Interspecific Differences in Desiccation Tolerance of Juvenile Land Snails

Despite close similarity of shell structure, young juveniles of Triodopsis albolabris are much superior to those of Mesodon normalis in retaining body water and in survival in low humidity. A simple linear regression model was developed to describe the relationship between the dehydration rate and the survival of multiple juveniles. Using this model, interspecific variation of individual water retention was demonstrated. The two species differ in survival and dehydration rate in low humidity largely because of their evolutionary divergence in physiological tolerance of desiccation. Their different adaptation to humidity and temperature has resulted in contrasting patterns of geographical distribution