Comparative Ethological and Biochemical Aspects of Courtship Pheromones In European Newts

In Y-maze tests, both males and females of the urodeles Triturus camifex Laurenti, 1768, T. alpestris Laurenti, 1768 and T. italicus Peracca, 1898 preferred the water flowing from a tank holding an isospecific courting couple over that with a sexually inactive one. This chemotactic effect was more pronounced in the less sex dimorphic species, i.e. T. italiens > T. alpestris > T. carnifex. In T. carnifex, both sexes were totally unresponsive to the glycoproteins of the abdominal gland of the male, secreted into the water during courting. On the other hand, progesterone, another secretory product of this gland, was found to act as an attractant for ripe females of this species, but not on sexually quiescent females. This action is compatible with that of a short-range courtship pheromone.