Eusarsiella zostericola
Phylum: Crustacea
Class: Ostracoda
Order: Myodocopa
Species name: Eusarsiella zostericola (Cushman 1906)
Synonyms: Sarsiella zostericola Cushman 1906
Common name: None
Date of introduction and origin
Eusarsiella zostericola was introduced into south-east English estuaries between 1870 and 1940 with trade from the USA Atlantic coast (Bamber 1987a & b; Kornicker 1975).
Method of introduction
It was introduced unintentionally in associated with the American oyster Crassostrea virginica.
Reasons for success
Rate of spread and methods involved
The species has a low rate of dispersal, mainly by benthic adults which are capable of swimming.
It is found in the Blackwater estuary in Essex and Medway estuary in Kent (Bamber 1987b), the Thames estuary and the Solent. No other European populations have been recorded.
Factors likely to influence spread and distribution
The species of ostracod has little dispersal ability; the juveniles are non-dispersive.
Effects on the environment
No effects known.
Effects on commercial interests
Control methods used and effectiveness
None used.
Beneficial effects
None known.
It is one of the many species introduced with American oysters. It is probably present in other estuaries, but as it is not present in British keys it is likely to be mis-identified or not identified. Although it is small in size, yet will be retained on 0.5 mm sieves, it is larger and more fecund than those of studied North American populations (Bamber 1987b).
Bamber, R.N. 1987a. A benthic myodocopid ostracod in Britain. Porcupine Newsletter, 4: 7-9.
Bamber, R.N. 1987b. Some aspects of the biology of the North American ostracod Sarsiella zostericola Cushman in the vicinity of a British power station. Journal of Micropalaeontology, 6: 57-62.
Kornicker, L.S. 1975. Spread of ostracodes to exotic environs on transplanted oysters. In: Biology and paleobiology of Ostracoda, A symposium, University of Delaware, 1972. Bulletins of American Paleontology, 65: 129-139.
Acknowledgements (contributions from questionnaire)
Dr R.N. Bamber, Aquatic Research Laboratories Ltd, Southampton.
Dr J. Whittaker, The Natural History Museum, London.