Cordylophora caspia

Invasion History

First Non-native North American Tidal Record: 1865
First Non-native West Coast Tidal Record: 1920
First Non-native East/Gulf Coast Tidal Record: 1865

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General Invasion History:

Cordylophora caspia was first described from the Caspian Sea by Pallas in 1771 and is believed to be native to the Black Sea-Caspian Sea region (Briggs 1931; Naumov 1969; Hutchinson 1993). Shipping has spread C. caspia through much of the world and this hydroid is now known from temperate and tropical coastal regions of every continent (except Antarctica), and from many fresh waters as well (Arndt 1984; Hutchinson 1993; Naumov 1969; Slobodkin and Bossert 1991).

Genetic studies (Folino-Rorem et al. 2009) indicate that multiple (at least four) genetic lineages of Cordylophora spp., possibly representing cryptic species, have been introduced in Europe, North America and South America. Most of these lineages have been widely distributed, and multiple lineages can occur at the same site. One lineage (2B) was confined to the Pacific Coast of North America, although it co-occurred with a more-widely distributed lineage (1B). Lineages differed ecologically- 1A was found only in freshwater, 2A and 2B only in brackish waters, while 1B was found at both fresh and brackish sites. This study was wide-ranging, but did not include the Ponto-Caspian basin, the presumed region of origin of the Cordylophora species complex (Folino-Rorem et al. 2009). Until the genetic diversity of the complex is further clarified we will continue to treat it as a single species of Ponto-Caspian origin.

North American Invasion History:

Invasion History on the West Coast:

Sometime between the 1920s and the 1950s, Cordylophora caspia was discovered in Pacific coast estuaries including San Francisco Bay, the Columbia River, and Puget Sound (Hand and Gwillam 1951; Carlton 1979; Cohen and Carlton 1995). The earliest record appears to be from freshwater – Lake Union, Seattle, Washington (Hand and Gwilliam 1951; Carlton 1979). In 1930, it was found at Antioch on the San Joaquin River (Hand and Gwilliam 1951), and has subsequently been found at many locations in the Delta and in other fresh and brackish tributaries of San Francisco Bay (Hand and Gwillam 1951; Carlton 1979; Cohen and Carlton 1995; Cohen et al. 2005). This hydroid has been found in many fresh and brackish Pacific tributaries, including Elkhorn Slough, California (in 1998, Wasson et al. 2001); Humboldt Bay, California (in 1968, Mace and Mackie 1970; Carlton 1979); Coos Bay, Oregon (in 1959, Mace and Mackie 1970; Carlton 1979); Alsea Bay, Oregon (in 1975, Carlton 1979); the Columbia River estuary (in 1965, Haertel and Osterberg 1967; Carlton 1979); Willapa Bay, Washington (Cohen et al. 2001); brackish Puget Sound tributaries (Cohen et al. 1998; Cohen et al. 2001); and Albert Head Lagoon in Victoria, British Columbia (in 1967, Mace and Mackie 1970). Folino-Rorem et al. (2009) found two genetic lineages of C. caspia on the West Coast, one (1B) widespread in North America and Europe, the other (2B) confined to the Pacific Coast. Both lineages were found at Pittsburg, California, in the inner San Francisco estuary (Folino-Rorem et al. 2009).

Invasion History on the East Coast:

The first published record of Cordylophora caspia in North America was that of Leidy (1870), in which he described its occurrence in the Schuykill River, a Delaware River tributary in Philadelphia, but he remarked on finding it at Newport, Rhode Island 'some years earlier'. It apparently spread up and down the coast, reaching brackish ponds on Martha's Vineyard in 1872 (Verrill and Smith 1873), and Chesapeake Bay by 1877 (Clarke 1878; Bibbins 1892). The spread of this hydroid on the East coast seems to have been quite spotty. The first record for the Miramichi estuary, New Brunswick, was 1912 (Fraser 1944); it was found in 1926 in Back Bay, Virginia (an arm of Currituck Sound) (USNM 42191, U.S. National Museum of Natural History 2007); in 1928 in Pamlico Sound, North Carolina (Pearse 1936); and in 1932 in Charles River, Massachusetts (Blake 1932). However, first records for some well-travelled and populated estuaries were much later: 1972 for the Hudson River, New York (Mills et al. 1997); 1974 for the Cooper and Ashepoo Rivers, South Carolina (Calder and Hester 1978); and 1995 for the Connecticut River (Smith et al. 2002). It is possible that this hydroid was overlooked in some estuaries for decades before its published discovery.

In the Great Lakes, C. caspia was first collected in Lake Erie in 1956, and was abundant by the 1960s (Davis 1957; Hubschman 1971; Hubschman and Kishler 1972). It has been collected from Lake Ontario (Rochester, New York) (Folino-Rorem et al. 2009) to Duluth, Michigan at the western end of Lake Superior (Grigorevich et al. 2003), and in the Finger Lakes, in the Great Lakes Basin. Genetic analysis indicates that C. caspia has been spread largely through sexually produced larvae which have settled on boats, ships, and barges (Darling and Folino-Rorem 2009).

Invasion History on the Gulf Coast:

Cordylophora caspia was collected in Shreveport, Louisiana, in the Red River in 1918, about 600 km from the Gulf; and by 1944, was collected in Lake Pontchartrain (Fraser 1944). It has subsequently been found in tributaries along the northern shore of the Gulf from the Suwanee River, Florida (Mason et al. 1994) to the Sabine River, Texas (McClung et al. 1978). In the Escambia River, Florida (in 1952-53), C. caspia was 'an abundant population occurring on saw grass stalks and roots' (Wurtz and Roback 1955). It was found at 23 locations in the New Orleans area and Vermillion Parish, Louisiana, including tidal fresh and brackish waters (Poirrier and Denoux 1973).

This hydroid has spread widely through the fresh waters of the Mississippi Basin. In 1909, it was collected in the Illinois River (Havana, Illinois) (Smith 1910), and spread in a scattered fashion to Kentucky (in 1922, Garman, cited by Hubschman and Kishler 1972), Louisiana (in 1918, Poirrier and Denoux 1973), Oklahoma (in~1968, Ransom 1981), and Kansas (in 1980, Ransom 1981).

Invasion History in Hawaii:

Cordylophora caspia was collected in 1967, in Kaneohe Bay, Oahu (Powers 1971, cited by Coles et al. 2002), and in 1974-1975 in an anchialine pond (connected to the sea through porous rock) on Maui (Cooke 1977, cited by Carlton and Eldredge 2009).

Invasion History Elsewhere in the World:

In Europe, Cordylophora caspia was probably first introduced in the late 17th century through canals linking the waterways of the Baltic and Black Seas (Olenin 2002). It spread rapidly, and was widespread in inland waters and estuaries in northern Europe, from Finland to the British Isles by the late 19th century (Allman 1872; Arndt 1984; Jensen and Knudsen 2005; Wolff 2005). More recently, C. caspia spread north to Bergen and Stavanger, Norway (by 1985, Hopkins 2002) and south to the Guadalquivir River, Spain (by 2001, Escot et al. 2003, cited by Garcia-Berthou et al. 2007), the Po River delta, Italy (Morri and Bianchi 1983), and other Mediterranean lagoons. It is widespread in the major freshwater rivers of Europe, including the Rhine (Vervoort 1964; Roos 1979), the Elbe (Nehring 2006), Weser, Oder, and Danube basins (Bij de Vaate et al. 2002).

In Central America, C. caspia was first collected on the Caribbean side of the Panama Canal in the Gatun Locks in 1925 (Hildebrand 1939; Fraser 1944; USNM 43378, U.S. National Museum of Natural History 2007). Subsequently, it was collected on the Pacific side in the Pedro Miguel Locks in 1975 (Arndt 1984, Cohen 2006; USNHM 89237, U.S. National Museum of Natural History 2007). Specimens have also been collected from Gamboa, Panama, on Gatun Lake, and they belonged to the widespread freshwater genotype 1A (Folino-Rorem et al. 2009). In South America, it is known from the coast and freshwaters of Brazil (Arndt 1984; Grohmann 2008; Farrapeira et al. 2011), Uruguay, Argentina (Grohmann 2008), and from Chilean fjords (in 2006, Galea 2007, Folino-Rorem et al. 2009).

Cordylophora caspia has been introduced to freshwater lakes and brackish estuaries in New Zealand (1st record 1885, Cranfield et al. 1998), Australia (1st Record 1922, Briggs 1931, Hewitt, personal communication), Iraq (Shatt-al-Arab estuary) and Shanghai, China (Arndt 1984).

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Description

Cordylophora caspia grows in erect, branching colonies, growing from a single stem, arising from stolons attached to the substrate. Sometimes one colony will grow on top of another. The shoots branch regularly or irregularly. Frequently, there is one main stem and shorter side branches. Annulations (rings) are present near the base of the stems and branches. A colony may have 40 or more hydranths. The hydranths are spindle-shaped when relaxed, ovoid when contracted, about 1-2 mm high, with a conical or bullet-shaped hypostome. There are scattered (usually 14-16, sometimes up to 27) tentacles. The gonophores are oval, arising from the stem or branches, and contain 7-16 eggs. Hydranths are white or pale pink and the stems are yellowish-brown. Stems are typically 30-45 mm in size, but may reach 150 mm or more (Calder 1971; Schuchert 2004; Calder 2010).

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Taxonomy

Ecology

General:

Cordylophora caspia is a sessile hydrozoan which lacks a planktonic medusa stage. Colonies grow on a solid substrates, with polyps arising from a creeping stolon. The polyps form bushy structures, with many hydranths, whose tentacles capture zooplankton. The polyps produce gonophores, which produce either eggs or sperm. Colonies are diecious (single-sexed). Female gonophores produce multiple eggs, typically 7-16, which are brooded and fertilized by sperm from the water column. The eggs develop into ciliated non-feeding planula larvae (Schuchert 2004). These larvae probably spend less than a day in the water before settlement (Sommer 1992).

Planulae of C. caspia settle and grow on a wide range of substrates, including shells, rock, wood, and vegetation. This hydroid has been found on a number of plants, including submerged plants (Ceratophyllum demersum- Coontail; Nitella sp.; Potamogeton sp.- Pondweeds; Elodea sp.- Waterweed; Vallisneria americana- Wild Celery), stalks of floating plants (Nymphaea odorata- White Water Lily), and roots and stems of emergents (Alternanthera philoxeroides- Alligatorweed; Phragmites australis - Common Reed) (Clarke 1878; Poirrier and Denoux 1973; Calder 1978; Roos 1979). It has also been reported from shells of living freshwater (native Unionidae, introduced Dreissena spp.- Zebra and Quagga Mussels) and brackish-water mussels (Mytilopsis leucophaeta- Dark False Mussel) (Calder 1978; Curry et al. 1981; Walton 1996). It has also been found on man-made substrates including old automobiles and nylon ropes (Roos 1979), buoys and ships (Woods Hole Oceanographic Institution 1952), and doubtless many others.

Cordylophora caspia grows in a vast range of aquatic environments, varying in salinity, temperature, currents, oxygen, etc. Survival tolerances vary greatly among populations as a result of both genetics and acclimation (Arndt 1984; Kinne 1956). Experimental limits were 24⁰C for C. caspia from Germany (Kinne 1956) and 30+⁰C for animals collected near Woods Hole, Massachusetts (Fulton 1962). Optimal temperatures for asexual growth appeared to be 11-18⁰C for German populations (Kinne 1956), 18-26⁰C for MA populations (Fulton 1962), 16-25⁰C for San Francisco estuary populations (Meek et al. 2012), and 23-30⁰C for colonies from Iraq (Arndt 1984). At least one genetic lineage of C. caspia (1A) ranges from Europe (UK and Germany) to the tropics (Panama) (Folino-Rorem et al. 2009). This hydroid is known to grow abundantly in fresh and brackish waters, and can tolerate exposure to full seawater (Kinne 1958; Mace and Mackie 1970; Arndt 1984). Tolerance to seawater may vary genetically. One lineage in Folino-Rorem et al.'s (2009) study was restricted to fresh water (lineage 1A), one to brackish water (2), and one inhabited both (1B). Cordylophora caspia is also tolerant of hypoxia, and had optimal growth at 40% of saturation (Fulton 1962). In the San Francisco estuary, it was associated with middle levels of oxygen concentration, low salinity, and low transparency (Wintzer et al. 2011a). This hydroid can respond to unfavorable conditions by regressing into a dormant state, consisting of bodies of tissue (menonts) in the stolons and stems, which serve as a diapause stage (Kinne 1956; Roos 1979; Jormalainen et al. 1994). In regions with milder climates, such as San Francisco Bay (Wintzer et al. 2011a) and South Carolina (Calder 1992) the hydroid is active all year, with extended polyps. In more severe climates, such as the Netherlands and Finland, hydroids may be dormant in winter (Roos 1979; Jormalainen et al. 1994) and sometimes also during periods of high predation in mid-summer (Jormalainen et al. 1994).

Food:

Zooplankton; Small epibenthos

Consumers:

Tenellia adspersa; amphipods, fishes

Trophic Status:

Carnivore

Carn

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Habitats

General Habitat	Vessel Hull	None
General Habitat	Swamp	None
General Habitat	Salt-brackish marsh	None
General Habitat	Oyster Reef	None
General Habitat	Fresh (nontidal) Marsh	None
General Habitat	Grass Bed	None
General Habitat	Canals	None
General Habitat	Rocky	None
General Habitat	Marinas & Docks	None
General Habitat	Tidal Fresh Marsh	None
General Habitat	Nontidal Freshwater	None
General Habitat	Coarse Woody Debris	None
Salinity Range	Limnetic	0-0.5 PSU
Salinity Range	Oligohaline	0.5-5 PSU
Salinity Range	Mesohaline	5-18 PSU
Salinity Range	Polyhaline	18-30 PSU
Tidal Range	Subtidal	None
Vertical Habitat	Epibenthic	None

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Tolerances and Life History Parameters

Minimum Temperature (ºC)	0	Based on geographic range
Maximum Temperature (ºC)	30	Experimental upper limits were 24 C for C. caspia from Germany (Kinne 1956) and 30+ C for animals collected near Woods Hole MA (Fulton 1962)
Minimum Salinity (‰)	0	This hydroid grows and reproduces in freshwater.
Maximum Salinity (‰)	35	Upper salinity ranges are based on experimental survival. The upper limit for sexual reproduction was 27 ppt ( Kinne 1958). Field salinity ranges are generally much lower (Arndt 1984; Lippson et al. 1979; Poirrier and Denoux 1973; Ruiz et al. unpublished data).
Minimum pH	6.2	Field data from TX (McClung and Davis 1983) and LA (Poirrier and Denoux 1973). Optimal growth in experiments occurred at 6.8-8.6, but no growth occurred at 5.1 (Fulton 1962).
Maximum pH	8.6	None
Minimum Duration	0.5	Sommer 1992
Maximum Duration	1	Sommer 1992
Maximum Height (mm)	150	Stems are typically 30 45 mm, but may reach 150 mm or more (Calder 1971; Schuchert 2004; Calder 2010)
Broad Temperature Range	None	Cold-temperate-Tropical
Broad Salinity Range	None	Fresh-Polyhaline

General Impacts

Economic impacts 

Cordylophora caspia has been reported from the cooling water systems of power plants in Illinois (Folino 2000), Brazil (Grohmann 2009), Finland (Vuorinen et al. 1984), Luxembourg (Massard and Geimer 1990), and the Ukraine (Simkina 1963). Fouling by C. caspia has required the shutdown of generators for cleaning and the use of toxic chemicals such as chlorine to prevent fouling (Folino 2000; Grohmann 2008). Other impacts are possible. It occurs in fouling on boats, ships, and buoys (Woods Hole Oceanographic Institution 1952), but is not widely reported as a ship fouling problem.

Ecological impacts

Cordylophora caspia is now a significant biomass component of the fouling community in the fresh-mesohaline regions of many estuaries around the world. It is also the only erect compound hydroid occurring in inland freshwater lakes (Pennak 1978; Hutchinson 1993). However, information on the ecological impact of its invasion is scarce, and mostly anecdotal, although some experimental studies have been conducted in Chesapeake Bay (see Von Holle and Ruiz 1997; Von Holle unpublished data).

Competition - Cordylophora caspia is a potential competitor for space in fouling communities. In field experiments on fouling plates (Key Bridge, Patapsco River, Maryland), where laboratory-grown colonies of C. caspia were added, abundances of the bryozoan Victorella pavida (cryptogenic), the entoproct Loxosomatoides laevis (introduced), and the protozoans Metafolliculina sp., and Stentor sp. were reduced (Von Holle and Ruiz 1997; Von Holle unpublished data).

Food/Prey - Cordylophora caspia is an important food for nudibranchs, which include many specialized predators of hydroids. Cordylophora caspia is apparently eaten by the nudibranch Tenellia adspersa, cryptogenic on the East Coast of North America, but widely introduced elsewhere (Gaulin et al. 1986; Chester 1996). Despite its nematocysts, C. caspia is also eaten by some generalized predators, such as amphipods (Roos 1979). Extensive feeding by the introduced amphipod Gammarus tigrinus (native in Chesapeake Bay) on C.caspia was reported in Dutch freshwaters by Roos (1979). In the San Francisco Bay estuary, C.caspia comprised 18-23% of the diet of the introduced Shimofuri goby (Tridentiger bifasciatus) (Matern and Brown 2005).

Predation -Although colonies of Cordylophora caspia in many bodies of water represent a substantial biomass of predators on zooplankton and mobile epibenthos (Bibbins 1892; Arndt 1984; Roos 1979), their role as predators has rarely been studied quantitatively. However, C. caspia predates on settling Zebra Mussel (Dreissena polymorpha) veligers, selecting smaller veligers, even as their filaments increase overall rates of settlement (Folino-Rorem and Stoeckel 2006).

Habitat Change - Cordylophora caspia colonies are dense and bushy, and constitute a substantial structural alteration to surfaces of wood, plants, rocks, etc., which may provide some protection from predators and currents (Roos 1979). In field experiments, the addition of laboratory-grown colonies of C. caspia resulted in increased abundances of Amphibalanus improvisus, Alitta succinea, and corophiid amphipods on fouling plates (Von Holle and Ruiz 1997; Von Holle unpublished data). In the Great Lakes basin, colonies of C. caspia provide substrate for settlement of larval Zebra Mussels (Dreissena polymorpha) (Folino-Rorem et al. 2006). This hydroid has been recorded as a fouling organism on living native freshwater bivalves (Amblema plicata, Potamilus purpuratus) in Louisiana (Curry et al. 1981), Zebra Mussels in the Great Lakes region (Folino-Rorem et al. 2006), and Zebra Mussels and Dark False Mussels (Mytilopsis leucophaeta) in the Hudson River (Walton 1996). However, impacts of C. caspia on these bivalves were not reported. 

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Regional Impacts

GL-I	Lakes Huron, Superior and Michigan		Economic Impact	Industry
Fouling of Collins Electrical Generating Plant, Morris, IL (Folino 2000).
NA-ET2	Bay of Fundy to Cape Cod		Ecological Impact	Food/Prey
The role of Cordylophora caspia as food for the cryptogenic nudibranch, Tenellia adspersa, has been studied in Great Bay, New Hampshire, in the Gulf of Maine (Gaulin et al. 1986; Chester 1986; Blezard 1998).
NA-ET3	Cape Cod to Cape Hatteras		Ecological Impact	Competition
Cordylophora caspia is a potential competitor for space in fouling communities. In field experiments on fouling plates (Key Bridge, Patapsco River, Maryland), where laboratory-grown colonies of C. caspia were added, abundances of the bryozoan Victorella pavida (s.l., cryptogenic), and the protozoans Metafolliculina sp., and Stentor sp. were reduced (Von Holle and Ruiz 1997; Ruiz et al. unpublished data).
NA-ET3	Cape Cod to Cape Hatteras		Ecological Impact	Habitat Change
Cordylophora caspia colonies are dense and bushy, and constitute a substantial structural alteration to the surfaces of wood, plants, rocks, etc. The hydroid can provide some protection from predators and currents for surrounding organisms. In field experiments, the addition of laboratory-grown colonies of C. caspia resulted in increased abundances of the barnacle Amphibalanus improvisus, the polychaete Alitta succinea, corophiid amphipods, and the introduced entoproct Loxosomatoides laevis on fouling plates (Von Holle and Ruiz 1997; Von Holle unpublished data).
NA-ET3	Cape Cod to Cape Hatteras		Ecological Impact	Food/Prey
Cordylophora caspia is eaten by the nudibranchs Tenellia spp. (native T. fuscata and cryptogenic T. aspersa). These nudibranchs can become very abundant on C. caspia, and are apparently limiting factors in C. caspia's abundance and distribution. The relative abundances and distributions of the two nudibranch species in Chesapeake Bay are poorly known (Ruiz et al. unpublished data; Vogel 1977).
B-XI	None		Economic Impact	Industry
Power plant fouling (Vuorinen et al. 1986)
B-XII	None		Economic Impact	Industry
Power plant fouling (Vuorinen et al. 1986)
B-X	None		Economic Impact	Industry
Power plant fouling (Vuorinen et al. 1986)
B-IX	None		Economic Impact	Industry
Power plant fouling (Vuorinen et al. 1986)
NEA-II	None		Economic Impact	Industry
Fouling by C. caspia was reported in power plants from the Moselle River, Luxembourg (Massard et al. 1990) and the Netherlands (Jenner and Jannsen-Mommen 1993).
NEA-II	None		Ecological Impact	Food/Prey
Extensive feeding by the introduced amphipod Gammarus tigrinus on C.caspia was reported in Dutch freshwaters by Roos (1979).
NEP-V	Northern California to Mid Channel Islands		Ecological Impact	Food/Prey
In the San Francisco Bay estuary, C. caspia comprised 18-23% of the diet of the introduced Shimofuri goby (Tridentiger bifasciatus) (Matern and Brown 2005).
P090	San Francisco Bay		Ecological Impact	Food/Prey
In the San Francisco Bay estuary, C. caspia comprised 18-23% of the diet of the introduced Shimofuri goby (Tridentiger bifasciatus) (Matern and Brown 2005)
N130	Great Bay		Ecological Impact	Food/Prey
Cordylophora caspia is apparently eaten by the nudibranch Tenellia adspersa, cryptogenic on the East Coast of North America, but widely introduced elsewhere (Gaulin et al. 1986; Chester 1997).
M130	Chesapeake Bay		Ecological Impact	Competition
Cordylophora caspia is a potential competitor for space in fouling communities. In field experiments on fouling plates (Key Bridge, Patapsco River, Maryland), where laboratory-grown colonies of C. caspia were added, abundances of the bryozoan Victorella pavida (s.l., cryptogenic), and the protozoans Metafolliculina sp., and Stentor sp. were reduced (Von Holle and Ruiz 1997; Von Holle unpublished data).
M130	Chesapeake Bay		Ecological Impact	Habitat Change
Cordylophora caspia colonies are dense and bushy, and constitute a substantial structural alteration to the surfaces of wood, plants, rocks, etc. The hydroid can provide some protection from predators and currents for surrounding organisms. In field experiments, the addition of laboratory-grown colonies of C. caspia resulted in increased abundances of the barnacle Amphibalanus improvisus, the polychaete Alitta succinea, corophiid amphipods, and the introduced entoproct Loxosomatoides laevis on fouling plates (Von Holle and Ruiz 1997; Von Holle unpublished data).
M130	Chesapeake Bay		Ecological Impact	Food/Prey
Cordylophora caspia is eaten by Tenellia spp. nudibranchs (native T. fuscata and cryptogenic T. aspersa). These nudibranchs can become very abundant on C. caspia, and are apparently limiting factors in C. caspia's abundance and distribution. The relative abundances and distributions of the two nudibranch species in Chesapeake Bay are poorly known (Ruiz et al. unpublished data; Vogel 1977).
B-XII	None		Ecological Impact	Habitat Change
In the Gulf of Bothnia, C. caspia was classified as having some habitat impacts (Zaiko et al. 2011).
B-IX	None		Ecological Impact	Competition
Moderate community impacts (Zaiko et al. 2011)
B-VII	None		Ecological Impact	Competition
Moderate community impacts, Curonian Lagoon (Zaiko et al. 2011)
B-VII	None		Ecological Impact	Habitat Change
Some habitat impacts, Vistula Lagoon (Zaiko et al. 2011)
B-IV	None		Ecological Impact	Habitat Change
Low level of habitat impacts, Odra Lagoon (Zaiko et al. 2011)
SA-II	None		Economic Impact	Industry
Cordylophora caspia caused fouling which decreased the efficiency of the cooling system of the Funil Hydroelectric Plant, Paraiba River, Rio de Janeiro, Brazil (Grohmann 2008). After the infestation started, cleaning of the system was required every four months instead of every six years, and costs were substantially increased (Grohmann 2008).
L047	_CDA_L047 (Little Calumet-Galien)		Economic Impact	Industry
Fouling of Collins Electrical Generating Plant, Morris, IL (Folino 2000).
B-XI	None		Ecological Impact	Habitat Change
In the Gulf of Bothnia, C. caspia was classified as having some habitat impacts (Zaiko et al. 2011).
CA	California		Ecological Impact	Food/Prey
In the San Francisco Bay estuary, C. caspia comprised 18-23% of the diet of the introduced Shimofuri goby (Tridentiger bifasciatus) (Matern and Brown 2005)., In the San Francisco Bay estuary, C. caspia comprised 18-23% of the diet of the introduced Shimofuri goby (Tridentiger bifasciatus) (Matern and Brown 2005)
MD	Maryland		Ecological Impact	Habitat Change
In field experiments, addition of laboratory-grown colonies of C. caspia resulted in increased abundances of Amphibalanus improvisus, Alitta succinea, and corophiid amphipods on fouling plates (Von Holle and Ruiz 1997; Von Holle unpublished data).
MD	Maryland		Ecological Impact	Competition
Cordylophora caspia is a potential competitor for space in fouling communities. In field experiments on fouling plates (Key Bridge, Patapsco River, Maryland), where laboratory-grown colonies of C. caspia were added, abundances of the bryozoan Victorella pavida (cryptogenic), the entoproct Loxosomatoides laevis (introduced), and the protozoans Metafolliculina sp., and Stentor sp. were reduced (Von Holle and Ruiz 1997; Von Holle unpublished data).

References

Skora, Michał; Guðni, E.; Guðbergsson; Copp, Gordon H. (2023) Evidence of successful recruitment of non-native pink salmon Oncorhynchus gorbuscha in Iceland, Journal of Fish Biology 104: 329-334
DOI: 10.1111/jfb.15556

Allman, George J. (1853) On the anatomy and physiology of Cordylophora, a contribution to our knowledge of the Tubularian Zoophytes, Philosophical Transactions of the Royal Society of London 143: 367-384

Allman, George James (1844) Synopsis of the genera and species of zoophytes inhabiting the fresh waters of Ireland, Annals of Natural History 13(1): 328-331

Allman, George James (1872) <missing title>, Ray Hardwicke, London. Pp. <missing location>

Altuna, Alvaro (2007) Bathymetric distribution patterns and biodiversity of benthic Medusozoa (Cnidaria) in the Bay of Biscay(north-eastern Atlantic)., Journal of the Marine Biological Association of the United Kingdom 87: 681-694

Arndt, Ernst Albert (1984) Ecological niche of Cordylophora caspia (Pallas, 1771), Limnologica 15(2): 469-477

Banta, William C.; Backus, Byron T. (1991) <missing title>, US Department of the Interior, Washington DC. Pp. <missing location>

Bibbins, Arthur (1892) On the distribution of Cordylophora in the Chesapeake estuaries, and the character of its habitat, Transactions of the Maryland Academy of Sciences 1: 213-228

Bij de Vaate,A.; Jazdzewski, K.; Ketelaars, H.A.M; Gollasch, S.; van der Velde, G. (2002) Geographical patterns in range extension of Ponto-Caspian macroinvertebrate species in Europe., Canadian Journal of Fisheries and Aquatic Science 59: 1159-1174

Bilger, Michael D.; Riva-Murray, Karen;Wall, Gretchen L. (2005) <missing title>, U. S. Geological Survey, Reston, VA. Pp. <missing location>

Blake, Charles H. (1932) Cordylophora in Massachusetts., Science 76: 345-346

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

Bouillon, Jean; Medel, Maria Dolores; Pagès, Francesc; Gili, Josep-Maria; Boero, Ferdinando ; Gravili, Cinzia (2004) Fauna of the Mediterranean Hydrozoa., Scientia Marina 68(suppl. 2): 5-438

Boulenger, Charles L. (1908) On Moerisia lyonsi, a new hydromedusan from Lake Qurun., Quarterly Journal of Microscopical Science 52: 357-378

Briggs, E. A. (1931) Notes on Australian athecate hydroids, Records of the Australian Museum 18: 299-282

Buschbaum, Christian; Lackschewitz, Dagmar; Reise, Karsten (2012) Nonnative macrobenthos in the Wadden Sea ecosystem, Journal of Ocean Management 68: 89-101

Buschbaum, Christian; Lackschewitz, Dagmar; Reise, Karsten (2012) Nonnative macrobenthos in the Wadden Sea ecosystem, Journal of Ocean Management 68: <missing location>

Calder, Dale R. (1971) Hydroids and hydromedusae of southern Chesapeake Bay., Virginia Institute of Marine Science, Special Papers in Marine Science 1: 1-125

Calder, Dale R. (1972) Phylum Cnidaria, Special Scientific Report, Virginia Institute of Marine Science 65: 97-102

Calder, Dale R. (1976) The zonation of hydroids along salinity gradients in South Carolina estuaries, In: (Eds.) Coelenterate Ecology and Behavior. , New York. Pp. 165-174

Calder, Dale R. (1992) Seasonal cycles of activity and inactivity in some hydroids from Virginia and South Carolina, U.S.A., Canadian Journal of Zoology 68: 442-450

Calder, Dale R. (2019) On a collection of hydroids (Cnidaria, Hydrozoa) from the southwest coast of Florida, USA, Zootaxa 4689(1): 1-141

Calder, Dale R.; Hester, Betty S. (1978) Phylum Cnidaria., In: Zingmark, Richard G.(Eds.) An Annotated Checklist of the Biota of the Coastal Zone of South Carolina. , Columbia. Pp. 87-93

Calder, Dale R.; Kirkendale, Lisa (2005) Hydroids (Cnidaria, Hydrozoa) from shallow-water environments along the Caribbean coast of Panama., Caribbean Journal of Science 41(3): 476-491

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

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>

Carlton, James T.; Eldredge, Lucius (2009) Marine bioinvasions of Hawaii: The introduced and cryptogenic marine and estuarine animals and plants of the Hawaiian archipelago., Bishop Museum Bulletin in Cultural and Environmental Studies 4: 1-202

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>

Chesapeake Bay Program 1998-2001 Benthic Database.. <missing URL>



Chester, Charles M. (1996) The effect of adult nutrition on the reproduction and development of the estuarine nudibranch, Tenellia adspersa (Nordmann, 1845), Journal of Experimental Marine Biology and Ecology 198: 113-130

Çinar, Melih Ertan; Yoke, Mehmet Baki; Açik, Sermin; Bakir, Ahmet Kerem (2014) Check-list of Cnidaria and Ctenophora from the coasts of Turkey, Turkish Journal of Zoology 38: Published online

Clark, S. F. (1878) A new locality for Cordylophora, American Naturalist 12: 231-234

Cohen, Andrew N. (2004) <missing title>, San Francisco Estuary Institute, San Francisco CA. Pp. 1-50

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

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

Coles, S. L.; DeFelice, R. C. : Eldredge, L. G. (2002a) Nonindigenous marine species in Kaneohe Bay, Oahu, Hawai`i, Bishop Museum Technical Report 24: 1-364

Coma, R.; Ribes, M.; Orejas, C. ; Gili, J.-M. (1999) Prey capture by a benthic coral reef hydrozoan, Coral Reefs 18: 141}145

Conde, Anxo; Dominguez, Jorge; Novais, Julio M.; Ramil, Fran (2013) First record of Cordylophora caspia (Hydrozoa: Cnidaria) in the Tagus estuary, central Portugal, Marine Biodiversity Records 6: e114

Cory, R. L.; Nauman, J. W. (1969) Epifauna and thermal additions in the upper Patuxent River estuary., Chesapeake Science 10(3-4): 210-217

Cory, Robert L. (1967) Epifauna of the Patuxent River Estuary, Chesapeake Science 8(2): 71-89

Crandall, Marc. E. (1977) Epibenthic Invertebrates of Croton Bay in the Hudson River, New York Fish and Game Journal 24(2): 178-196

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>

Curry, Mary G.; Everitt, Betty; Vidrine, Malcolm F. (1981) Haptobenthos on shells of living freshwater clams in Louisiana, The Wasmann Journal of Biology 39(1-2): 56-62

DAISIE (Delivering Alien Invasive Species Inventories to Europe) (2009) Handbook of alien species in Europe, Springer, Dordrecht, Netherlands. Pp. 269-374

Darling, John A.; Folino-Rorem, Nadine C. (2009) Genetic analysis across different spatial scales reveals multiple dispersal mechanisms for the invasive hydrozoan Cordylophora in the Great Lakes, Molecular Ecology 18: 4827-4840

Davis, Charles C. (1957) Cordylophora lacustris Allman from Chagrin Harbor, Ohio, Limnology and Oceanography 2(2): 158-159

de Montaudouin, Xavier; Sauriau, Pierre-Guy (2000) Contributions to a synopsis of marine species richness in the Pertuis-Charentais Sea with new insights into the soft-bottom macrofauna of the Marennes-Oleron Bay, Cahiers de Biologie Marine 41: 181-222

Dean, Thomas A.; Bellis, Vincent J. (1975) Seasonal and spatial distribution of epifauna in the Pamlico River Estuary, North Carolina, Journal of the Elisha Mitchell Scientific Society 91(1): 1-12

Deevey, Edward S. (1950) Hydroids from Louisiana and Texas, with remarks on the Pleistocene biogeography of the western Gulf of Mexico, Ecology 31: 334-367

Defenbaugh, Richard E. (1973) <missing title>, Dept. for Marine Resources Information, Center for Marine Resources, Texas A & M University, College Station, Tex.. Pp. <missing location>

Dziubinska, Anna; Janas, Urszula (2007) Submerged objects: a nice place to live and develop. Succession of fouling communities in the Gulf of Gdansk, Southern Baltic, Oceanological and Hydrobiological Studies 36(4): 65-78

Eaton, Lawrence (1994) Preliminary survey of benthic macroinvertebrates of Currituck Sound, North Carolina, Journal of the Elisha Mitchell Scientific Society 110(3/4): 121-129

Environment Canada (1994) Fraser River Benthic Invertebrate Catalogue, In: None(Eds.) None. , <missing place>. Pp. <missing location>

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

Farrapeira, Cristiane Maria Rocha; Tenório, Deusinete de Oliveira ; do Amaral, Fernanda Duar (2011) Vessel biofouling as an inadvertent vector of benthic invertebrates occurring in Brazil, Marine Pollution Bulletin 62: 832-839

Folino-Rorem, Nadine C.; Darling. John A.; D’Ausilio, Cori A. (2009) Genetic analysis reveals multiple cryptic invasive species of the hydrozoan genus Cordylophora., Biological Invasions 11(8): 1869-1882

Folino-Rorem, Nadine; Indelicato, Jennifer (2005) Controlling biofouling caused by the colonial hydroid Cordylophora caspia., Water Research 39: 2731-2739

Folino-Rorem, Nadine; Stoeckel, James S. (2006) Exploring the coexistence of the hydroid Cordylophora caspia and the zebra mussel Dreissena polymorpha: counterbalancing effects of filamentous substrate and predation, Aquatic Invaders 17(2): 6-16

Folino-Rorem, Nadine; Stoeckel, James; Thorn, Emily; Page, Laura (2006) Effects of artificial filamentous substrate on zebra mussel (Dreissena polymorpha) settlement., Biological Invasions 8: 89-96

Folino, Nadine (2000) The freshwater expansion and classification of the colonial hydroid Cordylophora (phylum Cnidaria, class Hydrozoa)., In: Pederson, Judith(Eds.) Marine Bioinvasions. , Cambridge. Pp. 139-143

Fraser, C. McLean (1944) Hydroids of the Atlantic Coast of North America, In: (Eds.) . , Toronto. Pp. 1-441

Fulton, Chandler (1962) Environmental factors influencing the growth of Cordylophora, Journal of Experimental Zoology 151: 61-78

Fulton, Chandler S. (1960) Culture of a colonial hydroid under controlled conditions, Science 132: 473-474

Fulton, Chandler S. (1963) Development of a hydroid colony, Developmental Biology 6: 333-369

Galea, Horia R. (2007) Hydroids and hydromedusae (Cnidaria: Hydrozoa) from the fjords region of southern Chile., Zootaxa 1597: 1-116

Garcia-Berthou, Emili; Boix, Dani; Clavero, Miguel (2007) Biological invaders in inland water: Profiles, distribution and threats., Springer, Dordrecht, Netherlands. Pp. 123-140

Gaulin, Gary; Dill, Lauren; Beaulieu, Juli; Harris, Larry G. (1986) Predation-induced changes in growth form in a nudibranch hydroid association., Veliger 28(4): 389-393

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

Gravili, Cinzia and 12 authors (2010) Nonindigenous species along the Apulian coast, Italy, Chemistry and Ecology 26: 121-142

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

Grigorovich, Igor A; Korniushin, Alexei V.; Gray, Derek K.; Duggan, Ian C.; Colautti, Robert I.; MacIsaac, Hugh J. (2003) Lake Superior: an invasion coldspot?, Hydrobiologia 499: 191-210

Grohmann, Priscila A. (2008) Bioincrustation caused by a hydroid species in the turbine cooling system at the Funil hydroelectric power plant, Itatiaia, Rio de Janeiro, Brazil, Naturalia 31: 16-21

Guajardo, M. G.; Sanchez, H. V.; Salvador Contreras, Y. (1987) The cnidarians Craspedacusta sowerbyi new-record and Cordylophora lacustris new-record Hydrozoa for the Mexican fauna in Nuevo Leon, Publicaciones Biologicas Facultad de Ciencias Biologicas Universidad Autonoma de Nuevo Leon 2(2): 51-54

Haertel, Lois, Osterberg, Charles (1967) Ecology of zooplankton, benthos and fishes in the Columbia River Estuary, Ecology 48(3): 459-472

Hand, Cadet; Gwilliam, G. F. (1951) New distribution records for two athecate hydroids, Cordylophora lacustris and Candelabrum sp., from the West Coast of North America, with revisions of their nomenclature, Journal of the Washington Academy of Sciences 41(6): 206-209

Hargitt, Charles W. (1908) Notes on a few Coelenterates of Woods Holl., Biological Bulletin <missing volume>: 95-120

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

Hildebrand, Samuel F. (1939) The Panama Canal as a passageway for fishes, with lists and remarks on the fishes and invertebrates observed, Zoologica (New york Zoological Society) 24: 15-45

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

Hopkins, C.C.E. (2002) Invasive aquatic species of Europe: Distribution, impacts, and management, Kluwer Academic Publishers, <missing place>. Pp. 240-253

Huang, Zongguo; Li, Chuanyan; Zh Zheng, Chengxing (1981) [The distribution of fouling organsims in the Chiangjiang River Estuary], Oceanologia et Limnologica Sinica 12(6): 531-536

Hubschman, J. H.; Kishler, W. J. (1972) Craspedacusta sowerbii Lankester 1880 and Cordylophora lacustris 1871 in western Lake Erie (Coelenterata), Ohio Journal of Science 72(6): 318-321

Hubschman, Jerry H. (1971) Lake Erie: Pollution abatement, then what?, Science 171: 536-540

Hutchinson, G. Evelyn (1993) The Zoobenthos. Vol. 4., A Treatise in Limnology., In: (Eds.) A Treatise on Limnology.. , New York. Pp. <missing location>

Jablonska-Barna, Izabela; Rychter, Agata; Kruk, Marek (2013) Biocontamination of the western Vistula Lagoon (south-eastern Baltic Sea, Poland), Oceanologia 53(3): 751-763

Jazdzewsi, Krzysztof; Konopacka, Alicja (2002) Invasive aquatic species of Europe: Distribution, impacts, and management., Kluwer Academic Publishers, Dordrecht. Pp. 383-398

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

Jones, M. L.; Rutzler, K. (1975) Invertebrates of the upper chamber, Gatun Locks, Panama Canal, with emphasis on Trochospongilla leidii (Porifera), Marine Biology 33: 57-66

Jormalainen, V.; Honkanen, T.; Vuorisalo, T.; Laithonen, Pasi (1994) Growth and reproduction of an estuarine population of the colonial hydroid Cordylophora caspia (Pallas) in the northern Baltic Sea, Helgoländer Meeresuntersuchungen 48: 407-418

Kelly, Jess P., Franks, Jessica L. (1995) Cordylophora lacustris (Cnidaria: Clavidae) from Livingston Reservoir in east Texas., Texas Journal of Science 47(4): 319-321

Kerckhof, Francis; Haelters, Jan; Gollasch, Stephan G. (2007) Alien species in the marine and brackish ecosystem: the situation in Belgian waters., Aquatic Invasions 2(3): 243-257

Kinne, O. (1956) Uber den einfluß des salzegehaltes und der temperatur auf wachstum, form, und vermehrung bei dem Hydroidpolypen Cordylophora caspia (PALLAS), Thecata, Clavidae)., Zoologische Jahrbucher Abteilung Allgemaine Zoologie und Physiologie der Tiere 66: 565-638

Kinne, Otto (1957) Adaption to salinity and temperature in a euryhaline hydroid, Biological Bulletin 113(2): 330

Kinne, Otto (1958) Adaption to salinity variation - some facts and problems., In: Prosser, C. Ladd(Eds.) Physiological Adaptation - A Symposium.. , Washington, D.C.. Pp. 92-106

Larsen, Peter F. (1985) The benthic fauna associated with the oyster reefs of the James River estuary, Virginia, U. S. A., Internationale Revue der Gesamten Hydrobiologie 70(9): 707-814

Leidy, Joseph (1870) Cordylophora americana, Proceedings of the Academy of Natural Sciences of Philadelphia 22: 113

Leland, Harry V.; Fend, Steven V. (1998) Benthic invertebrate distributions in the San Joaquin River, California, in relation to physical and chemical factors., Canadian Journal of Fisheries and Aquatic Science 55: 1051-1067

Leppäkoski, Erkki (1984) Introduced species in the Baltic Sea and its coastal ecosystems, Ophelia 3(Suppl. 3): 123-135

Leppäkoski, Erkki (1994) Non-indigenous species in the Baltic Sea., In: Boudouresque, C.F., Briand, F., and Nolan, C.(Eds.) Introduced Species in European Coastal Waters.. , Brussels. Pp. 67-75

Lippson, Alice J. (1973) Life in Chesapeake Bay, Johns Hopkins University Press, Baltimore, MD. Pp. <missing location>

Lippson, Alice Jane; Lippson, Robert L. (1997) <missing title>, Johns Hopkins University Press, Baltimore. Pp. <missing location>

Lipsey, Louis L., Jr.; Chimeny, Michael J. (1978) New distribution records of Cordylophora lacustris and Craspedacusta sowerbyi (coelenterata) in southern Illinois, Ohio Journal of Science 78(5): 280

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

Llansó, Roberto J.; Sillett, Kristine; Scott, Lisa (2011) <missing title>, Versar, Inc., Columbia MD. Pp. <missing location>

Lu, L.; Levings, C. D.; Piercey, G. E. (2007) Preliminary investigation on aquatic invasive species of marine and estuarine macroinvertebrates on floating structures in five British Columbia harbours, Canadian Manuscript Report of Fisheries and Aquatic Sciences 2814: 2-30

Mace, T.F.; Mackie, G.O. (1970) A study of an estuarine lagoon, with particular reference to Cordylophora lacustris., Canadian Journal of Zoology 48: 1454-1456

Mason, William T., Jr., Mattson, Robert A., Epler, John H. (1994) Benthic invertebrates and allied macrofauna in the Suwannee River and estuary ecosystem, Florida, Florida Scientist 57(4): 141-160

Massard, Joseph A.; Geimer, Gaby (1990) Notice sur les Bryozoaires du lac d'Echternach at du lac de la Haute-Sure ainsi que sur la presence de l'Hydrozoaire Cordylophora caspia (Pallas, 1771) dans las centrale nucleaire Cattenom, Bulletin de la Societe des Naturalistes Luxembourgeois 90: 163-168

Matern, Scott A.; Brown, Larry R. (2005) Invaders eating invaders: exploitation of novel alien prey by the alien shimofuri goby in the San Francisco estuary, California., Biological Invasions 7: 497-507

Mattson, Robert A. (2011) <missing title>, St. Johns River Water Management District, Palatka FL. Pp. unpaged

McClung, Dan; Davis, Jack R. (1983) Additional records of Cordylophophora lacustris., Southwestern Naturalist 28(1): <missing location>

McClung, G. Dan; Davis, Jack R.; Commander, Darrell; Pettitt, John; Cover, Ellen C. (1978) First records of Cordylophora lacustris, 1871 (Hydroida: Clavidae) in Texas with morphological and ecological notes., Southwestern Naturalist 23(3): 363-370

Meek, Mariah H.; Wintzer, Alpa P.; Wetzel, William C.; May, Bernie (2012) Climate change likely to facilitate the invasion of the non-native hydroid, Cordylophora caspia, in the San Francisco estuary, PLOS ONE 7(10): e46373

Migotto, Alvaro E.; Marques, Antonio C.; Morandini, André C.; da Silveira, Fábio L. (2002) Checklist of the Cnidaria Medusozoa of Brazil, Biota Neotropica 2(1): 1-31

Mills, Claudia; Marques, Antonio; Migotto, Alvaro E; Calder, Dale R.; Hand, Cadet (2007) The Light and Smith Manual: Intertidal invertebrates from Central California to Oregon (4th edition), University of California Press, Berkeley CA. Pp. 118-168

Mills, Edward L.; Scheuerell, Mark D.; Carlton, James T.; Strayer, David (1997) Biological invasions in the Hudson River: an inventory and historical analysis., New York State Museum Circular 57: 1-51

MIT Sea Grant 2003-2008 Introduced and cryptogenic species of the North Atlantic. <missing URL>



Mordukhai-Boltovskoi, Ph. D. (1964) Caspian fauna beyond the Caspian Sea, Internationale Revue der Gesamten Hydrobiologie 49(1): 139-170

Mordukhay-Boltovskoi, Ph. D. (1964) Caspian fauna in fresh waters outside the Ponto Caspian basin, Hydrobiologia 13(1-2): 159-164

Morri, C.; Bianchi, C. N. (1983) [Contributions to knowedge of the hydrozoans of the Italian lagoons: Hydropolyps of the Po Delta (north Adriatic)], Atti del Museo Civico di Storia Naturale di Trieste 35: 185-205

Nakano, Daisuke; Strayer, David L. (2014) Biofouling animals in fresh water: biology, impacts, and ecosystem engineering, Frontiers in Ecology and the Environment 12(3): 167: 175

Naumov, D. V. (1969) <missing title>, Israel Program for Scientific Translations, Jerusalem. Pp. <missing location>

Nehring, Stefan (2006) Four arguments why so many alien species settle into estuaries, with special reference to German River Elbe., Helgoland Marine Research 60: 127-134

NIMPIS (National Introduced Marine Pest Information System). 1998-2015 NIMPIS (National Introduced Marine Pest Information System). <missing URL>



Nunn, Julia; Minchin, Dan 2013 Marine non-native invasive species in Northern Ireland. <missing URL>



Obolewski, Krystian; Jarosiewicz, Anna; Ozgo, Ma?gorzata (2015) Invasive Ponto-Caspian hydrozoan Cordylophora caspia (Hydrozoa: Cnidaria) in southern Baltic coastal lakes, Estuarine, Coastal and Shelf Science 167: 147-153

Olenin, S., Leppakoski, E. 2000-2016 Inventory of Baltic Sea alien species. <missing URL>



Olenin, S., Olenina, I., Daunys, D., Gaiunaite, Z. (1999) <missing title>, Nordic Council of Ministers, Copenhagen. Pp. 185-202

Olenin, Sergej (2002) Black Sea-Baltic invasion corridors, CIESM Workshop Monographs 20: 29/33

Olenin, Sergej, Leppakoski, Erkki (1999) Non-native animals in the Baltic Sea: alteration of benthic habitats in coastal inlets and lagoons., Hydrobiologia 393: 233-243

Oliveira, Otto M. P. and 24 authors (2016) Census of Cnidaria (Medusozoa) and Ctenophora from South American marine waters, Zootaxa 4194: 1-256

Paavola, Marjo; Olenin, Sergei; Leppakoski, Erkki (2005) Are invasive species most successful in habits of low native species richness across European brackish water seas?, Estuarine Coastal and Shelf Science 64: 738-750

Paavolo, Marjo; Laine, Ari O.; Helavuori, Markius; Kraufvelin, Patrik (2008) Profiling four brackish water harbours: zoobenthic composition and invasion status., Boreal Environment Research 13: 159-175

Panov, Vadin, Krylov, Pyotr I., Telesh, Irena V. (1999) <missing title>, <missing publisher>, Copenhagen. Pp. <missing location>

Pearse, A. S. (1936) Estuarine animals at Beaufort, North Carolina, Journal of the Elisha Mitchell Scientific Society 52(2): 174-224

Pennak, Robert W. (1978) <missing title>, John Wiley & Sons, New York. Pp. <missing location>

Pennak, Robert W. (1989) <missing title>, John Wiley & Sons, Inc., New York. Pp. 603 pages

Poirrier, Michael A.; Denoux, Guy J. (1973) Notes on the distribution, ecology, and morphology of the colonial hydroid Cordylophora caspia (Pallas) in southern Louisiana, Southwestern Naturalist 18(2): 253-255

Poirrier, Michael A.; Mulino, Maureen M. (1977) Impact of the 1975 Bonnet Carré spillway opening on epifaunal invertebrates in southern Lake Pontchartrain, Journal of the Elisha Mitchell Scientific Society 93(1): 11-18

Potts, E. (1884) On the minute fauna of Fairmount Reservoir., Proceedings of the Academy of Natural Sciences of Philadelphia 36: 217-219

Pucherelli, Sherri F.; Keele, Jacque; Passamaneck, Yale J.; Beaver, John R.; Renicker, Thomas R. (2016) Range expansion of the invasive hydroid, Cordylophora caspia (Pallas, 1771), in Colorado River reservoirs, BioInvasions Records 5: In press

Ransom, John D. (1981) First record of Cordylophora lacustris Allman from Kansas, Transactions of the Kansas Academy of Sciences 84(4): 225-227

Ribeiro, Romeu S.; Mata, Ana M. T. ; Salgado, Ricardo; Gandra, Vasco; Afonso, Inês; Galhanas, Dina; Dionísio, Maria Ana; Chainho, Paula (2023) Undetected non-indigenous species in the Sado estuary (Portugal), a coastal system under the pressure of multiple vectors of introduction, Journal of Coastal Conservation 27(53): Published online
https://doi.org/10.1007/s11852-023-00979-3

Ristich, S. S., Crandall, M., Fortier, J. (1977) Benthic and epibenthic macroinvertebrates of the Hudson River I. Distribution, natural history, and community structure, Estuarine and Coastal Marine Science 5: 255-266

Roos, P. J. (1979) Two-stage life cycle of a Cordylophora population in the Netherlands, Hydrobiologia 62(3): 231-239

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>

Schuchert, Peter (1996) The marine fauna of New Zealand: Athecate hydroids oand their medusae (Cnidara: Hydrozoa), New Zealand Oceanographic Institute Memoir 106: 1-159

Schuchert, Peter (2004) Revision of the European athecate hydroids and their medusae (Hydrozoa, Cnidaria): Families Oceanidae and Pachycordylidae, Revue Suisse de Zoologie 111(2): 315-369

Siegfried, Clifford A.; Kopache, Mark E.; Knight, Allen W. (1980) The benthos of a portion of the Sacramento River (San Francisco Bay estuary) during a dry year, Estuaries 3(4): 296-307

Simberloff, Daniel (2006) Invasional meltdown 6 years later: important phenomenon, unfortunate metaphor, or both?, Ecology Letters 9: 912-919

Simkina. R. G. (1963) {On the ecology of the hydroid polyp Perigonimus megas Kinne- a new species in the fauna of the USSR.], Akademiya Nauk SSSR - Trudy Instituta Okeanologii 70: 216-224

Slobodkin, Lawrence B.; Bossert, Patricia E. (1991) Ecology and Classification of North American Freshwater Invertebrates, Academic Press, London. Pp. 125-143

Smith, Douglas G. (1991) <missing title>, University of Massachusetts, Boston. Pp. 1-236

Smith, Douglas G.; Werle, Sean F.; Klekowski, Edward (2002) The rapid colonization and emerging biology of Cordylophora caspia (Pallas,1771) (Cnidaria: Clavidae) in the Connecticut River, Journal of Freshwater Ecology 17(3): 423-430

Smith, Frank (1910) Hydroids in the Illinois River, Biological Bulletin 18(2): 67-68

Sommer, Christian (1992) Larval biology and dispersal of Eudendrium racemosum (Hydrozoa, Eudendriidae), Scientia Marina 56(2-3): 205

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

Spoon, Donald M. (1976) Microbial communities of the upper Potomac estuary: the Aufwuchs., In: Mason, William T.; Flynn, Kevin C.(Eds.) The Potomac Estuary: Biological Resources - Trends and Options. , Bethesda, MD. Pp. 63-69

Spoon, Donald M., Blanquet, Richard S. (1976) Life cycle and ecology of the minute hydrozoon Microhydrula, Transactions of the American Microscopical Society 97(2): 208-216

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

Sumner, Francis B.; Osburn, Raymond C.; Cole, Leon J.; Davis, Bradley M. (1913b) A biological survey of the waters of Woods Hole and vicinity Part II. Section III. A catalogue of the marine fauna Part II. Section IV. A catalogue of the marine flora, Bulletin of the Bureau of Fisheries 31: 539-860

Sytsma, Mark D.; Cordell, Jeffrey R.; Chapman, John W.; Draheim, Robyn, C. (2004) <missing title>, Center for Lakes and Reservoirs, Portland State University, Portland OR. Pp. <missing location>

Sytsma, Mark; Cordell, Jeff; Chapman, John; Miller, Rich; Draheim, Robyn; (2004) Lower Columbia River aquatic nonindigenous species survey 2001-2004: Final technical report, Portland State University, Portland. Pp. <missing location>

Trebitz, Anett S. and 5 authors (2010) Status of non-indigenous benthic invertebrates in the Duluth-Superior Harbor and the role of sampling methods in their detection, Journal of Great Lakes Research 36: 747-756

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



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



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

Vervoort, W. (1964) Note on the distribution of Garveia franciscana (Torrey 1902) and Cordylophora caspia (Pallas, 1771) in the Netherlands., Zoologische Mededelingen 39: 125-146

Von Holle, Betsy; Ruiz, Greg M. (1997) 25th Benthic Ecology Meeting- Abstracts, 25th Benthic Ecology Meeting, Portland ME. Pp. 97

Vuorinen, Ilppo; Laihonen, Pasi; Lietzén, Erkki (1986) Distribution and abundance of invertebrates causing fouling in power plants on the Finnish coast, Memoranda Societatis pro Fauna et Flora Fennica 62: 123-125

Walton, William C. (1996) Occurrence of zebra mussel (Dreissena polymorpha) in the oligohaline Hudson River, New York., Estuaries 19(3): 612-618

Wasson, Kerstin; Toft, Jason; Von Holle, Betsy; Ruiz, Gregory (2000) Detecting invasions of marine organisms: kamptozoan case histories., Biological Invasions 2: 59-74

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

Williams, Bolton S.; Hogan, Terry; Zo, Zinntae (1973) Hudson River Ecology: Proceedings of a Symposium, Hudson River Environmental Society, <missing place>. Pp. unpaged

Wintzer, Alpa P.; Meek, Mariah H.; Moyle, Peter B.; May, Bernie (2011a) Ecological insights into the polyp stage of non-native hydrozoans in the San Francisco Estuary, Aquatic Ecology 45: 151-161

Wittfoth, Anne K. J.; Zettler, Michael L. (2013) The application of a Biopollution Index in German Baltic estuarine and lagoon waters, Management of Biological Invasions 4: in press

Wolff, W. J. (2005) Non-indigenous marine and estuarine species in the Netherlands., Zoologische Verhandelingen 79(1): 1-116

Wolff, Wim (1999) Exotic invaders of the mes-oligohaline zone of estuaries in the Netherlands: why are there so many?, Helgoländer Wissenschaftliche Meeresuntersuchungen 52: 393-400

Wonham, Marjorie; Lewis, Mark A.; MacIsaac, Hugh J. (2005) Minimizing invasion risk by reducing propagule pressure: a model for ballast water exchange., Frontiers in Ecology and the Environment 3(9): 473-478

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

Wurtz, Charles B.; Roback, Selwyn S. (1955) Invertebrate fauna of some Gulf coast rivers, Proceedings of the Academy of Natural Sciences of Philadelphia 107: 167-206

Young, Craig S; Gobler, Christopher J. (None) Coastal ocean acidification and nitrogen loading facilitate invasions of the non-indigenous red macroalga, Dasysiphonia japonica, Biological Invasions <missing volume>: 1367-1391(

Zaiko, Anastasija; Lehtiniemi, Maiju; Narscius, Aleksas; Olenin, Sergej (2011) Assessment of bioinvasion impacts on a regional scale: a comparative approach, Biological Invasions 13: 1739-1765

Zettler, Michael L.; Daunys, Darius (2007) Long-term macrozoobenthos changes in a shallow boreal lagoon: Comparison of a recent biodiversity inventory with historical data., Limnologica 37: 170-185

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