Description: Thallus small no more than 1 to 3 mm high, filamentous with irregular branching.

Habitat: On small stones, shells, pottery and in fissures in the rock. Found in brackish water, sublittoral to 30 m.

Distribution: Widely distributed in the British Isles including the Shetlands. Europe: Atlantic coast of France, Germany, Baltic Sea and Norway. Atlantic coast of North America: Canada, New Hampshire and Massachusetts.

Similar Species: Most species of Cladophora are similar and difficult to identify, however this species is remarkably well recorded despite of its size.

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

iNaturalist: Cladophora pygmaea at iNaturalist World Species Observations database.

WoRMS: Cladophora pygmaea at World Register of Marine Species.