Species Specificity of Lamprey Mating Pheromones

The sea lamprey (Petromyzon marinus) uses a male mating pheromone, partially comprised of 7α, 12 α, 24-trihydroxy-3-one-5 α -cholan-24-sulfate (3kPZS). Observations of heterospecific spawning support the hypothesis that other species of lamprey use mating pheromones and that the pheromones used are not species specific. We present our ongoing effort to describe the species specificity of mating pheromones across the Petromyzontiformes, including chemical analyses of male odors and behavioral responses to natural and synthetized odors. Females of all species tested exhibited strong behavioral preferences for conspecific male odors. The preference for male odors partially overlapped between heterospecifcs. 3kPZS as a major component of the mating pheromone is not specific to sea lamprey. A comparison of the pheromones employed by lampreys offers support for existing phylogenies, insights to the evolution of signaling systems, and may be useful in efforts to restore or control lampreys which are species of concern throughout their range.