Temperature relationships of some tropical Pacific intertidal gastropods

Abstract

Among tropical Indo-West Pacific herbivorous intertidal gastropods, high intertidal neritids, and limpets and certain lower intertidal limpets are restricted to a narrow range of substratum types. Littorinids, planaxids, low intertidal neritids, most lower intertidal limpets, and the trochid Monodonta labio tolerate a wide variety of substrata. This pattern of substratum specialization is related to the overall adaptive strategies of the various groups: those with a large area of soft tissue in contact with the substratum (neritids and limpets) often specialize to a particular substratum, especially at high shore levels, while those in which the area of contact between animal and substratum is small do not. High intertidal neritids and limpets able to live on a wide range of substrata tend to be species of limited geographic distribution. It is concluded that, even within a tropically similar group of animals (raspers in this case) relevant dimensions of niche separation depend upon the structure of the environment as well as upon the structure of the animals themselves.