Functional adaptation for unique habitats in the species of intertidal limpetsPatelloida

Abstract

Many studies have shown that physical environmental factors cause phenotypic diversity in limpets. However, no studies have documented how substrate conditions (surface shape and topology) affect adhesive force and how they regulate shell morphology in limpets. The intertidal limpetPatelloida pygmaea, having a flat shell, is found exclusively on oyster shells, whileP. conulus, with an extremely high shell, is found onBatillaria cumingi. The adhesive force on theB. cumingiwas significantly greater inP. conulusthan inP. pygmaea, whereas the force on the oyster shell showed no significant difference between these species. On theB. cumingi, a significantly positive correlation was found between adhesive force and volume inP. conulus, and no significant correlation was found inP. pygmaea. In contrast, on the oyster shell, a significant positive correlation was found between adhesive force and volume in both of the two species. These results suggest that the shell ofP. conulusbecomes higher with increasing own shell size by keeping aperture area relative to body size as small as possible. These morphological differences are most likely due to an adaptation to utilize different habitats and adhere to substrates with different structure and topology.