Invasion History

First Non-native North American Tidal Record: 1947
First Non-native West Coast Tidal Record: 1947
First Non-native East/Gulf Coast Tidal Record: 1975

General Invasion History:

The origin of Botryllus schlosseri is currently unknown. In the Northeast Atlantic, it ranges from Norway to the Mediterranean (Hayward and Ryland 1991; Rinkevich et al. 1995; Ben-Shlomo et al. 2001; Lejeusne et al. 2010). On the coast of Asia, it ranges from Peter the Great Bay, Russia to Hong Kong and southern China (Nishikawa 1991; Huang 2001). It is now widespread on temperate coasts on both sides of the North and South Atlantic and Pacific, and oceanic islands such as Bermuda, the Azores, and New Zealand. It is a common component of fouling communities and has likely been spread largely by shipping and aquaculture transfers. A recent genetic analysis indicates that 'B. schlosseri' is a complex of at least five cryptic species (A-E), but only one, clade A, had a widespread distribution in the Northeast and Northwest Atlantic, and Northeast Pacific. The other clades had restricted distributions in Europe (Bock et al. 2012). However, Yund et al. (2015) have identified at least one subclade which appears to be native to the Northwest Atlantic. This subclade is most genetically diverse in that region, and 9 of its 12 haplotypes are unique. The divergence between the prevailing Northwest Atlantic haplotype and those from European waters is too great to be accounted for by evolution (Yund et al. 2015). We cannot exclude the occurrence of European genotypes or cryptic species in East Coast waters, and so we will treat B. schlosseri as a single cryptogenic species. A recent analysis of Clade A (Nydam et al. 2017) suggests a Pacific origin for Clade A, with highest genetic diversity in specimens from the Northeast Pacific. However these populations are introduced (Carlton 1979). Northwest Pacific populations were not included in Nydam et al.'s (2017) study, and could be a possible source of Clade A.

North American Invasion History:

Invasion History on the West Coast:

Botryllus schlosseri was first collected on the West Coast at Mare Island Naval Yard, in San Francisco Bay, California in 1947 (Carlton 1979) and has since spread to the north and south through ship-fouling, and aquaculture transfers. It was reported in San Diego, CA in 1965 (Lambert and Lambert 1998), and reached Humboldt Bay, CA by the 1970s and Coos Bay, OR by 1978 (Boyd et al. 2002, Carlton 1989). In surveys conducted between 1994 and 2003 it was collected in 16 embayments between San Francisco and Mexico (Lambert and Lambert 1998; Wasson et al. 2001; Cohen et al. 2002; Fairey et al. 2002; deRivera et al. 2005). In 2013, it was also reported in Morro Bay, CA (Smithsonian surveys). Further south, it was reported from Ensenada, Mexico in 2000 (Lambert and Lambert 2003) and Bahia San Quintin, Mexico in 2005 (Rodriguez and Ibarra-Obando 2008). It has been found in several areas north of San Francisco Bay including Tomales Bay (in 2001, Fairey et al. 2002), Bodega Harbor (in 1997, Stoner et al. 2002), San Juan Islands, WA (in the late 1960s or early 1970s, Lambert et al. 1987 cited in Lambert and Lambert, 1998), Vancouver Island, British Columbia (prior to 1998; Lambert and Lambert, 1998) and at its current northern limit, Sitka, AK in 2000 (Ruiz et al., unpublished data).  Zwahleb et al. (2022), consider records from Puget Sound before the 1990s to be doubtful, but found this tunicate tp be increasingly abundant after 1999.  Puget Sound populations have a low genetic diversity, indicative of recnet establishment (Zwahleb et al. (2022),

Invasion History on the East Coast:

Recent genetic analysis suggests that Botryllus schlosseri includes genotypes native to the Northwest Atlantic (Yund et al. 2015), although the presence of genotypes or cryptic species from elsewhere in the world cannot be excluded at this time. Consequently, we will treat it as a cryptogenic species in the Gulf of Mexico and and most of the East Coast. It should be noted, though that it has apparently recently expanded its range into Atlantic Canada, most likely by human transport, so that we will treat it as introduced in those bioregions (NA-ET1, NA-S2, NA-S3, comprising the Atlantic coast of Newfoundland and Nova Scotia, and the Gulf of St. Lawrence).

While we consider B. schlosseri cryptogenic in the Gulf of Maine and southward, it apparently a recent invader on the Atlantic coast of the Maritime Provinces, and the Gulf of St. Lawrence. Many of these populations have been identified as having Northwest Atlantic genotypes (Yund et al. 2015), so they may have been introduced from harbors futher south along the East Coast. Botryllus schlosseri is now abundant on the Atlantic coast of Nova Scotia at Lunenburg, and other locations, and in the Bras d'Or Lakes estuary on Cape Breton Island (Locke et al. 200; Sephton et al. 2011). It was collected in the Gulf of St. Lawrence by Hooper (cited by Callahan et al. 2010), on the west coast of Newfoundland in 1975 , but its occurrence in the Gulf was not widely published until it was found on Prince Edward Island in the Gulf of St. Lawrence by 2001 (Locke et al. 2007). In 2011, it was found on floating docks in Conception Bay, on the outer Atlantic coast of Newfoundland, but was removed as a control measure (Robinson 12/8/2011).

Botryllus schlosseri was first recorded in North America in about 1838 simultaneously from both Boston, Massachusetts (at a meeting of January 17, 1838, and thus almost certainly based upon 1837 collections; Couthouy 1838), and New York City (in a publication dated January 1, 1839, and thus based upon material collected no later than 1838) (James T. Carlton, personal communication). It was later described as B. gouldii from New York circa 1870 (Verrill 1871). Later accounts gave wider ranges: Portland, Maine southward to New Jersey. The current northern range includes the Gulf of Maine from Massachusetts Bay to Cobscook Bay, Maine (Yund and Feldgarden 1992; Blezard 1999; Dijkstra et al. 2007; MIT Sea Grant 2009); Passamaquoddy Bay, New Brunswick (LeGresley et al. 2008); the Atlantic coast of Nova Scotia at Lunenburg; the Bras d'Or lakes estuary on Cape Breton Island (Locke et al. 2007); and Placentia Bay, Newfoundland (Callahan et al. 2010). It was collected in the Gulf of St. Lawrence by Hooper, on the west coast of Newfoundland (in 1975, cited by Callahan et al. 2010), but its occurrence in the Gulf was not widely publicized until it was found on Prince Edward Island in the Gulf of St. Lawrence by 2001 (Locke et al. 2007).

It is now found as far south as Florida, but records between New Jersey and Florida are spotty. It has been reported in Beaufort and other areas of North Carolina (Van Name 1945, Sutherland and Karlson 1977, USNM 15481, U.S. Museum of Natural History 2003) and Chesapeake Bay (Gosner 1978). Plough (1978) collected it off Sapelo Island, GA and it was reported by Mook (1983) from the Indian River Lagoon, FL, but was not found in recent late summer surveys (e.g. Ruiz et al. unpublished data), but this species may grow best in winter and spring at lower latitudes.

In Chesapeake Bay, B. schlosseri was not reported in the course of an extensive survey of Chesapeake benthos in 1915-1922 (Cowles 1930) or in shoreline surveys near Norfolk, VA by Ferguson et al. (1949). However, it was reported as fouling the dredge, “Chinook”, in Hampton Roads, VA in 1923 (Visscher 1928). It was listed as a ‘rare species’ in deeper waters of the lower Bay by Wass (1965). A colony was collected at Virginia Institute of Marine Science (Gloucester Point, VA) in 1962 (Calder 1972), and it was common to abundant on piers in Norfolk, VA in 1964-1965 (Calder and Brehmer 1967). 'For nearly twenty years, it was a rare inhabitant of deep waters near the mouth of Chesapeake Bay’, as indicated in the checklist by Wass (1963). During the drought years of the mid 1960’s, B. schlosseri suddenly appeared at Gloucester Point on oyster trays and eventually erupted to cover nearly all tufts of eelgrass (Zostera marina) and widgeongrass (Ruppia maritima) inhabiting shallow waters in the lower York River and Mobjack Bay, VA. In 1973 Andrews reported: ‘It is a fast-growing pernicious pest on trays in the cool months of spring and fall but barely survives hot summers in Virginia...B. schlosseri was not vigorous in the wet year of 1971, but it was still present on trays of oysters in the spring of 1972. After Agnes it disappeared and no trace has been found at any fouling stations. It may not recover its distribution of the 1960's until another series of droughts occurs'. Botryllus schlosseri was abundant on fouling panels in Lynnhaven Bay, VA in 1977 (Otsuka and Dauer 1980) and common on settling plates (1994-95) in all of the major lower Bay regions sampled except Norfolk, VA (15-18ppt), and not at all sites. Botryllus schlosseri is much more common on spring-early summer plates than summer-fall plates (Ruiz et al. unpublished data). The spread of B. schlosseri in the lower Bay region in the 1960’s suggests a recent introduction, either from Europe or from further north along the East Coast. However, this pattern could also represent population fluctuations in response to long-term salinity or temperature changes.

Very few records are known from the Atlantic Coast south of Cape Hatteras, NC. Aside from the Pearse et al. record from Beaufort, NC cited by Van Name (1945), it was reported from Beaufort in 1971 by Sutherland and Karlson (1977) and collected off North Carolina in 1981 (USNM 15481, U.S. Museum of Natural History 2003). Plough (1978) collected it off Sapelo Island, GA. It was reported by Mook (1983) from the Indian River Lagoon, FL, but was not found in later surveys (e.g. Ruiz et al. unpublished data). However, it was not found on SERC plates deployed in summer months (June-Sept) in Charleston, SC and Jacksonville, FL harbors, or the Indian River Lagoon, FL (Ruiz et al. unpublished data). As noted for the Gulf, this species may grow best in winter and spring at lower latitudes.

Invasion History on the Gulf Coast:

Botryllus schlosseri was collected in the Gulf of Mexico in 1887 off Cedar Key, FL (USNMNH 6993, US. National Museum of Natural History 2003; Van Name 1921; Van Name 1945), and was collected from the Tortugas northwest to St. Andrew Sound, FL. Most USNMNH collections were made between December and April, though two were made in June. This temperate species may be most abundant in winter months in the Gulf. Botryllus schlosseri was never found on SERC settling plates deployed in this region during the summer (Ruiz et al. unpublished data).

Invasion History in Hawaii:

Invasion History Elsewhere in the World:

Botryllus schlosseri has been introduced to many remote parts of the world by shipping. It was reported as absent from Bermuda by Van Name (1921), but was listed as being present in Bermuda by Berrill (1932). It was first collected in the Azores Islands in 1971 (Morton and Britton 2000). In the Southern Hemisphere, it is known from Chile (in 1948, Valdivia et al. 2005; Ben-Shlomo et al. 2010), Argentina (in 1964, Orensanz et al. 2002; Ben-Shlomo et al. 2010), South Africa (in 1955, Monniot et al. 2001), Australia (in 1905, Kott 1985), and New Zealand (in 1922, Cranfield et al. 1998).


Description

Botryllus schlosseri is a colonial tunicate that can form colonies as large as 25 mm x 150 mm and up to 2 mm thick. Color is highly variable within and among colonies, and can be yellow, dark purple, red, brown or black. Colonies consist of many radial clusters of 5-20 zooids forming star-shaped systems. Individual zooids can be 1.75 mm - 5 mm long. There are 12-16 oral tentacles around the oral siphon and 7-9 stigmatal rows. The stomach has 8-10 folds and is somewhat spirally deflected with a prominent pyloric caecum. On each side of peribranchial cavity are 1-4 ovaries which are located above prominent testis. Tailed larvae, about 400 µm long, with eight ampullae, may be present in the cavity (Van Name 1945; Nishikawa 1991; Lambert and Lambert 1998).

A recent genetic analysis indicates 'Botryllus schlosseri' is probably a complex of cryptic species. Five clades (A-E) were identified in Europe, but only one of these (A) was found at sites in the Northwest Atlantic and Northeast Pacific. The other clades had restricted distributions on the coasts of Europe (Bock et al. 2012). However, Yund et al. (2015) have found that clade A is comprised of several subclades, at least one (BS2) of which is native to the Northwest Atlantic.


Taxonomy

Taxonomic Tree

Kingdom:   Animalia
Phylum:   Chordata
Subphylum:   Tunicata
Class:   Ascidiacea
Order:   Stolidobranchia
Family:   Styelidae
Genus:   Botryllus
Species:   schlosseri

Synonyms

Alcyonium borlasii (Turton, 1814)
Alcyonium schlosseri (Pallas, 1766)
Aplidium verrucosum (Dalyell, 1839)
Botryllus aurolineatus (Giard, 1872)
Botryllus badius (Alder & Hancock, 1912)
Botryllus bivittatus (Milne-Edwards, 1841)
Botryllus calendula (Giard, 1872)
Botryllus calyculatus (Alder & Hancock, 1912)
Botryllus castaneus (Alder & Hancock, 1848)
Botryllus gemmeus (Savigny, 1816)
Botryllus gouldii (Verrill, 1871)
Botryllus marionis (Giard, 1872)
Botryllus miniatus (Alder & Hancock, 1912)
Botryllus minutus (Savigny, 1816)
Botryllus namei (Hartmeyer and Michaelsen, 1928)
Botryllus polycyclus (Savigny, 1816)
Botryllus pruinosus (Giard, 1872)
Botryllus rubens (Alder and Hancock, 1848)
Botryllus rubigo (Giard, 1872)
Botryllus smaragdus (Milne-Edwards, 1841)
Botryllus stellatus (Gaertner, 1774)
Botryllus violaceus (Milne-Edwards, 1841)
Botryllus violatinctus (Hartmeyer, 1909)
Botryllus virescens (Alder and Hancock, 1848)
Botryllus morio (Giard, 1873)

Potentially Misidentified Species

Botrylloides diegensis
possibly native to northeast Pacific

Botrylloides nigrum
None

Botrylloides violaceus
northwest Pacific species, widely introduced

Botryllus planus
None

Ecology

General:

Life History- A colonial (or compound) tunicate consists of many zooids, bearing most or all of the organs of a solitary tunicate, but modified to varying degrees for colonial life. Colonial tunicates of the genera Botryllus have small zooids, arranged in systems, and fully embedded in a mass of tunic material. Each zooid has an oral siphon and an atrial canal, an opening to a shared cloacal chamber. Water is pumped into the oral siphon, through finely meshed ciliated gills on the pharynx, where phytoplankton and detritus is filtered, and passed on mucus strings to the stomach and intestines. Excess waste is expelled in the outgoing atrial water (Van Name 1945; Barnes 1983).

Colonial tunicates reproduce both asexually, by budding, and sexually, from fertilized eggs developing into larvae. Buds can form from the body wall of the zooid. Colonies vary in size and can range from small clusters of zooids to huge spreading masses. The zooids are hermaphroditic, with eggs and sperm being produced by a single individual. Eggs may be self-fertilized or fertilized by sperm from nearby animals, but many species have a partial block to self-fertilization. Eggs are internally fertilized and embryos are incubated in the atrial cavity. Once mature, they 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 can 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 (Van Name 1945; Barnes 1983). At Millport Scotland, B. schlosseri had only one generation per year, while at Plymouth, England, there were at least two (Millar 1954).

In all part of its native and introduced range, B. schlosseri is more frequently reported from anthropogenic stuctures than from natural surfaces, (Simkanin et al. 2012). Dock floats are especially favored habitats, probably because their motion provides rapid water exchange, and a fresh supply of food-laden water (Glasby 2001). Other colonized man-made structures include pilings, piers, aquaculture structures, and boat hulls (Carman et al. 2010; Davidson et al. 2010; Simkanin et al. 2012). Natural habitats include rocky reefs, bivalve colonies, seaweeds, and eelgrass (White and Orr 2011; Simkanin et al. 2012; Wong and Vercaemer 2012; Carman et al. 2016).

Food:

Phytoplankton

Consumers:

Crabs, snails, urchins, starfish

Competitors:

Other fouling organisms

Trophic Status:

Suspension Feeder

SusFed

Habitats

General HabitatGrass BedNone
General HabitatCoarse Woody DebrisNone
General HabitatOyster ReefNone
General HabitatMarinas & DocksNone
General HabitatVessel HullNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Tidal RangeLow IntertidalNone
Vertical HabitatEpibenthicNone

Life History


Tolerances and Life History Parameters

Minimum Temperature (ºC)-1Field Data- Calder 1966; Ruiz et al. unpublished data; Whitlatch et al. 1995
Maximum Temperature (ºC)30Brunetti 1974; Brunetti et al. 1980; Brunetti et al. 1984. Temperature tolerances vary with acclimation and geographical location. For B. schlosseri, from Lynn Harbor MA, acclimated at 17 C, the median lethal 24 h temperature (LT50) was 29.4 C, but signficantly lower (28.3) for this species from Bodega Bay CA (Sorte et al. 2013).
Minimum Salinity (‰)14Experimental and Field data- Brunetti et al. 1980 (Venice Lagoon); Epelbaum et al. 2009; Ruiz et al. unpublished data; Experimental data, Dijkstra and Harris 2007 (New Hampshire)
Maximum Salinity (‰)44Experimental data- Brunetti et al. 1980
Minimum Duration0Larva, laboratory (Brunetti and Geghi 1982)
Maximum Duration1Larva, laboratory. Typical value, ~50% settlement is 0.04 days (Brunetti and Geghi 1982)
Broad Temperature RangeNoneCold temperate-Subtropical
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

Economic Impacts

Shipping and Industry: The colonial ascidian Botryllus schlosseri is a common fouling organism in temperate harbors and on ships (Visscher 1927; Milkman 1967) and has been called 'a fast-growing pernicious pest' on oyster trays in lower Chesapeake Bay, but is absent or rare on natural oyster beds, presumably because of siltation (Andrews 1973). However, it is an important experimental organism in embryology, genetics, and immunology (Milkman 1967; Rinkevich et al. 1995).

Ecological Impacts

Competition: Bancroft (1903) listed hydroids, bryozoans, and 'worms' as competitors for space with B. schlosseri at Woods Hole, MA and Naples, Italy. Botryllus schlosseri is abundant and occasionally dominant in spring-early summer fouling communities in the lower Chesapeake Bay (Andrews 1973; Ruiz et al. unpublished data). When fouling plates in Lynnhaven Bay, VA were covered with wire mesh to exclude larger predators, B. schlosseri became the dominant fouling organism during December-March (Otsuka and Dauer 1982). In Long Island Sound, NY, recruitment of other fouling organisms, including native Spirorbis spp., was reduced in the vicinity of B. schlosseri colonies (Osman and Whitlatch 1995), and on colonial tunicates including B. schlosseri in Portsmouth Harbor, NH (Dijkstra et al. 2007). However, in Humboldt Bay (CA), fouling plate experiments (Nelson 2009) found that colonial tunicates (Botryllus schlosseri and Botrylloides violaceus), growing in sheets, were able to quickly occupy space on fouling plates, but did not decrease recruitment or species richness. In Langstone Harbor, Hampshire, England, Schmidt and Warner (1986) found that B. schlosseri paired with Trididemnum tenerum or Botrylloides leachii, on plexiglass panels resulted in stand-offs, colonies touching without overgrowth. However, B. schlosseri and the other species were always overgrown when paired with Diplosoma listerianum. In experiments in Wells Harbor, Maine, Botryllus schlosseri grew rapidly on some artificial substrates (rubber and metal), outcompeting native organisms, but grew more slowly on natural substrates (shell, marble, slate) (Tyrell and Byers 2007). In Bodega Harbor, California, Botryllus schlosseri was one of the eight most abundant fouling organisms both in 1969-1971 and in 2005-2009 (Sorte and Stachowicz 2011). Spawning periods and abundance of species in this group appeared to be favored by a 1?C increase in average temperatures at this site over a 30-year period (Sorte and Stachowicz 2011).

Botryllus schlosseri, Botrylloides violaceus, and a native sponge Halichrondria panicea were found to adversely affect native eelgrass Zostera marina in southeastern Nova Scotia by fouling the leaves of the grass, and reducing the availability of light. Fouling increased the mortality of the plants (Wong and Vercaemer 2012). Negative effects on eelgrass are likely to be widespread.

Habitat Change:

Based on experiments on fouling of eelgrass plants in Nova Scotia, the spread of Botrylloides violaceus and Botryllus schlosseri is likely to have an adverse impact on eelgrass beds, increasing mortality of the plants and decreasing their productivity (Wong and Vercaemer 2012).


Regional Impacts

NA-ET3Cape Cod to Cape HatterasEconomic ImpactFisheries
Botryllus schlosseri was 'a fast-growing pernicious pest' on oyster trays in lower Chesapeake Bay, but is absent or rare on natural oyster beds, presumably because of siltation (Andrews 1973). Botryllus schlosseri was found fouling aqaculture gear at nine sites, and cultured Bay Scallops (Argopecten irradians) at one site, of 26 aquaculture sites surveyed on Marthas Vineyard (Carman et al. 2010). This tunicate was also reported at aquaculture sites in New York State (Carman et al. 2010).
M130Chesapeake BayEconomic ImpactFisheries
Botryllus schlosseri was 'a fast-growing pernicious pest' on oyster trays in lower Chesapeake Bay, but is absent or rare on natural oyster beds, presumably because of siltation (Andrews 1973).
NA-ET3Cape Cod to Cape HatterasEconomic ImpactShipping/Boating
Botryllus schlosseri (Golden Star Tunicate) was a common fouling organism in a survey of ship fouling among ships in northeastern US ports (Visscher 1927).
NA-ET3Cape Cod to Cape HatterasEcological ImpactCompetition
Bancroft (1903) listed hydroids, bryozoans, and 'worms' as competitors for space with B. schlosseri at Woods Hole and Naples. B. schlosseri is abundant and occasionally dominant in spring-early summer fouling communities in lower Chesapeake Bay (Andrews 1973; Ruiz et al. unpublished data). When fouling plates in Lynnhaven Bay were covered with wire mesh to exclude larger predators, B. schlosseri became dominant during December-March (Otsuka and Dauer 1982). Recruitment of other fouling organisms including native Spirorbis spp. was reduced in the vicinity of B. schlosseri colonies in Long Island Sound (Osman and Whitlatch 1995).
M010Buzzards BayEcological ImpactCompetition
Bancroft (1903) listed hydroids, bryozoans, and 'worms' as competitors for space with B. schlosseri at Woods Hole and Naples.
M130Chesapeake BayEcological ImpactCompetition
B. schlosseri is abundant and occasionally dominant in spring-early summer fouling communities in the lower Bay (Andrews 1973; Ruiz et al. unpublished data). When fouling plates in Lynnhaven Bay were covered with wire mesh to exclude larger predators, B. schlosseri became dominant during December-March (Otsuka and Dauer 1982).
M040Long Island SoundEcological ImpactCompetition
Recruitment of other fouling organisms including native Spirorbis spp. was reduced in the vicinity of B. schlosseri colonies in Long Island Sound (Osman and Whitlatch 1995). Recruitment of other introduced fouling organisms (Diplosoma listerianum; Botrylloides spp.) was reduced in the vicinity of B. schlosseri colonies in Long Island Sound (Osman and Whitlatch 1995).
NEA-IINoneEcological ImpactCompetition
In Langstone Harbor, Hampshire, England, Schmidt and Warner (1986) found that B. schlosseri paired with Trididemnum tenerurum or Botrylloides leachii, on Plexiglass panels resulted in stand-offs, colonies touching without overgrowth. However, B. schlosseri and the other species were always overgrown when paired with Diplosoma listerianum.
NA-ET2Bay of Fundy to Cape CodEcological ImpactCompetition
Recruitment of fouling organisms was reduced on colonial organisms incluiding B. schlosseri in Portsmouth Harbor, NH (Dijkstra et al. 2007). In experiments in Wells Harbor, Maine, Botryllus schlosseri grew rapidly on some artficial substrates (rubber and metal), outcompeting native organisms, but grew more slowly on natural substrates (shell, marble, slate) (Tyrell and Byers 2007).
N120Wells BayEcological ImpactCompetition
In experiments in Wells Harbor, Maine, Botryllus schlosseri grew rapidly on some artficial substrates (rubber and metal), outcompeting native organisms, but grew more slowly on natural substrates (shell, marble, slate) (Tyrell and Byers 2007).
NEP-VIPt. Conception to Southern Baja CaliforniaEcological ImpactCompetition
Large monospecific colonies of Botyrllus schlosseri were noted at King Harbor and Port Hueneme, indicating strong competition (Lambert and Lambert 2003).
P060Santa Monica BayEcological ImpactCompetition
Large monospecific colonies of Botyrllus schlosseri were noted at King Harbor, indicating strong competition (Lambert and Lambert 2003).
P062_CDA_P062 (Calleguas)Ecological ImpactCompetition
Large monospecific colonies of Botyrllus schlosseri were noted at King Harbor and Port Hueneme, indicating strong competition (Lambert and Lambert 2003).
NEP-IVPuget Sound to Northern CaliforniaEcological ImpactCompetition
In fouling plate experiments in Humboldt Bay, Nelson (2009) found that colonial tunicates (Botryllus schlosseri and Botrylloides violaceus), growing in sheets, were able to quickly occupy space on fouling plates, but did not decrease recruitment or species richness.
P130Humboldt BayEcological ImpactCompetition
In fouling plate experiments in Humboldt Bay, Nelson (2009) found that colonial tunicates (Botryllus schlosseri and Botrylloides violaceus), growing in sheets, were able to quickly occupy space on fouling plates, but did not decrease recruitment or species richness.
N195_CDA_N195 (Cape Cod)Economic ImpactFisheries
Botryllus schlosseri was found fouling aqaculture gear at nine sites, and cultured Bay Scallops (Argopecten irradians) at one site, of 26 aquaculture sites surveyed on Marthas Vineyard (Carman et al. 2010).
NA-ET2Bay of Fundy to Cape CodEconomic ImpactFisheries
Botryllus schlosseri was reportedly fouling aquaculture sites in Maine (Carman et al. 2010).
NA-S3NoneEconomic ImpactFisheries
Botrylloides violaceus was reportedly fouling mussel (Mytilus edulis a)quaculture sites in Prince Edward Island (Carman et al. 2010; Arens et al. 2011). Fouling by B. schlosseri did not affect cultured mussels through competion for phytoplankton, unlike Ciona intestinalis or Styela clava (Comeau et al. 2015). However, fouling by Botryllus schlosseri and Botrylloides violaceus had little effect on mussel growth and production (Arens et al. 2011). High-pressure water spraying reduced fouling of mussels. However, further studies showed that frequent spraying could affect mussel production, and could increase the spread of B. schlosseri through fragmentation (Paetzold et al. 2012).
P112_CDA_P112 (Bodega Bay)Ecological ImpactCompetition
Botryllus sclosseri was one of the eight most abundant species in Bodega Harbor both in 1969-1971 and in 2006. Spawning periods and abundance of species in this group appeared to be favored by a 1⁰C increase in average temperatures at this site over a 30-year period (Sorte and Stachowicz 2011).
NEP-VNorthern California to Mid Channel IslandsEcological ImpactCompetition
Botryllus sclosseri was one of the eight most abundant species in Bodega Harbor both in 1969-1971 and in 2006. Spawning periods and abundance of species in this group appeared to be favored by a 1⁰C increase in average temperatures at this site over a 30-year period (Sorte and Stachowicz 2011). Heavy recruitment of B. schlosseri can affect subsequent community development. When recruitment was artifically enhanced (at Santa Cruz), communities remained dominated by B. schlosseri for several months, compared to controls (Sams and Keough 2012).
WA-IVNoneEcological ImpactHabitat Change
Fouling of the eelgrass Zostera capensis in Langebaans Lagoon by B. schlosseri is a concern, (Griffiths et al. 2009), but the present extent of the problem is unclear.
N130Great BayEcological ImpactCompetition
Recruitment of fouling organisms was reduced on colonial organisms incluiding B. schlosseri in Portsmouth Harbor NH (Dijkstra et al. 2007).
NA-ET1Gulf of St. Lawrence to Bay of FundyEcological ImpactCompetition
The native eelgrass Zostera marina was adversely affected by fouling by Botryllus schlosseri. However, fouling by a native sponge, Halichondria panicea, produced a greater reduction of chlorophyll than Botryllus schlosseri or any of the morphs of B. violaceus (Wong and Vercaemer 2012).
NA-ET1Gulf of St. Lawrence to Bay of FundyEcological ImpactHabitat Change
The spread of introduced fouling organisms (B. schlosseri and B. violaceus) to eelgrass beds is considered likely to reduce the primary productivity and the extent of grass beds in Nova Scotia waters (Wong and Vercaemer 2012).
AUS-VIIINoneEcological ImpactCompetition
Heavy recruitment of B. schlosseri can affect subsequent community development. However, impacts varied by site and season (Sams and Keough 2012).
P080Monterey BayEcological ImpactCompetition
Heavy recruitment of B. schlosseri can affect subsequent community development. When recruitment was artifically enhanced (at Santa Cruz), communities remained dominated by B. schloserris for several months, compared to controls.(Sams and Keough 2012).
P080Monterey BayEcological ImpactHabitat Change
Fouling plates (at Santa Cruz) with enhanced B. schlosseri recruitment also had increased densites of Balanus crenatus and an unidentified sponge (Sams and Keoguh 2012).
NEP-VNorthern California to Mid Channel IslandsEcological ImpactHabitat Change
i>B. schlosseri recruitment also had increased densites of Balanus crenatus and an unidentified sponge (Sams and Keoguh 2012).
N070Damariscotta RiverEconomic ImpactFisheries
Botrylloides violaceus was reportedly fouling aquaculture sites on the Damariscotta River( Bullard et al. 2015)
NEP-IVPuget Sound to Northern CaliforniaEcological ImpactFood/Prey
In feeding trials, the native crabs Hemigrapsus oregonensis, the flatworm Eurylepta leoparda and the nudibranch Hermissenda crassicornis fed heavily on the native tuinicate Distaplia occidentalis but at much lower rates on the non-native Botryllus schlosseri and Botrylloides violaceus) (Kincaid and de Rivera 2020).
P170Coos BayEcological ImpactFood/Prey
In feeding trials, the native crabs Hemigrapsus oregonensis, the flatworm Eurylepta leoparda and the nudibranch Hermissenda crassicornis fed heavily on the native tuinicate Distaplia occidentalis but at much lower rates on the non-native Botryllus schlosseri and Botrylloides violaceus) (Kincaid and de Rivera 2020).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NA-ET2 Bay of Fundy to Cape Cod 1838 Crypto Estab
NA-ET3 Cape Cod to Cape Hatteras 1871 Crypto Estab
NEP-IV Puget Sound to Northern California 1972 Def Estab
NEP-V Northern California to Mid Channel Islands 1947 Def Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 1887 Crypto Estab
NEP-VI Pt. Conception to Southern Baja California 1965 Def Estab
NEP-III Alaskan panhandle to N. of Puget Sound 1998 Def Estab
AUS-IV None 1985 Def Estab
AUS-VIII None 1977 Def Estab
AUS-X None 1995 Def Estab
AUS-VII None 1955 Def Estab
NZ-IV None 1922 Def Estab
NZ-VI None 1944 Def Estab
AR-V None 0 Crypto Estab
NEA-II None 0 Crypto Estab
NEA-III None 1776 Crypto Estab
NEA-IV None 0 Crypto Estab
MED-II None 0 Crypto Estab
MED-III None 0 Crypto Estab
MED-V None 0 Crypto Estab
MED-IX None 0 Crypto Estab
NWP-4a None 1941 Crypto Estab
MED-VII None 0 Crypto Estab
NWP-4b None 1951 Crypto Estab
NWP-3a None 1991 Crypto Estab
NWP-2 None 2001 Crypto Estab
AUS-III None 1985 Def Estab
AUS-VI None 1985 Def Estab
AUS-XIII None 1985 Def Estab
AUS-XII None 1985 Def Estab
AUS-V None 1985 Def Estab
MED-VI None 0 Crypto Estab
NEA-VI None 1971 Def Estab
CAR-VII Cape Hatteras to Mid-East Florida 1971 Crypto Estab
MED-I None 0 Crypto Estab
WA-IV None 2001 Def Estab
WA-V None 1946 Def Estab
NA-S3 None 1975 Def Estab
NWP-3b None 1953 Crypto Estab
SEP-C None 1948 Def Estab
P270 Willapa Bay 2000 Def Estab
M010 Buzzards Bay 1871 Crypto Estab
M020 Narragansett Bay 1880 Crypto Estab
M040 Long Island Sound 1874 Crypto Estab
M080 New Jersey Inland Bays 1929 Crypto Estab
M130 Chesapeake Bay 1923 Crypto Estab
S190 Indian River 1981 Crypto Estab
P050 San Pedro Bay 1994 Def Estab
P170 Coos Bay 1978 Def Estab
N130 Great Bay 1979 Crypto Estab
P180 Umpqua River 1986 Def Estab
P130 Humboldt Bay 1972 Def Estab
M060 Hudson River/Raritan Bay 1871 Crypto Estab
P020 San Diego Bay 1965 Def Estab
NEA-V None 0 Crypto Estab
AUS-XV None 1985 Def Estab
AUS-IX None 1985 Def Estab
P030 Mission Bay 1994 Def Estab
P023 _CDA_P023 (San Louis Rey-Escondido) 1995 Def Estab
P040 Newport Bay 1997 Def Estab
P060 Santa Monica Bay 1994 Def Estab
P062 _CDA_P062 (Calleguas) 1995 Def Estab
P064 _CDA_P064 (Ventura) 1995 Def Estab
P065 _CDA_P065 (Santa Barbara Channel) 1996 Def Estab
P058 _CDA_P058 (San Pedro Channel Islands) 2001 Def Estab
P080 Monterey Bay 1984 Def Estab
P086 _CDA_P086 (San Francisco Coastal South) 1994 Def Estab
P090 San Francisco Bay 1947 Def Estab
P110 Tomales Bay 2000 Def Estab
P112 _CDA_P112 (Bodega Bay) 1969 Def Estab
P286 _CDA_P286 (Crescent-Hoko) 2003 Def Estab
P290 Puget Sound 1998 Def Estab
G100 Apalachicola Bay 1955 Crypto Estab
G110 St. Andrew Bay 1995 Crypto Estab
G080 Suwannee River 1887 Crypto Estab
G060 Sarasota Bay 1952 Crypto Estab
G050 Charlotte Harbor 1913 Crypto Estab
G030 North Ten Thousand Islands 1982 Crypto Estab
G020 South Ten Thousand Islands 1982 Crypto Estab
S030 Bogue Sound 1971 Crypto Estab
S056 _CDA_S056 (Northeast Cape Fear) 1981 Crypto Estab
M120 Chincoteague Bay 1994 Def Estab
M070 Barnegat Bay 1938 Crypto Estab
M030 Gardiners Bay 2003 Crypto Estab
M026 _CDA_M026 (Pawcatuck-Wood) 1873 Crypto Estab
N195 _CDA_N195 (Cape Cod) 1871 Crypto Estab
N180 Cape Cod Bay 2000 Crypto Estab
N170 Massachusetts Bay 1838 Crypto Estab
N140 Hampton Harbor 2003 Crypto Estab
N100 Casco Bay 1945 Crypto Estab
N010 Passamaquoddy Bay 2004 Crypto Estab
NA-ET4 Bermuda 1932 Def Estab
N190 Waquoit Bay 1871 Crypto Estab
N185 _CDA_N185 (Cape Cod) 2003 Crypto Estab
N070 Damariscotta River 1992 Crypto Estab
N050 Penobscot Bay 2007 Crypto Estab
NA-ET1 Gulf of St. Lawrence to Bay of Fundy 2006 Def Estab
P027 _CDA_P027 (Aliso-San Onofre) 1994 Def Estab
P093 _CDA_P093 (San Pablo Bay) 1947 Def Estab
G090 Apalachee Bay 1978 Crypto Estab
S140 St. Catherines/Sapelo Sounds 1978 Crypto Estab
MED-IV None 0 Crypto Estab
N120 Wells Bay 2004 Crypto Estab
CIO-II None 2008 Def Estab
RS-3 None 2003 Def Estab
SA-I None 1962 Def Estab
SEP-A' None 2008 Def Estab
N165 _CDA_N165 (Charles) 2009 Crypto Estab
N060 Muscongus Bay 2009 Crypto Estab
N040 Blue Hill Bay 2009 Crypto Estab
NA-S2 None 2011 Def Unk
NEP-VII None 2012 Def Estab
WA-I None 2007 Def Estab
M100 Delaware Inland Bays 2013 Crypto Estab
P288 _CDA_P288 (Dungeness-Elwha) 2012 Def Estab
N110 Saco Bay 0 Crypto Estab
M050 Great South Bay 2013 Crypto Estab
P070 Morro Bay 2013 Def Estab
NWP-5 None 0 Crypto Estab
B-II None 0 Crypto Estab
B-I None 0 Crypto Estab
AR-IV None 2011 Def Estab
SA-III None 2002 Def Unk
M023 _CDA_M023 (Narragansett) 2003 Crypto Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude
767337 Ruiz et al., 2015 2012 2012-08-14 Spud Point North, Bodega Bay, California, USA Def 38.3301 -123.0572
767347 Ruiz et al., 2015 2012 2012-08-21 Lucas/Tides, Bodega Bay, California, USA Def 38.3284 -123.0445
767355 Ruiz et al., 2015 2012 2012-08-21 Porto Bodega, Bodega Bay, California, USA Def 38.3333 -123.0525
767367 Ruiz et al., 2015 2012 2012-08-22 Tomales-Marshall, Bodega Bay, California, USA Def 38.1514 -122.8888
767378 Ruiz et al., 2015 2012 2012-08-21 Tomales-Nick's Cove, Bodega Bay, California, USA Def 38.1980 -122.9222
767398 Ruiz et al., 2015 2012 2012-08-16 Tomales-SNPS, Bodega Bay, California, USA Def 38.1359 -122.8719
767410 Ruiz et al., 2015 2012 2012-08-17 Tomales- Shell Beach, Bodega Bay, California, USA Def 38.1163 -122.8713
767424 Ruiz et al., 2015 2013 2013-07-19 SeaWorld Marina, Mission Bay, CA, California, USA Def 32.7676 -117.2314
767442 Ruiz et al., 2015 2013 2013-07-23 Marina Village, Mission Bay, CA, California, USA Def 32.7605 -117.2364
767459 Ruiz et al., 2015 2013 2013-07-29 Mission Bay Yacht Club, Mission Bay, CA, California, USA Def 32.7778 -117.2485
767479 Ruiz et al., 2015 2013 2013-08-04 Bahia Resort Marina, Mission Bay, CA, California, USA Def 32.7731 -117.2478
767492 Ruiz et al., 2015 2013 2013-07-31 Campland on the Bay, Mission Bay, CA, California, USA Def 32.7936 -117.2234
767510 Ruiz et al., 2015 2013 2013-08-01 Hyatt Resort Marina, Mission Bay, CA, California, USA Def 32.7634 -117.2397
767525 Ruiz et al., 2015 2013 2013-08-03 Mission Bay Sport Center, Mission Bay, CA, California, USA Def 32.7857 -117.2495
767539 Ruiz et al., 2015 2013 2013-07-30 Hilton Resort Docks, Mission Bay, CA, California, USA Def 32.7791 -117.2128
767554 Ruiz et al., 2015 2013 2013-08-02 The Dana Marina, Mission Bay, CA, California, USA Def 32.7671 -117.2363
767565 Ruiz et al., 2015 2013 2013-08-05 Paradise Point Resort, Mission Bay, CA, California, USA Def 32.7730 -117.2406
767644 Ruiz et al., 2015 2013 2013-09-03 State Park Marina, Morro Bay, CA, California, USA Def 35.3459 -120.8423
767679 Ruiz et al., 2015 2013 2013-07-17 Naval Station San Diego, San Diego Bay, CA, California, USA Def 32.6867 -117.1333
767693 Ruiz et al., 2015 2013 2013-07-24 NAB ACU-1 Docks, San Diego Bay, CA, California, USA Def 32.6786 -117.1615
767717 Ruiz et al., 2015 2013 2013-07-21 Cabrillo Isle Marina, San Diego Bay, CA, California, USA Def 32.7272 -117.1995
767745 Ruiz et al., 2015 2013 2013-07-18 NAB Fiddlers Cove, San Diego Bay, CA, California, USA Def 32.6524 -117.1486
767762 Ruiz et al., 2015 2013 2013-07-26 Pier 32 Marina, San Diego Bay, CA, California, USA Def 32.6516 -117.1077
767772 Ruiz et al., 2015 2013 2013-07-20 Chula Vista Marina, San Diego Bay, CA, California, USA Def 32.6252 -117.1036
767785 Ruiz et al., 2015 2013 2013-07-28 Marriott Marquis and Marina, San Diego Bay, CA, California, USA Def 32.7059 -117.1655
767803 Ruiz et al., 2015 2011 2011-09-15 Richmond Marina Bay Yacht Harbor, San Francisco Bay, CA, California, USA Def 37.9117 -122.3494
767814 Ruiz et al., 2015 2011 2012-09-20 San Leandro Marina, San Francisco Bay, CA, California, USA Def 37.6979 -122.1912
767824 Ruiz et al., 2015 2011 2011-09-20 San Francisco Marina, San Francisco Bay, CA, California, USA Def 37.8067 -122.4432
767836 Ruiz et al., 2015 2011 2011-09-14 Coyote Point Marina, San Francisco Bay, CA, California, USA Def 37.5880 -122.3160
767846 Ruiz et al., 2015 2011 2011-09-16 Loch Lomond Marina, San Francisco Bay, CA, California, USA Def 37.9724 -122.4796
767857 Ruiz et al., 2015 2011 2011-09-13 Oyster Point Marina, San Francisco Bay, CA, California, USA Def 37.6725 -122.3864
767871 Ruiz et al., 2015 2011 2011-09-13 Redwood City Marina, San Francisco Bay, CA, California, USA Def 37.8046 -122.3985
767881 Ruiz et al., 2015 2011 2012-09-15 Berkeley Marina, San Francisco Bay, CA, California, USA Def 37.8758 -122.3181
767891 Ruiz et al., 2015 2011 2012-09-19 Sausalito Marine Harbor, San Francisco Bay, CA, California, USA Def 37.8609 -122.4853
767908 Ruiz et al., 2015 2011 2011-09-21 South Beach Harbor, San Francisco Bay, CA, California, USA Def 37.7797 -122.3871
767921 Ruiz et al., 2015 2011 2011-09-20 Jack London Square Marina, San Francisco Bay, CA, California, USA Def 37.7947 -122.2822
767933 Ruiz et al., 2015 2011 2011-09-22 Ballena Isle Marina, San Francisco Bay, CA, California, USA Def 37.7676 -122.2869
767952 Ruiz et al., 2015 2011 2011-09-12 Paradise Cay Yacht Harbor, San Francisco Bay, CA, California, USA Def 37.9156 -122.4769
767987 Ruiz et al., 2015 2012 2012-08-24 Richmond Marina Bay Yacht Harbor, San Francisco Bay, CA, California, USA Def 37.9134 -122.3523
768007 Ruiz et al., 2015 2012 2012-08-23 Sausalito Marine Harbor, San Francisco Bay, CA, California, USA Def 37.8609 -122.4853
768022 Ruiz et al., 2015 2012 2012-08-28 San Francisco Marina, San Francisco Bay, CA, California, USA Def 37.8071 -122.4341
768041 Ruiz et al., 2015 2012 2012-08-27 Port of San Francisco Pier 31, San Francisco Bay, CA, California, USA Def 37.8078 -122.4060
768063 Ruiz et al., 2015 2012 2012-09-11 Ballena Isle Marina, San Francisco Bay, CA, California, USA Def 37.7676 -122.2869
768086 Ruiz et al., 2015 2012 2012-08-30 Oyster Point Marina, San Francisco Bay, CA, California, USA Def 37.6633 -122.3817
768110 Ruiz et al., 2015 2012 2012-08-29 Coyote Point Marina, San Francisco Bay, CA, California, USA Def 37.5877 -122.3174
768132 Ruiz et al., 2015 2012 2012-09-04 Redwood City Marina, San Francisco Bay, CA, California, USA Def 37.5023 -122.2130
768155 Ruiz et al., 2015 2012 2012-09-06 Loch Lomond Marina, San Francisco Bay, CA, California, USA Def 37.9736 -122.4802
768176 Ruiz et al., 2015 2012 2012-09-05 Port of Oakland, San Francisco Bay, CA, California, USA Def 37.7987 -122.3228
768196 Ruiz et al., 2015 2012 2012-09-07 Jack London Square Marina, San Francisco Bay, CA, California, USA Def 37.7940 -122.2787
768236 Ruiz et al., 2015 2012 2012-09-13 San Leandro Marina, San Francisco Bay, CA, California, USA Def 37.6962 -122.1919
768252 Ruiz et al., 2015 2012 2012-09-12 Emeryville, San Francisco Bay, CA, California, USA Def 37.8396 -122.3133
768278 Ruiz et al., 2015 2013 2013-08-15 Ballena Isle Marina, San Francisco Bay, CA, California, USA Def 37.7656 -122.2858
768298 Ruiz et al., 2015 2013 2013-08-20 Coyote Point Marina, San Francisco Bay, CA, California, USA Def 37.5877 -122.3163
768317 Ruiz et al., 2015 2013 2013-08-22 Jack London Square Marina, San Francisco Bay, CA, California, USA Def 37.7926 -122.2746
768340 Ruiz et al., 2015 2013 2013-08-23 Loch Lomond Marina, San Francisco Bay, CA, California, USA Def 37.9723 -122.4829
768358 Ruiz et al., 2015 2013 2013-08-13 Oyster Point Marina, San Francisco Bay, CA, California, USA Def 37.6639 -122.3821
768382 Ruiz et al., 2015 2013 2013-08-14 Redwood City Marina, San Francisco Bay, CA, California, USA Def 37.5024 -122.2134
768402 Ruiz et al., 2015 2013 2013-08-19 Richmond Marina Bay Yacht Harbor, San Francisco Bay, CA, California, USA Def 37.9138 -122.3522
768419 Ruiz et al., 2015 2013 2013-08-12 San Francisco Marina, San Francisco Bay, CA, California, USA Def 37.8078 -122.4354
768450 Ruiz et al., 2015 2013 2013-08-16 Sausalito Marine Harbor, San Francisco Bay, CA, California, USA Def 37.8611 -122.4851

References

Aarnio, Katri; Törnroos, Anna; Björklund, Charlotta; Bonsdorff, Erik (2015) Food web positioning of a recent coloniser: the North American Harris mud crab Rhithropanopeus harrisii (Gould, 1841) in the northern Baltic Sea, Aquaitc Invasions 10: In press

Abbott, Donald P.; Lambert, Charles C.; Lambert, Gretchen; Newberry, A. Todd (2007) The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon (4th Edtion), University of California Press, Berkeley, CA. Pp. 949-964

Aldred, Nick; Clare, Anthony S. (2014) Mini-review: Impact and dynamics of surface fouling by solitary and compound ascidians, Biofouling 30(3): 259-270

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

Altman, Safra; Whitlatch, Robert B. (2007) Effects of small-scale disturbance on invasion success in marine communities., Journal of Experimental Marine Biology and Ecology 342: 15-29

Andrews, Jay D. (1973) Effect of tropical storm Agnes on epifaunal invertebrates in Virginia estuaries, Chesapeake Science 14(4): 223-234

Arens, Collin J.; Paetzold, S. Christine; Ramsay, Aaron; Davidson, Jeff (2011) Pressurized seawater as an antifouling treatment against the colonial tunicates Botrylloides violaceus and Botryllus schlosseri in mussel aquaculture, Aquatic Invasions 6(4): corrected proof

Bancroft, Frank W. (1903) Variation and fusion of colonies in compound ascidians, Proceedings of the California Academy of Sciences, Third Series 3(5): 137-185

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

Bell, Richard; Buchsbaum, Robert; Chandler, Mark (2005) Inventory of intertidal marine habitats, Boston Harbor Islands National Park area, Northeastern Naturalist 12(Special Isuue 3): 169-200

Ben-Shlomo, R.; Douek, J.; Rinkevich, B. (2001) Heterozygote deficiency and chimerism in remote populations of a colonial ascidian from New Zealand., Marine Ecology Progress Series 209: 109-117

Ben-Shlomo, Rachel; Reem, Eitan; Douek, Jacob; Rinkevich, Baruch (2010) Population genetics of the invasive ascidian Botryllus schlosseri from South American coasts, Marine Ecology Progress Series 412: 85-92

Ben-Shlomo,Rachel; Paz, Guy; Rinkevich, Baruch (2006) Postglacial-period and recent invasions shape the population genetics of botryllid ascidians along European Atlantic coasts., Ecosystems 9: 1118-1127

Bernier, Renée Y.; Locke, Andrea; Hanson, John Mark (2007) Lobsters and crabs as potential vectors for tunicate dispersal in the southern Gulf of St. Lawrence, Canada., Memoirs of the Museum of Victoria 4(1): 105-110

Berrill, N. J. (1932) Ascidians of the Bermudas, Biological Bulletin 62(1): 77-88

Blezard, David J. (1999) <missing title>, M.S. Thesis, University of New Hampshire, Durham, New Hampshire. Pp. <missing location>

Bock, Dan G.; MacIsaac, Hugh J.; Cristescu, Melania E. (2012) Multilocus genetic analyses differentiate between widespread and spatially restricted cryptic species in a model ascidian, Proceedings of the Royal Society of London B 279: 2377-2385

Boudreaux, Michelle L.; Stiner, Jennifer L.; Walters, Linda J. (2006) Biodiversity of sessile and motile macrofauna on intertidal oyster reefs in Mosquito Lagoon, Florida., Journal of Shellfish Research 25(3): 1079-1089

Boyd, Heather C., Brown, Stephen K., Harp, James A., Weissman, Irving L. (1986) Growth and sexual maturation of laboratory-cultured Monterey Botryllus schlosseri, Biological Bulletin 170: 91-109

Boyd, Heather C.; Weissman, Irving L.; Saito, Yasunori (1990) Morphological and genetic verification that Monterey Botryllus and Woods Hole Botryllus are the same species, Biological Bulletin 178: 239-250

Boyd, Milton J.; Mulligan, Tim J; Shaughnessy, Frank J. (2002) <missing title>, California Department of Fish and Game, Sacramento. Pp. 1-118

Breton, Gerard; Girard, Annie; Lagardere, Jean-Paul (1995) Especes animales benthiques des bassins du port du Havre (Normandie, France) rares, peu connues ou nouvelles pour la region., Bulletin Trimestrial de la Societe geologique de Normandie 82(2): 7-28

Brewin, Beryl L. (1946) Ascidians in the vicinity of the Portobello Marine Station, Transactions of the Royal Society of New Zealand 76(2): 87-81

Brewin, Beryl L. (1950) Ascidians of New Zealand Part IV. Ascidians in the vicinity of Christchurch, Transactions of the Royal Society of New Zealand 78(2): 344-353

Brunetti, R.; Beghi, L.; Bressan, M.; Marin, M. G. (1980) Combined effects of temperature and salinity on colonies of Botryllus schlosseri and Botrylloides leachi (Ascidiacea) from the Venetian Lagoon, Marine Ecology Progress Series 2: 303-314

Brunetti, Riccardo (1974) Observations on the life cycle of Botryllus schlosseri (Pallas) (Ascidiacea) in the Ventian Lagoon, Bollettino di Zoologia 41: 225-251

Brunetti, Riccardo; Geghi, Luigi (1982) Larval ecology of Botryllus schlosseri (Ascidiacea). A preliminary investigation, Naturalista Siciliano 6: 126-129

Brunetti, Riccardo; Griggio, Francesca; Mastrototaro, Francesco; 3, F Gasparini, Fabio; Gissi, Carmela (2020) Toward a resolution of the cosmopolitan Botryllus schlosseri species complex (Ascidiacea, Styelidae):, Zoological Journal of the Linnean Society 190: 1175-1192

Brunnetti, Riccardo; Marin, M. Gabriella, Bresson; Monica (1984) Combined effects of temperature and salinity on sexual reproduction and colonial growth of Botryllus schlosseri (Tunicata)., Bollettino di Zoologia 51: 405-411

Bullard, Stephan G.; Whitlatch, Robert B.; Osman, Richard W. (2004) Checking the landing zone: do invertebrate larvae avoid settling near superior spatial competitors?, Marine Ecological Progress Series 280: 239-247

Calder, Dale R.; Brehmer, Morris L. (1967) Seasonal occurrence of epifauna on test panels in Hampton Roads, Virginia., International Journal of Oceanology and Limnology 1(3): 149-164

Calder, Dale Ralph (1966) <missing title>, M.S. Thesis, College of William and Mary, Williamsburg, VA. Pp. <missing location>

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

Callahan, Ashley G.; Deibel, Don; McKenzie, Cynthia H.; Hall, Jennifer R.; Rise, Matthew L. (2010) Survey of harbours in Newfoundland for indigenous and non-indigenous ascidians and an analysis of their cytochrome c oxidase I gene sequences, Aquatic Invasions 5(1): corrected proof

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

Cardigos, F. and 5 authors (2006) Non-indigenous marine species of the Azores., Helgoland Journal of Marine Research 60: 160-169

Carlton, James T. (1979) History, biogeography, and ecology of the introduced marine and estuarine invertebrates of the Pacific Coast of North America., Ph.D. dissertation, University of California, Davis. Pp. 1-904

Carlton, James T. (1989) <missing title>, <missing publisher>, <missing place>. Pp. <missing location>

Carman, M. R.; Morris, J. A.; Karney, R. C.; Grunden, D. W. (2010) An initial assessment of native and invasive tunicates in shellfish aquaculture of the North American east coast, Journal of Applied Ichthyology 26(Suppl. 2): 8-11

Carman, Mary R. and 13 authors (2016) Distribution and diversity of tunicates utilizing eelgrass as substrate in the western North Atlantic between 39° and 47° north latitude (New Jersey to Newfoundland), Management of Biological Invasions Published online: <missing location>

Carman, Mary R.; Bullard, S.G.; Donnelly, J.P. (2007) Water quality, nitrogen pollution, and ascidian diversity in coastal waters of southern Massachusetts, USA., Journal of Experimental Marine Biology and Ecology 342: 175-178

Carman, Mary R.; Hoagland, K. Elaine; Green-Beach, Emma; Grunden, David W. (2009) Tunicate faunas of two North Atlantic-New England islands: Martha’s Vineyard, Massachusetts and Block Island, Rhode Island., Aquatic Invasions 4(1): 65-70

Castilla, Juan C. and 10 authors (2005) Down under the southeastern Pacific: marine non-indigenous species in Chile., Biological Invasions 7: 213-232

Chadwick-Furman; Nanette E.; Weissman, Irving L. (1995) Life histories and senescence of Botryllus schlosseri (Chordata, Ascidiacea) in Monterey Bay, Biological Bulletin 189: 36-41

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>

Cockrell, Marcy L.; Sorte, Cascade J.B. (2013) Predicting climate-induced changes in population dynamics of invasive species in a marine epibenthic community, Journal of Experimental Marine Biology and Ecology 440: 42-48

2005 Exotics Guide. San Francisco Estuary Institute, Oakland, CA, www.exoticsguide.org

Cohen, Andrew N. and 10 authors (2005) <missing title>, San Francisco Estuary Institute, Oakland CA. Pp. <missing location>

Cohen, Andrew N. and 12 authors (2002) Project report for the Southern California exotics expedition 2000: a rapid assessment survey of exotic species in sheltered coastal waters., In: (Eds.) . , Sacramento CA. Pp. 1-23

Cohen, Andrew N. and 22 authors (2001) <missing title>, Washington State Department of Natural Resources, Olympia. Pp. <missing location>

Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta., U.S. Fish and Wildlife Service and National Sea Grant College Program (Connecticut Sea Grant), Washington DC, Silver Spring MD.. Pp. <missing location>

Cohen, Andrew; and 16 authors. (1998) <missing title>, Washington State Department of Natural Resources, Olympia, Washington. Pp. 1-37

Cohen, C. Sarah; McCann, Linda; Davis, Tammy; Shaw, Linda; Ruiz, Gregory (2011) Discovery and significance of the colonial tunicate Didemnum vexillum in Alaska, Aquatic Invasions 6: corrected proof

Cohen, Sarah; Ruiz, Greg; Zabin, Chela; Alroy, Karen; Wang, Verena (2008) <missing title>, National Sea Grant Program & Prince William Sound Regional Citizens’ Advisory Council, Valdez AK. Pp. 1-20

Colarusso, Phil; Nelson, Eric; Ayvazian, Suzanne; Carman, Mary R.; Chintala, Marty; Grabbert, Sinead; Grunden, David (2016) Quantifying the ecological impact of invasive tunicates to shallow coastal water systems, Management of Biological Invasions 7: 33-42

Collado-Vides, L. (2002) Morphological plasticity of Caulerpa prolifera (Caulerpales, Chlorophyta) in relation to growth form in a coral reef lagoon, Botanica Marina 45: 123-129

Comeau, Luc A.; Filgueira, Ramon; Guyondet, Thomas; Somier, Remi (2015) The impact of invasive tunicates on the demand for phytoplankton in longline mussel farms, Aquaculture 441: 91-105

Couthouy, Joseph P. (1838) Descriptions of new species of Mollusca and shells, and remarks on several polypi found in Massachusetts Bay, Boston Journal of Natural History 2: 53-111

Cowles, R.P. (1930) A biological study of the offshore waters of Chesapeake Bay, United States Bureau of Fisheries Bulletin 46: 277-381

Crane, Laura C.; Goldstein, Jason S.; Thomas, Devin W.; Rexroth, Kayla S.; Watts, Alison W. (2021) Effects of life stage on eDNA detection of the invasive European green crab (Carcinus maenas) in estuarine systems, Ecological Indicators 124(107412): Published online

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>

de Rivera, Catherine, and 27 authors (2005a) <missing title>, National Fish and Wildlife Foundation, Washington, D.C.. Pp. <missing location>

Dexter, Ralph W. (1947) The marine communities of a tidal inlet at Cape Ann, Massachusetts: a study in bio-ecology, Ecological Monographs 17: 261-294

Dijkstra, Jennifer A.; Harris, Larry G. (2007) <missing title>, The New Hampshire Estuaries Project, Portsmouth, NH. Pp. 1-21

Dijkstra, Jennifer; Dutton, Anthony; Westerman, Erica; Harris, Larry (2008) Heart rate reflects osmotic stress levels in two introduced colonial ascidians Botryllus schlosseri and Botrylloides violaceus., Marine Biology 154: 805-811

Dijkstra, Jennifer; Harris, Larry G.; Westerman, Erica (2007) Distribution and long-term temporal patterns of four invasive colonial ascidians in the Gulf of Maine, Journal of Experimental Marine Biology and Ecology 342: 61-68

Dijkstra, Jennifer; Sherman,Hillary; Harris, Larry G. (2007) The role of colonial ascidians in altering biodiversity in marine fouling communities., Journal of Experimental Marine Biology and Ecology 342: 169171

Dybern, Bernt I. (1969) Distribution and ecology of ascidians in Kvirturdvikpollen and Vagsbopollen on the west coast of Norway, Sarsia 37: 21-40

Emara, Ahmed; Belal, Aisha (2004) Marine fouling in Suez Canal, Egypt, Egyptian Journal of Aquatic Research 30A: 189-206

Epelbaum, A.; Herborg, L. M.; Therriault, T. W.; Pearce, C. M. (2009) Temperature and salinity effects on growth, survival, reproduction, and potential distribution of two non-indigenous botryllid ascidians in British Columbia, Journal of Experimental Marine Biology and Ecology 399: 43-52

Epelbaum, Anya;Therriault, Thomas W.; Paulson, Amber; Pearce, Christopher M. (2009) Botryllid tunicates: Culture techniques and experimental procedures., Aquatic Invasions 4(1): 111-120

Espla, A. A. Ramos; Buencuerpo, V.; Vazquez, E.; Lafargue, F. (1992) Some biogeographical remarks about the ascidian littoral fauna of the straits of Gibraltar (Iberian sector), Bulletin de l'Institut Océanographique 9 (special): 125-131

Faasse, Marco (2012) The exotic isopod Synidotea in the Netherlands and Europe, A Japanese or American invasion (Pancrustacea: Isopoda)?, Nederlandse Faunistiche Mededelingen 108: 103-106

Fairey, Russell; Dunn, Roslyn; Sigala, Marco; Oliver, John (2002) <missing title>, California Department of Fish and Game, Sacramento. Pp. <missing location>

Ferguson, F. F.; Jones, E. R. (1949) A survey of the shoreline fauna of the Norfolk Peninsula., American Midland Naturalist <missing volume>: 436-446

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

Freeman, Aaren S.; Frischeisen, Alejandro; Blakeslee, April M. H. (2016) Estuarine fouling communities are dominated by nonindigenous species in the presence of an invasive crab, Biological Invasions Published online: <missing location>

Freestone, Amy L.; Ruiz, Gregory M.; Torchin, Mark E. (2013) Stronger biotic resistance in tropics relative to temperate zone: Effects of predation on marine invasion dynamics, Ecology 94(6): 1370-1377

Furlani, Dianne M. (1996) A guide to the introduced marine species in Australian waters., In: (Eds.) . , Hobart, Australia. Pp. <missing location>

Gartner, Heidi N.; Murray, Cathryn Clarke; Frey, Melissa A.; Nelson, Jocelyn C.; Larson, Kristen J.; Ruiz, Gregory M.; Therriault, Thomas W. (2016) Non-indigenous invertebrate species in the marine fouling communities of British Columbia, Canada, BioInvasions Records <missing volume>: <missing location>

Gittenberger, Adriaan; Moons, Jean Jacques Simeon (2011) Settlement and possible competition for space between the invasive violet tunicate Botrylloides violaceus and the native star tunicate Botryllus schlosseri in The Netherlands, Aquatic Invasions 6(4): 435-440

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

Gosner, Kenneth L. (1978) A field guide to the Atlantic seashore., In: (Eds.) . , Boston. Pp. <missing location>

Gould, Augustus A. (1841) <missing title>, Folsom, Wells, and Thurston, Cambridge. Pp. <missing location>

Gould, Augustus A. (1870) <missing title>, Wright and Potter, State Printers, Boston. Pp. <missing location>

Green, Stephanie J. and 7 authors (2021) Broad-scale acoustic telemetry reveals long-distance movements and large home ranges for invasive lionfish on Atlantic coral reefs, Marine Ecology Progress Series 673: 117-134

Griffiths, Charles L.; Robinson, Tamara B.; Mead, Angela (2009) Biological Invasions in Marine Ecosystems., Springer-Verlag, Berlin Heidelberg. Pp. <missing location>

Grosberg, Richard K. (1988) Life history variations within a population of the colonial ascidian Botryllus schlosseri. I. The genetic and environmental control of seasonal variation, Evolution 42(5): 900-920

Harris, Larry G.; Dijkstra, Jennifer A. (2007) <missing title>, New Hampshire Estuaries Project, <missing place>. 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

Hayward, P.J.; Ryland, J. S. (1990) <missing title>, 2 Clarendon Press, Oxford. Pp. <missing location>

Hewitt, Chad L. (1993) <missing title>, Ph.D. Dissertation, University of Oregon, Eugene. Pp. <missing location>

Huang, Zongguo (Ed.) (2001) <missing title>, Krieger, Malabar, FL. Pp. <missing location>

Jewett, E. B.; Hines, A. H.; Ruiz, G. M. (2005) Epifaunal disturbance by periodic low levels of dissolved oxygen; native vs. invasive species response., Marine Ecological Progress Series 304: 31-44

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

Kennedy, C., Pappal, A. L.; Bastidas, C.; ; Carlton, J. T.; David, A. A.; Dijkstra, J.A.; Duffey, S; Gibson, J.; Grady, S. P.; Green-Gavrielidis, (2020) . Report on the 2018 Rapid Assessment Survey of Introduced, Cryptogenic, and Native Marine Species at New England Marinas: Massachusetts to Maine. , <missing publisher>, Bostom MA. Pp. <missing location>

Keough, M. J. ; Ross, J. (1999) Introduced fouling species in Port Phillip Bay., In: Hewitt, C. L.; Campbell; M.;Thresher, R.; Martin,(Eds.) Marine Biological Invasions of Port Phillip Bay, Victoria. , Hobart, Tasmania. Pp. 193-225

Kincaid, Erin S.; de Rivera, Catherine E. (2021) Predators associated with marinas consume indigenous over non-indigenous ascidians, Estuaries and Coasts 44: 579-588

Kocak, F. ; Kucuksezgin, F. (2000) Sessile fouling organisms and environmental parameters in the marinas of the Turkish Aegean coast., Indian Journal of Marine Science 29: 149-157

Kott, P. (2005) Available online at http://www.environment.gov.au/biodiversity/abrs/publications/electronic-books/tunicates.html, 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

Kott, Patricia (2006) Observations on non-didemnid ascidians from Australian waters (1)., Journal of Natural History 40(3-4): 169-234

Koukouras, Athanasios; Voultisiado-Koukoura, Eleni; Kevrekidis, Theodoros; Vafidis, Dimitri (1995) Ascidian fauna of the Aegean Sea with a checklist of the Mediterranean and Black Sea species, Annales de l Institut Oceanographique, Paris 71(1): 19-34

Lacoursiere-Roussel, Anais and 6 authors (2012) Disentangling invasion processes in a dynamic shipping-boating network, Molecular Ecology 21: 4227-4241

Lacoursiere-Roussel, Anais; Forrest, Barrie M.; Guichard, Frederic; Piola, Richard F.; McKindsey, Christopher W. (2012) Modeling biofouling from boat and source characteristics: a comparative study between Canada and New Zealand, Biological Invasions 14: published online

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

Lambert, Gretchen (2019) Fouling ascidians (Chordata: Ascidiacea) of the Galápagos: Santa Cruz and Baltra Islands, Aquatic Invasions 14: 132-149

LeGresley, Murielle M.; Martin, Jennifer L.; McCurdy, Paul; Thorpe, Bruce; Chang, Blythe D. (2008) Nonindigenous tunicate species in the Bay of Fundy, eastern Canada, ICES Journal of Marine Science 65: 770-774

Lejeusne, Christophe; Bock, Dan G.; Therriault, Thomas W.; MacIsaac. Hugh J.; Cristescu, Melania E. (2011) Comparative phylogeography of two colonial ascidians reveals contrasting invasion histories in North America, Biological Invasions 13(3): 635-650

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

Locke, Andrea; Hanson, Mark; Ellis, Karla M.; Thompson, Jason; Rochette, Rémy (2007) Invasion of the southern Gulf of St. Lawrence by the clubbed tunicate (Styela clava Herdman): Potential mechanisms for invasions of Prince Edward Island estuaries., Journal of Experimental Marine Biology and Ecology 342: 69-77

Locke, Andrea; Hanson, John Mark; MacNair, Neil G.; Smith, Arthur H. (2009) Rapid response to non-indigenous species. 2. Case studies of invasive tunicates in Prince Edward Island, Aquatic Invasions 4(1): 249-258

Lopez-Legentil, Susanna; Legentil, Miquel L.; Erwin, Patrick M.; Turon, Xavier (2015) Harbor networks as introduction gateways: contrasting distribution patterns of native and introduced ascidians, Biological Invasions 17: 1623-1638

López-Legentil, Susanna; Turon, Xavier; Planes, Serge (2006) Genetic structure of the star sea squirt, Botryllus schlosseri, introduced in southern European harbours., Molecular Ecology 15: 3957-3967

Lord, Joshua P.; Calini, Jeremy M.; Whitlatch, Robert B. (2015) Influence of seawater temperature and shipping on the spread and establishment of marine fouling species, Marine Biology 162: 2481-2492

Loveland, Robert E.; Shafto, Sylvia S. (1984) Fouling Organisms, In: Kennish, Michael J., and Lutz, Richard A.(Eds.) Ecology of Barnegat Bay, New Jersey.. , Berlin. Pp. 226-20

Loveland, Robert E.; Vouglitois, James J. (1984) Benthic fauna., In: Kennish, Michael J./, and Lutz, Richard A.(Eds.) Ecology of Barnegat Bay, New Jersey.. , Berlin. Pp. 135-170

Low-Pfeng, Antonio; Recagno, Edward M. Peters (2012) <missing title>, Geomare, A. C., INESEMARNAT, Mexico. Pp. 236

Ma, K.C.K.; Deibel, D.; McKenzie, C. H. (2011) Cold Harvest: Aquaculture Canada, 17 Aquaculture Association of Canada, <missing place>. Pp. 58-63

2006-2016 MarLin- Marine Life Information Network. http://www.marlin.ac.uk/aboutMarLIN.php

Martin, Jennifer L.; LeGresley, Murielle M.; Thorpe, Bruce; McCurdy, Paul (2011) Non-indigenous tunicates in the Bay of Fundy, eastern Canada (2006-2009), Aquatic Invasions 6(4): corrected proof

Massachusetts Office of Coastal Zone Management (2013) Rapid assessment survey of marine species at New England floating docks and rocky shores, Massachusetts Office of Coastal Zone Management, Boston MA. Pp. <missing location>

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

McCarthy, Anna; Osman, Richard W.; Whitlatch, Robert B. (2007) Effects of temperature on growth rates of colonial ascidians: A comparison of Didemnum sp. to Botryllus schlosseri and Botrylloides violaceus., Journal of Experimental Marine Biology and Ecology 342: 172-174

McKenzie, Cynthia H.; Matheson, Kyle; Caines, Scott; Wells, Terri (2016) Surveys for non-indigenous tunicate species in Newfoundland, Canada (2006-2014): a first step towards understanding impact and control, Management of Biological Invasions 7(1): 21-32

McNaught, Douglas C.; Norden, Wendy S. (2011) Generalized regional spatial patterns of larval recruitment of invasive ascidians, mussels, and other organisms along the coast of Maine, Aquatic Invasions 6(4): 519-523

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

Milkman, Roger (1967) Genetic and developmental studies on Botryllus schlosseri., Biological Bulletin 131: 229-243

Millar, R. H. (1954) The annual growth and reproductive cycle of four ascidians, Journal of the Marine Biological Association of the United Kingdom 31(1): 41-61

2003-2008 Introduced and cryptogenic species of the North Atlantic. http://massbay.mit.edu/exoticspecies/exoticmaps/introduced.html

2009-2012 Marine Invader Tracking and Information System (MITIS). http://massbay.mit.edu/mitis/

Monniot, Claude; Monniot, Francoise; Griffiths, Charles; Schleyer, Michael (2001) South African Ascidians., Annals of the South African Museum 108(1): 1-141

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

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

Moura, Carlos J.; Collins, Allen G.; Santos, Ricardo S.; Lessios, Harilaos (2019) Predominant east to west colonizations across major oceanic barriers: Insights into the phylogeographic history of the hydroid superfamily Plumularioidea, suggested by a mitochondrial DNA barcoding marker, Ecology and Evolution 9: :13001–13016.

Muirhead, Jim R.; Leung, Brian; van Overdijk, Colin; Kelly, David W.; Nandakumar, Kanavillil; Marchant, Kenneth R.; MacIsaac, Hugh J. (2006) Modelling local and long-distance dispersal of invasive emerald ash borer Agrilus planipennis (Coleoptera) in North America, Diversity and Distributions 12: 71–79

Murray, Cathryn Clarke, and 5 authors (2014) Spatial distribution of marine invasive species: environmental, demographic and vector drivers, Diversity and Distributions 20: 824-836

Murray, Cathryn Clarke; Pakhomov, Evgeny A.; Therriault, Thomas W. (2011) Recreational boating: a large unregulated vector transporting marine invasive species, Diversity and Distributions 17: 1161-1172

Naranjo, S. A.; Carballo, J. C.; Garcia-Gomez, J. C. (1996) Effects of environmental stress on ascidian populations in Algeciras Bay (southern Spain)., Marine Ecology Progress Series 144: 119-131

Nelson, Matthew L. (2009) <missing title>, Humboldt State University, Eureka, California. Pp. <missing location>

Nishikawa, T. (1991) The ascidians of the Japan Sea. II., Publications of the Seto Marine Biological Laboratory 35: 25-170

Nishikawa, Teruki (1991) The Ascidians of the Japan Sea., Publication of the Seto Marine Biological Laboratory 35(1/3): 25-170

Orensanz, Jose Maria and 14 other authors (2002) No longer the pristine confines of the world ocean: a survey of exotic marine species in the southwestern Atlantic, Biological Invasions 4(1-2): 115-143

Osman, Richard W.; Whitlatch, Robert B. (1995) The influence of resident adults on recruitment: a comparison to settlement., Journal of Experimental Marine Biology and Ecology 190: 169-198

Otsuka, Cary M.; Dauer, Daniel M. (1982) Fouling community dynamics in Lynnhaven Bay., Estuaries 5(1): 10-22

Paetzold, S. Christine; Hill, Jonathan; Davidson, Jeff (2012) Efficacy of high-pressure seawater spray against colonial tunicate fouling in mussel aquaculture: inter-annual variation, Aquatic Invasions 7: in press

Pederson, Judith, and 13 authors (2021) 2019 Rapid Assessment Survey of marine bioinvasions of southern New England and New York, USA, with an overview of new records and range expansions, Bioinvasions Records 10(2): 22-–237

Plough, Harold H. (1978) <missing title>, Johns Hopkins University Press, Baltimore. Pp. <missing location>

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

Ramalhosa Patrício; Gestoso, Ignacio Rocha Rosana M.; Lambert, Gretchen; Canning-Clode, João (2021) Ascidian biodiversity in the shallow waters of the Madeira Archipelago: Fouling studies on artificial substrates and new records, Regional Studies in Marine Science 43(1901672): Published online

Ramsay, Aaron; Davidson, Jeff; Landry, Thomas; Arsenault, Garth (2008) Process of invasiveness among exotic tunicates in Prince Edward Island, Canada., Biological Invasions 10(8): 1311-1316

Raoux, Aurore; Pezy, Jean-Philippe; Sporniak, Thomas; Dauvin, Jean-Claude (2021) Does the invasive macro-algae Sargassum muticum (Yendo) Fensholt, 1955 offer an appropriate temporary habitat for mobile fauna including non-indigenous species?, Ecological Indicators 126(107624): Published online

Reem, Eitan; Douek, Jacob; Katzir, Gadi; Rinkevich, Baruch (2013) Long-term population genetic structure of an invasive urochordate: the ascidian Botryllus schlosseri, Biological Invasions 15(1): 225-241

Rho, Boon Jo (1995) The Ascidians (Tunicata) from Chindo Islands, Korea, Korean Journal of Systematic Zoology 11(1): 125-145

Rho, Boon Jo; Lee, Ji-Eun (1991) A systematic study of the Ascidians in Korea, Korean Journal of Systematic Zoology 7(2): 195-220

Richards, Horace Gardiner (1938) <missing title>, Bruce Humphries, Inc., Boston. Pp. <missing location>

Rinkevich, Baruch; Paz, Guy; Douek Jacob; Ben-Shlomo, Rachel (2001) Allorecognition and microsatellite allele polymorphism of Botryllus schlosseri from the Adriatic Sea., In: Sawada, H.; Yokosawa H.; Lambert, CC.(Eds.) The biology of ascidians.. , Tokyo. Pp. 426-435

Rinkevich, Baruch; Porat, Ram; Goren, Menachem (1995) Allorecognition elements on a urochordate histocompatibility locus indicate unprecendented extensive polymorphism, Proceedings of the Royal Society of London. Series B: Biological Sciences 259: 319-324

Rinkevich, Baruch; Shapira, Michal; Weissman, Irving; Saito, Yasunori (1992) Allogeneic responses between three remote populations of the cosmopolitan ascidian Botryllus schlosseri, Zoological Science 9: 989-994

Rius, M.; Griffths, C. W. (2011) Alien & Invasive Animals: A South African Perspective, Random House Struik, Johannesburg, South Africa. Pp. 71-75

Robinson, Andrew (12/8/2011) Invasive species found in Foxtrap harbour, St. Johns Telegram (Newfoundland) <missing volume>: published online

Robinson, April; Cohen, Andrew N.; Lindsey, Brie; Grenier, Letitia (2011) Distribution of macroinvertebrates across a tidal gradient, Marin County, California, San Francisco Estuary and Watershed Science 9(3): published online

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

Rosa, M. and 6 authors (2013) Biofouling ascidians on aquaculture gear as potential vectors of harmful algal introductions, Harmful Algae 23: 1-7

Ruiz, Gregory M. and 6 authors (2006) <missing title>, Prince William Sound Regional Citizens’ Advisory Council & U.S. Fish & Wildlife Service, Edgewater MD. Pp. <missing location>

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.

Sagasti, Alexandra; Schaffner, Linda G.; Duffy, J. Emmett (2000) Epifaunal communities thrive in an estuary with hypoxic epsiodes., Estuaries 23(4): 474-487

Sams, Michael A.; Keough, Michael J.1 AND MICHAEL J. KEOUGH (2012) Contrasting effects of variable species recruitment on marine sessile communities, Ecology 93: 1134-1146

Schmidt, Gunter H.; Warner, George F. (1986) Spatial competition between colonial ascidians: the importance of stand-off., Marine Ecology Progress Series 31: 101-104

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

Sephton, Dawn; Vercaemer, Benedikt; Nicolas, Jean Marc; Keays, Joanne (2011) Monitoring for invasive tunicates in Nova Scotia, Canada (2006-2009), Aquatic Invasions 6(4): 391-403

Simkanin, Christina; Davidson, Ian C.; Dower, John F.; Jamieson, Glen; Therriault, Thomas W. (2012) Anthropogenic structures and the infiltration of natural benthos by invasive ascidians, Marine Ecology 33: 499-511

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

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

Sorte, Cascade J. B.; Jones, Sierra J.; Miller, Luke P. (2013) Geographic variation in temperature tolerance as an indicator of potential population responses to climate change, Journal of Experimental Marine Biology and Ecology 400: 209-217

Sorte, Cascade J. B.; Stachowicz, John J. (2011) Patterns and processes of compositional change in a California epibenthic community, Marine Ecology Progress Series 435: 63-74

Sorte, Cascade, J. B.; Williams, Susan L.; Zerebecki, Robyn A. (2010) Ocean warming increases threat of invasive species in a marine fouling community, Ecology 91(8): 2198-2204

Stoner, Douglas S.; Ben-Shlomo, Rachel; Rinkevich, Baruch; Wiessman, Irving (2002.) Genetic variability of Botryllus schlosseri invasions to the east and west coasts of the USA., Marine Ecology Progress Series 243: 93-100

Sumner, Francis B., Osburn, Raymond C., Davis, Bradley M. (1913a) A biological survey of the waters of Woods Hole and vicinity. Part I. Section I. Physical and Zoological. Section II. Botanical, Bulletin of the Bureau of Fisheries 31: 1-544

Sutherland, John P.; Karlson, Ronald H. (1977) Development and stability of the fouling community at Beaufort, North Carolina, Ecological Monographs 47: 425-446

Tovar-Hernández, M. A.; Villalobos-Guerrero, T. F.; Yáñez-Rivera, B., Aguilar-Camacho, J. M.; Ramírez-Santana, I. D. (2012) [Guide to exotic aquatic invertebrates in Sinaloa] , Geomare, A. C., USFWS, INE-SEMARNAT, Mazatlán, México. Pp. 41

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

Trott, Thomas J. (2004) Cobscook Bay inventory: a historical checklist of marine invertebrates spanning 162 years., Northeastern Naturalist 11(Special issue 2): 261-324

Turon, X. (1987) [The ascidians of Tossa de Mar (Girona). General features. Faunistics and taxonomy,], Miscellanea Zoologica 11: 221-231

Turon, Xavier (1990) Distribution and abundance of ascidians from a locality on the northeast coast of Spain, Marine Ecology 11(4): 391-408

Turon, Xavier; Cañete, Juan I.; Sellanes, Javier; Rocha, Rosana M.; López-Legentil, Susanna (2016) Too cold for invasions? Contrasting patterns of native and introduced ascidians in subantarctic and temperate Chile, Management of Biological Invasions 7: 77-86

Tyrrell, Megan C.; Byers, James E. (2007) Do artificial substrates favor nonindigenous fouling species over native species?, Journal of Experimental Marine Biology and Ecology 342: 54-60

2002-2021 Invertebrate Zoology Collections Database. <missing description>

2004 Flora of the Washington-Baltimore Area. http://persoon.si.edu/dcflora/checklook.cfm

2003-2015 Nonindigenous Aquatic Species Database. Gainesville, FL. http://nas.er.usgs.gov

Valdivia, Nelson; Heidemann, Astrid; Thiel, Martin; Molis, Markus, Wahl, Martin (2005) Effects of disturbance on the diversity of hard-bottom macrobenthic communities on the coast of Chile., Marine Ecology Progress Series 299: 45-54

Van Name, Willard G. (1910) Compound ascidians of the coasts of New England and neighboring British provinces., Proceedings of the Boston Society of Natural History 34(339-424): <missing location>

Van Name, Willard G. (1921) Ascidians of the West Indian region and southeastern United States., Bulletin of the American Museum of Natural History 44: 283-494

Van Name, Willard G. (1945) The North and South American ascidians, Bulletin of the American Museum of Natural History 84: 1-462

Vaughan, David B.; Grutter, Alexandra S.; Hudson, Kate S. (2018) Cleaner shrimp are a sustainable option to treat parasitic disease in farmed fish, Scientific Reports 8: 13959

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

Vazquez, , E.; Urgorri, V. (1992) Cino especies del genero Molgula Forbes & Hanley, 1848., Miscellania Zoologia 16: 129-137

Vazquez, E.; Urgorri, V. (1992) [Fouling ascidians in the inlet of A Grana, Ria de Ferrol, (Galicia, Spain)], Nova Acta Cientifica Compostelana (Bioloxia) 3: 161-167

Verrill, A. E. (1871) Brief descriptions of new and imperfectly known ascidians from New England, American Journal of Science Ser. 3 1: 211-212

Verrill, A. E. (1898) Descriptions of new American actinians, with critical notes on other species., American Journal of Science Series 4. 6: 493-498

Verrill, A.E.; Smith, S.I. (1873) <missing title>, 1 Report of the United States Commission of Fish and Fisheries, <missing place>. Pp. 1-757

Visscher, J. Paul (1927) Nature and extent of fouling of ship's bottoms., Bulletin of the Bureau of Fisheries 43: 193-252

Wass, Melvin L. (1963) Check list of the marine invertebrates of Virginia., Special Scientific Report, Virginia Institute of Marine Science 24: 1-56

Wass, Melvin L. (1972) A checklist of the biota of lower Chesapeake Bay, Special Scientific Report, Virginia Institute of Marine Science 65: 1-290

Wasson, Kerstin; Zabin, C. J.; Bedinger, L.; Diaz, M. C.; Pearse J. S. (2001) Biological invasions of estuaries without international shipping: the importance of intraregional transport, Biological Conservation 102: 143-153

Wells, Christopher D. and 23 authors (2014) Report on the 2013 rapid assessment survey of marine species at New England bays and harbors, Massachusetts Office of Coastal Zone Management, Boston MA. Pp. 32

Westerman, Erica L.; Whitlatch, Robert; Dijkstra, Jennifer A.; Harris, Larry G. (2009) Variation in brooding period masks similarities in response to changing temperatures, Marine Ecology Progress Series 391: 13-19

Whitlatch, Robert B.; Osman, Richard (2000) Geographical distributions and organism-habitat associations of shallow water introduced marine fauna in New England., In: Pederson, Judith(Eds.) Marine Bioinvasions. , Cambridge MA. Pp. 61-65

Whitlatch, Robert B.; Osman, Richard W. (2009) Post-settlement predation on ascidian recruits: predator responses to changing prey density., Aquatic Invasions 4(1): 121-131

Whitlatch, Robert B.; Osman, Richard W.; Frese, Annette, Malatesta, Richard, Mitchell, Patricia, Sedgwick, Lynn (1995) The ecology of two introduced marine ascidians and their effects on epifaunal organisms in Long Island Sound, In: Balcom, N. C.(Eds.) Proceedings of the Northeast Conference on Non-Indigenous Aquatic Nuisance Species. , Groton, CT. Pp. 28-29

Wiltshire, K.; Rowling, K.; Deveney, M. (2010) <missing title>, South Australian Research and Development Institute, Adelaide. Pp. 1-232

Wong, Melisa C.; Vercaemer, Bénédikte (2012) Effects of invasive colonial tunicates and a native sponge on the growth, survival, and light attenuation of eelgrass (Zostera marina), Aquatic Invasions 7: in press

Wonham, Marjorie J.; Carlton, James T. (2005) Trends in marine biological invasions at local and regional scales: the Northeast Pacific Ocean as a model system, Biological Invasions 7: 369-392

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

Yund, Philip O., Feldgarden, Michael (1992) Rapid proliferation of historecognition alleles in populations of a colonial ascidian, Journal of Experimental Zoology 263: 442-445

Yund, Philip O.; Collins, Catherine; Johnson, Sheri L. (2015) Evidence of a native northwest Atlantic COI haplotype clade in the cryptogenic colonial ascidian Botryllus schlosseri, Biological Bulletin 216: 201-216

Zerebecki, Robyn A.; Sorte, Cascade J. B. (2011) Temperature tolerance and stress proteins as mechanisms of invasive species success, PLOS ONE 6(4): e14806, 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