Description
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Animalia | Chordata | Ascidiacea | Stolidobranchia | Styelidae | Styela |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1994 | Unknown | Unknown | Introduced | Regular Resident | West Atlantic | Western Pacific | Shipping(Fouling Community) |
History of Spread
The tunicate Styela clava (Leathery Tunicate) is native to the Northwest Pacific, from Shanghai to the Sea of Ohotsk and the southeastern Bering Sea (Benyaminson, in Golikov et al. 1976; Nishikawa 1991). It has become widely distributed in coastal waters, though ship fouling and transport with oysters (Buizer 1980; Cohen and Carlton 1995; Lutzing 1999). In 1933, it was first collected in the Northeast Pacfic in Newport Beach CA, and has subsequently spread south to San Diego (1959), and north to San Francisco bay (1949), Coos Bay OR (1993) and Vancover Island British Columbia (1995) (Carlton and Cohen 1995). In the northeast Atlantic, it was recorded at Plymouth, England in 1953, and has subsequently spread east, along the southern North Sea to the Limfjord and Kattegat in Denmark and south to Britanny (Buizer 1999; Lutzen 1999). In 1972, it invaded Port Philip Bay, Australia , and in 1977, Sydney Harbour (Hewitt et al. 1999).
In the Northwest Atlantic, Styela clava was collected in 1968 in Long Island Sound, and in 1970 in Beverly MA, in Massachusetts Bay (Carlton 2000 personal communication; Berman et al. 1992). It has since spread north to Prince Edward Island (Whitlach and Osman 2001), and south to an NJ coastal inlet ~50 km north of Cape May (McDermott, personal communication, 1999). In Novermber, 2003, several S. clava were found washed ashore on Cape Henlopen, at the mouth of Delaware Bay (Fofonoff, unpublished data). In the Chesapeake Bay region, in 1994, a single specimen of S. clava (Catalog number 20711) was collected in Chincoteague VA (U.S. National Museum of Natural History 2002; Linda Cole, personal communication). In an August 2013 field trip, we found established populations of S. clava on floats and pilings at Merritt Harbor, Chincoteague VA, Indian River Inlet DE., and Cape May Harbor NJ (Fofonoff, personal observations)
References- Berman et al. 1992; Buizer 1980; Cohen and Carlton 1995; Golikov et al. 1976; Hewitt et al. 1999; Lutzen 1999; Nishikawa 1991; U.S. National Museum of Natural History 2002; Whitlach and Osman 2001
Invasion Comments
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | -2.0 | 23.0 | ||
| Salinity (‰) | 18.0 | 35.0 | 30.0 | 32.0 |
| Oxygen | ||||
| pH | ||||
| Salinity Range | poly-eu |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | 50.0 | 50.0 |
| Typical Adult Size (mm) | 63.0 | 63.0 |
| Maximum Adult Size (mm) | 75.0 | 75.0 |
| 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
The establishment of Styela clava (Leathery Tunicate) in the Chesapeake Bay region is uncertain, as it is known from only one population at present (U.S. National Museum of Natural History 2002, Fofonoff, personal boservations 2013). Consequently, economic impacts are unknown.
References- U.S. National Museum of Natural History 2002
Economic Impacts Outside of Chesapeake Bay
The largest economic impacts of S. clava have been seen in Prince Edward Island, Canada, where dense populations of tunicates have fouled cages used for aquaculture of fish, and ropes, racks, and other gear used in mussel culture. Locke et al. 2007; Arsenault et al. 2009). The tunicates compete with cultured mussels, reducing mussel harvests by ~50%. The estimated economic impact 34-88 miliion $CAN per year (Coulatti et al. 2006). On the positive side, Styela clava is a popular food item in Korea. Fisheries for Styela clava, in New England, for the Korean market appear feasible (Karney and Rhee 2009).
Ecological Impacts on Chesapeake Native Species
In experiments on fouling plates in New England waters Styela clava (Leathery Tunicate) appears capable of limiting recruitment of other fouling organisms, through predation (by filtration) of their larvae (Osman and Whitlach 2000). In European waters, S. clava appears to have partially replaced several native tunicate species (Lutzen 1999). However, the establishment of this species, and the extent of its impacts in the Chesapeake Bay region, are unknown. At present, we know of only one population at Chincoteague VA (U.S. National Museum of Natural History 2002; Paul Fofonoff, personal observaion, 2013).
Ecological Impacts on Other Chesapeake Non-Native Species
References
Barnes, Robert D. (1983) Invertebrate Zoology., , Philadelphia. Pp. 883Berman, Jody; Harris, Larry; Lambert, Walter; Buttrick, Melanie; Dufresne, Michael (1992) Recent invasions of the Gulf of Maine: Three contrasting ecological histories., Conservation Biology 6: 435-441
Buizer, D.A.G. (1980) Explosive development of Styela clava Herdman, 1882, in the Netherlands after its introduction (Tunicata, Ascidiacea)., Bulletin Zoologisch Museum Universiteit van Amsterdam 7: 181-185
Carlton, James T. (1979) History, biogeography, and ecology of the introduced marine and estuarine invertebrates of the Pacific Coast of North America, , Davis. Pp. 1-904
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.
Golikov, A. N. and 7 other editors. (1976) [Animals and plants of Peter the Great Bay.], , Leningrad. Pp.
Hewitt, C.L.; Campbell, M.L.; Thresher, R.E.; Martin, R.B. (1999) Marine Biological Invasions of Port Phillip Bay, Victoria, In: (Eds.) . , Hobart, Tasmania. Pp.
Hewitt, Chad L.; Campbell, Marnie L. (2000) Historical and Modern Invasions to Port Phillip Bay, Australia: The Most Invaded Southern Embayment?, In: (Eds.) Marine Bioinvasions. , . Pp. 120-126
Keough, M. J. ; Ross, J. (1999) Introduced fouling species in Port Phillip Bay., In: Hewitt, C. L.; Campbell; M.;Thresher, R.; Martin,(Eds.) Marine Biological Invasions of Port Phillip Bay, Victoria. , Hobart, Tasmania. Pp. 193-225
Lutzen, J. (1998) Styela clava Herdman (Urochordata, Ascidiacea), a successful immigrant to North West Europe: ecology, propagation and chronolgy of spread, Helgolander Meeresuntersuchungen 52: 383-391
Millar, R.H. (1971) Ascidians as fouling organisms., In: Jones, E.B. Gareth; Eltringham S.K.(Eds.) Marine borers, fungi and fouling organisms of wood. , Brussels. Pp. 185-195
Nishikawa, Teruki (1991) The Ascidians of the Japan Sea., Publication of the Seto Marine Biological Laboratory 35: 25-170
Osman, Richard W.; Whitlatch, Robert B. (2000) Ecological interactions of invading ascidians within epifaunal communities of southern New England., In: Peterson, Judith(Eds.) Marine Bioinvasions. , Cambridge. Pp. 164-174
Rho, Boon Jo; Lee, Ji-Eun (1991) A systematic study of the Ascidians in Korea, Korean Journal of Systematic Zoology 7: 195-220
Weiss, Howard M.; Bennett, Don; Dawley, Ellen; Jokinen, Eileen; Klemens, Michael W.; O'Donnell, Jane; Pondick, Jeffrey S.; Rubega, Margaret (1995) Marine animals of southern New England and New York., Bulletin of the State Geological and Natural History Survey of Connecticut 115: 1-19.16
Whitlatch, Robert B.; Osman, Richard (2000) Geographical distributions and organism-habitat associations of shallow water introduced marine fauna in New England., In: Pederson, Judith(Eds.) Marine Bioinvasions. , Cambridge MA. Pp. 61-65