Description: Unicellular, endophytic in Blidingia and possibly also other species.

Habitat: Endophytic in Blidingia in the upper littoral.

Distribution: Widespread, probably common on all shores of the British Isles from the Shetlands to the Channel Islands. Europe: France to Scandinavia. Atlantic coast of North America: Canada to Massachusetts.

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

iNaturalist: Halochlorococcum moorei at iNaturalist World Species Observations database.

WoRMS: Halochlorococcum moorei at World Register of Marine Species.