sea urchin

Red sea coral reef scene showing clown fish, sea urchins, star puffer fish, brain coral, squirrel fish, sea anenome, and lettuce coral

Rocky shore line ecosystem zonation of species.  Some of the animals and pants featured include whelks, mussels, bladderwrack, star fish, top shells, periwinkles, crabs, branacles, and anenomes.  Illustration from The Hidden Universe: Adventures in Biodiversity by Alexandre Antonelli

Giant kelp Macrocystis pyrifero illustration from A Life on Our Planet by David Attenborough

Sea otter Enhydra lutris floating in the sea on its back, holding a clam and favoured stone, and peering at the viewer

European Rockpool diagram showing lots of shoreline crustaceans, bivalves, anenomes, and gastropods, sea weeds, and background