Biodiversity & Conservation

A red seaweed - Odonthalia dentata

Odonthalia dentata

Image Keith Hiscock - Odonthalia dentata photographed in the Isle of Man. Image width ca 20 cm.
Image copyright information

Distribution map

Odonthalia dentata recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

Why do the maps differ?

Sightings Have you seen Odonthalia dentata?
If so please submit your record.

Odonthalia dentata is not listed under any importance categories.

Taxonomy icon Taxonomy Taxon English term
Phylum Rhodophyta Red seaweeds
Class Florideophyceae
Authority (Linnaeus) Lyngbye, 1819
Recent synonyms None
Map icon Recorded Distribution in Britain and Ireland Recorded throughout Scotland and Ireland including the Isle of Man on the west coast of Britain and Flamborough Head on the east coast and an isolated recording in Lyme Bay.
Habitat information icon Habitat information Odonthalia dentata can be found growing on boulders, bedrock and mobile substrata in lower-shore pools and from near extreme low water to approximately 20 m depth. Found at moderately to extremely wave-exposed sites and at wave-sheltered sites with exposure to strong tidal currents.
Text page icon Description Brownish-red to deep purple in colour, darkening with age, with a glossy surface. Frond 2-6 cm across, regularly alternately notched with sharply pointed apices, and thickened in centre forming a midrib in older parts of the plant. Fronds attached to the substratum by a solid discoid holdfast 5-13 mm in diameter, composed of fused radiating, root like, rhizomes.
Identifying features
  • Frond less than 2 mm across main axes.
  • Axes arising singly or in dense tufts with a variable overall shape.
  • Secondary branches arise from the margins of young and mature axes.
  • Reproductive bodies formed in dense clusters along the margins of main axes.
Additional information icon Additional information Fronds are perennial but plants on mobile substrata do not survive the winter.

This review can be cited as follows:

Marie Skewes 2007. Odonthalia dentata. A red seaweed. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 03/09/2010]. Available from: <http://www.marlin.ac.uk/speciesinformation.php?speciesID=3942>