Floris van Breugel / Giant Red Sea Urchins (Strongylocentrotus franciscanus) Purple sea urchins (Strongylocentrotus purpuratus) and Sea Anenomes (Anthopleura) underwater, in tide pools along Californian coastline, USA.

Fred Bavendam / Purple Sea Urchin (Strongylocentrotus purpuratus) and Red Sea Urchin (Strongylocentrotus franciscanus) group, Channel Islands, California

Flip Nicklin / Purple Sea Urchin (Strongylocentrotus purpuratus) with tube feet extended into water to feed, California

Georgette Douwma / Purple sea urchins, California USA

Olga Kamenskaya / Purple sea urchin (Strongylocentrotus purpuratus) off the coast of Svalbard, Norway. September.

Richard Herrmann / Red Sea Urchin (Strongylocentrotus franciscanus) and Purple Sea Urchin (Strongylocentrotus purpuratus) feeding on Southern Sea Palm (Eisenia arborea) creating urchin barren, Santa Cruz Island, Channel...

Franco Banfi / Purple sea urchin (Strongylocentrotus purpuratus) Little Strytan dive site, Eyjafjordur nearby to Akureyri, northern Iceland, North Atlantic Ocean.

Norbert Wu / Purple Sea Urchin (Strongylocentrotus purpuratus) group feeding on Giant Kelp (Macrocystis pyrifera), creating urchin barren, California

Norbert Wu / Brittle Star (Ophiothrix spiculata) group and Purple Sea Urchins (Strongylocentrotus purpuratus), California

Norbert Wu / Purple Sea Urchin (Strongylocentrotus purpuratus), Vancouver Island, British Columbia, Canada

Norbert Wu / Sunflower Sea Star (Pycnopodia helianthoides) and Purple Sea Urchin (Strongylocentrotus purpuratus) in feeding on Frilled Sea Anemones (Metridium senile), Vancouver Island, British Columbia, Canada

Jeff Rotman / Purple Sea Urchins (Strongylocentratus purpuratus) colony feeding on kelp bases. Channel Islands, USA, Pacific Ocean.