Dermal Application of Courtship Pheromones Does Not Influence Receptivity in Female Red-Legged Salamanders (Plethodon shermani)

Abstract

Abstract During courtship, adult male plethodontid salamanders transfer protein pheromones that augment female receptivity. The majority of plethodontid species apply pheromones transdermally (to the female's dorsal skin). These pheromones apparently diffuse through the skin and enter into circulation, a unique type of pheromone delivery in vertebrates. In contrast, a behavioral and physiological transition occurred in the Plethodontinae, resulting in one clade of species (Plethodon glutinosus group) that uses a different pheromone delivery mode. Males within this clade apply pheromones directly to the nares of a female, and the pheromones subsequently are detected by the vomeronasal organ. We tested whether female Red-Legged Salamanders (Plethodon shermani), despite normally detecting pheromones via the vomeronasal organ, have retained the ancestral ability to respond to pheromones delivered transdermally. We staged courtship encounters and recorded the behavior of females given either pheromones or cont...