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<br />Elmblad, personal communication> and field radiographs revealed no vertebral injuries. <br />Another injury type observed in three fish from the White River was torn skin in <br />the gular region between the mandible and isthmus along the interior margin of the <br />mandible. The tears were 30- to 60-mm long and occurred on one or both sides and <br />appeared severe enough to affect the respiratory efficiency due to leakage through the <br />openings. There was no evidence that this injury was caused by the electrofishing <br />event, but I have observed similar injuries on Colorado pikeminnow caught by <br />electrofishing in other studies. <br />Forty-seven Colorado pikeminnow were x-rayed, including 46 caught by <br />electrofishing and one found dead of unknown causes. Thirty-four of the 46 fish (74%) <br />caught by electrofishing had no apparent vertebral injuries and 12 fish (26%) had <br />elass-1 vertebral compressions. No vertebral misalignments (Class-2 injuries) or <br />fractures (elass-3 injuries) were observed. Three fish (7%) had acute vertebral <br />compressions attributed to the electrofishing event and nine fish (20%) had vertebral <br />compressions classified as congenital or chronic in origin. Length of fish with vertebral <br />compressions ranged 387-701-mm total length and was similar to that of non-injured <br />fish (Figure 1; Table 2). Most fish (67%) had compressions that affected only two <br />vertebrae (Table 2). None of the fish had multiple compressions. eompressed <br />vertebrae were located from the 10th to the 48th vertebrae, but the majority of <br />compressions occurred between the 16th and 34th vertebrae which is the area between <br />the origins of the dorsal and anal fins (Table 2). Acute injuries affected 2-11 vertebrae <br />and compressed them an average of 35% (SO, 15.39; range 18-48%) of original width. <br />Congenital and chronic abnormalities affected from two to four vertebrae and <br /> <br />11 <br />