Description: Thallus filamentous and very delicate, spreading over the substrate with erect branches to a height of 3.5 cms. Extensively branched with opposite or whorls of branchlets.

Habitat: Epiphytic, epizoic and epilithic in the sublittoral to 18 m.

Distribution: Widely distributed in the British Isles but rarely recorded from the east coast. Europe: Mediterranean, Portugal, Spain and the Netherlands. Further afield: Argentina, South Africa and New Zealand.

Similar Species: Other species of Antithamnionella .

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

iNaturalist: Antithamnionella spirographidis at iNaturalist World Species Observations database.

WoRMS: Antithamnionella spirographidis at World Register of Marine Species. Accepted name: Antithamnionella spirographidis (Schiffner) E.M.Wollaston, 1968. AphiaID: 144521.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Ceramiaceae; Ceramioideae; Dohrnielleae; Antithamnionella