Climatic conditions driving a part of changes in the biochemical composition in land snails: Insights from the endangered Codringtonia(Gastropoda: Pulmonata)

Abstract

Most land snails in order to ensure their survival under adverse environmental conditions interrupt their activity entering a state of dormancy. The transition from activity to dormancy is accompanied by several changes in the animals' physiology. To identify these changes we examined the seasonal patterns in the biochemical composition and the LDH activity of three different tissues in four endangered land snail species. Additionally, within a phylogenetic framework we investigated the correlation of the measured parameters with the spatial and climatic variables of the sampling sites. Our results indicate that there are both differences and similarities in the pattern exhibited by the four species, depending on the physiological parameter investigated and the climatic conditions of the sampling sites, which sometimes have a significant effect on the seasonal pattern exhibited. Snails can successfully deal with the winter dormancy by maintaining high metabolite concentrations and stable water content whereas there is no indication of anaerobic pathways' activation. At the same time, they deal successfully with the low humidity and high temperatures during the summer, but they are forced to maintain low metabolite concentrations and seem to activate anaerobic pathways to meet their energy demands. Therefore, from a biochemical perspective, it seems that winter is a less stressful period for snails compared to summer. According to the prevailing climate change scenarios, the Mediterranean region is going to exhibit a sudden transition towards a dryer and longer summer. This transition will exert a very high adaptation pressure on the already vulnerable Codringtonia species. Thus, it could be that this endemic Greek genus is truly on the verge of extinction. © 2016 Institute of Zoology, Slovak Academy of Sciences