Spawning Sea Lamprey

In addition to investigating chemosensory cues such as pheromones and alarm cues, researchers are also testing antagonists—compounds that specifically block a sea lamprey’s ability to detect pheromones—as a means to disrupt mating. Shown here is an experiment with an antagonist in a natural stream. While the antagonists were present in the river, the sea lamprey did not initiate spawning behaviors. However, when the antagonist application was halted, natural spawning behaviors ensued, as shown in this photo. Photo credit: Andrea Miehls, USGS.