Shell morphology of an intertidal patellograstropod (cellana exarata) varies with shore type

C. exaratalimpets (locally called‘opihi) are a crashed fishery & are culturally important, Inhabit the emergent tidal zone –never submerged & periodically washed by waves1, Evolutionary trade off in shell shape between thermal stress & predation2,3, Shells maladapted to thermal stress on islands with humans2, Will negatively affect sustainability considering global warming4, May be differences in shell morphology between shores with more (boulder) and less (bench) thermal refuges