Olfactory responses of male and female red‐spotted newts to sex pheromones from the opposite sex

Functional characterization of sex pheromones in olfactory responses is essential for the study of chemical communications in amphibians. Using Y‐maze olfactory preference tests, we have investigated the olfactory responses of male and female red‐spotted newts, Notophthalmus viridescens, to the crude extracts of the opposite sex's genial and cloacal pheromones. Both male and female cloacal pheromone extracts caused the opposite sex to initiate olfactory responses by leaving the starting area in the Y‐maze, but only subject males exposed to female cloacal pheromone extracts completed olfactory choice by entering the side arm of the Y‐maze which received the pheromones. For genial pheromone extracts, only female genial pheromone extracts induced initial olfactory responses from test males. Neither male nor female genial pheromone extracts made the opposite sex complete olfactory choice. Pre‐exposure of test females to male pheromone extracts increased the likelihood of initial olfactory responses. The latency for initial olfactory responses of test females that were previously exposed to male genial extracts was significantly shorter than that of control females.