Megabalanus coccopoma

Invasion History

First Non-native North American Tidal Record: 2001
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 2001

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General Invasion History:

Megabalanus coccopoma is native to the southeastern Pacific, ranging from Mexico to Peru. In the US, it was first reported from Louisiana in 2001 and its non-native range now extends throughout the Gulf of Mexico and along the Atlantic coast of Florida, Georgia, South Carolina, and North Carolina. Elsewhere in the world, introduced populations have been reported from Belgium, the Netherlands, West Africa, Japan, Australia and Brazil, and the Galapagos Islands. 

North American Invasion History:

Invasion History on the East Coast:

In 2005, living and apparently established populations were found near Fort Pierce, Florida, in the Indian River Lagoon (Ruiz et al., unpublished data). In June 2006, a single specimen of M. coccopoma was collected from a buoy washed up on Ossabaw Island, Georgia (USGS Nonindigenous Species Program 2006). By 2007, populations were well-established in the Intracoastal Waterway, around St. Augustine, Florida, with settlement occurring in March-August. Settlement was not seen in creeks opening into the waterway, probably because of their lower salinity (Gilg et al. 2010). In 2006–2008, this barnacle was collected from Port Royal Sound, SC to Core Sound, NC (Southeast Regional Taxonomic Center 2011). Severe winters in 2010 and 2011 may have led to declines in M. coccopoma in the St. Augustine area and the Carolinas (USGS Nonindigenous Species Program 2008; Southeast Regional Taxonomic Center 2011). However, populations are expected to be resilient, according to Matthew Gilg (Edwards, 11/16/2011). 

Invasion History on the Gulf Coast:

In 2001, large numbers of Megabalanus coccopoma were collected attached to pilings at Grand Isle, Louisiana (Perreault 2004). Barnacles above the high-tide mark had been killed by cold, and there were no signs of recruitment. Perreault (2004) found additional non-recruiting and/or dead populations elsewhere in the Gulf of Mexico, at Destin, Florida, and Port Aransas, Texas. These occurrences suggested that reproducing populations might be located elsewhere in the Gulf, perhaps on offshore oil platforms (Perreault 2004). More recently, established populations were found at Port Aransas in 2010 (Cohen et al. 2014). Cohen et al. (2014) also collected Megabalanus spp. in Pensacola and Tampa Bay, Florida, but these appear to belong to at least one different, cryptic species. Megabalanus coccopoma is established in Tamaulipas state, Mexico, about 300 km south of the US border (Celis et al. 2007).

Invasion History Elsewhere in the World:

In the 1970s, Megabalanus coccopoma was collected from buoys in Dutch waters, and misidentified as Balanus perforatus. In 1997–1999, it was found to be widespread on buoys in Belgian waters. Populations consisted of two or more generations, suggesting successful over-wintering and survival (Kerckhof and Cattrijsse 2001). Francis Kerckhof considers this species to be established in the southern North Sea (Kerckhof 2006, personal communication). In 2010, M. coccopoma was observed on fishing boats at Faraja, in the Gambia, West Africa, and was subsequently found growing on rocks along the shore, and in a private collection made in 2006 (Kerckhof et al. 2010). In Brazil, the first collection was from the Baia da Guanabara, near the city of Rio de Janeiro in 1974, and it currently ranges from the states of Espirito Santo to Rio Grande do Sul. In many locations in this range, it has become the dominant species, and appears to have partially replaced previously reported populations of M. tintinnabulum (Young 1994).

Megabalanus coccopoma was collected in 1994 in Australia, at Manly, near Sydney, New South Wales (Yamaguchi et al. 2009). It has been collected from a ship at Brisbane Queensland Neil et al. 2005, cited by Yamaguchi et al. 2009), and is established between Sydney and Newcastle, and in Port Phillip Bay, Victoria (Dafforn et al. 2009; Yamaguchi et al. 2009). In 2004, M. coccopoma was collected on the hull of a ship which travels between Kobe, Japan, and Australia. It is established in Japan from the south eastern coast from Kobe, on the Seto Inland Sea to Tokyo Bay, north to Ogatsu Bay, in Miyagi Prefecture (Yamaguchi et al. 2009). It has also been collected in New Zealand waters, on the floating wreckage of a fishing boat (Williams et al. 2008), and on an oil rig (Hopkins et al. 2011)—both in 2008. This barnacle was found to be established in many locations on the south eastern coast of Japan from Kobe, on the Seto Inland Sea to Tokyo Bay, north to Ogatsu Bay, in Miyagi Prefecture (Yamaguchi et al. 2009). In 2010, Megabalanus coccopoma was found on barges and buoys off Kwa Zulu, South Africa, on the Indian Ocean coast.  In 2019, it was found living at two locations on the Kwa Zulu coast (Pfaff et al. 2022).  Megabalanus coccopoma is regarded as introduced in the Galapagos Islands from the coast of South America, before the first barnacle surveys in the 1960s (Zullo 1991, cited by Carlton et al. 2019).

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Description

Megabalanus coccopoma is a large barnacle, sometimes globular or cylindrical in shape and up to 50 mm in diameter. Its plates are slightly rough or finely ribbed. The orifice is moderately small, usually less than one-half the basal diameter, and it is subtriangular to subovate in shape. The scutum has a very broad, obtusely inflected tergal segment, and strong, closely set growth ridges. The margin along the aperture is strongly toothed, with longitudinal striae faint or absent. The articular ridge is four-fifths the length of the tergal margin, and the adductor ridge is strong and well-separated from the articular ridge. The tergum is moderately narrow, with a moderately long spur, separated by its own width or less from the basiscutal angle. Its growth ridges are faint to moderately strong, with an articular ridge approximately four-fifths the length of the scutal margin. The color is usually deep red, occasionally with fine white longitudinal lines or stripes. The radii are deep purple or reddish purple. The scutum is purple to reddish-purple, while the tergum is white (Pilsbry 1916; Ross 1962; Laguna 1985; Henry and McLaughlin 1986). Larval development of this species has been described and illustrated by Severno and Resgalla (2005). 
 
Megabalanus coccopoma could be potentially confused with M. californicus, M. peninsularis, or M. vinaceus in the northeastern Pacific (California-Panama), or with M. tintinnabulum or M. stultus in its introduced range in the northwestern Atlantic (Texas-Georgia) (Henry and McLaughlin 1986). 
 
A genetic analysis of Megabalanus spp. collected on the Gulf and southeastern coast of the US and Brazil concluded that most populations were M. coccopoma, although multiple lineages of this species were present. However, at least one cryptic species of Megabalanus was present (Cohen et al. 2014). 

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Taxonomy

Ecology

General:

Megabalanus coccopoma, 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). The nauplii feed in the plankton and go through five successive molts, spending 6 to 20 days (about 3 weeks) in the water column (Severino and Resgalla 2005), before molting into a non-feeding cypris stage, covered with a pair of chitinous shells. Cyprids swim, investigating suitable surfaces, and then settle, secreting a shell and molting into the first juvenile barnacle stages. Juvenile and adult barnacles are filter feeders, sweeping the water with their long, bristled appendages that gather phytoplankton, zooplankton, and detritus (Barnes 1983). 
 
Megabalanus coccopoma prefers intertidal and shallow subtidal (less than 100 m depth) regions of marine waters. Newman and McConnaughey (1987) describe this species as an opportunist and highly gregarious, settling on disturbed or previously cleared substrates, especially manufactured structures such as buoys and boats. It is a common fouler of boats, ships, buoys, and other manufactured structures (Woods Hole Oceanographic Institution 1952; Newman and McConnaughey 1987; Kerckhof and Cattrijsse 2001). In Itapocoroy Bay, Brazil, it is an abundant fouler of aquaculture ropes and floats used in oyster and mussel culture (Severino and Resgalla 2005). It also frequently grows on mollusk shells (e.g., Pseudochama corrugata, Ross 1962; 'mussels', Young 1994). Henry and McLaughlin (1986) list one specimen from a Humpback Whale (Megaptera novaeangliae). 
 
The temperature range of this species is difficult to infer from its known occurrences. It occurred near San Diego, California during an El Niño year in 1985, and then in small numbers after that (three specimens, Newman and McConnaughey 1987), and failed to survive winter conditions in Louisiana (Perreault 2004) but has survived several winters on coastal buoys in Belgium (Kerckhof and Cattrijsse 2001; Kerckhof, personal communication). In Itapocoroy Bay, Brazil, it reproduces year-round at a temperature range of 17–30ºC (Severino and Resgalla 2005). 

Food:

Phytoplankton, zooplankton

Consumers:

Fishes, crabs, flatworms

Competitors:

Other fouling organisms

Trophic Status:

Suspension Feeder

SusFed

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Habitats

General Habitat	Marinas & Docks	None
General Habitat	Rocky	None
General Habitat	Vessel Hull	None
Salinity Range	Polyhaline	18-30 PSU
Salinity Range	Euhaline	30-40 PSU
Tidal Range	Subtidal	None
Tidal Range	Low Intertidal	None
Vertical Habitat	Epibenthic	None

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Life History

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Tolerances and Life History Parameters

Minimum Temperature (ºC)	4.7	Functional temperature, FT50, minimum temperature for 50% response. LT50 (50% lethal temperature was 2. 3 C) (Crickenberger 2014).
Minimum Salinity (‰)	26	Minimum salinity, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Maximum Salinity (‰)	38	Maximum salinity, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Minimum Dissolved Oxygen (mg/l)	7.5	Minimum dissolved oxygen, mg/ml, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Maximum Dissolved Oxygen	8.5	Maximum dissolved oxygen, mg/ml, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Minimum pH	5.5	Minimum pH, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Maximum pH	10.5	Minimum pH, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Minimum Reproductive Temperature	16	Experimental, nauplius-cypris-juvenile, animals from Fernandina FL, Crickenberger 2014; Crikcenberger et al. 2017.
Maximum Reproductive Temperature	30	Reproducing year-round, annual cycle, Itapocoroy Bay, Brazil, Severno and Resgalla 2005
Minimum Reproductive Salinity	26	Reproducing year-round, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Maximum Reproductive Salinity	38	Reproducing year-round, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Minimum Reproductive Dissolved Oxygen	7.5	Reproducing year-round, annual cycle, Itapocoroy Bay, Brazil, Severno and Resgalla 2005
Maximum Reproductive Dissolved Oxygen (mg/l)	8.5	Reproducing year-round, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Minimum Reproductive pH	5.5	Reproducing year-round, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Maximum Reproductive pH	10.5	Reproducing year-round, annual cycle, Itapocoroy Bay, Brazil, Severino and Resgalla 2005
Minimum Duration	5	22 C, experimental, Crickenberger 2014.
Maximum Duration	20	Larval duration, experimental, 20 C, Severino and Resgalla 2005
Maximum Height (mm)	50	Ross 1962
Broad Temperature Range	None	Warm temperate-tropical
Broad Salinity Range	None	Polyhaline-Euhaline

General Impacts

Economic Impacts

Megabalanus coccopoma is currently rare in US waters. However, within its native range, from Mexico to Peru, it is common fouler of boats, ships, buoys, and other manufactured structures (Woods Hole Oceanographic Institution 1953; Newman and McConnaughey 1987; Kerckhof and Cattrijsse 2001). 
 
Fisheries- In Itapocoroy Bay, Brazil, it is an abundant fouler of aquaculture ropes and floats used in oyster and mussel culture (Severno and Resgalla 2005). 
 
Ecological Impacts 

The ecological impacts of this barnacle’s invasion in Brazil have not been carefully studied. However, it appears to have largely replaced populations of M. tintinnabulum, reported in the 1920s–1940s (Young 1994). In experiments in Mosquito Lagoon, Florida, Megabalanus coccopoma located on fouling plates reduced the settlement of larvae of Eastern Oyster (Crassostrea virginica) but did not affect the growth of oyster spat (Yuan et al. 2016). 

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Regional Impacts

SA-II	None		Economic Impact	Fisheries
Barnacles, dominated by M. coccopoma, foul ropes used in mussel culture in Itapocoroy Bay (Santa Catarina, Brazil). The ropes sometimes break from the weight of attached barnacles (Severino and Resgalla 2005). Didemnum perlucidum was common but not dominant in mussel farms in southern Brazil. It does overgrow mussels, so could 'be damaging to the bivalve industry' (da Rocha et al. 2010). In later studies, ,emM. coccopoma was found to affect the growth of cultured mussels, delaying or preventing their growth to marketable size. Monthly cleaning of the mussels and the culture 'socks' improved the growth of the mussels, but damaged small mussels, but increased labor costs, (Lins and Rocha 2020).
SA-II	None		Ecological Impact	Competition
Megabalanus coccopoma appears to have largely replaced populations of M. tintinnabulum, reported in the 1920s-1940s (Young 1994).
CAR-I	Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida		Ecological Impact	Competition
In experiments in Mosquito Lagoon, Florida, Megabalanus coccopoma, on fouling plates, reduced the settlement of larvae of Eastern Oyster (Crassostrea virginica), but did not affect the growth of oyster spat (Yuan et al. 2016).
S190	Indian River		Ecological Impact	Competition
In experiments in Mosquito Lagoon, Florida, Megabalanus coccopoma, on fouling plates, reduced the settlement of larvae of Eastern Oyster (Crassostrea virginica), but did not affect the growth of oyster spat (Yuan et al. 2016).
FL	Florida		Ecological Impact	Competition
In experiments in Mosquito Lagoon, Florida, Megabalanus coccopoma, on fouling plates, reduced the settlement of larvae of Eastern Oyster (Crassostrea virginica), but did not affect the growth of oyster spat (Yuan et al. 2016).

References

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

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

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

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

Cangussu, Leonardo C. and 5 authors (2010) Substrate type as a selective tool against colonization by non-native sessile invertebrates, Brazilian Journal of Oceanography 58(3): 219-231

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

Cohen, Ocean R.; Walters, Linda J.; Hoffman, Eric A. (2014) Clash of the titans: a multi-species invasion with high gene flow in the globally invasive titan acorn barnacle, Biological Invasions Published online: <missing location>

Crickenberger, Sam (2016) Predicting a range shift and range limits in an introduced tropical marine invertebrate using species distribution models, Hydrobiologia 763: 193-205

Crickenberger, Sam; Moran, Amy (2013) Rapid range shift in an introduced tropical marine invertebrate, PLOS ONE 8(10): e78008

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

Crickenberger, Samuel (2014) <missing title>, Clemson University, Clemson SC. Pp. 135 pp.

da Silva, Eder Carvalho; Barros, Francisco (2011) [Benthic macrofauna introduced in Brazil: List of marine and freshwater species and actual distribution], Oecologia Australis 15(2): 326-344

Dafforn, K. A.; Johnston, E. L.; Glasby, T. M. (2009) Shallow moving structures promote invader dominance., Biofouling 25(3): 277-287

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

Edwards, Jennifer (11/16/2011) Cold holds invasive species at bay, St. Augustine Record <missing volume>: published online

Farrapeira, Cristiane Maria Rocha (2010) Shallow water Cirripedia of the northeastern coast of Brazil: The impact of life history and invasion on biogeography, Journal of Experimental Marine Biology and Ecology 392: 210-219

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

Gastaldi, Marianela; DePaula, Thiago S.; Narvarte, Maite A.; Lôbo-Hajdu. Gisele; Hajdju, Eduardo (2018) Marine sponges (Porifera) from the Bahía San Antonio (North Patagonian Gulfs, Argentina), with additions to the phylogeography of the widely distributed Cliona aff. celata and Hymeniacidon perlevis, and the description of two new species, Marine Biology Research 14(7): 682-716
https://doi.org/10.1080/17451000.2018.1506136

Gilg, Matthew R. and 6 authors (2010) Spatio-temporal settlement patterns of the non-native titan acorn barnacle,Megabalanus coccopoma, in northeastern Florida, Journal of Crustacean Biology 30(1): 146-150

Hedge, Luke H.; Johnston, Emma L. (2012) Propagule pressure determines recruitment from a commercial shipping pier, Biofouling 28(1): 73-85

Henry, Dora P.; McLaughlin, Patsy A. (1986) The recent species of Megabalanus (Cirripedia: Balanomorpha) with special emphasis on Balanus tintinnabulum (Linnaeus) sensu lato., Zoologische Verhandelingen 235: 5-69

Hopkins, Grant A.; Forrest, Barrie M.; Jiang, Weimin; Gardner, Jonathan P. A. (2011) Successful eradication of a non-indigenous marine bivalve from a subtidal soft-sediment environment, Journal of Applied Ecology <missing volume>: published online

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

Kerckhof, F.; Haelters, J.; Degraer, S. (2010) The barnacles Chirona (Striatobalanus) amaryllis (Darwin 1854) and Megabalanus coccopoma (Darwin 1854) (Crustacea, Cirripedia): two invasive species new to tropical West African waters, African Journal of Marine Science 32(2): 265 -268

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

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

Lins, Daniel M. ; Rocha, Rosana M. (2023) Marine aquaculture as a source of propagules of invasive fouling species , Polar Biology 11(e5456): Published online

Lopes, Rubens M. (Ed.) (2009) <missing title>, Ministry of the Environment, Brasilia, Brazil. Pp. 1-440

Lutaenko, Konstantin A.; Furota,Toshio; Nakayama, Satoko; Shin, Kyoungsoon; Xu, Jing (2013) <missing title>, Northwest Pacific Action Plan- Data and Information Network Regional Activity Center, Beijing, China. Pp. <missing location>

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

Newman, William A.; McConnaughey, Ronald R. (1987) A tropical eastern Pacific barnacle, Megabalanus coccopoma in southern California, followowing El Nino 1982-1983., Pacific Science 41(1-4): 31-36

Perreault, Ray T. (2004) An exotic tropical barnacle Megabalanus coccopoma in Louisiana: its probable arrival and environmental implications., Proceedings of the Louisiana Academy of Sciences 66: 13-16

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

Quintanilla, Elena; Thomas Wilke; Ramırez-Portilla, Catalina; Sarmiento, Adriana; Sanchez, Juan A.2017 (2017) Taking a detour: invasion of an octocoral into the Tropical Eastern Pacific, Biological Invasions <missing volume>(17): 2583–2597
DOI 10.1007/s10530-017-1469-2

Rocha, Rosana M.; Cangussu, Leonardo C.; Braga, Mariana P. (2010) Stationary substrates facilitate bioinvasion in Paranaguá bay in southern Brazil, Brazilian Journal of Oceanography 58(Special Issue 4): 23-28

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 (1962) Results of the Puritan-American Museum of Natural History Expedition to western Mexico 15. The littoral Balanomorph Cirripedia., American Museum Novitates 2084: 1-44

Severino, Alexandra; Resgalla, Charrid, Jr. (2005) [Larval development of the Megabalanus coccopoma (Darwin, 1854) and temporal variation in Itapocoroy Bay (Santa Catarina, Brazil).], Atlantica 27(1): 5-16

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

Silveira, Nilce Gomes; de Souza, Rosa Cristina Corrêa Luz; Fernandes, Flavio da Costa; Silva, Edson Pereira (2006) Occurrence of Perna perna, Modiolus carvalhoi (Mollusca, Bivalvia, Mytilidae) and Megabalanus coccopoma (Crustacea, Cirripedia) off Areia Branca, Rio Grande do Norte state, Brazil., Biociencias 14(1): 89-90

Simoes, Nuno; Wakida-Kusunoki, Armando T.; Cruz-Sánchez, José Luís; Alvarez, Fernando; andVillalobos-Hiriart, José Luis (2021) On the presence of Charybdis (Charybdis) hellerii (A. Milne-Edwards, 1867) on the Mexican coast of the Gulf of Mexico, BioInvasions Records 8(3): 670–674

South Carolina Department of Natural Resources (2007) <missing title>, South Carolina Department of Natural Resources, Columbia SC. Pp. 1-95

Southeast Regional Taxonomic Center 2011 Titan acorn barnacle (<i>Megabalanus coccopoma</i>). <missing URL>



Spinuzzi, Samantha and 5 authors (2012) <missing title>, University of Central Florida, Orlando FL. Pp. unpaged

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

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



USGS Nonindigenous Aquatic Species Program 2003-2024 Nonindigenous Aquatic Species Database. https://nas.er.usgs.gov/



Williams, Rissa; Gould, Brendan; Christian, Sheree (2008) Shipwrecks: an international biosecurity risk?, Surveillance 35(1): 1-6

Woods Hole Oceanographic Institution, United States Navy Dept. Bureau of Ships (1952) Marine fouling and its prevention., United States Naval Institute., Washington, D.C.. Pp. 165-206

Yamaguchi, Toshiyuki and 10 authors (2009) The introduction to Japan of the Titan barnacle, Megabalanus coccopoma (Darwin, 1854) (Cirripedia: Balanomorpha) and the role of shipping in its translocation., Biofouling 25(4): 325-333

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

Young, Paulo S. 1998 Maxillopoda. Thecostraca.. <missing URL>



Young, Paulo S. (2000) Cirripedia Thoracica (Crustacea) collected during the "Campagne de la Calypso (1961-1963) from the Atlantic shelf of South America., Zoosystema 22(1): 85-100

Yuan, W. Samantha; Hoffman, Eric A.; Walters, Linda J. (2016) <missing title>, 18 <missing publisher>, <missing place>. Pp. 689-701

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

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