Thalassiosira tealata

Division: Bacillariophyta
Class: Coscinodiscophyceae
Order: Thalassiosirales
Species name: Thalassiosira tealata Takano
Synonyms: None
Common name: A centric diatom
Date of introduction and origin
Thalassiosira tealata was first detected in English waters at Blakeney, Gloucestershire, in 1950 (Wallentinus in press). Its origin is unknown. As it was not found in Atlantic plankton samples prior to 1950 it is presumed to be an introduction. It has also been found in Japanese waters (Takano 1980).
Method of introduction
The method of introduction is unknown, but ballast transport cannot be ruled out and imported oysters have also been hypothesised as a potential vector (Rincé & Paulmier 1986; Wallentinus in press).
Reasons for success
Rate of spread and methods involved
It was found in English waters in 1950 and off Norway in 1968 (G.R. Hasle pers. comm. in Wallentinus in press). The method of spread is unknown.
It is distributed from the English Channel to Norway (Wallentinus in press).
Factors likely to influence spread and distribution
Effects on the environment
Effects on commercial interests
Control methods used and effectiveness
None used.
Beneficial effects
None known.
The sample containing Thalassiosira tealata was collected near Blakeney, Gloucestershire from the river Severn in 1950, but not examined at that time. Its presence in European waters was known for some years (G.R. Hasle pers. comm.) but the species was not described until 1980 by Takano.
Rincé, Y., & Paulmier, G. 1986. Donnée novelles sur la distribution de la diatomée marine Coscinodiscus wailesii Gran & Angst (Bacillariophyceae). Phycologia, 25: 73-79.
Takano, H. 1980. New and rare diatoms from Japanese marine waters - V. Thalassiosira tealata sp. nov. Bulletin of the Tokai Regional Fisheries Research Laboratory, 103, 55-63.
Wallentinus, I. In press. Status of introductions of non-indigenous marine species to north Atlantic waters: introductions and transfers of plants. ICES co-operative research report.
Acknowledgements (contributors)
Prof. G.R. Hasle, University of Oslo.