Eusarsiella zostericola
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
Unknown
Rate of spread and methods involved
The species has a low rate of dispersal, mainly by benthic
adults which are capable of swimming.
Distribution
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
None.
Control methods used and effectiveness
None used.
Beneficial effects
None known.
Comments
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).
References
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.