Mnemiopsis leidyi (sea walnut)
Index
- Pictures
- Identity
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Description
- Distribution
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Biology and Ecology
- Climate
- Air Temperature
- Water Tolerances
- Natural enemies
- Notes on Natural Enemies
- Pathway Causes
- Pathway Vectors
- Economic Impact
- Environmental Impact
- Threatened Species
- Risk and Impact Factors
- Uses List
- Similarities to Other Species/Conditions
- Prevention and Control
- References
- Links to Websites
- Organizations
- Contributors
- Distribution Maps
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Top of pageIdentity
Top of pagePreferred Scientific Name
- Mnemiopsis leidyi A. Agassiz, 1865
Preferred Common Name
- sea walnut
Other Scientific Names
- Mnemiopsis gardeni L. Agassiz, 1860
- Mnemiopsis mccradyi Mayer, 1900
Local Common Names
- Denmark: amerikansk ribbegople
- Finland: amerikankampamaneetti
- Germany: Meerwalnuss; Rippenqualle
- Lithuania: mnemiopsis
- Netherlands: Amerikaanse langlobribkwal
- Norway: amerikansk kammanet; amerikansk lobemanet
- UK: American comb jelly; comb jelly; comb jellyfish; sea gooseberry; warty comb jelly
Summary of Invasiveness
Top of pageThe native habitat of the ctenophore M. leidyi is the Atlantic coast of North and South America where it can live over a broad range of salinity and temperature conditions. M. leidyi is a polymorphic species with wide environmental tolerance and high phenotypic variability. It may reach high numbers in conditions of abundant prey (zooplankton concentrations) in optimal salinity and temperature conditions in native areas. It is a self-fertilizing hermaphrodite, pre-adapted to rapid colonization (Kremer, 1976). Pianka reported that up to 100% normal development has been repeatedly obtained from self-fertilized eggs of single ctenophores, and the significance of out-breeding in ctenophores is controversial. In addition, M. leidyi has an ability to regenerate from fragments larger than one quarter of an individual. It is also a generalist carnivorous feeder. It was accidentally introduced first into the Black Sea in the early 1980s, possibly with ballast water from the northwestern Atlantic coastal region. From the Black Sea, it spread north to the Sea of Azov, south to the Sea of Marmara and to the eastern Mediterranean. In 1999, it reached the Caspian where it is currently expanding at an even more rapid rate than in the Black Sea. In 2005, it was found in the Adriatic Sea. In 2006, it was first recorded in the North Sea and the Baltic Sea.
Taxonomic Tree
Top of page- Domain: Eukaryota
- Kingdom: Metazoa
- Phylum: Ctenophora
- Class: Tentaculata
- Order: Lobata
- Family: Bolinopsidae
- Genus: Mnemiopsis
- Species: Mnemiopsis leidyi
Notes on Taxonomy and Nomenclature
Top of pageUntil recently, three species were included in the Mnemiopsis genus: M. gardeni, M. leidyi and M. mccrady (Moser, 1908, 1909; Mayer, 1912; Main, 1928; Pratt, 1935). When the genus Mnemiopsis appeared in the Black Sea observations of the new ctenophore were significantly aggravated by the inconsistencies between the descriptions of the morphological features of the Mnemiopsis genus by researchers (L. Agassiz, 1860; A. Agassiz, 1865; Fewkes, 1881) and the later descriptions of this genus by Mayer (1912), Main (1928), and Pratt (1935).
Description
Top of pageM. leidyi is characterized by the presence of two large mobile lobes referred to as lateral or oral lobes). The oral lobes are derivatives of the ctenophore body (spherosome). Four smaller lobes are situated under the two principal oral lobes. Closing over one another by their distal edges, they completely envelop the mouth area of the animal (Agassiz, 1860; Mayer, 1912; Seravin, 1994).
Under the oral lobes, four smaller lobes are located called auricles. When oral lobes are closed, they completely cover the auricles. At the oral edge of the body, on either flattened side, there is a tentacular apparatus. The central part of the tentacular apparatus is located above the lip of the slit-like mouth. Right and left of the tentacular bulb, fascicles of thin tentacles extend over the sides of the body following special deep grooves. Both sides of the long slit-like mouth are bordered with a row of short simple tentacles, which are continuous with those of the deep lateral furrows.
Distribution
Top of pageM. leidyi was first discovered in the northwestern Black Sea in November 1982 (Pereladov, 1988) where it most probably was introduced with ballast waters from the northern American coastal area. By the autumn of 1988 it was found everywhere in the Black Sea (Vinogradov et al., 1989). M. leidyi spread to the Sea of Azov via the Kerch Strait in August 1988 (Studenikina et al., 1991); a first peak followed in September 1989. It can live in the Sea of Azov only during warm seasons, dying when temperature reaches 3°C and re-appears every spring or summer depending on direction of the current (Shiganova et al., 2001). Then probably in 1989-1990 it spread to the Sea of Marmara with the Black Sea currents (Shiganova, 1993). It now occurs year-round in the upper water layer of the Sea of Marmara. M. leidyi was first recorded in Saronikos Gulf during late spring-summer 1990, as well as in the neighbouring, eutrophic Elefsis Bay (Aegean Sea). Swarms were observed during summer in several coastal areas of the Aegean Sea (Skyros, Limnos and Alonissos Islands, Halkidiki Peninsula) in 1991-1996. Furthermore M. leidyi populations were rare along the Limnos coasts in summer 1997, 1998, and 1999 (Shiganova et al., 2001). Further east, M. leidyi appeared in Mersin Bay in spring 1992 (Kideys and Niermann, 1994), and in Syrian coastal waters in October 1993 (Shiganova, 1997).
Distribution Table
Top of pageThe 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.
Last updated: 10 Feb 2022Continent/Country/Region | Distribution | Last Reported | Origin | First Reported | Invasive | Reference | Notes |
---|---|---|---|---|---|---|---|
Asia |
|||||||
Azerbaijan | Present | Original citation: Shiganova et al. (2004) | |||||
Georgia | Present | Introduced | First reported: 1980 - 1989 | ||||
Iran | Present | Original citation: Shiganova et al. (2004) | |||||
Israel | Present | Introduced | 2009 | ||||
Kazakhstan | Present | Introduced | 1999 | ||||
Syria | Present | Original citation: Shiganova et al. (2001) | |||||
Turkey | Present | Introduced | First reported: 1980 - 1989 | ||||
Turkmenistan | Present | Original citation: Shiganova et al. (2004) | |||||
Europe |
|||||||
Belgium | Present | Introduced | 2007 | ||||
Bulgaria | Present | Introduced | First reported: 1980 - 1989 | ||||
Denmark | Present | Introduced | 2005 | ||||
Finland | Present | Introduced | 2006 | ||||
France | Present | Introduced | 2004 | ||||
Germany | Present | Introduced | 2006 | ||||
Greece | Present | Introduced | First reported: 1980 - 1989 | ||||
Italy | Present | Introduced | 1980 | ||||
Netherlands | Present | Introduced | 2006 | ||||
Norway | Present | Introduced | 1850 | ||||
Poland | Present | Introduced | 2007 | ||||
Romania | Present | Introduced | First reported: 1980 - 1989 | ||||
Russia | Present, Widespread | Introduced | 1999 | Invasive | First found in Caspian Sea in 1999 | ||
-Southern Russia | Present | ||||||
Slovenia | Present | ||||||
Spain | Present | Introduced | 2009 | ||||
Sweden | Present | Introduced | 2006 | ||||
Ukraine | Present | Introduced | 1982 | ||||
Sea Areas |
|||||||
Atlantic - Northeast | Present | ||||||
Atlantic - Western Central | Present | Native | As Mnemiopsis sp. | ||||
Mediterranean and Black Sea | Present | Introduced | Invasive |
History of Introduction and Spread
Top of pageThe native habitat of the ctenophore, Mnemiopsis, is the temperate to subtropical estuaries along the Atlantic coast of North and South America (Kremer, 1994; Mianzan, 1999).
Risk of Introduction
Top of pageM. leidyi is able to occupy and establish itself in any temperate or subtropical productive or eutrophicated coastal area, semi-closed seas or estuaries where salinity is not less than 4‰ and temperature not higher than 28°C.
Habitat List
Top of pageCategory | Sub-Category | Habitat | Presence | Status |
---|---|---|---|---|
Brackish | Inland saline areas | Present, no further details | ||
Littoral | Coastal areas | Present, no further details | ||
Brackish | Estuaries | Present, no further details | ||
Marine | ||||
Marine | Inshore marine | Present, no further details | ||
Marine | Pelagic zone (offshore) | Present, no further details | ||
Marine | Benthic zone | Present, no further details |
Biology and Ecology
Top of pageM. leidyi is a hermaphrodite with two fascicles of gonads (ovaries and testicles) in its gastrodermis. The gonads of the Black Sea Mnemiopsis are located along eight meridional canals of the gastrovascular system. They are localized in the spaces between the ctens (comb flappers). The rows of ovaries face the principal symmetry planes - saggital and tentacular. On the opposite side of each meridional canal, rows of testicles extend. Thus, in adjacent canals, the rows of testicles are arranged in a mirror-like manner, which is characteristic of Lobata. Gonads are formed in the central parts of the canals from the level of the statocyst almost up to the extreme ctens toward the oral edge of the body.
Nutrition
Associations
Environmental Requirements
Optimal conditions for M. leidyi are temporal or subtropical climates. Climatic conditions control epidemics of M. leidyi even in optimal environments and spread to adjacent seas from the Black Sea to the Sea of Azov or eastern Mediterranean or from the Southern Caspian to the Middle and Northern Caspian (Shiganova et al., 2007).
Climate
Top of pageClimate | Status | Description | Remark |
---|---|---|---|
C - Temperate/Mesothermal climate | Preferred | Average temp. of coldest month > 0°C and < 18°C, mean warmest month > 10°C |
Air Temperature
Top of pageParameter | Lower limit | Upper limit |
---|---|---|
Absolute minimum temperature (ºC) | 2 | 3 |
Mean annual temperature (ºC) | 20 | 25 |
Mean maximum temperature of hottest month (ºC) | 27 | 31 |
Mean minimum temperature of coldest month (ºC) | 4 | 6 |
Water Tolerances
Top of pageParameter | Minimum Value | Maximum Value | Typical Value | Status | Life Stage | Notes |
---|---|---|---|---|---|---|
Depth (m b.s.l.) | 25 | 50 | Optimum | 100 m+ tolerated. Present in the upper layer above the thermocline in warm seasons; in upper layer up to 25-50 m during other seasons. During unfavourable conditions they go down and stay near bottom | ||
Dissolved oxygen (mg/l) | >1 | Optimum | ||||
Salinity (part per thousand) | 6 | 25 | Optimum | 4-39 tolerated | ||
Water temperature (ºC temperature) | 23 | 26 | Optimum | 6-31 tolerated |
Natural enemies
Top of pageNatural enemy | Type | Life stages | Specificity | References | Biological control in | Biological control on |
---|---|---|---|---|---|---|
Beroe ovata | Predator |
Notes on Natural Enemies
Top of pageOnly few animals are known to feed on M. leidyi, foremost of which are the scyphomedusan Chysaora quinquecirrha and the ctenophore Beroe ovata (Purcell et al., 2001).
Pathway Causes
Top of pageCause | Notes | Long Distance | Local | References |
---|---|---|---|---|
Interconnected waterways | Yes | Shiganova et al. (2001) |
Pathway Vectors
Top of pageVector | Notes | Long Distance | Local | References |
---|---|---|---|---|
Ship ballast water and sediment | Yes | |||
Water | Yes | Yes | Shiganova et al. (2001) |
Economic Impact
Top of pageLosses for fishery industry are large for countries surrounding the Black, Azov and Caspian Sea areas.
Environmental Impact
Top of pageM. leidyi is a real ecosystem engineer. It affects physical conditions of several recipient productive ecosystems; for example in - the decrease in water transparency, hydrochemical - change nutrients contents and biota. After M. leidyi invasion cascading effects occurred at the higher trophic levels, from a decreasing zooplankton stock to collapsing planktivorous fish to dolphins (bottom-up). Similar effects occurred at lower trophic levels: from a decrease in zooplankton stock to an increase in phytoplankton, relaxed from zooplankton grazing pressure (top-down) and from increasing bacterioplankton to increasing zooflagellata and infusoria (Shiganova at al., 2004 a,b).
Threatened Species
Top of pageThreatened Species | Conservation Status | Where Threatened | Mechanism | References | Notes |
---|---|---|---|---|---|
Huso huso (beluga) | CR (IUCN red list: Critically endangered); USA ESA listing as threatened species | Mediterranean and Black Sea | Predation | US Fish and Wildlife Service (2004) | Black Sea basin |
Risk and Impact Factors
Top of page- Proved invasive outside its native range
- Has a broad native range
- Abundant in its native range
- Highly adaptable to different environments
- Is a habitat generalist
- Pioneering in disturbed areas
- Capable of securing and ingesting a wide range of food
- Highly mobile locally
- Fast growing
- Has high reproductive potential
- Gregarious
- Has high genetic variability
- Altered trophic level
- Damaged ecosystem services
- Ecosystem change/ habitat alteration
- Increases vulnerability to invasions
- Modification of hydrology
- Modification of natural benthic communities
- Modification of nutrient regime
- Modification of successional patterns
- Negatively impacts aquaculture/fisheries
- Negatively impacts tourism
- Competition - monopolizing resources
- Pest and disease transmission
- Herbivory/grazing/browsing
- Interaction with other invasive species
- Predation
- Rapid growth
- Highly likely to be transported internationally accidentally
Similarities to Other Species/Conditions
Top of pageM. leidyi may be mixed with other representatives of another Lobata species of genus Bolinopsis. B. infundibuilum, occursin the northern Atlantic, North, Baltic and Barrens Sea (Greve, 1970; Seravin, 1998) and the subtropical species B. vitrea, which occurs in the Mediterranean Sea and southern coastal America (Shiganova et al., 2004c; Oliveiro and Migotto, 2006). Oral lobes of both species originate about half-way between the mouth and the infundibulum while in M. leidyi oral lobes originate near the level of the infundibulum.
Prevention and Control
Top of pageDue 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.
There should be strict control of ballast waters in harbours to avoid introduction of alien species.
References
Top of pageAgassiz A, 1865. North American Acalephae. llustrated catalog of the Museum of Compar. Zool., 1-234.
Costello MJ, Emblow C, White R, 2001. Patrimoines Naturels [ed. by White R].
Fewkes JW, 1881. Studies of the jelly-fish of Narragansett Bay. Bull. Mus. Compar. Zool, 8:141-182.
Harbison GR, 1993. The potential of fishes for the control of gelatinous zooplankton, ICES C.M., 74.
Kamshilov MM, 1960. Feeding of ctenophore Beroe cucumis Fab. Dokl. Acad. Nauk SSSR, 130:1138-1140.
Main RJ, 1928. Feeding mechanism Mnemiopsis. Biol. Bull, 55:69-78.
Shiganova T, Bulgakova Yu, 2002. http://www.caspianenvironment.org.
Distribution References
CABI, Undated. Compendium record. Wallingford, UK: CABI
CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI
Links to Websites
Top of pageWebsite | URL | Comment |
---|---|---|
Caspian Environment Programme | http://www.caspianenvironment.org/ | |
GISD/IASPMR: Invasive Alien Species Pathway Management Resource and DAISIE European Invasive Alien Species Gateway | https://doi.org/10.5061/dryad.m93f6 | Data source for updated system data added to species habitat list. |
Global register of Introduced and Invasive species (GRIIS) | http://griis.org/ | Data source for updated system data added to species habitat list. |
Regional Biological Invasions Centre | http://www.zin.ru/rbic/ |
Organizations
Top of pageRussian Federation: P. P. Shirshov Institute of Oceanology RAS, 36 Nakhimovsky Avenue, 117997 Moscow, http://www.ocean.ru
Contributors
Top of page04/02/08 Original text by:
Tamara Shiganova, PP Shirshov Inst. of Oceanology, Russian Academy of Sciences, Nakhimovsky avenue, 3617997 Moscow, Russia
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