Nick Upton / Velvet swimming crab (Necora puber) in a rock pool, hiding among Coralweed (Corallina officinalis), Cornwall, UK, March.

Nick Upton / Strawberry anemone (Actinia fragracea) in a rock pool alongside Coralweed (Corallina officinalis), Cornwall, UK, March.

Nick Upton / Common shore crab (Carcinus maenas) hiding among Coralweed (Corallina officinalis) in a rock pool, Cornwall, UK, March.

Nick Upton / Coralweed (Corallina officinalis) from Atlantic Ocean. Cornwall, England, UK. September.

Philippe Clement / Common Coral Weed / Coralweed (Corallina officinalis) washed ashore on beach, Normandy, France. September

Sue Daly / Coral Weed (Corallina officinalis) English Channel, off the coast of Sark, Channel Islands, July

Nick Upton / Feathery red alga (Plocamium sp.) growing alongside Coral weed (Corallina officinalis) in a rockpool, Crail, Fife, UK, July.

Nick Upton / Coral weed (Corallina officinalis) growing in a rockpool, North Berwick, East Lothian, UK, July

Nick Upton / Coral weed (Corallina officinalis) growing in a rockpool, Crail, Fife, UK, July

Nick Upton / Coral weed (Corallina officinalis) growing in a rockpool, North Berwick, East Lothian, UK, July

Sue Daly / Purse Sponge (Scypha ciliata) on Coral Weed (Corallina officinalis). Channel Islands, UK, June.

Alex Hyde / Coral weed (Corallina officinalis) from rockpool, Isle of Skye, Scotland, UK