Portugal to Angola and offshore islands, Azores to Mediterranean. Planktotrophic. Lives in colonies from the lower mediolittoral (in microcavities and crevices with sciaphile conditions) down to the low infralittoral. Grazer, detritus feeder? There is a sexual dimorphism based upon the size: males are the smallest (the species could possibly be protandrous hermaphrodite).

The form “kutschigi” Brusina, shows well defined spiral ribs of equal strength. All intergrades between extreme forms, from smooth to strongly corded, exist in a same population. 20cm deep, in calcareous algae, Ognina, Siracusa, SE. Sicily. 3mm.