Comparing the Mineralization of Two Limpet Species Lottia pelta and Lottia digitalis Between Species and Intertidal Location

Abstract

Intertidal gastropods have a variety of behavioral and physical adaptations to help them survive in the environment. One of the most obvious is the evolution of an outer shell for defense, which can protect organisms from dangers such as predators, as well as heat and wave force. The limpet species Lottia pelta and Lottia digitalis are two limpets with different external shell morphologies that live in overlapping habitats in the intertidal environment. In this study I aim to compare whether the visibly different shell morphological traits extend to the amount and distribution of mineralization within the shell and if this changes by tidal height. To do this I CTscanned 31 limpet shells with phantoms of a known density to map the actual distribution of material densities. I found that while the overall density of each shell across species and intertidal height were not significantly different, the distribution of density differed for L. digitalis in low intertidal vs every other treatment. This difference that sets the low intertidal L. digitalis apart from the rest could be a result of the increased need for defense in a region that is often submerged and vulnerable to predation.