GASTROPOD SHELLS RECYCLED - AN EXAMPLE FROM A ROCKY TIDAL FLAT IN THENORTHERN RED-SEA

Gastropod recycling at a rocky intertidal flat in the Northern Bay of Safaga (Red Sea, Egypt) is a process of increasing encrustation, chang ing secondary inhabitants, and probably decreasing shell strength. Enc rustation by coralline red algae starts in the living gastropods, with the aperture area staying free of epigrowth. The dead gastropod shell s are colonized by hermit crabs, tend to be more heavily encrusted and show encrustation of the aperture. This justifies the description 'pa gurized' and the conclusion that coralline red algae produce the same pagurization features as predominantly suspension-feeding invertebrate s. After the shells are abandoned by inhabitants that carry them aroun d, further growth of coralline algae leads to rhodoliths, which are so metimes colonized by stomatopods. Secondary inhabitants therefore infl uence not only the taphocoenoses of gastropods but also the formation of rhodoliths.