (Bishop & Crisp, 1958). Later it was found along the entire Atlantic coast of France, northern Spain and Portugal (Fischer- Piette & Forest, 1961; O’Riordan & Ramsay, 1999). The first records from Germany were in 1953 from Cuxhafen and in 1955 from Helgoland and Sylt (Kühl, 1963). It was absent from Danish coasts in 1959 (Barnes & Barnes, 1960). The first record from the Danish Wadden Sea is from 1978 (Theisen, 1980), but it was apparently close to its northern limit and died out in winters with ice- formation (Jensen & Knudsen, 2005). It has been found every year between 2004 and 2008 in the Wadden Sea, and in 2007 it was found near the eastern entrance of the Limfjord (Jensen, 2009). It has not been found in other Nordic countries, but is on the Swedish alert list (Främmande Arter, 2008).

It was pointed out by den Hartog (1953) that contrary to most introduced species, E. modestus spread more rapidly to the south of its original introduction(s). Prevailing currents usually transport planktonic larvae northwards from the English Channel to the southern North Sea and the Wadden Sea as well as up along the coast of England and Scotland (Wolff, 2005). The rate of secondary spread has been calculated as 20-70 km per year (Bishop & Crisp, 1958; Geller, 1994).

Vector It is believed to have arrived on hulls of navy vessels during World War II (den Hartog, 1953; Crisp, 1958). Secondary dispersal may have been as epifauna on shellfish or through planktonic larvae in ballast water. Ecology

Elminius modestus prefers sheltered shores (Allen et al., 2006). It grows very fast and tolerates lower salinity and higher temperatures than most native barnacles, except the other introduced species, Balanus improvisus Darwin, 1854. Even small specimens can create very strong water currents by fast beating of the “cirri”, the modified thoracic legs (Crisp & Southward, 1961). Although it often occurs high in the intertidal, it prefers settling at depths of 3-4 m in the absence of competitors (Houghton & Stubbings, 1963). When Elminius modestus is out of water during low tide it traps a bubble of air under the closed opercular plates. It can then utilize the oxygen in that air bubble (Rainbow, 1984; Davenport & Irwin, 2003). The lowest temperature tolerated by E. modestus is about -6° C (Harms & Anger, 1989), and the highest temperature is about 38° C (Harms, 1984). In its native area water temperature varies between 4 and 21° C (Harms, 1999). Low winter temperatures causes high mortality and strongly decreased settling the following year (Harms & Anger, 1989). E. modestus is relatively euryhaline, though it is an osmoconformer (Foster, 1970). It survives periods of low salinity by closing the opercular plates, but cannot tolerate permanently low salinity (Rainbow, 1984). Total life span has been estimated as 5 years (Barnes, 1971).

Elminius modestus feeds mostly on small zooplankton, but can also filter phytoplankton (Rainbow, 1984). As an epibiont on commercial shellfish such as mussels and oysters, it is assumed to compete with these organisms for food. However, stable isotope analyses show that there is some degree of resource partitioning (Dubois et al., 2007). Elminius modestus is one of the barnacles that accumulates Zn and other heavy metals taken up from dietary sources in its tissues, and it has been proposed to use it as a biomonitor (Walker et al., 1975; Rainbow & Wang, 2001). Other studies have concluded that it is unsuitable (Elliott et al., 1985). It has also been used in toxicity tests for chemicals used to dissolve oil-spills. Adults were more tolerant than larvae, but activity of cirri was affected by low concentrations. Acute toxicity stopped larval locomotion and development was retarded or completely inhibited (Corner et al., 1968).

Elminius modestus may be host of the parasitic isopod Hemioniscus balani (Spence Bate, 1860), which causes female castration in barnacles. Just one individual of this parasite is enough to cause castration (see: http://species-identification.org/species.php?species_group=crustacea&id=530)

Reproduction Elminius modestus, like almost all barnacles, is hermaphroditic, though it requires cross- fertilization. It reaches sexual maturity about 8 weeks after settling, at a diameter of 6-7 mm (Rainbow, 1984). Breeding begins when the water temperature exceeds 6º C (Harms, 1984). An average sized animal produces about 1800-4000 eggs (Barnes & Barnes, 1968) and using a generation time of only 14 weeks and release of 12 broods per year very high fecundity has been calculated (Crisp & Davenport, 1955). E. modestus produces successive broods throughout the year, each brood being released after 2 weeks (Barnes & Barnes, 1968), though in winter months development may take 60-80 days (Crisp & Davies, 1955). E. modestus produces a chemical, which induces the nauplius larvae inside the ovisac to move vigorously till the egg capsule ruptures and the nauplius hatches (Hill et al., 1988). The nauplius I is 250 x 125 µm (Barnes & Barnes, 1965). Nauplius larvae are positively phototactic (Barnes & Klepal, 1972). Duration of larval stages from hatching to cypris varies from about 40 days at 6º C to less than 10 days at 24º C, and also mortality in the laboratory was much higher at low temparatures (Harms, 1984). Mortality of nauplius larvae was lowest at salinities between 20 and 30 ppt, and development ceases around 16 ppt (Harms, 1999). Cypris larvae are attracted to places where adult conspecifics are present (Knight-Jones & Stevenson, 1950).

Impacts

Elminius modestus competes with other shallow water barnacles for space. At its northern limit reproduction begins later than in the native species, and other species have already settled by the time E. modestus is ready to settle. Also, it is able to settle at higher levels of the shore than S. balanoides as well as deeper into subtidal levels (Harms, 1984). Because it may reproduce throughout the year it has a high reproductive potential, and in some places it is the dominating barnacle species (Lawson et al., 2004; Watson et al., 2005). In some places it may have completely replaced the native barnacles (Lawson et al., 2004). E. modestus is frequently found fouling ships’ hulls (den Hartog, 1953; Gollasch, 2002), which not only causes further spread of the species, but also is a nuissance to the shipping industry. It is suitable as test organism for toxicity tests because it produces larvae throughout the year and the larvae are the most sensitive stage (Corner et al., 1968).

References

Allen, B.M., Power, A.M., O'Riordan, R.M., Myers, A.A. and McGrath, D. 2006. Increases in the abundance of the invasive barnacle Elminius modestus Darwin in Ireland. Biology and Environment: Proceedings of the Royal Irish Academy 106B(2): 155-161.

Barnes, H. 1971. Organic production by Elminius modestus Darwin in an enclosed basin. Journal of Experimental Marine Biology and Ecology 6: 79-82.

Barnes, H. and Barnes, M. 1960. Recent spread and present distribution of the barnacle Elminius modestus Darwin in north-west Europe. Proceedings of the Zoological Society of London 135: 137-145.

Barnes, H. and Barnes, M. 1965. Egg size, and their variation with local, geographical, and specific factors in some common cirripedes. Journal of Animal Ecology 34(2): 391-402.

Barnes, H. and Barnes, M. 1968. Egg numbers, metabolic efficiency of egg production and fecundity; local and regional variations in a number of common cirripedes. Journal of Experimental Marine Biology and Ecology 2: 135-153.

Barnes, H. and Barnes, M. 1969. Elminius modestus Darwin: Records of its present distribution and abundance in the Baie de St. Malo and in the region of St. Jean-de-Luz. Journal of Experimental Marine Biology and Ecology 3: 156- 161.

Barnes, H. and Klepal, W. 1972. Phototaxis in stage I nauplius larvae of two cirripedes. Journal of Experimental Marine Biology and Ecology 10: 267-273.

Bishop, M.W.H. and Crisp, D.J. 1958. The distribution of the barnacle Elminius modestus Darwin in France. Proceedings of the Zoological Society of London 131: 109-134.

Buckeridge, J.S. and Newman, W.A. 2010. A review of the subfamily Elminiinae (Cirripedia: Thoracica: Austrobalanidae), including a new genus, Protelminius nov., from the Oligocene of New Zealand. Zootaxa 2349: 39-54.

Corner, E.D.S., Southward, A.J. and Southward, E.C. 1968. Toxicity of oil-spill removers (‘detergents’) to marine life: an assessment using the intertidal barnacle Elminius modestus. Journal of the Marine Biological Association of the United Kingdom 48: 29-47.

Crisp, D.J. 1958. The spread of Elminius modestus Darwin in North-West Europe. Journal of the Marine Biological Association of the United Kingdom 37: 483-520.

Crisp, D.J. and Davies, P.A. 1955. Observations in vivo on the breeding of Elminius modestus grown on glass slides. Journal of the Marine Biological Association of the United Kingdom 34: 357-380.

Crisp, D.J. and Patel, B. 1961. The interaction between breeding and growth rate in the barnacle Elminius modestus Darwin. Limnology and Oceanography 6(2): 105-115.

Crisp, D.J. and Southward, A.J. 1961. Different types of cirral activity of barnacles. Philosophical Transactions of the Royal Society B 243: 271-308.

Davenport, J. and Irwin, S. 2003. Hypoxic life of intertidal acorn barnacles. Marine Biology 143: 555-563.

Dubois, S., Orvain, F., Marin-Léal, J.C., Ropert, M. and Lefebvre, S. 2007. Small-scale spatial variability of food partitioning between cultivated oysters and associated suspension-feeding species, as revealed by stable isotopes. Marine Ecology Progress Series 336: 151-160.

Elliott, N.G., Ritz, D.A. and Swain, R. 1985. Interaction between copper and zinc accumulation in the barnacle Elminius modestus Darwin. Marine Environmental Research 17: 13-17.

Eno, N.C., Clark, R.A. and Sanderson, W.G. 1997. Non-native marine species in British waters: a review and directory. Joint Nature Conservation Committee, Peterborough, UK, 136pp.

Fischer-Piette, E. and Forest, J. 1961. Nouveaux progrès du Cirripède austral Elminius modestus Darwin sur les côtes atlantiques françaises et ibériques. Crustaceana 2(4): 293-299.

Foster, B.A. 1970. Responses and acclimation to salinity in the adults of some balanomorph barnacles. Philosophical Transactions of the Royal Society of London B 256: 377-400.

Främmande Arter 2008. Havstulpan (Elminius modestus). Fact-sheet available at http://www.frammandearter.se/5arter/pdf/Elminius_modestus.pdf (accessed on 19 March 2010).

Geller, J.B. 1994. Marine biological invasions as models of dispersal: tracking secondary spread and introgressive gene flow. California Cooperative Oceanic Fisheries Investigations (CalCOFI) Report 35: 68-72.

Gollasch, S. 2002. The importance of ship hull fouling as a vector of species introductions into the North Sea. Biofouling 18(2): 105-121.

Harms, J. 1984. Influence of water temperature on larval development of Elminius modestus and Semibalanus balanoides (Crustacea, Cirripedia). Helgoländer Meeresuntersuchungen 38: 123-134.

Harms, J. 1987. Energy budget for the larval development of Elminius modestus (Crustacea: Cirripedia). Helgoländer Meeresuntersuchungen 41: 45-67.

Harms, J. 1999. The neozoan Elminius modestus Darwin (Crustacea, Cirripedia): Possible explanations for its successful invasion in European water. Helgoländer Meeresuntersuchungen 52: 337-345.

Harms, J. and Anger, K. 1989. Settlement of the barnacle Elminius modestus Darwin on test panels at Helgoland (North Sea): A ten year study. Topics in Marine Biology. Scientia Marina 53(2-3): 417-421.

Hartog, D. den 1953. Immigration, dissemination and ecology of Elminius modestus Darwin in the North Sea, especially along the Dutch coast. Beaufortia 4(33): 9-20.

Hill, E.M., Holland, D.L., Gibson, K.H., Clayton, E. and Oldfield, A. 1988. Identification and hatching factor activity of monohydroxyeicosapentaenoic acid in homogenates of the barnacle Elminius modestus. Proceedings of the Royal Society of London. Series B, Biological Sciences 234: 455-461.

Houghton, D.R. and Stubbings, H.G. 1963. On the vertical distribution of Elminius modestus Darwin. Journal of Animal Ecology 32(2): 193-201.

Jensen, K.R. 2009. National Report Denmark, 2008. Pp. 41-63 In: ICES. Report of the Working Group on Introduction and Transfers of Marine Organisms (WGITMO), 11-13 March 2009, Washington, D.C., USA, 220pp.

Jensen, K.R. and Knudsen, J. 2005. A summary of alien marine benthic invertebrates in Danish waters. Oceanological and Hydrobiological Studies 34, Supplement 1: 137-162.

Kerckhof, F. 2002. Barnacles (Cirripedia, Balanomorpha) in Belgian waters, an overview of the species and recent evolutions, with emphasis on exotic species. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Biologie 72 Supplement: 93-104.

Kerckhof, F. and Cattrijsse, A. 2001. Exotic Cirripedia (Balanomorpha) from buoys off the Belgian coast. Senckenbergiana Maritima 31(2): 245-254.

Knight-Jones, E.W. and Stevenson, J.P. 1950. Gregariousness during settlement in the barnacle Elminius modestus Darwin. Journal of the Marine Biological Association of the United Kingdom 29: 281-297.

Knight-Jones, E.W. and Waugh, G.D. 1949. On the larval development of Elminius modestus Darwin. Journal of the Marine Biological Association of the United Kingdom 28: 413-428.

Kühl, H. 1954. Über das Auftreten von Elminius modestus Darwin in der Elbmündung. Helgoländer Wissenschaftlichen Meeresuntersuchungen 5: 53-56.

Kühl, H. 1963. Die Verbreitung von Elminius modestus Darwin (Cirripedia Thoracica) an der deutschen Küste. Crustaceana 5(2): 99-111.

Lawson, J., Davenport, J. and Whitaker, A. 2004. Barnacle distribution in Lough Hyne Marine Nature Reserve: a new baseline and an account of invasion by the introduced Australasian species Elminius modestus Darwin. Estuarine, Coastal and Shelf Science 60: 729-735.

Leloup, E. and Lefevere, S. 1952. Sur la présence dans les eaux de la côte blge du cirripède, Elminius modestus Darwin, 1854, du copépode parasite, Mytilicola intestinalis Steuer, 1902, et du polychète, Mercierella enigmatica Fauvel, 1922. Institut royal des Sciences naturelles de belgique Bulletin 28(48): 1-12.

Muxagata, E., Williams, J.A. and Sheader, M. 2004. Composition and temporal distribution of cirripede larvae in Southampton water, England, with particular reference to the secondary production of Elminius modestus. ICES Journal of Marine Science 61: 585-595.

O'Riordan, R.M. and Ramsay, N.F. 1999. The current distribution and abundance of the Australasian barnacle Elminius modestus in Portugal. Journal of the Marine Biological Association of the United Kingdom 79: 937-939.

O'Riordan, R.M., Culloty, S., Davenport, J. and McAllen, R. 2009. Increases in the abundance of the invasive barnacle Austrominius modestus on the Isle of Cumbrae, Scotland. Marine Biodiversity Records 2: e91 (4pp) (doi: 10.1017/S1755267209001079).

Rainbow, P.S. 1984. An introduction to the biology of British littoral barnacles. Field Studies 6: 1-51.

Rainbow, P.S. and Wang, W.-X. 2001. Comparative assimilation of Cd, Cr, Se, and Zn by the barnacle Elminius modestus from phytoplankton and zooplankton diets. Marine Ecology Progress Series 218: 239-248.

Ross, P.M., Burrows, M.T., Hawkins, S.J., Southward, A.J. and Ryan, K.P. 2003. A key for the identification of the nauplii of common barnacles of the British Isles, with emphasis on Chthamalus. Journal of Crustacean Biology 23(2): 328-340.

Schmidt, G.H. 1982. Random and aggregative settlement in some sessile marine invertebrates. Marine Ecology Progress Series 9: 97-100.

Theisen, B.F. 1980. Elminius modestus Darwin i Danmark. Flora og Fauna 86(1): 17-19.

Walker, G., Rainbow, P.S., Foster, P. and Crisp, D.J. 1975. Barnacles: Possible indicators of Zn pollution? Marine Biology 30: 57-65.

Watson, D.I., O'Riordan, R.M., Barnes, D.K.A. and Cross, T. 2005. Temporal and spatial variability in the recruitment of barnacles and the local dominance of Elminius modestus Darwin in SW Ireland. Estuarine, Coastal and Shelf Science 63: 119-131.

Wolff, W.J. 2005. Non-indigenous marine and estuarine species in The Netherlands. Zoologische Mededelingen 79(1): 1-116.