Viral pyrogen affects thermoregulatory behavior of wintering Planorbarius corneus (L.) snails (Mollusca: Gastropoda)

Exogenous pyrogens, isolated from viruses, bacteria and fungi, are widely used in research on fever in endotherms. The present study investigates the use of viral pyrogen poly (I:C) for inducing the symptoms of so-called behavioral fever in ectothermic animals Planorbarius corneus (Mollusca: Gastropoda). The observations of thermoregulatory behavior of the snails placed in the temperature gradient showed that the snails which were injected with 750 ng g⁻¹ polyinosinic-polycytidylic acid-poly (I:C), after remaining latent for more than 24 h, moved to warmer areas (with the temperature around 30 °C) and stayed there until the end of the experiment. Transferred to the culture, they lived for a period similar to that of the control snails. Our observations indicate that P. corneus snails can exhibit a symptoms of fever response to poly (I:C) and could be used as model animals in the research on behavioral fever in invertebrates.