Sea stars possess hundreds of tube feet for suction attachments to rocks. Mussels secrete elastic byssal threads to secure their shells. Different species, different approaches to the problem. When you walk toward the sea during a minus tide, notice how you pass through zones of different organisms that depend on how much time is air time. The first zone constitutes the spray area where organisms get showers only during the highest of water levels, and life is more a matter of air than water survival.
Storm surges provide good growing conditions while dry summers stress living here.
Black lichen, periwinkles, limpets, and acorn barnacles are found in this highest zone the penthouse apartment. Next is a region where life-forms spent time underwater daily at high tide. Black turban snails, mussels, ochre sea stars, and tiny porcelain crabs that scurry about sometimes chasing each other are among those organisms that stay put much of the time. These representative species are only the most obvious, the most easily found. Part of the allure of tidepools lies in the beauty of the arrangement of the organisms in watery cracks of rock surfaces and in miniature swimming pools.