Description: A minute alga. The creeping prostrate axes produce simple erect filaments, unbranched or with few branches no more tham 5 mm high.

Habitat: Rare. Epizoic on hydroids in the sublittoral to depths of 10 m.

Distribution: Few sites scattered around the British Isle including the Shetlands. Europe: Atlantic coast of Spain, Norway, and Iceland. Greenland. Atlantic coast of North America: Canada, Massachusetts and Rhode Island. Further afield: Arctic Sea: Spitzbergen, Novaya Zemlya, the Kara Sea to Baffin Bay.

Similar Species: All species of Acrochaetium, and other small filamentous algae, are similar, and difficult to identify.

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

iNaturalist: Meiodiscus spetsbergensis at iNaturalist World Species Observations database.

WoRMS: Meiodiscus spetsbergensis at World Register of Marine Species.