Chemotesting Movements and Chemosensory Sensitivity to Amino Acids in the European Pond Turtle, Emys Orbicularis L.

Abstract

The European pond turtle Emys orbicularis is an amphibious animal detecting and locating food by chemoreception both on land and in water (Honigmann, 1921). This turtle makes regular low-amplitude movements of the lower jaw that promote the propulsion of water to chemoreceptors within the nasal and oral cavities which may be regarded as stimulus acquisition behavior after the terminology of Atema (1987). de term these movements “jaw testing movements” (JTM). Various changes in the sensory medium and the animal’s emotional state elicit an increase of the JTM frequency which serves as an indicator of chemosensory perception of stimuli. In this study, we examined the reaction of Emys orbicularis to some L-amino acids. Such agents are effective stimuli for chemoreceptor3 of most aquatic animals and are generally found in the aquatic medium (Bardach, 1975).