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Experimental Groun Fin Removed <br />PIT tag--dorsal musculature Right pelvic <br />PIT tag--body cavity Left pelvic <br />V. I. tag Left pectoral <br />Carlin Right pectoral <br />Acrylic dye Lower caudal <br />Control Anal <br />To evaluate the effects the different secondary marks may have on fish growth and <br />survival, a separate group of Colorado squawfish were handled and fin clipped <br />similarly to those in the tag/mark treatment groups (Figure 2). A control group <br />(no fins removed) were included. Each group consisted of 10 fish. Fins were <br />removed with conventional scissors. Fish were held in an indoor raceway. <br />In a separate experiment, PIT tags were also implanted in hatchery <br />broodstock and evaluated. A total of 526 hatchery-reared and wild juvenile and <br />adult razorback sucker (mean total length=462 mm; range 230-653 mm) and 164 <br />hatchery-reared adult (weight and length data were not recorded at the time of <br />tagging) Colorado squawfish broodstock were implanted with PIT tags in the body <br />cavity in September 1989. These fish were periodically examined for the presence <br />of the PIT tag when they were used for spawning. A control group (no tag) was <br />not established for these two species in this separate experiment. <br />Ta in and Marking <br />Prior to tagging or marking, all immature fish, including control groups, <br />were anesthetized with MS-222. Individual fish were weighed to the nearest 0.1 <br />g, and measured to the nearest 2 mm FL. Where practical, one person was <br />responsible for tagging or marking fish within a specific experimental group for <br />all three species. This was conducted to eliminate variability among workers. <br />7 <br />