Into the Deep: Diving Record for the Dice Snake Natrix tessellata (Laurenti, 1768) in Lake Orta, NW Italy

Abstract

Many snakes live close to water, with several groups displaying morphological, physiological, or behavioral adaptions to aquatic environments. Although marine snakes have been found at depths beyond 200 m, freshwater snakes are rarely reported at depths larger than a few meters. Here we report freshwater depth records for the dice snake Natrix tessellata, an aquatic snake belonging to the family Natricidae. Dice snake was observed at depths down to 17 m, including in habitats below the thermocline, in Lake Orta (Northern Italy). These observations open new perspectives related to the biology and physiology of Palearctic freshwater snakes belonging to the family Natricidae.