Invasion History

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

General Invasion History:


North American Invasion History:


Shell: Conical to tubular, white or grey; basal outline sinuous; plates thin, and usually with 2 wide, longitudinal and whiter folds, but there may be numerous ridges basally on each plate in crowded specimens; internally without ribs; radii with very oblique summits, and growth lines parallel to parietal edge of adjacent plate, so that only inferior margin of radius abuts smoothly against adjacent plates; alae wider than radii, but also have oblique summits; orifice diamond-shaped in outline, and toothed; base membranous (Foster, 1978).” “Opercular plates: Scutum triangular; externally with 2 longitudinal, dark bands; internally with a moderately prominent articular ridge, but without an adductor ridge or pits or scars for depressor muscles. Tergum with wide articular furrow; prominent articular ridge confluent with basitergal angle which is protruded from basal margin and folded on itself to form a channeled spur confluent with basitergal angle; concave basal margin with crests for depressor muscles, depending on at carinal end; carinal margin convex and somewhat thicker than central part of valve, which bears minute, calcareous projections (Foster 1978).” “Mouthparts: Labrum has 2 or 3 teeth on its crest on each side of central notch. Mandible has 5 teeth, 5th set close to a series of 4 or 5 spines, last at lower angle curved and more prominent. Maxillule has a notch with a row of short setae beneath an upper pair of stout setae; rest of cutting edge with 3 major setae on upper part and a group of shorter setae at lower angle (Foster 1978).” “Cirri: Cirrus I has an anterior ramus longer than posterior ramus. Cirrus II has subequal rami, about as long as posterior ramus of cirrus I. Cirrus III has anterior ramus slightly longer than posterior ramus, which is as long as anterior ramus of cirrus I. Cirri IV-VI all subequal in length, segments have 4 pairs of setae on anterior face and, in intermediate segments, and extra, small, proximal pair of setae no longer than short spines at and between bases of major pairs. Penis without a basidoral point (Foster 1978).” “Taxonomy: Although included in the Balanidae by virtue of the structure of the labrum, Elminius, as herein defined, still stands apart from the majority of the Balanidae by the lack of a basidoral point to the penis, as well as by the weak shell construction. Elminius may thus be a derivative of an early 6-plated balanid, before the articulation of radii and adjacent parietes occurred, and may warrant separate family ranking (Foster 1978).” Key Characteristic: The most obvious key characteristic differentiating Elminius from native East Coast species is the 4-plated shell construction. All native acorn barnacles of the North Atlantic have 6 plates.


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Arthropoda
Subphylum:   Crustacea
Class:   Maxillopoda
Subclass:   Thecostraca
Infraclass:   Cirripedia
Superorder:   Thoracica
Order:   Sessilia
Suborder:   Balanomorpha
Superfamily:   Balanoidea
Family:   Balanidae
Genus:   Austrominius
Species:   modestus


Austrominius modestus (Buckeridge and Newman 2010, None)
Elminius modestus (Darwin 1854, None)

Potentially Misidentified Species



Phytoplankton, detritus


Nucella lapillus (Dogwhelk)

Trophic Status:

Suspension Feeder



General HabitatMarinas & DocksNone
General HabitatRockyNone
General HabitatVessel HullNone

Tolerances and Life History Parameters

Minimum Temperature (ºC)4Field temperature, New Zealand (Harms 1999)
Maximum Temperature (ºC)21Field temperature, New Zealand (Harms 1999)
Minimum Salinity (‰)14Experimental, Wales, Foster 1970
Maximum Salinity (‰)47Experimental, Wales, Foster 1970
Minimum Reproductive Temperature6Experimental, hatching to metamorphosis, 60% survival (Harms 1982)
Maximum Reproductive Temperature24Experimental, hatching to metamorphosis, 95% survival, highest tested (Harms 1982)
Minimum Reproductive Salinity16Experimental, hatching to metamorphosis, 70% survival, )% at 12 ppt (Harms 1982)
Maximum Reproductive Salinity40Experimental, hatching to metamorphosis, 40% survival, (Harms 1982)
Minimum Duration7Experimental, hatching to metamorphosis, 24 C, highest tested (Harms 1982)
Maximum Duration42Experimental, hatching to metamorphosis at 6 CHarms 1982)
Broad Temperature RangeNoneCold temperate-Warm-temperate
Broad Salinity RangeNoneMesohaline-Euhaline

General Impacts

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
AUS-X None 1854 Native Estab
AUS-VIII None 0 Native Estab
AUS-IX None 1854 Native Estab
NZ-IV None 1854 Native Estab
NZ-VI None 0 Native Estab
NZ-II None 0 Native Estab
NEA-II None 1944 Def Estab
NEA-V None 1955 Def Estab
NEA-III None 1957 Def Estab
AR-V None 1977 Def Estab
NEA-IV None 1953 Def Estab
AUS-VII None 0 Native Estab
WA-IV None 1950 Def Failed
MED-II None 1995 Def Estab
WA-I None 2005 Def Unk
B-I None 2016 Def Estab
B-II None 2016 Def Estab
B-II None 0 None None

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Arenas, F. and 13 authors. (2006) Alien species and other notable records from a rapid assessment survey of marinas on the south coast of England., Journal of the Marine Biological Association of the United Kingdom 86: 329-1337

Barker, M. F. (1976) Culture and morphology of some New Zealand barnacles (Crustacea: Cirripedia), New Zealand Journal of Marine and Freshwater Research 10(1): 139-158

Barnett, B. E.; Crisp, D. J. (1970) Laboratory studies of gregarious settlement in Balanus balanoides and Eliminius modestus in relation to competition between these species., Journal of the Marine Biological Association of the United Kingdom 59: 581-590

Barnett, B. E.; Edwards, S. C.; Crisp, D. J. (1979) A field study of settlement behavior in Balanus Balanoides and Elminius modestus (Cirripedia: Crustacea) in relation to competition between them., Journal of the Marine Biological Association of the United Kingdom 59: 575-580

Bishop, John D. D.; Wood, Christine A.; Lévêque, Laurent; Yunnie, Anna L. E.; Viard, Frédérique (2015b) Repeated rapid assessment surveys reveal contrasting trends in occupancy of marinas by non-indigenous species on opposite sides of the western English Channel, Marine Pollution Bulletin 95: 699-706

Bishop, M. W. H. (1947) Establishment of an immigrant barnacle in British coastal waters, Nature 159(4041): 501-502

Bishop, M. W.; Crisp, D. J.; Fischer-Piette, E.; Prenant, M. (1957) Sur l’écologie des Cirripèdes de la côte atlantique française., Bulletin de l'Institut Océanographique, Monaco 1099: 1-12

Bishop, Marcus W. (1951) Distribution of barnacles by ships., Nature 167(4248): 531

Bonvechio, Kimberly I.; Barthel, Brandon; Carroll, Jessica (2018) Health and Genetic Structure of the American Eel in Florida, Southeastern Naturalist 17(3): 483-455

Bracewell, Sally A.; Spencer, Matthew; Marrs, Rob H.; lIes, Matthew; Robinson, Leonie A. (2012) Cleft, crevice, or the inner thigh: ‘another place’ for the establishment of the invasive barnacle Austrominius modestus (Darwin, 1854), PLOS ONE 7(11): e48863

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

Burfeind, Dana D.; Pitt, Kylie A.; Connolly, Rod M.; Byers, James E. (2012) Performance of non-native species within marine reserves, Biological Invasions published online: <missing location>

Carballo-Bolaños, Rodrigo Denis, Vianney Huang, Ya-Yi Keshavmurthy, Shashank Chen, Chaolun Allen (2019) Temporal variation and photochemical efficiency of species in Symbiodinaceae associated with coral Leptoria phrygia (Scleractinia; Merulinidae) exposed to contrasting temperature regimes, PLOSOne 14: e0218801

Cawthorne, D. F. (1978) Tolerance of some Cirripede Nauplii to fluctuating salinities., Marine Biology 46: 321-325

Cawthorne, D. F.; Davenport, J. (1980) The effects of fluctuating temperature, salinity, and aerial exposure upon larval release in Balanus balanoides and Elminius modestus., Journal of the Marine Biological Association of the United Kingdom 60: 367-377

Chainho, Paula and 20 additional authors (2015) Non-indigenous species in Portuguese coastal areas, lagoons, estuaries, and islands, Estuarine, Coastal and Shelf Science <missing volume>: <missing location>

Collin, Samuel B.; Tweddle, Jacqueline F.; Shucksmith, Rachel J. (2015) Rapid assessment of marine non-native species in the Shetland Islands, Scotland, BioInvasions Records 4: In press

De Mesel, Ilse; Kerckhof, Francis; Norro, Alain; Rumes, Bob; Degraer, Steven (2015) Succession and seasonal dynamics of the epifauna community on offshore wind farm foundations and their role as stepping stones for non-indigenous species, Hydrobiologia 756: 37-50

Dineen, J. F. Jr.; Hines, A. H. (1994) Effects of salinity and adult extract on settlement of the oligohaline barnacle Balanussubalbidus, Marine Biology 119: 423-430

Gallagher, Mary Catherine; Davenport, John; Gregory, Susan; McAllen, Rob; O'Riordan, Ruth (2015) The invasive barnacle species, Austrominius modestus: Its status and competition with indigenous barnacles on the Isle of Cumbrae, Scotland, Estuarine, Coastal and Shelf Science 152: 134-141

Geller, Jonathan B. (1984) Marine biological invasions as models of dispersal: tracking secondary spread and introgressive gene flow., California Cooperative Fisheries Investigations 35: 65-72

Glenner, Henrik; Lützen, Jørgen; , Pacheco-Riaño, Laura Camila; Noever, Christoph (2021) Expansion of the barnacle Austrominius modestus (Darwin, 1854) (Cirripedia, Thoracica, Balanidae) into Scandinavian waters based on collection data and niche distribution modeling, Aquatic Invasions 16: 675-689: <missing location>

Glenner, Henrik; Hoeg, Jens T. (1995) A new motile, multicellular stage involved in host invasion by parasitic barnacles (Rhizocephala), Nature 377: 147-150

Gomes-Filho; J G. F.; Hawkins, S. J.; Aquino-Souza, R.; Thompson, R. C. (2010) Distribution of barnacles and dominance of the introduced species lminius modestus along two estuaries in South-West England, Marine Biodiversity Records 3: published online

Goulletquer, Philippe; Bachelet, Guy; Sauriau, Pierre; Noel, Pierre (2002) Invasive aquatic species of Europe: Distribution, impacts, and management, Kluwer Academic Publishers, Dordrecht. Pp. 276-290

Green, Leon and 7 authors (2021) Sperm performance limits the reproduction of an invasive fish in novel salinities, Diversity and Distributions 27: 1091–1105

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

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

Hedgpeth, J. W. (1980) The problem of introduced species in management and mitigation, Helgoländer Meeresuntersuchungen 33: 662-673

Holmes, Samuel; Callaway, Ruth (2021) Fouling communities and non-native species within five ports along the Bristol Channel, South Wales, UK, Estuarine Coastal and Shelf Science 252(1107295): Publiished online

Hui, E.; Moyse, J. (1982) Settlement of Elminius modestus cyprids in contact with adult barnacles in the field., Journal of the Marine Biological Association 62: 477-482

Jensen, Kathe R.; Knudsen, Jorgen (2005) A summary of alien marine benthic invertebrates in Danish waters., Oceanological and Hydrobiological Studies 34 (suppl. 1): 137-161

Larman, V.N.; Gabbott, P. A. (1975) Settlement of cyprid larvae of Balanus balanoides and Eliminius modestus induced by extracts of adult barnacles and other marine animals., Journal of the Marine Biological Association of the United Kingdom 55: 183-190

Lavigne, Andrea S. Sunesen, Ines Sar, Eugenia A. (2015) Morphological, taxonomic and nomenclatural analysis of species of Odontella, Trieres and Zygoceros (Triceratiaceae, Bacillariophyta) from Anegada Bay (Province of Buenos Aires, Argentina), Diatom Research 30: 307-331

Leidenberger, Sonja; Obst, Matthias; Kulawik, Robert; Stelzer, Kerstin; Heyer, Karin; Hardisty, Alex; Bourlat, Sarah J. (2015) Evaluating the potential of ecological niche modelling as a component in marine non-indigenous species risk assessments, Marine Pollution Bulletin 97: 470-487

Liu, Wenliang; Liang, Xiaoli ; Zhu, Xiaojing (2015) A new record and mitochondrial identification of Synidotea laticauda Benedict, 1897 (Crustacea: Isopoda: Valvifera: Idoteidae) from the Yangtze Estuary, China, Zootaxa 4294: 371-380

McCollin, Tracy; Brown, Lyndsay (2014) Native and non-native marine biofouling species present on commercial vessels using Scottish dry docks and harbours, Management of Biological Invasions 5(2): 85-96

Nall, Christopher R.; Guerin, Andrew J.; Cook, Elizabeth J. (2015) Rapid assessment of marine non-native species in northern Scotland and a synthesis of existing Scottish records, Aquatic Invasions 10(1): 107–121

Noel, Pierre Y. (2011) In the wrong place- Alien marine crustaceans: Distribution, biology, impacts, Springer, Dordrecht, Netherlands. Pp. 345-375

Norris, James N. (2010) Marine Algae of the northern Gulf of California: Chlorophyta and Phaeophyceae, Smithsonian Contributions to Botany 94: 1276

O'Riordan, Ruth M; Ramsay, Neil (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, Ruth M.; Murphy, Orla (2000) Variations in the reproductive cycle of Elminius modestusin southern Ireland, Journal of the Marine Biological Association of the United Kingdom 80: 607-616

O’Riordan, Ruth M.; Culloty, Sarah; Davenport, John; McAllen, Rob (2009) Increases in the abundance of the invasive barnacle Austrominius modestus on the Isle of Cumbrae, Scotland, Marine Biodiversity Records 2: 1-4

O’Shaughnessy, Kathryn A.; Harding, Juliana M.; Burge, Erin J. (2014) Ecological effects of the invasive parasite Loxothylacus panopaei on the flatback mud crab Eurypanopeus depressus with implications for estuarine communities, Bulletin of Marine Science 90(2): 611-621

Pongparadon, Supattra; Zuccarello, Giuseppe C.; Prathep, Anchana (2017) High morpho-anatomical variability in Halimeda macroloba (Bryopsidales, Chlorophyta) in Thai waters, Phycological Research 65: 136-145
doi: 10.1111/pre.12172

Pyefinch, K. A. (1950) Notes on the ecology of ship-fouling organisms., Journal of Animal Ecology 19: 29-35

Ritz, D. A.; Foster, B. A. (1968.) Comparison of the temperature responses of barnacles from Britain, South Africa, and New Zealand, with special reference to temperature acclimation in Elminius modestus., Journal of the Marine Biological Association of the United Kingdom 48: 545-559

Ross, P.M.; Burrows, M. T.; Hawkins, S. L.; Southward, A. J.; 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(7): 328-340

Rubal, Marcos; Maldre, Kelli; ,Sousa-Pinto, Isabel; Veiga, Puri (2021) Current distribution and abundance of Austrominius modestus (Darwin, 1854) and other non-indigenous barnacles along the northern coast of Portugal, Regional Studies in Marine Science 41(101586): Published online

Seed, R.; Harris, S. (1980) The epifauna of the fronds of Laminaria digitata Lamour in Strangford Lough, Northern Ireland, Proceedings of the Royal Irish Academy 80B: 91-106

Simkanin, Christina and 7 authors (2005) Using historical data to detect temporal changes in the abundances of intertidal species on Irish shores., Journal of the Marine Biological Association of the United Kingdom 85: 1329-1340

Watson, Douglas; O'Riordan, Ruth M.; Barnes, David K. A.; Cross, Tom (2005) Temporal and spatial variability in the recruitment of barnacles and the local dominance of Elminius modestus in SW Ireland., Estuarine and Coastal Marine Science 63: 119-131

Wirtz, Peter; Araujo, Ricardo; Southward, Alan J. (2006) Cirripedia of Madeira., Helgoland Marine Research 60: 207-212

Witte, Sophia; Buschbaum, Christian; van Beusekom, Justus E. E.; Reise, Karsten (2010) Does climatic warming explain why an introduced barnacle finally takes over after a lag of more than 50 years?, Biological Invasions published online: <missing location>

Zibrowius, Helmut (2002) Assessing scale and impact of ship-transported alien fauna in the Mediterranean?, CIESM Workshop Monographs 20: 63-68

Zullo, Victor August (1963) <missing title>, University of California, Berkeley CA. Pp. 1-368