Biodiversity & Conservation

A red seaweed - Polyides rotundus - General information

Polyides rotundus

Image Jason Hall-Spencer - Polyides rotundus. Image width ca 7 cm.
Image copyright information

  • #
Distribution map

Polyides rotundus 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 Polyides rotundus?
If so please submit your record.

Polyides rotundus is not listed under any importance categories.

General information

Key Icon Researched by: Will Rayment Text page icon Refereed by:

Taxonomy icon Taxonomy

Phylum Rhodophyta Red seaweeds
Class Rhodophyta Red seaweeds
Map icon Recorded distribution in Britain and Ireland Occurs around all coasts of Britain and Ireland. There is a paucity of records from south east England which may reflect a lack of suitable substrata.
Habitat information icon Habitat information Grows attached to rock and stones in pools in the lower intertidal and subtidally to 20 m. The holdfast is often buried by coarse, sandy deposits.
Text page icon Description A dark red or blackish seaweed with smooth, cartilaginous, cylindrical fronds, branching dichotomously in roughly the same plane. The fronds rise from a fleshy, discoid holdfast up to 2 cm in diameter. The reproductive bodies occur as oval shaped swellings along the sides of the branches or occasionally encircling them. The seaweed grows up to 20 cm in length.

This review can be cited as follows:

Will Rayment 2003. Polyides rotundus. 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/speciesfullreview.php?speciesID=4168>