Meeting Abstract
During reproduction, it is vital for animals to coordinate the timing of behavioral and physiological cycles. The sea lamprey, Petromyzon marinus, relies on pheromone communication for reproduction. Sexually mature male sea lamprey release a multicomponent sex pheromone through their gills that attracts mates. Sea lamprey are primarily nocturnal, but it is unknown if male pheromone release is consistent with this behavioral pattern. We investigated if sea lamprey exhibit a diel pattern of pheromone release, and whether it is driven by biosynthetic production or is a byproduct of elevated respiration due to increased behavioral activity. We quantified pheromone release and production by measuring 3keto-petromyzonol sulfate (3kPZS, a main pheromone component) and its biosynthetic precursor petromyzonol sulfate (PZS) in holding water and tissue samples at 6 different times of day. Behavioral activity and respiration rates were measured using visual observations and video analysis. 3kPZS release exhibited a diel pattern with elevated release during nighttime hours. This pattern was disrupted by holding lamprey in constant darkness or light for 7 days. Trends in hepatic synthesis and circulatory transport of PZS and 3kPZS were consistent with 3kPZS release, whereas trends in respiration rates were less consistent. Our results suggest elevated levels of pheromone production and release at night evolved to match nocturnal increases in behavioral activity. Synchronizing these cycles may be imperative for reproductive success by ensuring reproduction occurs at optimal times, which is especially important in a species having a single, reproductive event.
