Agardhiella subulata
Division: Rhodophyta
Class: Rhodophyceae
Order: Gigartinales
Species name: Agardhiella subulata (C. Agardh) Kraft & Wynne
Synonyms: Neoagardhiella baileyi (Kutzing) Wynne & Taylor
Common name: None
 
Date of introduction and origin
Agardhiella subulata was first introduced into the Solent before 1973 (Farnham & Irvine 1979). It is thought to have originated in the Pacific or the east coast of the USA (C.A. Maggs pers. comm.).
 
Method of introduction
It was perhaps introduced unintentionally with shellfish (W.F. Farnham pers. comm.).
 
Reasons for success
Unknown.
 
Rate of spread and methods involved
Unknown.
 
Distribution
This species is restricted in Britain to the Solent. It is still sporadic in occurrence, but is mainly localised to Langstone and Chichester harbours, West Sussex. It may also occur in Spain, but this record needs to be confirmed (W.F. Farnham pers. comm. 1995). Other than these, no European populations are known, but are anticipated.
 
Factors likely to influence spread and distribution
Unknown. (This species has been introduced into the Solent but appears unable to spread except on a slow, gradual basis.)
 
Effects on the environment
Unknown.
 
Effects on commercial interests
Unknown.
 
Control methods used and effectiveness
None used.
 
Beneficial effects
It may be a potential source of carrageenan (W.F. Farnham pers. comm.).
 
Comments
Taxonomic research remains to be done to establish which species this is and thereby indicate where it has come from (e.g. see Farnham 1980). The species present in the Solent may be Neoagardhiella gaudichaudii, not A. subulata but W.F. Farnham (pers. comm.) recommends acceptance as A. subulata for now.
 
References
Farnham, W.F. 1980. Studies on aliens in the marine flora of southern England. In: The shore environment, volume 2: ecosystems, ed. by J.H. Price, D.E.G. Irvine & W.F. Farnham, 875-914. London, Academic Press. (Systematics Association Special Volume, No. 17B.)
 
Farnham, W.F., & Irvine, L.M. 1979. Discovery of members of the red algal family Solieriaceae in the British Isles. British Phycological Journal, 14: 123.
 
Acknowledgements (contributions from questionnaire)
Dr C.A. Maggs, Queen's University of Belfast.
Dr W.F. Farnham, University of Portsmouth.