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<br />compressed vertebrae an average of 23% (SO, 12.40; range 12-56%) of original width. <br />There were no clear relationships between the occurrence of compressed <br />vertebrae and observed electrofishing events or physiological state at capture. Fish <br />with compressed vertebrae (both congenital/chronic and acute) were captured at <br />distances between 0 and 2.4 m from the nearest electrode and their physiological state <br />at capture included: swimming (n=4), stunned (n=5), tetanized (n=1) and unknown <br />(n=2). Only one fish with vertebral injuries had associated external injuries (bruises and <br />muscle compaction) and it was the fish with the most extensive compressions <br />(11 vertebrae). <br />Of the 46 fish caught by electrofishing and x-rayed, 19 were previously captured <br />by either electrofishing ( n=15) or trammel net (n= 4), 1-8 years prior to 1996. There <br />was no evidence of multiple vertebral injuries in the radiographs of fish caught more <br />than once by electrofishing. <br />Fifteen of the 46 x-rayed fish were later recaptured between 1997 and 2002. <br />Fish with no vertebral injury (n=10) grew an average of 17.2 mm/year (SO, 12.74; range <br />2.8-41.5; Table 3). Four fish with congenital or chronic injuries grew 15.6 mm/year <br />(SO, 6.30; range 8.3-23.4) and the one recaptured fish with acute injuries grew 9.9 <br />mm/year after 2 years at large. <br /> <br />DISCUSSION <br /> <br />The acute injury rate of Colorado pikeminnow attributed to electrofishing (7%) <br />was much lower than that reported for salmonids collected in the wild with similar <br /> <br />12 <br />