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<br />Proximity to the nearest electrode was reported for 40 Colorado pikeminnow. At <br />capture, five fish touched an anode, 17 fish were one meter or less from an electrode, <br />16 fish were from 1 to 2 m, and two fish were from 2 to 3 m from an electrode. <br />Physiological state at capture was observed for 42 fish; 64% were stunned (narcosis) <br />by the electrical current, 24% were swimming toward an electrode (electrotaxis), and <br />12% were tetanized (tetany) when netted. The physiological response of fish to the <br />electric field generally intensified as their mean distance from the anode decreased but <br />for each physiological response, the range of distances varied widely and overlapped. <br />Fish in electrotaxis were caught at a mean distance from the anode of 1.3 m (range 0-3 <br />m; SD, 1.077), stunned fish were caught at 0.9 m (range 0-2.4 m; SD, 0.709), and <br />tetanized fish were caught at 0.6 m (range 0-1.5 m; SO, 0.747). Fish that touched an <br />anode exhibited a variety of responses to the electrical current: two were tetanized, two <br />were stunned, and one was in electrotaxis (swimming). <br />Three of 47 fish examined had external injuries associated with electrofishing. <br />One fish had several injuries within an area approximately 75-mm posterior to the <br />insertion of the dorsal fin. These injuries included bruises (brands), three small <br />puncture wounds, and lateral muscle compaction that gave a bulging appearance at the <br />injury. The bruises were small and positioned along the dorsal surface unlike large, <br />lateral-surface bruises typically seen on electofishing-injured trout. The punctures <br />formed a triangle along the lateral surface and dorsal midline. Radiographs of this fish <br />revealed Class-1 compressions in 11 vertebrae at the injury. This fish was captured <br />while swimming toward an anode, but unfortunately the distance at capture was not <br />reported. <br /> <br />9 <br />