Green sea fingers (Codium fragile subsp. fragile)
|Researched by||Judith Oakley||Refereed by||Admin|
|Authority||(Suringar) Hariot, 1889|
|Other common names||-||Synonyms||Codium fragile capense (Suringar) Hariot, 1889, Codium fragile tomentosoides (Suringar) Hariot, 1889, Codium fragile subsp. tomentosoides|
Recorded distribution in Britain and IrelandRecorded from the Orkneys, south east Scotland, south and south west England, the west coast of Wales, Ireland and the west coast of Scotland.
Global distributionRecorded in the Netherlands, western Mediterranean Sea and Atlantic Spain to Norway.
HabitatCodium fragile fragile grows in high densities and can dominate canopy species in infralittoral rocky reef communities.
- Large green algae with spongy texture.
- Dichotomously branching.
- Utricles have a pronounced median or submedian constriction.
- Utricles are sharply mucronate.
Additional informationThis alien species originated in the Pacific Ocean around Japan. It was introduced from mainland Europe to the River Yealm in Devon in 1939. It has been found to displace native species of Codium tomentosum.
There is extreme difficulty in distinguishing subspecies from each other. When viewed in section under a microscope, the utricles are shorter and stouter in the tomentosoides subspecies than in the Codium fragile subspecies atlanticum. Work by Provan et al. (2005) identified the species initially by the presence of numerous pointed spines on the surface of the alga, and by subsequent DNA sequencing.This non-native species is known to occur in a number of marine Special Areas of Conservation (mSACs), in the UK e.g. Pembrokeshire. The impacts or rate of dispersal are not known due to earlier morphological confusion with native species.
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Eno, N.C., Clark, R.A. & Sanderson, W.G. (ed.) 1997. Non-native marine species in British waters: a review and directory. Peterborough: Joint Nature Conservation Committee.
Gibson, R., Hextall, B. & Rogers, A., 2001. Photographic guide to the sea and seashore life of Britain and north-west Europe. Oxford: Oxford University Press.
Guiry, M.D. & Nic Dhonncha, E., 2002. AlgaeBase. World Wide Web electronic publication http://www.algaebase.org,
JNCC (Joint Nature Conservation Committee), 1999. Marine Environment Resource Mapping And Information Database (MERMAID): Marine Nature Conservation Review Survey Database. [on-line] http://www.jncc.gov.uk/mermaid
Maggs, C.A., 2005b. Green sea fingers Codium fragile subsp. tomentosoides. Marine Aliens project. [On-line] http://www.marlin.ac.uk/marine_aliens/marine_aliens.htm,
Provan, J., Murphy, S. & Maggs, C.A., 2005. Tracking the invasive history of the green alga Codium fragile ssp. tomentosoides. Molecular Ecology, 14, 189-194.
Silva, P.C., 1955. The dichotomous species of Codium in Britain. Journal of the Marine Biological Association of the United Kingdom, 34, 565-577.
This review can be cited as:
Last Updated: 13/08/2007