The effects of thermal stress on Nucella lamellosa and Lottia pelta radula

Abstract

Radula formation in gastropods has been shown to be sensitive to the environmental conditions, including substrate type and low temperatures. However, little work is available on the effect of high temperature stresses on rate of radula development. This study is a first-order attempt in examining the relationship of radula production and temperature between two gastropod species with very different uses for their radula—a predator, Nucella lamellosa, and a grazer, Lottia pelta—under elevated temperature conditions. Row density of new radula growth, and relative tooth wear along the anterior end of the radula, were compared between species and across 3 temperature settings. A negative correlation between water temperature and row density was observed for both study species. Furthermore, elevated temperature was negatively correlated with both feeding rates and tooth wear in N. lamellosa. This study suggests that stress from elevated temperatures is detrimental to radula development between species, and that temperature stress leads to a reduction in feeding, and thus, reduced usage of the radula.