Can Parasites Change Thermal Preferences of Hosts?

Abstract

Scientific literature provides many examples of parasite-induced changes in thermal preferences of animals. These alterations can be interpreted as a defense response of hosts, a by-product of parasitic invasion or host manipulation aimed at increasing chances of parasite transmission. In this chapter we present an overview of ectothermic host-parasite relationships using snail-parasite, insect-parasite, and fish-parasite interactions to provide an answer to the initial question. Interestingly, in all the above examples (regardless of the systematic position of hosts) the invasion of eukaryotic parasites is correlated with host thermal behavior, benefiting parasites. It should be emphasized that although numerous analysis of this phenomenon sound convincing, without thorough understanding of the molecular basis of thermal behavior of ectotherms they fail to provide sufficient explanation. We are convinced that research on the mechanism of thermal preferences of ectothermic animals in terms of physiology, metabolism, neuromodulation, and immunology will clarify the suggested impact of parasites on thermal behavior of their hosts.