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6 <br />used as seines over gravel bars and through runs and pools. Sex and <br />spawning condition of all captures were noted. Males running milt were <br />usually tuberculated over the entire body and easily sexed. Fish were <br />considered possible females if they were'not tuberculated or were only <br />slightly tuberculated on the head and had swollen genital papillae or <br />distended abdomens. Fish were listed as indeterminant sex if none of <br />the above indicators were present. <br />Larval Fish Sampling <br />The Yampa River was intensively sampled every 8 km for larval <br />squawfish from river km 195 (mile 121) to its confluence with the Green <br />River. The sampling was conducted August 12-28, 1982, approximately 2 <br />weeks after the major spawning period. Dipnet and seine (pore size 0.8 <br />to 1.6 mm) samples were taken from specific habitat types. Samples were <br />fixed in 10%, formalin and taken to the Larval Fish Laboratory, Colorado <br />State University, Fort Collins, for sorting, identification, and curation. <br />RESULTS <br />Migratory Movement <br />Of the 12 fish in the radiotagged sample population, five (numbers <br />1, 4, 5, 9, and 10) migrated to or near the previously identified spawning <br />area at river km 26.4 (mile 16.4), and at least four of them returned to <br />the general vicinity of their premigratory residence (Fig. 2). Fish <br />number 1, a ripe male, was captured in a trammel net at river km 26.7 <br />(mile 16.6), July 10, with an inoperable transmitter. Fish numbers 2, <br />6, and 8 (Fig. 3), were considered nonmigrants; they were recorded only <br />in the general vicinity of their original capture, had operational <br />transmitters after the spawning period, and were not found in Yampa