Introduction to Marine Biology 3rd Edition by George Karleskint, Richard Turner, James Small

Exercise 17

In the rocky intertidal, organisms characteristic of the upper intertidal include lichens, periwinkles, some limpet species, and isopods. The middle intertidal has barnacles, mussels, limpets, various periwinkles, rock boring urchins, and algae such as rockweeds. The lower intertidal in temperate regions typically has a dense turf of large seaweeds, abundant molluscs, sea stars, and brittle stars. The tropical lower intertidal, in contrast, is characterized by short turf algae. Boring urchins, anemones, sponges, bryozoan, sea cucumbers, and keyhole limits are common animal inhabitants.