Balanus balanus found at depths of up to and grows on bedrock, boulders, pebbles and shells. It seems to favour habitats with strong currents and when overcrowding occurs, adopts different shapes to fit the space available. It is often found growing alongside another barnacle, "Balanus crenatus". Other species often found in its vicinity include "Tubularia larynx", "Obelia geniculata", "Pomatoceros triqueter", "Pecten maximus", "Hydroides norvegica", "Chlamys opercularis" and "Sertularia" species. Coralline algae was often present as were the whelk, the European edible sea urchin ("Echinus esculentus"), the great spider crab ("Hyas araneus") and the shore crab ("Carcinus maenas"). The main predator is the
Iberian shrew juveniles, the fur is also adapted for cold, damp habitats: each guard hair possesses an indentation along its length that helps to prevent water from reaching the body. The skull of "S. granarius" can be used to distinguish it from other species belonging to the European "Sorex araneus" group of shrews. Comparatively, the snout of "S. granarius" is small and flat, the mandible possesses a diminished coronoid process and a narrow angular process, and the temporal fossa of the skull resembles a triangle. The "Sorex araneus" group of European shrews consists of "S. araneus", "S. coronatus", and "S. granarius", with