Antithamnionella spirographidis
Date of introduction and origin
Antithamnionella spirographidis was first reported
from Plymouth docks by Westbrook (1934). It was introduced to
Europe prior to 1911 (C.A. Maggs pers. comm.) and was introduced to
Britain from the Mediterranean. It is thought to have originated in
the North Pacific (Lindstrom & Gabrielson 1989).
Method of introduction
It was probably carried on the hulls and mooring ropes of
ships, although it could also have been introduced with
oysters.
Reasons for success
A very rapid vegetative reproduction accounts for its
success.
Rate of spread and methods involved
It spreads by remote dispersal through shipping activities,
aided by its ability to grow on ropes, buoys and other artificial
surfaces such as plastic (C.A. Maggs pers. comm.).
Distribution
The species is found on the south coast of England, south and
west coasts of Wales, Ireland, and the west coast of Scotland.
European populations occur in northern France and in the
Mediterranean.
Factors likely to influence spread and distribution
Although ephemeral, this species spreads by fragmentation and
the rapid production of new thalli.
Effects on the environment
Unknown.
Effects on commercial interests
It may cause fouling in marinas.
Control methods used and effectiveness
None used.
Beneficial effects
None known.
Comments
Wollaston (1986) commented that Antithamnionella
spirographidis was introduced into Australia from Europe by
shipping and it is associated with dockyards and harbours. In their
natural habitats, Antithamnionella spirographidis and
A. ternifolia are very similar in appearance so
microscopic examination is required to distinguish them (Maggs
& Hommersand 1993).
References
Lindstrom, S.C., & Gabrielson, P.W. 1989. Taxonomic and
distributional notes on northeast Pacific Antithamnionaceae
(Ceramiales: Rhodophyta). Japanese Journal of Phycology,
37: 221-235.
Maggs, C.A., & Hommersand, M.H. 1993. Seaweeds of the
British Isles. Volume 1: Rhodophyta. Part 3A:
Ceramiales. London, HMSO, for Natural History Museum.
Westbrook, M.A. 1934. Antithamnion spirographidis
Schiffner. Journal of Botany, 72: 65-68.
Wollaston, E.M. 1968. Morphology and taxonomy of southern
Australian genera of Crouanieae Schmitz (Ceramiaceae: Rhodophyta).
Australian Journal of Botany, 16: 217-417.
Acknowledgements (contributions from questionnaire)
Dr C.A. Maggs, Queen's University of Belfast.