Snake tongue-flicking: transfer mechanics to Jacobson's organ

Abstract

Cinematographic analysis of the open-mouthed tongue flick of rat snakes (Elaphe) revealed elevation of the anterior processes following tongue retraction into the lingual sheath. The ventral surface of the tongue makes contact with these processes on each retraction and these processes are directly aligned with Jacobson's (vomeronasal) organ in the roof of the mouth. Scanning electron microscopic examination of the anterior process surface reveals an increased surface area through oblique ridges. Experimental removal of these structures prevents open-field detection of food odors in garter snakes (Thamnophis). These data indicate that this structure is the vehicle for transfer of substances to Jacobson's organ during snake chemosensation.