Species description: A dark red seaweed that can grow up to 1 m in length. The lance-shaped blade is up to 20 cm across with a wavy margin and smaller blades may proliferate from the main blade. It has a short stipe and a small disc-like holdfast. The texture is slippery and smooth to the touch, but this slimy sensation does not transfer to the skin.

Habitat: Lives on shells and stones in the shallow subtidal, and can occasionally be found on the low shore in rockpools, but is most often found on artificial substrata in marinas and harbours. Can tolerate low salinity.

Distribution: First reported from Northern Ireland in 2017 from Carrickfergus marina, and now also reported from Millbay in Islandmagee. There are also few records from the southwest of Ireland. So far the only records from Britain are from southern England and Wales, but there have been some reports from the Outer Hebrides.

Similar Species: Could potentially be confused with some other red seaweeds with a similar colour and texture but most of these are unlikely to be found on pontoons etc. in a marina. The small, disc-like holdfast should make identification certain.

Key Identification Features:

• Elongated blades with extensions.
• Slippery texture that does not transfer to skin.
• Small, disc-like holdfast.

Distribution Map from NBN: Grateloupia turuturu at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Grateloupia turuturu at iNaturalist World Species Observations database.

WoRMS: Grateloupia turuturu at World Register of Marine Species. Accepted name: Grateloupia turuturu Yamada, 1941. AphiaID: 295880.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Halymeniales; Grateloupiaceae; Grateloupia