Colpomenia peregrina
Date of introduction and origin
Colpomenia peregrina was introduced in 1907 from
France into Cornwall and Dorset (Cotton 1908). This species occurs
naturally in the Pacific Ocean and was introduced from the Pacific
coast of North America.
Method of introduction
It was introduced to France from the Pacific coast of America
with juvenile American oysters Crassostrea virginica.
There was natural migration from France to Britain, and it may also
have been introduced unintentionally with commercial oysters from
France.
Reasons for success
This species lacks predators and has a rapid growth
rate.
Rate of spread and methods involved
It has spread throughout Britain from southern England in 1907
to the Isle of Man by 1923, the Outer Hebrides by 1936 and the
Orkneys by 1940 (Lund 1949; Norton 1976; Wilkinson 1975),
marginally by natural means of dispersion.
Distribution
It is distributed throughout Britain although populations are
larger on western coasts. In Europe it is found from Iberia to
southern Norway. It has a world-wide distribution in temperate
waters (South & Tittley 1986).
Factors likely to influence spread and distribution
Temperature and other conditions for reproduction affect its
spread.
Effects on the environment
It has negligible effects on the environment.
Effects on commercial interests
When growing attached to oysters it floats away with the
oyster when the air-filled thalli grow large enough, hence its name
of oyster thief (Farnham 1980) but this does not occur in
England.
Control methods used and effectiveness
None used.
Beneficial effects
None known.
Comments
It is found almost world-wide in temperate areas. There is
some debate as to whether Colpomenia peregrina and C.
sinuosa are separate species or variants of a single
species.
References
Cabioc'h, J., Floc'h, J.H., Toquin, A. le., Boudouresque,
C.F., Meinesz, A. & Verlaque, M. 1992. Guide des alguesdes
mers d'Europe. Paris and Lausanne, Delachaux &
Nestlé.
Cotton, A.D. 1908. Colpomenia sinuosa in Britain.
Journal of Botany, London, 46:
82-83.
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.)
Lund, S. 1949. Remarks on some Norwegian marine algae.
Blyttia, 7: 56-64.
Norton, T.A. 1976. The marine algae of the eastern border
counties of Scotland. British Phycological Journal,
11: 19-27.
South, G.R., & Tittley, I. 1986. A checklist and
distributional index of the benthic marine algae of the
North Atlantic Ocean. St Andrews & London, Huntsman Marine
Laboratory & British Museum (Natural History).
Wilkinson, M. 1975. The marine algae of Orkney. British
Phycological Journal, 10: 387-397.
Acknowledgements (contributions from questionnaire)
Mr I. Tittley, Natural History Museum, London.