Description
The predator-prey relationship is an important fuel for evolution. Over time, prey develop adaptations that help protect them from predators and predators develop adaptations and strategies that help them capture prey more efficiently, and this continuous cycle results in the eventual evolution of all species involved. This cycle is evident in the relationship between the predatory snail Mexacanthina lugubris lugubris and its barnacle prey Chthamalus fissus. We examined when C. fissus develop adaptive defensive morphologies (narrow operculums) during early juvenile development and the effects of early exposures of their main predator M. lugubris on barnacle survival. We performed an intertidal survey of barnacles and snails at Bird Rock, San Diego to determine morphology distributions in the intertidal and see if it has changes since a previous 2004 study. In lab, we cultivated newly settled barnacles for 8 weeks in 4 experimental groups and exposed these groups to snails at different stages in development to see when these defensive morphologies develop. The intertidal surveys showed that general barnacle size at Bird Rock has decreased since the previous 2004 study, with barnacles exhibiting smaller average operculum widths. This indicates a possible increase in defensive morphologies since 2004. The lab results show that barnacles exposed to snails at settlement showed the highest mortality rates compared to other groups that were exposed later. Thus, increasing snail abundances in San Diego in response to increasing sea surface warming due to climate change, may have negative consequences on barnacles, an important foundation species in intertidal habitats.
Defensive Morphologies of the Barnacle Chthamalus fissus
The predator-prey relationship is an important fuel for evolution. Over time, prey develop adaptations that help protect them from predators and predators develop adaptations and strategies that help them capture prey more efficiently, and this continuous cycle results in the eventual evolution of all species involved. This cycle is evident in the relationship between the predatory snail Mexacanthina lugubris lugubris and its barnacle prey Chthamalus fissus. We examined when C. fissus develop adaptive defensive morphologies (narrow operculums) during early juvenile development and the effects of early exposures of their main predator M. lugubris on barnacle survival. We performed an intertidal survey of barnacles and snails at Bird Rock, San Diego to determine morphology distributions in the intertidal and see if it has changes since a previous 2004 study. In lab, we cultivated newly settled barnacles for 8 weeks in 4 experimental groups and exposed these groups to snails at different stages in development to see when these defensive morphologies develop. The intertidal surveys showed that general barnacle size at Bird Rock has decreased since the previous 2004 study, with barnacles exhibiting smaller average operculum widths. This indicates a possible increase in defensive morphologies since 2004. The lab results show that barnacles exposed to snails at settlement showed the highest mortality rates compared to other groups that were exposed later. Thus, increasing snail abundances in San Diego in response to increasing sea surface warming due to climate change, may have negative consequences on barnacles, an important foundation species in intertidal habitats.