Meeting Abstract
The sensory trap hypothesis predicts males use signals that mimic nonsexual cues to gain access to mates. In theory, deceptive signaling might lead to honest communication if females evolve to discriminate the mimic from the model and react appropriately to each per the context. We investigated if and how female sea lamprey (Petromyzon marinus) discern a nonsexual chemical cue from a male pheromone that mimics it. Sea lamprey migrate into streams following chemical cues released by larvae residing in nursery habitats near spawning grounds. Sexually mature males signal to females using a sex pheromone that partially mimics the larval cue; the major component of the male pheromone 3-keto petromyzonol sulfate (3kPZS) is also released by larvae and influences the nonsexual migratory behavior of sea lamprey and other species that do not use it as a sex pheromone. We postulated females discriminate between the larval cue and the male pheromone using petromyzonol sulfate (PZS), a behavioral antagonist of 3kPZS. Chemical analysis confirmed that both larvae and males release 3kPZS but revealed proportionally more PZS in larval odor than male odor. In a natural stream, 100% of females chose the nest baited with a mixture of 3kPZS and PZS typical of males over that of larvae when each was applied at the same concentration of 3kPZS. Our results indicate females use a behavioral antagonist to avoid orienting towards larval odor while tracking the male pheromone that mimics it, and offer rare evidence females can adapt to use mimetic male signals for honest communication.
