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<br />between juvenile and adult fish or lack of reproductive success in the past. <br /> <br />. ~ <br />Apart from this group of small pike, there was no apparent difference in <br />length frequency distributions for pike between major river reaches (Figure <br />3) . <br /> <br />The length-weight relationship for the Yampa pike population was: <br />logW = -5.107 + 2.985logL W=weight; L=length <br />The condition factors (K) for these pike ranged from 0.552 to 1.026, and <br />averaged 0.712. Both of these population parameters appear low relative to <br />ranges reported in Carlander (1969), and suggest a lean body shape and below <br />average condition for Yampa pike. Condition of the pike deteriorated <br />noticeably during the pre-runoff and runoff periods when river turbidity <br />increased. This was evidenced by numerous lacerations and abrasions. A large <br />rounded abrasion was especially evident on the tip of the lower jaw of many <br />pike. Three pike appeared blind in one eye. These abrasion injuries were not <br />as apparent during the base flow sampling period. <br />Scale samples were collected from all northern pike sampled. Impressions <br />of scales are being made on acetate slides for later age-growth analyses. <br />Evidence of spawning by northern pike in the river was observed in late <br />April to May. The first ripe male (TL 584 rom) was collected at Lay Cr. (RM <br />88.2) on April 22, 1988. On May 5, sampling from two backwaters at RM 51.5 <br />resulted in four ripe male pike (TL 510-611 rom), four green females (TL 713- <br />783 rom), and one ripe female (TL 864 rom). By May 22-23, spent pike females <br />(TL 638-947 rom) were collected at RM 113.2, 98.6, and 51.5. Upstream in the <br />Hayden to Craig reach, three ripe males (TL 446-809 mm) and one ripe female <br />(TL 809 rom) were captured at RM 151.5, 145.1, and 144.6. on May 25, 1988. No <br />ripe adults were observed in June 1988. <br /> <br />11 <br />