Description: Thallus cylindrical, erect densley tufted to 4 cms long, internodes ecorticate. Spines on the cortical bands, each spine multicellular and merging at the base with the cortical band.

Habitat: Very common. Epilithic, epizoic or epiphytic. Littoral. Generally on the more exposed shores.

Distribution: Very common in the British Isles. Europe: Portugal, Spain, France, Faroes, Norway and Iceland.

Similar Species: Other spiny specimens: C.ciliatum; C.erchinotum; C.gadiatum.

Key Identification Features:

• Multicellular spines merging with the cortical bands.

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

iNaturalist: Ceramium shuttleworthianum at iNaturalist World Species Observations database.

WoRMS: Ceramium shuttleworthianum at World Register of Marine Species. Accepted name: Ceramium shuttleworthianum (Kützing) Rabenhorst, 1847. AphiaID: 144563.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Ceramiaceae; Ceramioideae; Ceramieae; Ceramium