Antithamnionella spirographidis

Division: Rhodophyta
Class: Rhodophyceae
Order: Ceramiales
Species name: Antithamnionella spirographidis (Schiffner) Wollaston
Synonyms: Antithamnion spirographidis Schiffner, Antithamnion tenuissimum Gardner
Common name: None
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.).
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
Effects on commercial interests
It may cause fouling in marinas.
Control methods used and effectiveness
None used.
Beneficial effects
None known.
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).
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.