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Juvenile Sampling <br />Juvenile chubs were collected in both Yampa Canyon and Island Park using <br />seines (7.6 m x 1.5 m; 0.5 cm mesh) and pulsed DC backpack electrofishing in side <br />channels, isolated pools, main channels, and backwaters (see Appendix). Juvenile <br />sampling was conducted in September and October. All juvenile fish captured during the <br />seining efforts were fixed in 10% buffered formalin and later transferred to 70% ethanol <br />(Kelsch and Shields 1996). <br />Humpback Chub Identification <br />Adult chubs were identified using characteristics described in Douglas et al. <br />(1989) and Muth (1990). Characters used for field identification were anal fin ray counts, <br />Caudle peduncle width and depth, angle of the anal fin in relation to the caudal fin, fin <br />shape, head shape, presence of a nuchal hump, and mouth position. Juvenile chubs were <br />identified under a dissecting microscope using similar characteristics as adults though the <br />presence of a nuchal hump was never considered. Darrel Snyder and Kevin Bestgen <br />(Colorado State University, Larval Fish Laboratory) assisted with verification of juvenile <br />samples. <br />Data Analysis <br />Due to the few humpback chub collected, robust data analyses were not possible. <br />Total catch per effort was calculated by comparing electrofishing time, trammel netting <br />