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served as the control (no PIT tag). A third group was neither PIT tagged nor fin clipped. Fish in each of the three groups were checked twice (at day 134 and 265) during the 8.7-month study period. Data Analysis Tag retention was defined as the number of fish retaining tags or marks through each observation period divided by the numbers of fish that survived those periods. Survival was defined as the number of fish alive at each observation period divided by the numbers of fish present at the beginning of the study. Differences in tag retention and survival among treatments was determined by Chi-square tests using a 0.05 level of significance. Student's "t" test was applied where appropriate. The effect of the tag or mark on growth (Appendix; Tables 11-13) was analyzed by comparing the difference between the mean FL at the start and termination of the study for each of the experimental and control groups. Statistical significance was assumed at P < 0.05. RESULTS AND DISCUSSION Dexter NFHTC Colorado Squawfish Broodstock. Sixteen of 164 fish PIT-tagged in the body cavity died during the 24-month evaluation period. Tag verification was 98'/o for 158 fish examined 20 months following tagging. Ten fish could not be accounted for between 20 and 24 months; tag verification was 100% (n=148) at 24 months. PIT tags have also been useful for long-term individual identification of captive broodstock of other species: largemouth bass (Micropterus salmoides) (Williamson 1986; Harvey and Campbell 1989); striped bass (Morone saxatilis), red drum (Sciaenoas ocellatus) (Jenkins and Smith 1990), and channel catfish (Ictalurus punctatus) 13