What adaptations allow organisms to survive in the supralittoral zone of a rocky beach?

Many of these creatures avoid sun and drying air as well as prey by hiding in cracks or under rocks, some even have their own burrows at low tide. Creatures like Barnacles and oysters are able to tightly close their valves in order to avoid drying out when the tide goes out, they come out to geed only when the tide is covering them. Some creatures have camouflage that makes them nearly invisible. Those that are constantly in the water being pounded by the waves are very tough to withstand the hard hits. Some creatures are incredibly flexible or even flat so they are able to bend rather than breaking when they get it if they even get hit in that form ...