title: Effects of sex pheromones and sexual maturation on locomotor activity in female sea lamprey (Petromyzon marinus).
abstract: Synchronization of male and female locomotor rhythmicity can play a vital role in ensuring reproductive success. Several physiological and environmental factors alter these locomotor rhythms. As sea lamprey, Petromyzon marinus, progress through their life cycle, their locomotor activity rhythm changes multiple times. The goal of this study was to elucidate the activity patterns of adult female sea lamprey during the sexual maturation process and discern the interactions of these patterns with exposure to male pheromones. During these stages, preovulated and ovulated adult females are exposed to sex pheromone compounds, which are released by spermiated males and attract ovulated females to the nest for spawning. The locomotor behavior of adult females was monitored in a natural stream with a passive integrated tag responder system as they matured, and they were exposed to a sex pheromone treatment (spermiated male washings) or a control (prespermiated male washings). Results showed that, dependent on the hour of day, male sex pheromone compounds reduce total activity (p < 0.05) and cause increases in activity during several daytime hours in preovulated and ovulated females. These results are one of the first examples of how sex pheromones modulate a locomotor rhythm in a vertebrate, and they suggest that the interaction between maturity stage and sex pheromone exposure contributes to the differential locomotor rhythms found in adult female sea lamprey. This phenomenon may contribute to the reproductive synchrony of mature adults, thus increasing reproductive success in this species.
authors.affiliation: Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Erin J
authors.initials: EJ
authors.lastname: Walaszczyk
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Johnson
authors.forename: Juan Pedro
authors.initials: JP
authors.lastname: Steibel
authors.forename: Weiming
authors.initials: W
authors.lastname: Li
mesh_terms: D000818:Animals; D005260:Female; D016014:Linear Models; D009043:Motor Activity / Q000187:drug effects*; D010060:Ovulation / Q000187:drug effects / Q000502:physiology; D048428:Petromyzon / Q000502:physiology*; D016012:Poisson Distribution; D012724:Sex Attractants / Q000494:pharmacology*; D012741:Sexual Maturation / Q000187:drug effects*
chemical_list: D012724:Sex Attractants
keywords: agnathan; arrhythmicity; diel rhythms; locomotor activity; maturation; sex pheromone