Largemouth Bass Selected for Differential Vulnerability to Angling Exhibit Similar Routine Locomotory Activity in Experimental Ponds

A growing body of work is focused on attempting to understand the biological mechanism(s) by which some fish are highly vulnerable to angling while others are not. We used electromyogram telemetry to monitor routine locomotory activity of artificially selected largemouth bass Micropterus salmoides in experimental ponds to test two potential explanatory hypotheses: (1) that the difference in angling vulnerability between high-vulnerability (HV) bass and low-vulnerability (LV) bass is related to a difference in routine activity level between the two groups, and (2) that the difference in vulnerability between HV and LV bass is related to a difference in the diel activity pattern displayed by each group (e. g., LV fish are more active at night, a time where there is typically little bass fishing effort). Neither hypothesis was supported by our results. Differences in vulnerability to angling in artificially selected lines of largemouth bass were not related to inherent differences in routine locomotory activity in our ponds. Mean daily activity levels were close to 5% of maximum swim speed in both groups, which we estimated to reflect a mean swimming distance of approximately 5,875 m (range = 1,280-9,670 m) per day. There was also no difference in the diel pattern of activity displayed by the two groups. Both HV and LV bass displayed a significant diurnal activity pattern: 16% and 19% higher activity levels during the day than at night, respectively. These results contribute to the ongoing efforts to understand the behavioral basis of vulnerability to angling in largemouth bas and other fish species.