GENETIC AND PHYSIOLOGICAL ADAPTATIONS OF THE PROSOBRANCH LANDSNAIL POMATIAS OLIVIERI TO MICROCLIMATIC STRESSES ON MOUNT CARMEL, ISRAEL

Abstract

ABSTRACT Slope orientation in the Mediterranean climate may lead to different adaptations of the faunistic elements to the environment. The south-facing slope (SF) of Lower Nahal Oren (Mount Carmel) is more exposed to solar radiation and therefore is warmer, drier, and has a lower vegetation coverage than the north-facing slope (NF). Resistance to desiccation and genetic diversity of the northeastern Mediterranean prosobranch landsnail Pomatias Olivieri, whose southern border is on Mount Carmel, were examined to elucidate potential physiological and genetic adaptations to contrasting microclimatic conditions. The body water content and the extrapallial fluid content were significantly higher in fully-hydrated SF-snails than in those from NF. Similar rates of water loss were found during normothermic and hyperthermic desiccation in SF-snails, whereas in NF-snails water loss increased in hyperthermic conditions. Thus, the snails on the opposite slopes differ in their physiological responses to high ambient ...