Balanus trigonus

Invasion History

First Non-native North American Tidal Record: 1885
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 1885

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General Invasion History:

Balanus trigonus was described using specimens from the Pacific (Indonesia, Colombia, Peru, Australia, and New Zealand) (Darwin 1854). This species appears to have a broad native distribution in the Pacific and Indian Oceans, including Australia and Japan, southern California (north to Monterey Bay), Peru, the Red Sea, and the southern tip of Africa. It may be introduced to New Zealand where it has a limited range (Cranfield et al. 1998), although it was reported from there by Darwin (1854).

Balanus trigonus is introduced in the Atlantic Basin (Carlton et al. 2011), where it was first recorded in Brazil in 1867. It is found on both sides of the Atlantic and throughout the Mediterranean. In the Western Atlantic, it occurs from North Carolina to Argentina, and in the Eastern Atlantic it is known from the Azores to South Africa. It seems to have colonized the warmer, more saline parts of the Atlantic long before reaching the East and Gulf coasts of the United States (US). It was found on a ship returning from the West Indies in 1877 (Pilsbry, 1916; US National Museum of Natural History 2012). This barnacle generally prefers subtidal habitats in warm-temperate to tropical waters (Werner 1967; Utinomi 1970; Southward 1975; Laguna 1985).

North American Invasion History:

Invasion History on the East Coast:

In U.S. waters, Balanus trigonus was found on the hull of ships arriving at Cape Cod in 1877 and 1879 (Zullo 1992; USNM 51541 and 21550, U.S. National Museum of Natural History 2012), but it was not found until 1961 on the Atlantic coast, in Biscayne Bay, Florida (Moore and McPherson 1963). In 1963 it was collected near Cape Lookout, North Carolina, at, or near, the northern limit of its range (Ross et al. 1964). This barnacle is now widespread from Florida to North Carolina (Werner 1967; Zullo and Lang 1978; Williams et al. 1984; Crickenberger and Sotka 2009).

Invasion History on the Gulf Coast:

In 1885, Balanus trigonus was collected off the Florida Coast in the Gulf of Mexico (Henry pers. comm., cited by Werner 1967). Currently its known range in the Gulf is from the southern tip of Florida, through Louisiana and Texas (Gittings 1985) to Tamaulipas, Mexico (Celis et al. 2007). Most records are from clear, high-salinity waters, including offshore oil platforms (Gittings et al. 1986). Carlton et al. (2011) correct and expand the chronology of Atlantic collections reported by Werner (1967) and Zullo (1992), and provide a detailed discussion of its history in the Western Atlantic. 

Invasion History Elsewhere in the World:

Balanus trigonus was first recorded in the Atlantic from Florianopolis, Brazil in 1864 (Carlton et al., 2011). It now ranges from North Carolina (35° N) and the Azores (38° N) south to Rio Grande do Sul, Brazil (27° S) and False Bay, South Africa (34° S) (Zullo 1992; US National Museum of Natural History 2012). In the Eastern Atlantic, it was first found on the West African Coast, Madeira, and the Azores between 1887 and 1909 (Zullo 1992). In the Mediterranean, as far as we are aware, the earliest dated record is from Sicily in 1927 (Zullo 1992). One empty specimen of B. trigonus was found on a buoy in Belgian waters in 1997-1998 (Kerckhof and Cattrijsse 2001).

While B. trigonus is native to Korea and southern Japan (Utinomi 1970; Kim 1992), it appears to be sporadically introduced by shipping to the northern Sea of Japan, where it has not become established (Zvyagintsev 2003). It has been listed as introduced to New Zealand (1960, Cranfield et al. 1998). Cranfield et al. (1998) give the first date of occurrence as 1960, and do not mention Darwin’s New Zealand specimens, or other early collections (Darwin 1854; Jennings 1917, cited by Foster 1967). Its distribution is limited to the region around Auckland (Foster 1967). Dromgoole and Foster (1983) considered it a species of 'uncertain native status'.

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Description

Balanus trigonus is a small to medium-size barnacle, ranging from conical to nearly-cylindrical in shape and reaching up to 25 mm in diameter. Its shell is composed of six overlapping plates, which are folded with wide longitudinal spaces (radii) which narrow at the top, and with transverse striations around a roughly triangular central opening (orifice). The shell has narrow white longitudinal ribs, and is colored or mottled with colored or mottled with purplish pink. . Inside the orifice are two large valves covering the appendages of the animal. Each valve is composed of two parts, the scutum and the tergum. The scutum is distinguished by one to six longitudinal rows of pits. Balanus trigonus can be distinguished by the scutum, which has one to six longitudinal rows of pits (Darwin 1854). The tergum is externally smooth and flat, with 'scarcely a trace of a longitudinal furrow' (Darwin 1854). The spur of the tergum is broad, being one-third to one-half of the width (Darwin 1854; Pilsbry 1916; Foster 1967; Werner 1967). Larval stages are illustrated by Barker (1976) and Lang (1979).

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Taxonomy

Ecology

General:

Balanus trigonus prefers saline (26-40 ppt), subtidal habitats in warm-temperate, subtropical and tropical seas (Werner 1967). This species, like many other barnacles, is hermaphroditic, but is capable of cross-fertilization. The fertilized eggs are brooded in the mantle cavity, sometimes for several months, and are released as nauplius larvae with three pairs of appendages (Barnes 1983). Balanus trigonus in culture produced broods of 1,000 to 35,000 eggs, averaging ~13,000 eggs (El-Komy and Kajihara 1991)..The nauplii feed in the plankton and go through five successive molts, spending at least 4 -11 days in the water column before molting into a non-feeding cypris stage, covered with a pair of chitinous shells (Barker 1976). Cyprids swim, investigating suitable surfaces and then settle, secreting a shell, and molting into the first juvenile barnacle stage (Barnes 1983). Juvenile and adult barnacles are filter feeders, sweeping the water with their long bristled appendages, and gathering phytoplankton, zooplankton, and detritus (Barnes 1983). Balanus trigonus grows on a wide range of hard surfaces, including mangroves, rocks, oysters, crabs, pilings, docks and ship hulls (Werner 1967; Zullo 1992).

Food:

Phytoplankton, zooplankton

Trophic Status:

Suspension Feeder

SusFed

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Habitats

General Habitat	Rocky	None
General Habitat	Marinas & Docks	None
General Habitat	Mangroves	None
General Habitat	Oyster Reef	None
General Habitat	Coarse Woody Debris	None
General Habitat	Vessel Hull	None
Salinity Range	Polyhaline	18-30 PSU
Salinity Range	Euhaline	30-40 PSU
Tidal Range	Subtidal	None

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Tolerances and Life History Parameters

Maximum Temperature (ºC)	37	50% of adults survived 20 h in water at 37ºC.(Ritz and Foster 1968)
Minimum Salinity (‰)	22	Lowest tested (Thiyagarajan et al. 2003)
Maximum Salinity (‰)	40	Typical Red Sea salinity.
Minimum Reproductive Temperature	18	Lowest tested (Thiyagarajan et al. 2003).
Maximum Reproductive Temperature	28	Highest tested (Thiyagarajan et al. 2003).
Minimum Reproductive Salinity	22	Lowest Tested(Thiyagarajan et al. 2003).
Maximum Reproductive Salinity	40	Typical Red Sea salinity.
Minimum Duration	4.5	28 C (Thiyagarajan et al. 2003).
Maximum Duration	15	20 C, Barker 1976
Minimum Width (mm)	25	Maximum adult size (Darwin 1854)
Broad Temperature Range	None	Warm temperate-Tropical
Broad Salinity Range	None	Polyhaline-Euhaline

General Impacts

Economic Impacts 

Shipping- We have not found specific reports of economic impacts for Balanus trigonus in North American waters. However, it is common in subtropical waters, frequently reported from ship hulls, and contributes to barnacle fouling of ships and harbor structures (Utinomi 1970; Moore et al. 1974; Zullo 1992).

Ecological Impacts

Fouling communities including B. trigonus were studied in North Carolina, off Cape Lookout. This barnacle was the most common species on fouling plates, together with the octocoral, Titanideum frauenfeldii. However, there was no evidence of spatial competition, since much space remained unoccupied. Balanus trigonus suffered considerable mortality from sea urchin (Arbacia punctulata) predation and sediment scour (Williams et al. 1984). These studies did not indicate unique impacts resulting from this barnacle’s invasion. However, B. trigonus is a potential competitor with other fouling organisms in suitable habitats.

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References

Abdelsalam, Khaled Mahmood (2018) First record of the exotic lysmatid shrimp Lysmata vittata (Stimpson, 1860) (Decapoda: Caridea: Lysmatidae) from the Egyptian Mediterranean coast, Mediterranean Marine Science 19(1): 124-131

Ashton, G. V.; Davidson, I. C.; Geller, J.; Ruiz, G. M. (2016) Disentangling the biogeography of ship biofouling: barnacles in the Northeast Pacific, Global Ecology and Biogeography 25: 739;750

Bacon, Peter R. (1976) The Cirripedia of Trinidad, Studies of the Fauna of Curacao and other Caribbean Islands 163: 1-55

Baker, H. R. (1984) Diversity and zoogeography of marine Tubificidae (Annelida, Oligochaeta), with notes on variation in widespread species, Hydrobiologia 115: 191-196

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

Barnes, Robert D. (1983) Invertebrate Zoology, Saunders, Philadelphia. Pp. 883

Bitar, Ghazi; Kouli-Bitar, Souha (2001) Nouvelles donnees sur la faune et la flore benthiques de la cote libanaise. Migration Lessepsienne, Thalassia Salentina 25: 71-74

Bumbeer, Janaína de Araújo; da Rocha, Rosana Moreira (2012) Detection of introduced sessile species on the near shore continental shelf in southern Brazil, Zoologia 29(2): 126-134

California Academy of Sciences 2005-2015 Invertebrate Zoology Collection Database. <missing URL>



Canning-Clode, João; Fofonoff, Paul; McCann, Linda; Carlton, James T.; Ruiz, Gregory (2013) Marine invasions on a subtropical island: fouling studies and new records in a recent marina on Madeira Island (Eastern Atlantic Ocean), Aquatic Invasions 8(3): 261-270

Carlton, James T.; Newman, William A.; Pitombo, Fábio Bettini (2011) In the wrong place- Alien marine crustaceans: Distribution, biology, impacts, Springer, Dordrecht. Pp. 159-213

Celis, Antonio; Rodríguez-Almaráz, Gabino; Álvarez, Fernando (2007) [The shallow-water thoracican barnacles (Crustacea) of Tamaulipas, Mexico], Revista Mexicana de Biodiversidad 78: 325-337

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>

Chapman, John W.; Breitenstein, Ralph A.; Carlton, James T. (2013) Port-by-port accumulations and dispersal of hull fouling invertebrates between the Mediterranean Sea, the Atlantic Ocean and the Pacific Ocean, Aquatic Invasions 8: in press

Cranfield, H.J.; Gordon, D.P.; Willan, R.C.; Marshall, B.A; Battershill, C.N.; Francis, M.P.; Nelson, W.A.; Glasby, C.J.; Read, G.B. (1998) <missing title>, The National Institute of Water and Atmospheric Research, New Zealand. Pp. <missing location>

Crickenberger, Sam; Sotka, Erik (2009) Temporal shifts of fouling communities in Charleston Harbor, with a report of Perna viridis (Mytilidae), Journal of the North Carolina Academy of Science 125(2): 78-84

Dando, P. R.; Southward, A.J. (1980) A new species of Chthamalus (Crustacea: Cirripedia) characterized by enzyme electrophoresis and shell morphology: with a revision of other species of Chthamalus from the Western shores of the Atlantic Ocean., Journal of the Marine Biological Association 60: 787-831

Darwin, Charles (1854) A Monograph on the Sub-class Cirripedia: With Figures of All the Species: The Balanidæ (or Sessile Cirripedes); the Verrucidæ, Etc, The Ray Society, London. Pp. <missing location>

del Monaco, Carlos; Capelo, Juan (2000) [The genera Balanus, Chthamalus and Tetraclita from the coast of Nueva Esparta, Venezuela], Memoria de la Fundacion La Salle de Ciencias Naturales 154: 77-197

Dromgoole, F. I., Foster, B. A. (1983) Changes to the marine biota of the Auckland Harbour, Tane 29: 79-96

El-Komy, M. M.; Kajihara, T. (1991) Breeding and moulting of barnacles under rearing conditions, Marine Biology 108: 83-89

Farrapeira, Christiane M. R. (2010) Barnacles (Crustacea:Cirripedia) of the estuarine and marine areas of the port of Recife (Pernambuco, Brazil), Cahiers de Biologie Marine 50: 199-129

Farrapeira, Cristiane Maria Rocha; de Melo,Arthur Vinícius de Oliveira Marrocos; Barbosa, Débora Ferreira; da Silva, Karla Maria Euzebio (2007) Ship hull fouling in the port of Recife, Pernambuco, Brazilian Journal of Oceanography 55(3): 207-221

Fortic, Ana ; Mavric; Borut; Pitacco; Valentina; Lipej, Lovrenc (2021) Temporal changes of a fouling community: Colonization patterns of the benthic epifauna in the shallow northern Adriatic Sea, Regional Studies in Marine Science 45(101818): Published online

Foster, B. A. (1967) A guide to the littoral balanomorph barnacles of New Zealand, Tuatara 15(2): 75-85

Gerovasileiou, Vasilis; Voultsiadou, Eleni; Issaris, Yiannis; Zenetos, Argyro (2016) Alien biodiversity in Mediterranean marine caves, Marine Ecology 37: 239-256

Gittings, Stephen R. (1985) Notes on barnacles (Cirripedia: Thoracica) from the Gulf of Mexico., Gulf Research Reports 8(1): 35-41

Gittings, Stephen R.; Dennis, George D.; Harry, Harold W. (1986) <missing title>, Texas A&M Sea Grant, College Station TX. Pp. 1-36

Glasby, T. M. (2001) Development of sessile marine assemblages on fixed versus moving substrata., Marine Ecology Progress Series 215: 37-47

Gonzalez, J. A.; Martin, L. Herrera, R.; Gonzalez Lorenzo, G.; Espino. F.; Barquin-Diez, J.; Southward, A.J. (2011) Cirripedia of the Canary Islands: distribution and ecological notes, Journal of the Marine Biological Association of the United Kingdom 92: 129-141

Henry, Dora P.; McLaughlin, Patsy A. (1975) The barnacles of the Balanus amphitrite complex (Cirripedia, Thoracica)., Zoologische Verhandelingen 141: 1-203

Holm, Eric R. (2012) Barnacles and biofouling, Integrative and Comparative Biology Published online: <missing location>

Huang, Xuguang, Bingyu;; Guo, Donghu; Zhong;, Yanping; Li, Shunxing; Liu, Xin;; Laws, Edward A.; Huang, Bangqin (2021) Blackfordia virginica blooms shift the trophic structure to smaller size plankton in subtropical shallow waters, Marine Pollution Bulletin 182(111990): Published online

Ignacio, Barbara L.; Julio, Luciana M.; Junqueira, Andrea O. R; Ferreira-Silva, Maria A. G. (2010) Bioinvasion in a Brazilian Bay: filling gaps in the knowledge of southwestern Atlantic biota, PLOS ONE 5(9): <missing location>

Innocenti, G. (2006) Collections of the Natural History Museum, Zoological Section «la Specola» of the University of Florence. XXIII. Crustacea, class Maxillopoda, subclass Thecostraca, infraclass Cirripedia, Atti della Societa Toscana di Scienze Naturali Memorie, series B. 113: 1-11

Jones, Diana S. (1992) A review of Australian fouling barnacles, Asian Marine Biology 9: 89-100

Jones, Diana S. (2004) Barnacles (Cirripedia: Thoracica) of the Dampier Archipelago, Western Australia., Records of the Western Australia Museum Suppl. 66: 121-157

Jones, Diana S.; Hewitt, Melissa A.; Sampey, Alison (2000) Checklist of the Cirripedia of the South China Sea, Raffles Bulletin of Zoology Supplement 8: 233-307

Karlson, Ronald H.; Osman, Richard W (2012) Species composition and geographic distribution of invertebrates in fouling communities along the east coast of the USA: a regional perspective, Marine Ecology Progress Series 458: 255–268

Kerckhof, Francis; Cattrijsse, Andre (2001) Exotic Cirripedia (Balanomorpha) from buoys off the Belgian Coast., Senckenbergiana Maritima 31(2): 245-254

Kim, I-H. (1992) Invasion of foreign barnacles into Korean waters, Korean Journal of Systematic Zoology 8(2): 163-176

Koukouras, Anathasios; Matsa, Athanasia (1998) The thoracican cirriped fauna of the Aegean Sea: New information, checklist of the Mediterranean species, faunal comparisons., Senckenbergiana Maritima 28(4/6): 133-142

Laguna, Jorge (1985) <missing title>, M.S. Thesis, University of California, San Diego. Pp. <missing location>

Laguna, Jorge E. (1990) Shore barnacles (Cirripedia, Thoracica) and a revision of their provincialism and transition zones in the tropical Eastern Pacific, Bulletin of Marine Science 46(2): 406-424

Lang, William H. (1979) Larval development of shallow water barnacles of the Carolinas (Cirripedia: Thoracica) with keys to naupliar stages., NOAA Technical Report NMFS Circular 421: 1-39

Lira, Simone Maria de Albuquerque ; Farrapeira, Cristiane Maria Rocha (2010) Sessile and sedentary macrofauna from the Pirapama Shipwreck, Pernambuco, Brazil, Biota Neotropica 10(4): published online

Marques, Antonio C. and 17 authors (2013) Rapid assessment survey for exotic benthic species in the São Sebastião Channel, Brazil, Latin American Journal of Aquatic Research 41(2): 265-285

Mook, David (1983) Indian River fouling organisms, a review, Florida Scientist 26(3/4): 162-167

Moore, Hilary B., McPherson, B. F. (1963) Colonization of the Miami area by the barnacle Balanus trigonus Darwin and a note of its occurrence on the test of an echinoid., Bulletin of Marine Science of the Gulf and Caribbean 13(3): 418-421

Moore, Hilary B.; Albertson, Helen D.; Miller, Sigmund M. (1974) Long-term changes in the settlement of barnacles in the Miami area., Bulletin of Marine Science 24: 86-100

Morton, B.; Britton, J.C. (2000) Origins of the Azorean intertidal biota: the significance of introduced species, survivors of chance events., Arquipelago. Life and Marine Sciences supplement 2 (part A): 29-51

Nelson, W. G.; Savercool, T. E.; Rodda, Neth and J. R. (1994) A comparison of the fouling community development on stabilized oil-ash and concrete reefs., Bulletin of Marine Science 55(2-3): 1303-1315

Newman, William A. (2007) The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon, University of California Press, Berkeley CA. Pp. 475-481

Pearl Harbor Legacy Project undated Arthropoda. <missing URL>



Pecarevic, M.; Mikus, J.; Cetinic, A. Bratos; Dulcic, J.; Calic, M. (2013) Introduced marine species in Croatian waters (Eastern Adriatic Sea), Mediterranean Marine Science 14(1): 224-237

Pequegnat, Willis E. (1964) The epifauna of a California siltstone reef, Ecology 45(2): 272-283

Pestana, L. B.; Dias, G. M.; Marques, A. C . (2021) Spatial and temporal diversity of non-native biofouling species associated with marinas in two Angolan bays, African Journal of Marine Science 42(4): 413-422

Pestana, Lueji Barros; Dias, Gustavo Muniz; Marquesa, Antonio Carlos (2017) A century of introductions by coastal sessile marine invertebrates in Angola, South East Atlantic Ocean, Marine Pollution Bulletin 125: 426-a432

Pilsbry, Henry A. (1916) The sessile barnacles contained in the collections of the U.S. National Museum, including a monograph of the American species., United States National Museum Bulletin 93: 1-366

Pires-Teixeira, Larissa M. Neres-Lima, Vinicius Creed, Joel C. (2021) How do biological and functional diversity change in invaded tropical marine rocky reef communities?, Diversity 13(353): Published online

Pitombo, F. B. (2004) Phylogenetic analysis of the Balanidae (Cirripedia, Balanomorpha)., Zoologica Scripta 33(3): 261-276

Ramadan, Sh. E.; Kheirallah, A. M.; Abdel-salam, Kh. M. (2006) Marine fouling community in the Eastern harbour of Alexandria, Egypt compared with four decades of previous studies, Mediterranean Marine Science 7/2: 19-29

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

Rodríguez-Almaraz, Gabino A.; García-Madrigal, María del Socorro (2014) [Aquatic Invasive Species in Mexico], Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, <missing place>. Pp. 337-371

Ross, Arnold, Cerame-Vivas, M. J., McCloskey, L. R. (1964) New barnacle records for the coast of North Carolina, Crustaceana 7(4): 312-313

Ruiz, Gregory M.; Geller, Jonathan (2018) Spatial and temporal analysis of marine invasions in California, Part II: Humboldt Bay, Marina del Re, Port Hueneme, and San Francisco Bay, Smithsonian Environmental Research Center & Moss Landing Laboratories, Edgewater MD, Moss Landing CA. Pp. <missing location>

Schmitt, Russel J. and 6 authors 2006 Advancing marine biotechnology: Use of OCS oil platforms as sustainable sources of marine natural products. <missing URL>



Shahdadi, Adnan; Sari, Alireza; Naderloo, Reza (2014) A checklist of the barnacles (Crustacea: Cirripedia: Thoracica) of the Persian Gulf and Gulf of Oman with nine new records, Zootaxa 3784: 201-223

Soors, Jan; Faasse, Marco; Stevens, Maarten; Verbessem, Ingrid; De Regge, Nico;Van den Bergh, Ericia (2010) New crustacean invaders in the Schelde estuary (Belgium), Belgian Journal of Zoology 140: 3-10

Southward, A. J. (1975) Intertidal and shallow water Cirripedia of the Caribbean., Studies of the Fauna of Curacao and other Caribbean Islands 150: 1-153

Southward, A. J. (1998) New observations on barnacles (Crustacea: Cirripedia) of the Azores regions., Arquipelago. Life and Marine Sciences 16A: 11-27

Spivey, H. R. (1976) The cirripeds of the Panama Canal, Corrosion and Marine Fouling 1(1): 43-50

Sylvester, Francisco and 8 authors (2011) Hull fouling as an invasion vector: can simple models explain a complex problem?, Journal of Applied Ecology 48: 415-423

Thiyagarajan, Vengatesen; Harder,Tilmann; Quin, Pei-Yuan (2003) Combined effects of temperature and salinity on larval development and attachment of the subtidal barnacle Balanus trigonus, Journal of Experimental Marine Biology and Ecology 287: 223-236

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database. http://collections.nmnh.si.edu/search/iz/



U.S. National Parasite Collection Unit, United States Department of Agriculture 2000 U.S. National Parasite Collection. <missing URL>



Utinomi, Huzio (1970) Studies on the Cirripedian Fauna of Japan.IX., Distributional Survey of Thoracic Cirripeds in the Southeastern part of the Japan Sea, Publications of the Seto Marine Biological Laboratory 17(5): 339-372

Wassick, Ann; Hunsucker, Kelli Z.; Swain, Geoff (2022) A baseline survey to document the distribution and abundance of native and non-native barnacle species in Port Canaveral, Florida, Bioinvasion Records 11: Published online

Wells, Harry W. (1966) Barnacles of the northeastern Gulf of Mexico., Quarterly Journal of the Florida Academy of Sciences 29(4): 81-95

Werner, William (1967) The distribution and ecology of the barnacle Balanus trigonus., Bulletin of Marine Science 17(1): 67-84

Williams, A. Houston; Sutherland, J. P.; Hooper, M. R. (1984) Population biology of Balanus trigonus on a subtidal rocky outcrop near Beaufort, North Carolina, Journal of the Elisha Mitchell Scientific Society 100(1): 1-11

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

Young, Paulo S. (1994) Superfamily Balanoidea Leach (Cirripedia, Balanomorpha) from the Brazilian coast., Boletim do Museo Nacional (Zoologia) 356: 1-36

Zevina, G. B. (1988) Underwater scraping of ship foulings in tropical waters., Soviet Journal of Marine Biology <missing volume>: 41-46

Zullo, Victor A. (1979) Marine flora and fauna of the Northeastern United States. Arthropoda: Cirripedia, NOAA Technical Report NMFS Circular 425: 1-29

Zullo, Victor A. (1992) Balanus trigonus Darwin (Cirripedia, Balanidae) in the Atlantic Basin: an introduced species?, Bulletin of Marine Science 50(1): 66-74

Zullo, Victor A., Miller, William, III (1986) Barnacles (Cirripedia: Balanidae) from the lower Pleistocene James City formation, North Carolina coastal plain, with the description of a new species of Balanus da costa, Proceedings of the Biological Society of Washington 99(4): 717-730

Zullo, Victor A.; Lang, William H. (1978) An annotated Checklist of the biota of the coastal zone of South Carolina, University of South Carolina Press, Columbia SC. Pp. 158-160

Zvyaginstev, A. Yu.; Radashevsky, V. I.; Ivin, V. V.; Kashin, I. A.; Gorodkov, A. N. (2011) Nonindigenous species in the far-eastern seas of Russia, Russian Journal of Biological Invasions 2(1): 164-182

Zvyagintsev, A. Yu. (2003) Introduction of species into the Northwestern Sea of Japan and the problem of marine fouling., Russian Journal of Marine Biology 29(Suppl. 1:): 10-21

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