Biodiversity & Conservation

Harpoon weed - Asparagopsis armata

Asparagopsis armata

Image Fiona Crouch - Asparagopsis armata at Wembury Point. Image width ca XX cm.
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Distribution map

Asparagopsis armata recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

Why do the maps differ?

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Asparagopsis armata is not listed under any importance categories.

Taxonomy icon Taxonomy Taxon English term
Phylum Rhodophyta Red seaweeds
Class Florideophyceae
Authority Harvey, 1855
Recent synonyms None
Map icon Recorded Distribution in Britain and Ireland Tetrasporophyte plants occur as far north as Shetland but not eastern Scotland. Gametophyte plants (red on the map) are described as present in south-west England and in western Ireland but occur sporadically and may be absent for many years.
Habitat information icon Habitat information The sexual (gametophyte) plant is found in the shallow sublittoral or in deep littoral pools attached to other algae by its barbed axes. The asexual (tetrasporophyte) plant is typically found sublittorally and is epiphytic or sometimes free-living.
Text page icon Description The sexual (gametophyte) plant is delicate, up to 30 cm tall, with barbed branches and is rosy pink, yellowish-pink or whitish-pink in colour. The thallus has prominent major axes, bare in lower parts but densely tufted above. The plant is attached to other algae by barbed rhizoids. The asexual (tetrasporophyte) plant is a rose-pink in colour, and is formed of irregularly-branched, polysiphonous axes that are usually aggregated into spherical or hemispherical masses 1-3 cm in diameter.
Identifying features
  • Apical tufts of sexual (gametophyte) plant pyramidal in outline, composed of spirally-arranged branches arising in pairs.
  • The plants have barbed rhizoids which are smooth except for the barbs.
  • Cystocarps are shortly stalked, relatively large and clustered on main axis.
Additional information icon Additional information The asexual (tetrasporangial) phase of Asparagopsis armata was once described as a separate species, Falkenbergia rufolanosa. The alga is a non-native species first recorded in Ireland in Galway Bay in 1939 and Britain in 1949 at Lundy in the Bristol Channel.

This review can be cited as follows:

Marie Skewes 2003. Asparagopsis armata. Harpoon weed. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 09/02/2010]. Available from: <http://www.marlin.ac.uk/speciesinformation.php?speciesID=2643>