Description
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Animalia | Cnidaria | Anthozoa | Actinaria | Edwardsidae | Nematostella |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1963 | Established | Unknown | Cryptogenic | Regular Resident | Unknown-Marine | Unknown-Marine | Shipping(Ballast Water,Dry Ballast),Fisheries(Oysters-accidental),Natural Dispersal(Natural Dispersal) |
History of Spread
Nematostella vectensis (Starlet Sea Anemone) is a small estuarine mud-dwelling sea anemone with a somewhat enigmatic distribution. Its known range includes the south and east coasts of Britain on the Northeast Atlantic (Sheader et al. 1997; Stephenson 1935), the coast of the Northwest Atlantic from Nova Scotia to LA, and the Northwest Pacific (WA-CA) (Hand and Uhlinger 1994). It was first described from the Isle of Wight, England (Stephenson 1935). The limited and localized distribution of N. vectensis on the European coast (southeast England only, Norfolk to the Fleet), suggests that the English population may have been an introduction from North America, possibly brought with oysters (Crassostrea virginica, Eastern Oyster) (Sheader et al. 1997). On the Pacific coast, N. vectensis may have been seen before 1946 in San Francisco and Tomales Bay, but the first verified collection was in Alameda County, CA (Hand 1957). It is now found from San Francisco Bay north to the San Juan Islands, Puget Sound WA (Hand and Uhlinger 1994). In San Francisco Bay, it is regarded as a cryptogenic species (Cohen and Carlton 1995). Successful crosses of females from 6 locations (England, MD, GA, CA, OR, WA) and males from 4 locations (Nova Scotia, MD, GA, OR) suggest that populations from both sides of the Atlantic, and the northeast Pacific constitute a single species. All 24 combinations tested produced viable larvae (Hand and Uhlinger 1994).
'The potentially long-lived larvae (Hand and Uhlinger 1992) provide one obvious device for spreading populations of N. vectensis, and might have at times past have allowed it to spread from one ocean to the other via a transpolar route. Equally, ship's ballast waters could have carried larvae and metamorphosed anemones great distances as well. Oysters have been transported widely between estuaries and oceans, and those movements could have carried the anemone between the Atlantic and the Pacific oceans, and in and out of the Gulf of Mexico' (Hand and Uhlinger 1994).
Recent genetic studies indicate that populations from the southeastern United States have the highest genetic diversity, and that this anemone is native to the East Coast of North America, and was introduced to the West coast and to England (Reitzell et al. 2007). In the northwest Atlantic, the wide latitudinal distribution of N. vectensis is indicative of native status, but the relatively recent discovery of this species in well-studied areas is puzzling. It was first found on this coast in 1939, at Woods Hole MA by Crowell (1946). No anemone of this type was mentioned in extensive early surveys of that area (Smith and Verrill 1873; Sumner et al. 1913). Its typical habitat, in shallow, marshy lagoons, is unusual for an anemone, but the site in which it was found (Mill Pond) was surveyed by Sumner et al. (1913), and probably examined occasionally by many other Woods Hole scientists. Extension of this species' range along the coast by oyster trasplants or shipping is possible.
Atlantic Coast records are summarized below:
Gulf of Mexico - St. Marks FL (before 1983), Ocean Springs MS (before 1983), Golden Meadow LA (Hand and Uhlinger 1994).
Cape Hatteras and South - Tar Landing Bay NC (before 1980); Sole Legare Island, Ashley River marsh, Wapoo Creek SC; Sapelo Island GA (Hand and Uhlinger 1994).
Chesapeake Bay - See below.
Mid-Atlantic Bight - Indian River estuary DE (Atlantic coast north of Chesapeake), before 1974 (Hand and Uhlinger 1994). Little Egg Harbor NJ, 1979 (Hand and Uhlinger 1994).
Long Island Sound - Mystic and Niantic River CT, 1978 (Hand and Uhlinger 1994).
Narragansett Bay - Bissel Cove, North Kingstown RI, before 1973 (Hand and Uhlinger 1994).
Vineyard Sound, Buzzards Bay - Mill Pond, Vineyard Sound, Woods Hole MA, abundant (Crowell 1946); Sippewissett (Buzzards Bay) MA; Pocassett River (Buzzards Bay) Bourne MA (Hand and Uhlinger 1994).
Gulf of Maine - Rye NH (before 1975); Spurwink River marsh (before 1983) (Hand and Uhlinger 1994); Minas Basin and Kingsport, Nova Scotia (Bailey and Bleakney 1966; Frank and Bleakney 1966).
Chesapeake Bay records:
Potomac River - Machodoc Creek, VA, considered common in oligohaline waters, 1963, 'not yet found elsewhere' (Calder 1972).
Upper Bay (Rhode River) - Abundant in fall 1987- summer 1988 (Posey and Hines 1991). Not seen since (Hines et al. unpublished data).
History References - Calder 1972; Cohen and Carlton 1995; Crowell 1946; Frank and Bleakney 1966; Hand 1957; Hand and Uhlinger 1992; Hand and Uhlinger 1994; Posey and Hines 1991; Sheader et al. 1997; Verrill and Smith 1873; Stephenson 1935; Sumner et al. 1913
Invasion Comments
None
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | -1.5 | 32.5 | ||
| Salinity (‰) | 2.0 | 52.0 | 7.0 | 42.0 |
| Oxygen | anoxic | |||
| pH | ||||
| Salinity Range | oligo-poly |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | 15.0 | 15.0 |
| Typical Adult Size (mm) | 25.0 | 25.0 |
| Maximum Adult Size (mm) | 60.0 | 60.0 |
| Maximum Longevity (yrs) | ||
| Typical Longevity (yrs |
Reproduction
| Start | Peak | End | |
|---|---|---|---|
| Reproductive Season | |||
| Typical Number of Young Per Reproductive Event |
|||
| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
|||
| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
|||
| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Hand and Uhlinger (1994) have suggested that Nematostella vectensis (Starlet Sea Anemone) could be a significant predator of oyster larvae in Chesapeake Bay and elsewhere. However, its apparent scarcity and sporadic appearance (Hines and Posey 1991) argues against a role in recruitment of oysters and other commercially important shellfish.
References - Hand and Uhlinger 1994; Hines and Posey 1991
Economic Impacts Outside of Chesapeake Bay
Nematostella vectensis could be an important predator of oysters, mussels, and other commercially important shellfish (Hand and Uhlinger 1994). However, this is unstudied. Because of its ease of culture, N. vectensis may be a useful laboratory animal for cnidarian studies (Hand and Uhlinger 1992).
References - Hand and Uhlinger 1992; Hand and Uhlinger 1994
Ecological Impacts on Chesapeake Native Species
Nematostella vectensis (Starlet Sea Anemone) has been found in only 2 locations in Chesapeake Bay. In one of those locations, the Rhode River subestuary, which has been extensively studied, this anemone appeared only for a short period in 1987-88, and was not seen for about 10 years before or afterwards (Posey and Hines 1991). It is possible that this anemone is normally kept in very low abundance by predators such as Palaemonetes pugio (Posey and Hines 1991), or that the species briefly invaded the estuary from marsh habitats. Exclusion and addition experiments run by Posey and Hines indicated that N. vectensis had significant impacts on community compostion during its period of abundance.
Predation - When cups containing Nematostella vectensis (buried in sediment) were added to enclosures (which prevented shrimp predation), densities of the polychaete Streblospio benedicti were reduced, compared to control cups lacking anemones. Laboratory observations indicate that N. vectensis preys on this polychaete, and also on settling pediveligers of the clam Macoma balthica. Predation on the anemones by shrimp increases settlement of S. benedicti (Posey and Hines 1991). Hand and Uhlinger (1991) suggest that N. vectensis could be an important predator of oyster (Crassostrea virginica, Eastern Oyster) larvae , but this role has not been documented.
Food/Prey - Palaemonetes pugio (Grass Shrimp )appears to be an aggressive predator of Nematostella vectensis in field enclosures, although rates of predation were low in the laboratory. In enclosures containing shrimps, abundances were 14-25% of those in control enclosures lacking predators (Posey and Hines 1991). Predation may be a major factor restricting distribution of N. vectensis (Hand and Uhlinger 1991). The importance of N. vectensis in the diet of shrimp or other predators has not been studied.
Referencs- Hand and Uhlinger 1991; Posey and Hines 1991
Ecological Impacts on Other Chesapeake Non-Native Species
Impacts of Nematostella vectensis on introduced biota in Chesapeake Bay are not known. The bivalve Rangia cuneata (Wedge Clam) is one animal which occurs in the same habitat as N. vectensis. Rangia cuneata's recruitment could be affected by anemone predation on settling larvae, since the similarly sized pediveligers of Macoma balthica were found to be eaten by N. vectensis in the laboratory (Posey and Hines 1991). References- Posey and Hines 1991
References
Bailey, Kanioulano; Bleakney, J. Sherman (1966) First Canadian record of the brackish water anthozoan Nematostella vectensis Stephenson, Canadian Field-Naturalist 80: 251-252Calder, Dale R. (1972) Phylum Cnidaria, Special Scientific Report, Virginia Institute of Marine Science 65: 97-102
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, , Washington DC, Silver Spring MD.. Pp.
Crowell, Sears (1946) A new sea anemone for Woods Hole, Massachusetts, Journal of the Washington Academy of Sciences 36: 57-60
Frank, Peter G.; Bleakney, J. Sherman (1978) Asexual reproduction, diet, and anomalies of the anemone Nematostella vectensis in Nova Scotia, Canadian Field-Naturalist 92: 259-263
Frank, Peter; Bleakney, J. Sherman (1976) Histology and sexual reproduction of the anemone Nematostella vectensis Stephenson 1935, Journal of Natural History 10: 441-449
Hand, Cadet; Uhlinger, Kevin R. (1992) Culture, sexual and asexual reproduction, and growth of the sea anemone Nematostella vectensis, Biological Bulletin 182: 169-176
Hand, Cadet (1957) Another sea anemone from California, Journal of the Washington Academy of Sciences 47: 411-414
Hand, Cadet; Uhlinger, Kevin R. (1994) Unique, widely distributed, estuarine sea anemone, Nematostella vectensis Stephenson: A review, new facts, and questions, Estuaries 17: 501-508
Hand, Cadet; Uhlinger, Kevin R. (1995) Asexual reproduction by transverse fission and some anomalies in the sea anemone Nematostella vectensis, Invertebrate Biology 114: 9-18
Posey, Martin H.; Hines, Anson H. (1991) Complex predator-prey interactions within an estuarine benthic community, Ecology 72: 2155-2169
Reitzel, Adam M.; Darling, John A.; Sullivan, James C.; Finnerty, John R. (2008) Global population genetic structure of the starlet anemone Nematostella vectensis: multiple introductions and implications for conservation policy., Biological Invasions 10: 1197-1213
Sheader, M.; Suwailem, A.M.; Rowe, G.A. (1997) Anemone, Nematostella vectensis, in Britain: Consideration for conservation management, Aquatic Conservation: Marine and Freshwater Ecosystems 7: 13-25
Stephenson, T. A. (1935) The British Sea Anemones, , London. Pp.
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
Verrill, A.E.; Smith, S.I. (1873) VIII. Report upon the invertebrate animals of Vineyard Sound and the adjacent waters, with an account of the physical characters of the region., 1 , . Pp. 1-757