Chemosensory Communication in the Sea Lamprey: Implications for Sea Lamprey Control

The sea lamprey is an invader of the Great Lakes that helped cause the devastating collapse of native fish communities during the mid-1900s.  From the 1960s to present, sea lampreys in the Great Lakes have been suppressed by a control program primarily focused on the use of selective lampricides that target sea lamprey larvae.  A more comprehensive approach to sea lamprey control that targets multiple vulnerabilities in the organism’s life history is needed to further suppress sea lamprey populations and make restoration of Great Lakes fish communities possible.  Recently, much progress has been made in the understanding of chemosensory communication in the sea lamprey, which is broadly thought by experts to be exploitable for sea lamprey control purposes, and could serve to strengthen the sea lamprey control program.  Specifically, potent reproductive pheromones have been characterized and identified including; a migratory pheromone released by larval sea lamprey that signals the suitability of a stream for spawning, and a mating pheromone released by sexually mature male sea lampreys that signals to sexually mature females a males readiness to mate.  More recently, a sea lamprey alarm cue has been discovered that is released from dead and decaying sea lampreys and may signal to spawning-phase sea lampreys that an area is not suitable for inhabitation.  Both reproductive pheromones and the alarm cue likely play a critical role in the successful reproduction of a species that dies shortly after spawning.  Therefore, the ability to manipulate behaviors of sea lampreys using pheromones and alarm cues to disrupt reproduction or better target the application of lampricides may greatly improve sea lamprey control while simultaneously reducing the application of lampricides.  Chemosensory research results and the implications for sea lamprey control will be described in more detail.