Codium fragile subsp. tomentosoides
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Biology and Ecology
- Latitude/Altitude Ranges
- Water Tolerances
- Natural enemies
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Impact Summary
- Economic Impact
- Environmental Impact
- Threatened Species
- Social Impact
- Risk and Impact Factors
- Similarities to Other Species/Conditions
- Prevention and Control
- Links to Websites
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Codium fragile subsp. tomentosoides
International Common Names
- English: dead man’s fingers; green fleece
Local Common Names
- Netherlands: viltwier
- UK/England and Wales: green sea fingers
- USA: sputnik weed
Summary of InvasivenessTop of page
C. fragile ssp. tomentosoides is considered as an invasive marine alga as it has the capacity to spread rapidly via asexual reproduction and fragmentation, and has invaded many coastal waters including those of Europe and America. Its spread has also had a negative impact on benthic communities. C. fragile ssp. tomentosoides can become a dominant member in invaded habitats and can alter community composition and function. In addition, it can tolerate wide ranges of temperature and salinity which contribute to it becoming a dominant species when conditions permit.
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Chlorophyta
- Class: Bryopsidophyceae
- Order: Bryopsidales
- Family: Codiaceae
- Genus: Codium
- Species: Codium fragile subsp. tomentosoides
Notes on Taxonomy and NomenclatureTop of page
The centre of Codium fragile diversity is assumed to be in East Asia (Japan and Korea), where the species is highly variable (Silva, 1955; Provan et al., 2005). In general, C. fragile is considered to have six subspecies, three of which (including C. fragile ssp. tomentosoides) are considered as weeds in several parts of the world (Silva, 1955; 1957; Trowbridge, 1998; 1999). However, in Japan and Korea, C. fragile is considered a single species with no subspecies (Segawa, 1996; Chavanich et al., 2006).
DescriptionTop of page
C. fragile ssp. tomentosoides is a dark green alga, up to 1 m in length. It is composed of dichotomous cylindrical branches, 0.5-1.0 cm in diameter. It is made up of interwoven filaments ending in a layer of swollen utricles that cover the surface of the thallus (Villalard-Bohnsack, 1995). Reproduction of C. fragile ssp. tomentosoides is either by motile unicells or vegetative fragments(Chapman, 1999; Mathieson et al.,2003). C. fragile ssp. tomentosoides also has parthenogenetic gametes that germinate without fertilization (Trowbridge, 1999). During the winter, extensive fragmentations occur as a result of low temperatures which cause thallus constriction and segmentation (Fralick and Mathieson, 1972).
DistributionTop of page
C. fragile ssp. tomentosoides has spread throughout the northern and southern hemispheres including the northeastern and northwestern Atlantic, the Mediterranean, Australia, New Zealand, the eastern central Pacific, and southeastern Pacific. In east Asia (Japan and Korea), where Codium fragile is a native species, its spread is restricted to areas where water temperatures are between 10-20°C (Lee and Kang, 1986; Segawa, 1996). However, when invading new habitats, C. fragile ssp. tomentosoides can withstand temperatures as low as -2°C (Fralick and Mathieson, 1972).
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Atlantic, Northeast||Widespread||Introduced||Invasive||Trowbridge, 1999; Provan et al., 2005; Guiry and Guiry, 2007|
|Atlantic, Northwest||Widespread||Introduced||Invasive||Trowbridge, 1999; Hubbard and Garbary, 2002; Begin and Scheibling, 2003; Provan et al., 2005|
|Atlantic, Southeast||Widespread||Introduced||Invasive||Begin and Scheibling, 2003|
|Atlantic, Western Central||Widespread||Introduced||Invasive||Provan et al., 2005|
|Indian Ocean, Eastern||Widespread||Introduced||Invasive||Trowbridge, 1999|
|Mediterranean and Black Sea||Widespread||Introduced||Invasive||Trowbridge, 1999; Provan et al., 2005; Guiry and Guiry, 2007|
|Pacific, Eastern Central||Widespread||Introduced||Invasive||Trowbridge, 1999|
|Pacific, Northwest||Localised||Native||Not invasive||Provan et al., 2005; Chavanich et al., 2006|
|Pacific, Southeast||Widespread||Introduced||Invasive||Provan et al., 2005|
|Pacific, Southwest||Widespread||Introduced||Invasive||Trowbridge, 1998; Begin and Scheibling, 2003|
|Japan||Present||Present based on regional distribution.|
|-Hokkaido||Localised||Native||Not invasive||Provan et al., 2005|
|-Honshu||Localised||Native||Not invasive||Provan et al., 2005; Chavanich et al., 2006|
|Korea, Republic of||Localised||Native||Not invasive||Chavanich et al., 2006|
|Turkey||Widespread||Introduced||Invasive||Guiry and Guiry, 2007|
|Algeria||Widespread||Introduced||Invasive||Guiry and Guiry, 2007|
|South Africa||Widespread||Introduced||Invasive||Begin and Scheibling, 2003|
|Tunisia||Widespread||Introduced||Invasive||Guiry and Guiry, 2007|
|Canada||Present||Present based on regional distribution.|
|-New Brunswick||Widespread||Introduced||Invasive||Hubbard and Garbary, 2002; Begin and Scheibling, 2003|
|-Nova Scotia||Widespread||Introduced||Invasive||Chapman, 1999; Hubbard and Garbary, 2002; Begin and Scheibling, 2003|
|-Prince Edward Island||Widespread||Introduced||Invasive||Hubbard and Garbary, 2002; Begin and Scheibling, 2003|
|USA||Present||Present based on regional distribution.|
|-California||Widespread||Introduced||Invasive||Trowbridge, 1999||First found in 1977|
|-Connecticut||Widespread||Introduced||Invasive||Carlton and Scanlon, 1985; Begin and Scheibling, 2003||First found in Fishers Island Sound in 1961|
|-Maine||Widespread||Introduced||Invasive||Carlton and Scanlon, 1985; Begin and Scheibling, 2003||First found in Boothbay Habour in 1964|
|-Massachusetts||Widespread||Introduced||Invasive||Carlton and Scanlon, 1985; Begin and Scheibling, 2003||First found on south shore of Cape Cod in 1961|
|-New Hampshire||Widespread||Introduced||Invasive||Carlton and Scanlon, 1985; Provan et al., 2005||First found in Isles of Shoals, Appledore Island in 1983|
|-New Jersey||Widespread||Introduced||Invasive||Carlton and Scanlon, 1985; Trowbridge, 1999||First found in Barnegat Bay in 1966|
|-New York||Widespread||Introduced||Invasive||Carlton and Scanlon, 1985; Begin and Scheibling, 2003||First found in Long Island Sound in 1957|
|-North Carolina||Widespread||Introduced||Invasive||Carlton and Scanlon, 1985; Provan et al., 2005||First found in Onslow Bay between Cape Fear and Cape Lookout in 1979|
|-Rhode Island||Widespread||Introduced||Invasive||Carlton and Scanlon, 1985; Trowbridge, 1999||First found in Narragansett Bay between 1962 and 1968|
|-Virginia||Widespread||Introduced||Invasive||Carlton and Scanlon, 1985; Trowbridge, 1999||First found in Assateague Channel in 1976|
|Chile||Widespread||Introduced||Invasive||Neill et al., 2003; Provan et al., 2005||First record in Northern Chile in 1998|
|Denmark||Widespread||Introduced||Invasive||Trowbridge, 1999||First recorded in 1919|
|France||Widespread||Introduced||Invasive||Provan et al., 2005; Guiry and Guiry, 2007|
|Greece||Widespread||Introduced||Invasive||Provan et al., 2005; Tsiamis and Panayotidis, 2007||First found in Maliakos Gulf in 1992|
|Ireland||Widespread||Introduced||Invasive||Trowbridge, 1999; Provan et al., 2005; Guiry and Guiry, 2007||First recorded in 1941|
|Italy||Widespread||Introduced||Invasive||Guiry and Guiry, 2007|
|Netherlands||Widespread||Introduced||Invasive||Trowbridge, 1999; Provan et al., 2005||First recorded in ca. 1900|
|Norway||Widespread||Introduced||Invasive||Trowbridge, 1999||First recorded in 1946|
|Portugal||Widespread||Introduced||Invasive||Guiry and Guiry, 2007|
|Slovenia||Widespread||Introduced||Invasive||Provan et al., 2005|
|Spain||Widespread||Introduced||Invasive||Provan et al., 2005; Guiry and Guiry, 2007|
|Sweden||Widespread||Introduced||Invasive||Trowbridge, 1999||First recorded in 1933|
|UK||Widespread||Introduced||Invasive||Trowbridge, 1999; Provan et al., 2005; Guiry and Guiry, 2007||First recorded in England in 1939, and first recorded in Scotland in 1953|
|Australia||Present||Present based on regional distribution.|
|-New South Wales||Widespread||Introduced||Invasive||Trowbridge, 1999|
|-South Australia||Widespread||Introduced||Invasive||Trowbridge, 1999|
|-Victoria||Widespread||Introduced||Invasive||Trowbridge, 1999||First found in 1995 at Corner Inlet|
|-Western Australia||Widespread||Introduced||Invasive||Trowbridge, 1999|
|New Zealand||Widespread||Introduced||Trowbridge, 1999; Begin and Scheibling, 2003||first found in Auckland Harbour in 1973|
History of Introduction and SpreadTop of page
C. fragile ssp. tomentosoides is native to east Asia; the first exotic occurrence being in Holland around 1900, presumably introduced with shellfish (Silva, 1955, 1957). It then spread rapidly across the Mediterranean and Europe during the World War II (Silva, 1955, 1957; Trowbridge and Todd, 1999). It was first observed in Long Island Sound on the northwest Atlantic Coast in 1957 (Bouck and Morgan, 1957). Later in 1977, it was found in San Francisco Bay, California, USA (Silva, 1979). In the southern hemisphere, it was first found in Auckland Harbour, New Zealand in 1973 (Dromgoole, 1975).
Risk of IntroductionTop of page
There are three potential vectors for the transoceanic and or transcontinental dispersal of C. fragile ssp. tomentosoides:
HabitatTop of page
C. fragile ssp. tomentosoides can be found year around on open coasts, estuaries, tide pools, and intertidal and subtidal zones. It attaches to rocks, shells, or other hard substrates, and is often covered with epiphytic species (Villalard-Bohnsack, 1995). It is also found in sheltered habitats such as bays and harbours (Mathieson et al., 2003). In its native range, C. fragile is a member of the underwater understory assemblage below the dominant canopy species whereas in disturbed or invaded habitats, C. fragile is a dominant canopy species (Chavanich et al., 2006). In addition, in its native range, it can be found to depths of 18 m, and colonizes novel substrates such as floating docks and piles (Chavanich et al., 2006).
Habitat ListTop of page
|Coastal areas||Principal habitat||Harmful (pest or invasive)|
|Coastal areas||Principal habitat||Natural|
|Coastal areas||Principal habitat||Productive/non-natural|
|Mud flats||Present, no further details||Harmful (pest or invasive)|
|Mud flats||Present, no further details||Natural|
|Mud flats||Present, no further details||Productive/non-natural|
|Intertidal zone||Present, no further details||Harmful (pest or invasive)|
|Intertidal zone||Present, no further details||Natural|
|Intertidal zone||Present, no further details||Productive/non-natural|
|Salt marshes||Present, no further details||Harmful (pest or invasive)|
|Salt marshes||Present, no further details||Natural|
|Salt marshes||Present, no further details||Productive/non-natural|
|Estuaries||Present, no further details||Harmful (pest or invasive)|
|Estuaries||Present, no further details||Natural|
|Estuaries||Present, no further details||Productive/non-natural|
|Benthic zone||Principal habitat||Harmful (pest or invasive)|
|Benthic zone||Principal habitat||Natural|
|Benthic zone||Principal habitat||Productive/non-natural|
Biology and EcologyTop of page Genetics
Provan et al.(2005) reported that in its native range of Japan, there were low levels of genetic variation in C. fragile ssp. tomentosoides, with only four haplotypes present. Two of these haplotypes were also found in populations introduced to other countries from Japan. The authors conclude that there were at least two separate introductions of C. fragile ssp. tomentosoides from Japan.Reproductive Biology
Sexual, parthenogenetic and vegetative reproduction has been reported in C. fragile ssp. tomentosoides (Fralick and Mathieson, 1972; Chapman, 1999; Trowbridge, 1999). Gametangia containing two types of biflagellate cells have been found, although the function of male gametes is still unclear (Prince, 1988; Trowbridge, 1999). Bulleri et al. (2007) found that habitat had an influence on the growth and reproduction of C. fragile ssp. tomentosoides.
Fralick and Mathieson (1973) showed that optimal conditions for net photosynthesis of C. fragile ssp. tomentosoides were between 21-24°C and 900-1100 foot-candles.
ClimateTop of page
|Cf - Warm temperate climate, wet all year||Tolerated||Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year|
|Cs - Warm temperate climate with dry summer||Preferred||Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers|
|Cw - Warm temperate climate with dry winter||Tolerated||Warm temperate climate with dry winter (Warm average temp. > 10°C, Cold average temp. > 0°C, dry winters)|
|Df - Continental climate, wet all year||Tolerated||Continental climate, wet all year (Warm average temp. > 10°C, coldest month < 0°C, wet all year)|
|Ds - Continental climate with dry summer||Tolerated||Continental climate with dry summer (Warm average temp. > 10°C, coldest month < 0°C, dry summers)|
|Dw - Continental climate with dry winter||Tolerated||Continental climate with dry winter (Warm average temp. > 10°C, coldest month < 0°C, dry winters)|
Latitude/Altitude RangesTop of page
|Latitude North (°N)||Latitude South (°S)||Altitude Lower (m)||Altitude Upper (m)|
Water TolerancesTop of page
|Parameter||Minimum Value||Maximum Value||Typical Value||Status||Life Stage||Notes|
|Depth (m b.s.l.)||1||9||Optimum|
|Salinity (part per thousand)||30||35||Optimum||12-40 tolerated|
|Water temperature (ºC temperature)||10||25||Optimum||-2-34 tolerated|
Natural enemiesTop of page
|Natural enemy||Type||Life stages||Specificity||References||Biological control in||Biological control on|
|Elysia maoria||Herbivore||Whole plant||to genus||Trowbridge, 1995|
|Elysia viridis||Herbivore||Whole plant||to genus||Trowbridge and Todd, 2001|
|Lacuna vincta||Herbivore||Whole plant||not specific||Chavanich and Harris, 2004|
|Placida dendritica||Herbivore||Whole plant||to genus||Harris and Mathieson, 2000; Trowbridge, 1995|
|Strongylocentrotus droebachiensis||Herbivore||Whole plant||not specific||Prince and LeBlanc, 1992|
|Turbo smaragdus||Herbivore||Whole plant||not specific||Trowbridge, 1995|
Notes on Natural EnemiesTop of page
Natural enemies of C. fragile ssp. tomentosoides are usually herbivores such as molluscs, crustaceans, and echinoderms (Harris and Mathieson, 2000; Harris and Tyrrell, 2001; Scheibling and Anthony, 2001; Trowbridge and Todd, 2001; Chavanich and Harris, 2002; Chavanich and Harris, 2004). However, because these herbivores are small and C. fragile ssp. tomentosoides is not a palatable alga (Prince and LeBlanc, 1992; Trowbridge, 1995; Chavanich and Harris, 2004), the impact of herbivores on C. fragile ssp. tomentosoides populations is quite low. One group of snails of the genus Sacoglossa, typically found associated with siphonaceous alga, contain several species that are known to feed on C. fragile (Trowbridge, 1992; 1993; Harris and Mathieson, 2000; Trowbridge and Todd, 2001; Trowbridge, 2002; van Bragt, 2004).
Means of Movement and DispersalTop of page
C. fragile ssp. tomentosoides can be spread or introduced through natural dispersal such as water currents and by accidental introduction via ship’s hulls and shellfish. It also can be spread via boating, and packing material for fishery products.
There are four major dispersal mechanisms of C. fragile ssp. tomentosoides (from Carlton and Scanlon, 1985):
Harris and Tyrrell (2001) also report on the possible linkage between the spread of C. fragile ssp. tomentosoides and climate change in the Gulf of Maine, USA.
Impact SummaryTop of page
Economic ImpactTop of page
C. fragile ssp. tomentosoides can have an economic impact on shellfish and fishing industries. It can smother mussels and scallops, reduce the biomass of oysters, lift the shellfish off the sea floor, foul the nets, and clog scallop dredges (Trowbridge, 1999). This leads to an increase in labour costs during harvesting and processing associated with the need to remove the algae (Carlton and Scanlon, 1985; Trowbridge, 1999).
Environmental ImpactTop of page
Impact on Habitats
Because C. fragile ssp. tomentosoides is an opportunistic alga, its spread can alter the ecosystem by replacing the dominant species such as kelp (Harris and Tyrrell, 2001). In native habitats, C. fragile ssp. tomentosoides not only increases its density in benthic communities but also colonizes novel substrates like floating docks and pilings (Chavanich et al., 2006).
Threatened SpeciesTop of page
Social ImpactTop of page
In native ranges in Korea, C. fragile is consumed by local people as soup.
Risk and Impact FactorsTop of page Invasiveness
- Invasive in its native range
- Proved invasive outside its native range
- Highly adaptable to different environments
- Is a habitat generalist
- Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
- Pioneering in disturbed areas
- Long lived
- Fast growing
- Has high reproductive potential
- Reproduces asexually
- Has high genetic variability
- Altered trophic level
- Damaged ecosystem services
- Ecosystem change/ habitat alteration
- Increases vulnerability to invasions
- Infrastructure damage
- Modification of natural benthic communities
- Modification of successional patterns
- Monoculture formation
- Negatively impacts aquaculture/fisheries
- Reduced native biodiversity
- Threat to/ loss of native species
- Competition - monopolizing resources
- Competition - shading
- Competition - smothering
- Interaction with other invasive species
- Rapid growth
- Highly likely to be transported internationally accidentally
- Difficult to identify/detect as a commodity contaminant
- Difficult/costly to control
Similarities to Other Species/ConditionsTop of page
Gross morphological differences among the subspecies of C. fragile are not obvious. However, they can be differentiated on the variation in size and shape of utricles (Silva, 1955, 1957). C. fragile ssp. tomentosoides has utricles with pointed apices and a distinct constriction in the middle (Villalard-Bohnsack, 1995; Trowbridge, 1999).
Prevention and ControlTop of page
Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
To date there are no obvious action plans involving the management and eradication of C. fragile ssp. tomentosoides. There are also no plans to restore habitats invaded by this alga. However, Trowbridge (1999) suggests several potential methods of reducing and preventing further spread of C. fragile ssp. tomentosoides:
- Chemical treatment such as using Diquat, Stomp, copper sulphate or sodium hypochlorite
- Mechanical control such dredging and dragging
- Manual removal
- Biological control by using specialized sea slugs (ascoglossans) that feed on Codium species.
- Prevent contaminated shellfish from being introduced to new areas
- Exclusion of drift thalli to prevent the dispersal of gametes.
ReferencesTop of page
Bulleri F; Branca MG; Abbiati M; Airoldi L, 2007. Development of reproductive structures in the introduced green alga, Codium fragile ssp. tomentosoides, in the northern Adriatic Sea. European Journal of Phycology, No. 42:137-144.
Chapman AS, 1999. From introduced species to invader: what determines variation in the success of Codium fragile ssp. tomentosoides (Chlorophyta) in the North Atlantic Ocean? Helgoländer Meeresuntersuchungen, No. 52:277-289.
Chavanich S; Harris LG, 2002. The influence of macroalgae on seasonal abundance and feeding preference of a subtidal snail, Lacuna vincta (Montagu) (Littorinidae) in the Gulf of Maine. Journal of Molluscan Studies, No. 68:73-78.
Chavanich S; Harris LG, 2004. Impact of the non-native macroalgae, Codium fragile (Sur.) Hariot ssp. tomentosoides (van Goor) Silva, on the native snail, Lacuna vincta (Montagu), in the Gulf of Maine. The Veliger, No. 47:85-90.
Chavanich S; Harris LG; Je JongGeel; Kang RaeSeon, 2006. Distribution pattern of the green alga Codium fragile (Suringar) Hariot, 1889 in its native range, Korea. Aquatic Invasions, 1(3):99-108. http://www.aquaticinvasions.ru/2006/AI_2006_1_3_Chavanich_etal.pdf
Fletcher RL; Blunden G; Smith BE; Rogers DJ; Fish BC, 1989. Occurrence of a fouling, juvenile, stage of Codium fragile ssp. tomentosoides (Goor) Silva (Chlorophyceae, Codiales). Journal of Applied Phycology, No. 1:227-237.
Harris LG; Jones AC, 2005. Temperature, herbivory and epibiont acquisition as factors controlling the distribution and ecological role of an invasive seaweed. Biological Invasions, 7(6):913-924. http://www.springerlink.com/content/l6871206466n4655/fulltext.pdf
Prince JS; LeBlanc WG, 1992. Comparative feeding preference of Strongylocentrotus droebachiensis (Echino-idea) for the invasive seaweed Codium fragile ssp. tomentosoides (Chlorophyceae) and four other seaweeds. Marine Biology, No. 113:159-163.
Provan J; Murphy S; Maggs CA, 2005. Tracking the invasive history of the green alga Codium fragile ssp. tomentosoides. Molecular Ecology, 14(1):189-194. http://www.blackwell-synergy.com/rd.asp?code=MEC&goto=journal
Scheibling RE; Anthony SX, 2001. Feeding, growth and reproduction of sea urchins (Strongylocentrotus droeba-chiensis) on single and mixed diets of kelp (Laminaria spp.) and the invasive alga Codium fragile ssp. tomen-tosoides. Marine Biology, No. 139:139-146.
Silva PC, 1979. The benthic algal flora of central San Francisco Bay. In: San Francisco Bay: the Urbanized Estuary [ed. by Conomos TJ] California, USA: American Association for the Advancement of Science, 287-345.
Trowbridge CD, 1999. An assessment of the potential spread and options for control of the introduced green macroalga Codium fragile ssp. tomentosoides on Australian shores. Consultancy Report. Hobart, Australia: CSIRO Marine Research/ Center for Research on Introduced Pests.
Trowbridge CD, 2002. Local elimination of Codium fragile ssp. tomentosoides: indirect evidence of sacoglossan herbivory? Journal of the Marine Biological Association of the United Kingdom, No. 82:1029-1030.
Tsiamis K; Panayotidis P, 2007. Occurrence of Codium fragile subsp. tomentosoides (van Goor) P.C. Silva (Chlorophyta: Bryopsidophyceae: Bryopsidales: Codiaceae) in Greece. Aquatic Invasions, 2(1):74-76. http://www.aquaticinvasions.ru/2007/AI_2007_2_1_Tsiamis_Panayotidis.pdf
ContributorsTop of page
21/12/07 Original text by:
Suchana Chavanich, Chulalongkorn University, Department of Marine Science, Faculty of Science, Bangkok 10330, Thailand
Distribution MapsTop of page
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