Electric field-induced detachment and vibration analysis for Sea Lamprey

ABSTRACT Objective Sea Lamprey Petromyzon marinus, a known ecological threat to native fish populations in the Great Lakes, uses its oral suction disc to navigate challenging environments when moving upstream to spawn. This study investigated the physiological response of adult Sea Lamprey to detach under pulsed direct current electric fields. Methods Adult Sea Lampreys in an attaching position were exposed to pulsed direct current electric fields at four different field strengths (0.7, 1.1, 1.3, and 1.9 V/cm). Behavioral responses, including detachment and vibration, were observed and analyzed. Fast Fourier transform analysis was applied to the vibration data to quantify the frequency of vibration that nondetached Sea Lamprey exhibited. Statistical correlations between detachment rates and vibration responses to sex, weight, and length were evaluated to determine the influencing factors. Results The highest detachment rate (91%) was observed at 1.1 V/cm, with the detachment rate greater than 70% for other field strengths. The fast Fourier transform analysis revealed that the vibration frequencies closely matched the signal, whereas stronger fields elicited a more pronounced vibration amplitude without significantly increasing detachment. Nondetached animals exhibited “twitching” behavior that was synchronized with the electric field frequency. Sex, weight, and length had minimal influence on the detachment rates and vibration responses. Conclusions This study provided insights into the behavioral responses of Sea Lamprey under electric fields, highlighting the potential for optimizing electric deterrents for selective control. Although not all Sea Lampreys detach during electroshocking, understanding their behavior can be crucial in maximizing detachment rates and contributing to improved management strategies for this invasive species.