Description: Thallus dichotomously branched, terete, to 25 cms long with a felt-like surface and spongy feel. Surface covered with mucronate utricles visible using a microscope.

Habitat: Epilithic, common in places in the mid-littoral and upper sublittoral.

Distribution: Detailed under subspecies q.v.

Similar Species: Codium tomentosum and Codium vermilara neither of which has mucronate utricles.

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

iNaturalist: Codium fragile at iNaturalist World Species Observations database.

WoRMS: Codium fragile at World Register of Marine Species.