BEHAVIORAL THERMOREGULATION OF THE PERIWINKLE NODILITTORINA-PERUVIANAINHABITING THE ROCKY INTERTIDAL OF CENTRAL CHILE - A LABORATORY AND FIELD-STUDY

As an attempt to explain the distribution patterns of the periwinkle N odilittorina peruviana, the aim of this study was to investigate the s patial movement of individuals in response to environmental temperatur e. Furthermore, the relationship between body temperature and environm ental temperature as a function of body size, and the effects of envir onmental temperature on behavioral thermoregulation was tested. In the field, the body temperature (Tb) of N. peruviana showed a significant correlation with environmental temperature. However, comparisons betw een body and environmental temperatures revealed that Tb-values were h igher than surrounding air and rocky surface temperatures. This patter n can be indicative of behavioral thermoregulation (i.e. by local migr ation). In fact, under laboratory conditions snails significantly avoi ded microhabitats with higher temperatures, showing a preferential bod y temperature of 14 degrees C. We conclude that like many other ectoth erms, prosobranch gastropods are able to regulate their body temperatu re by the use of behavioral responses of thermoregulation, which may p artially explain their pattern of spatial distribution in the rocky in tertidal of central Chile.