Invasion History
First Non-native North American Tidal Record: 1986First Non-native West Coast Tidal Record: 1986
First Non-native East/Gulf Coast Tidal Record:
General Invasion History:
Microcosmus squamiger is native to the coast of Australia, where it is widespread. Available records include most of the Australian states (Kott 1985; Australian Faunal Directory 2009), but we are unaware of records from the Northern Territories. It also occurs in several locations including the Indo-Pacific region, from Vizhinjam, India, the Arabian Sea (Abdul and Sivakumar 2007), the Red Sea (Michaelsen 1918, cited by Kott 1985), Ibo Island, Mozambique, (Monniot 2002), and New Zealand (1st record in 2003, Inglis et al. 2005). This species appears to have been frequently transported in ship fouling and may be introduced in New Zealand and is definitely introduced in South Africa, where it is known from the harbor of Port Elizabeth, in the Indian Ocean (Rius et al. 2008; Griffiths et al. 2009). Other recent invasions have occurred on the coasts of California and Mexico (Lambert and Lambert 1998; Lambert and Lambert 2003; Rius et al. 2008; Rodriguez and Ibarra-Obando 2008), the western Mediterranean (Mastrototaro and Dappiano 2005; Turon et al. 2007), the Atlantic coast of Spain, Madeira, and the Canary Islands (Turon et al. 2007).
North American Invasion History:
Invasion History on the West Coast:
Microcosmus squamiger was first collected in Alamitos Bay, Long Beach, California in 1986 (Lambert and Lambert 1998). By 1994 its range extended from San Diego Bay to Santa Barbara Harbor (Lambert and Lambert 1998; Lambert and Lambert 2003). In 2000 it was collected in Ensenada, Mexico, (Lambert and Lambert 2003) and in 2002 it was observed fouling cultured oysters in Bahia San Quintin, Baja California (Rodriguez and Ibarra-Obando 2008). In 2015-2016, M. squamiger was found growing on several fouling plates at the Oakland Yacht Club in San Francisco Bay (Tracy et al. 2017). We consider this population to be established.
Invasion History in Hawaii:
Microcosmus squamiger is not established in Hawaii, but has been found in fouling on ships travelling from California to Honolulu, Pearl Harbor, and Barber's Point harbors (Godwin 2003).
Invasion History Elsewhere in the World:
Microcosmus squamiger was first collected in the Mediterranean Sea in 1971 at Savona, Italy in the western basin near the French border, but was initially misidentified by Monniot as M. exasperatus (Monniot 1981, Mastrototaro and Dappiano 2005). In 1963 it was collected in the Tyrrhenian Sea at Bizerte, Tunisia (Mastrototaro and Dappiano 2005), and the central basin, at Taranto, Italy by 1977 (Mastrototaro and Dappiano 2005). This seems to be its present eastward limit - it has not been recorded in the Adriatic or the eastern basin where M. exasperatus has been found (Turon et al. 2007). To the west, M. squamiger occurs along the Mediterranean coast of Spain from Barcelona to Alicante (in 1988) and Algeciras Bay near Gibraltar (in 1996) (Turon et al. 2007). In 1994 it was collected at Cape Trafalgar on the Atlantic Ocean and has subsequently been collected at several sites in the Gulf of Cadiz, at Cascais, Portugal and on the Bay of Biscay at Santander and in the Ria San Vicente (Turon et al. 2007). It has also been collected at Madeira and Tenerife, Canary Islands off the coast of northwest Africa (Turon et al. 2007). In 2007, it was found in 8 locations on the Pacific coast of Japan, and 2014, in Okinawa (Nishikawa and Ueda 2011; Nishikawa `07, boith cited by Bae eta l. 2022(. In 2022, Microcosmus squamiger was found in two harbors on Jeju Island, South Korea (Bae et al. 2022).
Description
Microcosmus squamiger is a solitary tunicate, but usually occurs in dense clumps or aggregates. Each tunicate can grow up to 50 mm in diameter. The surface of the tunic rises into ridges and swellings with adhesive projections. The tunic is purple, leathery, tough, and sometimes hard and brittle. The apertures are usually located on short, wart-like siphons about a third of the body length and are directed away from each other. But sometimes the oral siphon is terminal with a long straight siphon, while the atrial siphon is short and about half-way along the body (Kott 1985).
This species is frequently confused with the very similar species Microcosmus exasperatus (Mastrototaro and Dappiano 2005; Turon et al. 2007). One of the few characteristics used to distinguish between the two species is the shape of the internal siphonal spines. The spines of M. squamiger are very short, about 15-25 µm long, and shaped like fingernails with serrated rims, while M. exasperatus has longer pointed spines, about 40-50 µm long, which are posteriorly hooked (Kott, 1985; Mastrototaro and Dappiano 2005).
Taxonomy
Taxonomic Tree
| Kingdom: | Animalia | |
| Phylum: | Chordata | |
| Subphylum: | Tunicata | |
| Class: | Ascidiacea | |
| Order: | Stolidobranchia | |
| Family: | Pyuridae | |
| Genus: | Microcosmus | |
| Species: | squamiger |
Synonyms
Microcosmus exasperatus australis (Michaelsen, 1908)
Potentially Misidentified Species
Many confused records in the Mediterranean- most reports of M. exasperatus are actually M. squamiger (Turon et al. 2007).
Ecology
General:
Life History- A solitary tunicate is ovoid, elongate or vase-like in shape, with two openings or siphons. Most solitary tunicates attach to substrates by their side or base, but some attach with a conspicuous stalk. They are sessile filter feeders with two siphons, an oral and an atrial siphon. Water is pumped in through the oral siphon, where phytoplankton and detritus is filtered by the gills, and passed on mucus strings to the stomach and intestines. Waste is then expelled in the outgoing atrial water.
Solitary ascidians are hermaphroditic, meaning that both eggs and sperm are released to the atrial chamber. Eggs may be self-fertilized or fertilized by sperm from nearby animals, but many species have a partial block to self-fertilization. Depending on the species, eggs may be externally or internally fertilized. In external fertilizers, eggs and sperm are released through the atrial siphon into the surrounding water column were fertilization takes place. In internal fertilizers, eggs are brooded and fertilized within the atrial chamber and then released into the water column upon hatching. Fertilized eggs hatch into a tadpole larva with a muscular tail, notochord, eyespots, and a set of adhesive papillae. The lecithotrophic (non-feeding, yolk-dependent) larva swims briefly before settlement. Swimming periods are usually less than a day and some larvae settle immediately after release, but the larval period can be longer at lower temperatures. Once settled, the tail is absorbed, the gill basket expands, and the tunicate begins to feed by filtering (Barnes 1983).
Food:
Phytoplankton; Detritus
Trophic Status:
Suspension Feeder
SusFedHabitats
| General Habitat | Marinas & Docks | None |
| General Habitat | Rocky | None |
| Salinity Range | Polyhaline | 18-30 PSU |
| Salinity Range | Euhaline | 30-40 PSU |
| Tidal Range | Subtidal | None |
| Vertical Habitat | Epibenthic | None |
Life History
Tolerances and Life History Parameters
| Maximum Duration | 1 | Swimming time of larva (Turon et al. 2010) |
| Maximum Length (mm) | 50 | Kott 1985 |
| Broad Temperature Range | None | Warm temperate-Tropical |
| Broad Salinity Range | None | Polyhaline-Euhaline |
General Impacts
Economic Impacts
Oyster culture racks, ropes, and shells (of Crassostrea gigas, Pacific Oyster) in Bahia San Quintin, Baja California, Mexico were badly fouled by tunicates beginning in 2002. Microcosmus squamiger was a major organism in this fouling (Rodriquez and Ibarra-Obando 2008).
Ecological Impacts
Competition: Microcosmus squamiger now greatly outnumbers Styela canopus in San Diego Bay. It forms single-species patches at some locations suggestive of competition (Lambert and Lambert 2003), for example it forms dense monospecific crusts, and can outcompete native species in shallow water communities. Microcosmus squamiger is considered a potential threat to Mediterranean littoral communities, but further monitoring is needed to assess its impacts (Turon et al. 2007).
Regional Impacts
| NEP-VI | Pt. Conception to Southern Baja California | Economic Impact | Fisheries | ||
| Oyster culture racks, ropes, and shells (of Crassostrea gigas, Pacific Oyster) in Bahia San Quintin, Baja California, Mexico were badly fouled by tunicates, beginning in 2002. Microcosmus squamiger was a major organism in this fouling (Rodriquez and Ibarra-Obando 2008). | |||||
| NEP-VI | Pt. Conception to Southern Baja California | Ecological Impact | Competition | ||
| Microcosmus squamiger now greatly outnumbers Styela canopus, an earlier invader, in San Diego Bay. It forms single-species patches at some locations, suggestive of competition (Lambert and Lambert 2003). | |||||
| P020 | San Diego Bay | Ecological Impact | Competition | ||
| Microcosmus squamiger now greatly outnumbers an earlier invader, Styela canopus in San Diego Bay. It forms single-species patches at some locations, suggestive of competition (Lambert and Lambert 2003). | |||||
| MED-II | None | Ecological Impact | Competition | ||
| 'The ability of M. squamiger to form dense, monospecific crusts that outcompete native species in shallow water communities (authors' personal observation) indicates that it is a potential threat to Mediterranean littoral communities and deserves further monitoring' (Turon et al. 2007). | |||||
| CA | California | Ecological Impact | Competition | ||
| Microcosmus squamiger now greatly outnumbers an earlier invader, Styela canopus in San Diego Bay. It forms single-species patches at some locations, suggestive of competition (Lambert and Lambert 2003). | |||||
Regional Distribution Map
| Bioregion | Region Name | Year | Invasion Status | Population Status |
|---|---|---|---|---|
| NEP-VI | Pt. Conception to Southern Baja California | 1986 | Non-native | Established |
| AUS-II | None | 0 | Native | Established |
| AUS-IV | None | 0 | Native | Established |
| AUS-V | None | 0 | Native | Established |
| AUS-VII | None | 0 | Native | Established |
| AUS-IX | None | 0 | Native | Established |
| AUS-X | None | 0 | Native | Established |
| AUS-XII | None | 1928 | Native | Established |
| AUS-III | None | 0 | Native | Established |
| AUS-VIII | None | 0 | Native | Established |
| RS-1 | None | 0 | Crypogenic | Established |
| RS-2 | None | 0 | Crypogenic | Established |
| RS-3 | None | 0 | Crypogenic | Established |
| MED-I | None | 1996 | Non-native | Established |
| AUS-XIII | None | 0 | Native | Established |
| MED-II | None | 1971 | Non-native | Established |
| WA-V | None | 1950 | Non-native | Established |
| MED-III | None | 1963 | Non-native | Established |
| P020 | San Diego Bay | 1994 | Non-native | Established |
| P050 | San Pedro Bay | 1986 | Non-native | Established |
| P030 | Mission Bay | 1994 | Non-native | Established |
| P023 | _CDA_P023 (San Louis Rey-Escondido) | 1994 | Non-native | Established |
| P027 | _CDA_P027 (Aliso-San Onofre) | 1994 | Non-native | Established |
| P040 | Newport Bay | 1994 | Non-native | Established |
| P060 | Santa Monica Bay | 1994 | Non-native | Established |
| P062 | _CDA_P062 (Calleguas) | 1994 | Non-native | Established |
| P064 | _CDA_P064 (Ventura) | 1996 | Non-native | Established |
| P058 | _CDA_P058 (San Pedro Channel Islands) | 1992 | Non-native | Established |
| MED-IV | None | 1977 | Non-native | Established |
| EA-III | None | 1995 | Crypogenic | Established |
| NZ-IV | None | 2004 | Crypogenic | Established |
| SP-XXI | None | 2003 | Non-native | Unknown |
| P065 | _CDA_P065 (Santa Barbara Channel) | 2001 | Non-native | Established |
| NEA-V | None | 1994 | Non-native | Established |
| WA-I | None | 1992 | Non-native | Established |
| CIO-I | None | 0 | Crypogenic | Established |
| CIO-II | None | 2004 | Crypogenic | Established |
| NEA-VI | None | 2009 | Non-native | Established |
| NEP-V | Northern California to Mid Channel Islands | 2015 | Non-native | Established |
| P090 | San Francisco Bay | 2016 | Non-native | Established |
| MED-VI | None | 2015 | Non-native | Established |
| NWP-3a | None | 2022 | Non-native | Established |
| NWP-2 | None | 2014 | Non-native | Established |
| NWP-3b | None | 2007 | Non-native | Established |
Occurrence Map
| OCC_ID | Author | Year | Date | Locality | Status | Latitude | Longitude |
|---|---|---|---|---|---|---|---|
| 767427 | Ruiz et al., 2015 | 2013 | 2013-07-19 | SeaWorld Marina, Mission Bay, CA, California, USA | Non-native | 32.7676 | -117.2314 |
| 767463 | Ruiz et al., 2015 | 2013 | 2013-07-29 | Mission Bay Yacht Club, Mission Bay, CA, California, USA | Non-native | 32.7778 | -117.2485 |
| 767482 | Ruiz et al., 2015 | 2013 | 2013-08-04 | Bahia Resort Marina, Mission Bay, CA, California, USA | Non-native | 32.7731 | -117.2478 |
| 767496 | Ruiz et al., 2015 | 2013 | 2013-07-31 | Campland on the Bay, Mission Bay, CA, California, USA | Non-native | 32.7936 | -117.2234 |
| 767697 | Ruiz et al., 2015 | 2013 | 2013-07-24 | NAB ACU-1 Docks, San Diego Bay, CA, California, USA | Non-native | 32.6786 | -117.1615 |
| 767749 | Ruiz et al., 2015 | 2013 | 2013-07-18 | NAB Fiddlers Cove, San Diego Bay, CA, California, USA | Non-native | 32.6524 | -117.1486 |
| 767766 | Ruiz et al., 2015 | 2013 | 2013-07-26 | Pier 32 Marina, San Diego Bay, CA, California, USA | Non-native | 32.6516 | -117.1077 |
| 767775 | Ruiz et al., 2015 | 2013 | 2013-07-20 | Chula Vista Marina, San Diego Bay, CA, California, USA | Non-native | 32.6252 | -117.1036 |
| 767789 | Ruiz et al., 2015 | 2013 | 2013-07-28 | Marriott Marquis and Marina, San Diego Bay, CA, California, USA | Non-native | 32.7059 | -117.1655 |
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): 124-131Abdul, Jaffar Ali H.; Sivakumar, V. (2007) Occurrence and distribution of ascidians in Vizhinjam Bay (south west coast of India)., Journal of Experimental Marine Biology and Ecology 342: 189-190
Ali, H. Abdul Jaffar; Sivakumar, V.; Tamilselvi, M. (2009) Distribution of alien and cryptogenic ascidians along the southern coasts of Indian peninsula, World Journal of Fish and Marine Sciences 1(4): 305-312
Ashton, G. V.; Davidson, I. C.; Geller, J.; Ruiz, G. M. (2016) Disentangling the biogeography of ship biofouling: barnacles in the NortheastPacific, Global Ecology and Biogeography 25: 739-750
Bae, Seongjun; Lee, Seung-Hyun; Kim, Ji Min; Yi, Chang-Ho (2022) First record of the invasive ascidian Microcosmus squamiger Michaelsen, 1927 (Ascidiacea: Pyuridae) in Jeju Island, South Korea, BioInvasions Records 11: Published online
Barnes, Robert D. (1983) Invertebrate Zoology, Saunders, Philadelphia. Pp. 883
Bastida-Zavala, Rolando; de León-González, Jesús Ángel; Carballo Cenizo, José Luis; Moreno-Dávila, Betzabé (2014) [Aquatic Invasive Species in Mexico], Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, <missing place>. Pp. 317-336
Bonvechio, Kimberly I.; Barthel, Brandon; Carroll, Jessica (2018) Health and Genetic Structure of the American Eel in Florida, Southeastern Naturalist 17(3): 483-455
https://doi.org/10.1656/058.017.0311
California Department of Fish and Wildlife (2014) Introduced Aquatic Species in California Bays and Harbors, 2011 Survey, California Department of Fish and Wildlife, Sacramento CA. Pp. 1-36
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
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>
Del Pasqua, Michela; Schulze, Anja; Tovar-Hernandez, Maria Ana; Keppel, Erica; Marco Lezzi;, Maria; Gambi, Maria Cristina ; Giangrande, Adriana (2018) Clarifying the taxonomic status of the alien species Branchiomma bairdi and
Fairey, Russell; Dunn, Roslyn; Sigala, Marco; Oliver, John (2002) Introduced aquatic species in California's coastal waters: Final Report, California Department of Fish and Game, Sacramento. Pp. <missing location>
Fisheries and Oceans Canada 2018b Haplosporidium costale (SSO) of Oysters. https://www.dfo-mpo.gc.ca/science/aah-saa/diseases-maladies/hcoy-eng.html
Godwin, Scott L. (2003) Hull fouling of maritime vessels as a pathway for marine species invasions to the Hawaiian Islands., Biofouling 19 (Suppl): 123-131
Griffiths, Charles L.; Robinson, Tamara B.; Mead, Angela (2009) Biological Invasions in Marine Ecosystems., Springer-Verlag, Berlin Heidelberg. Pp. <missing location>
Haupt, T. M.; Griffiths, C. L.; Robinson, T. B.;Tonin, A. F. G. (2010) Oysters as vectors of marine aliens, with notes on four introduced species associated with oyster farming in South Africa, African Zoology 45: 52-62
Holman, Luke E.; Parker-Nance, Shirley; de Bruyn, Mark; Creer, Simon; Carvalho, Gary; Rius, Marc (2021) Managing human-mediated range shifts: understanding spatial, temporal and genetic variation in marine non-native species, Philosophical Transactions of the Royal Society of London B 377: 20210025
Inglis, Graeme; Gust, Nick; Fitridge, Isla ; Floerl, Oliver; Woods, Chris. Barbara Hayden, Graham Fenwick (2005c) Gulf Harbour Marina: Baseline survey for non-indigenous marine species., Biosecurity New Zealand Technical Paper 2005(12): 1-39
Jaffar Ali H. Abdul; Sivakumar, V.; Selvi, M. Tamar (2010) New records of colonial ascidians from the southwest coast off India, Middle East Journal of Scientific Research 5(5): 366-373
Kott, P. (2005) Catalogue of Tunicata in Australian waters, Queensland Museum, Brisbane. Pp. 1-301
Kott, Patricia (1985) The Australian Ascidiacea Part 1, Phlebobranchia and Stolidobranchia., Memoirs of the Queensland Museum 23: 1-440
Lambert, C. C.; Lambert, G. (1998) Non-indigenous ascidians in southern California harbors and marinas., Marine Biology 130: 675-688
Lambert, Charles C; Lambert, Gretchen (2003) Persistence and differential distribution of nonindigenous ascidians in harbors of the Southern California Bight., Marine Ecology Progress Series 259: 145-161
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
Mastrotaro, F; Dappiano, M. (2005) New record of the non-indigenous species Microcosmus squamiger (Ascidiacea: Stolidobranchia) in the harbour of Salerno (Tyrrhenian Sea, Italy)., JMBA2- Biodiversity Records (online) <missing volume>: <missing location>
Mastrotaro, Francesco; Petrocelli, Antonella; Cecere, Ester; Matarese, Alfonso (2004) Nonidigenous species settle down in the Taranto Seas, Biogeographia 25: 47-58
Mastrototaro, F.; D’Onghia, G.; Tursi, A. (2008) Spatial and seasonal distribution of ascidians in a semi-enclosed basin of the Mediterranean Sea., Journal of the Marine Biological Association of the United Kingdom 88(5): 1053-1061
Mead, A.; Carlton, J. T.; Griffiths, C. L. Rius, M. (2011b) Introduced and cryptogenic marine and estuarine species of South Africa, Journal of Natural History 39-40: 2463-2524
Monniot, C. (1981) Apparition de L'ascidie Microcosmus exasperatus dans les ports Mediterraneens., Tethys 10(1): 59-62
Monniot, Claude (2002) Stolidobranch ascidians from the tropical western Indian Ocean., Zoological Journal of the Linnean Society 135: 65-120
Monniot, Claude; Monniot, Francoise; Griffiths, Charles; Schleyer, Michael (2001) South African Ascidians., Annals of the South African Museum 108(1): 1-141
Önen, Sinem Ayd'n (2021) First occurrence of fouling ascidian species Microcosmus squamiger Michaelsen, 1927 and Didemnum ahu Monniot C. & Monniot F., 1987 in ?zmir Bay (Eastern Aegean Sea), Journal of Natural History 54(29-30): 1897-1912
Ordonez, Victor; Pascual, Marta; Rius, Marc; Turon, Xavier (2013) Mixed but not admixed: a spatial analysis of genetic variation of an invasive ascidian on natural and artificial substrates, Marine Biology 160: 1645-1660
Otero, M.; Cebrian, E.; Francour, P.; Galil, B.; Savini, D. (2013) <missing title>, International Union for Conservation of Nature, Malaga, Spain. Pp. 136
Pineda, M. Carmen; McQuaid, Christopher D.; Turon, Xavier; Lopez-Legentil, Susanna; Ordonez, Výctor; Rius, Marc (2012) Tough adults, frail babies: An analysis of stress sensitivity across early life-history stages of widely introduced marine invertebrates, PLOSOne 7(10): e46672
Rius, M.; Griffths, C. W. (2011) Alien & Invasive Animals: A South African Perspective, Random House Struik, Johannesburg, South Africa. Pp. 71-75
Rius, Marc and 7 authors (2014) Range expansions across ecoregions: interactions of climate change, physiology and genetic diversity, Diversity and Distributions 23: 76-88
Rius, Marc; Branch, George M.; Griffiths, Charles L.; Turon, Xavier (2010) Larval settlement behaviour in six gregarious ascidians in relation to adult distribution, Marine Ecology Progress Series 418: 151-163
Rius, Marc; Pascual, Marta; Turon, Xavier (2008) Phylogeography of the widespread marine invader Microcosmus squamiger, (Ascidiacea) reveals high genetic diversity of introduced populations and non-independent colonizations., Diversity and Distributions 15(5): 818-828
Rius, Marc; Pineda, Mari Carmen; Turon, Xavier (2009) Population dynamics and life cycle of the introduced ascidian Microcosmus squamiger in the Mediterranean Sea., Biological Invasions 11(10): 2181-2194
Rius, Marc; Turon, Xavier; Ordonez, Victor; Pascual, Marta (2012) Tracking invasion histories in the sea: facing complex scenarios using multilocus data, PLOS ONE 7(4): e35815
Rius, Marc;Turon, Xavier; Dias, Gustavo M.; Marshall, Dustin J. (2009) Propagule size effects across multiple life-history stages in a marine invertebrate, Functional Ecology 24(3): 685-693
Rodriguez, Laura F.; Ibarra-Obando, Silvia E. (2008) Cover and colonization of commercial oyster (Crassostrea gigas) shells by fouling organisms in San Quintin Bay, Mexico, Journal of Shellfish Research 27(2): 337-343
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>
Ruiz, Gregory; Geller, Jonathan (2021) Spatial and temporal analysis of marine invasions: supplemental studies to evaluate detection through quantitative and molecular methodologies, Marine Invasive Species Program, California Department of Fish and Wildlife, Sacramento CA. Pp. 153 ppl.
Simkanin, Christina; Fofonoff, Paul W.; Larson, Kriste; Lambert, Gretchen; Dijkstra, Jennifer A.; Ruiz, Gregory M. (2016) Spatial and temporal dynamics of ascidian invasions in the continental United States and Alaska, Marine Biology 163: Published online
Tamilselvi, M. ; Sivakumar, V.; Ali, H. Abdul Jaffar; Thilaga, R. D. (2011) Distribution of alien tunicates (ascidians) in Tuticorin coast, India, World Journal of Zoology 6(2): 164-172
Tracy, Brianna M.; Reyns, Nathalie B. (2014) Spatial and temporal patterns of native and invasive ascidian assemblages in a Southern California embayment, Aquatic Invasions 9: In press
Turon, X. (1986) Morfologia de las espicul e las especies de la familia Didemnidae (Ascidiacea) del litoral de Cataluna e islas Baleares., Miscellania Zoologia Barcelona 10: 213-222
Turon, Xavier; Nishikawa, Teruaki; Rius, Marc (2007) Spread of Microcosmus squamiger (Ascidiacea: Pyuridae) in the Mediterranean Sea and adjacent waters., Journal of Experimental Marine Biology and Ecology 342: 185-188
Vaz-Pinto, F. and 5 authors (2014) Invasion success and development of benthic assemblages: Effect of timing, duration of submersion and substrate type, Marine Environmental Research 94: 72-79
Virgili. Riccardo; Tandua, Valentina; Katsanevakis, Stelos; Terlizzi, Francesco; Villani, Guido; Fontano. Angelo; Crocetta, Fabio (2022) The Miseno Lake (Central-Western. Mediterranean Sea): An overlooked reservoir of non-indigenous and cryptogenic ascidians in a marine reserve, Frontiers in Marine Science 9(866906): Published online
Zhan, Aibin; Briski, Elizabeta; Bock, Dan G.; Ghabooli, Sara; MacIsaac, Hugh J. (2015) Ascidians as models for studying invasion success, Marine Biology 162: 2449-2470