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<br />I <br />I <br />I <br /> ,-., <br />I ..-.) <br />...'1 r-, <br /> r:;::'~ <br /> <br />Eggs and I-day posthatch larvae contained significantly greater selenium concentrations <br /> <br />Ll than the female parent (about 2- to S-fold) and these concentrations were strongly correlated with <br /> <br />dietary exposure of the parent These results indicated that selenium assimilated from the diet of <br /> <br />the female parent was transferred to the eggs in a concentration-dependent manner. Selenium <br /> <br />concentrations in larvae exposed to clean water and diet for 30 days were 20 to 76% lower than <br /> <br />in newly hatched larvae, and the magnitude of reduction was related to initial whole-body <br /> <br />selenium concentrations. <br /> <br />The biological significance of selenium residues observed in eggs and larvae are difficult <br /> <br />to interpret due to the lack of replicate spawns for three treatments and the small sample size. <br /> <br />Hatchability of eggs containing] ,8-1].6 I1gig selenium averaged 84% and the incidence of <br /> <br />deformities in the resulting larvae averaged 13%. Survival oflarvae containing 2.8-13.4 ,lgig <br /> <br />selenium at hatch averaged 87% after 30 days. Overall survival of progeny from the] 0 spawns <br /> <br />average 72%. Selenium concentrations in eggs (9.8 to 11.6 I1gig) produced by females with <br /> <br />muscle tissue selenium residues of2.5-3.0 pgig fall in the Jow to moderate hazard category for <br /> <br />potential selenium-induced reproductive impairment in fish. However, the female with the <br /> <br />highest muscle plug selenium concentration of 5.2 I1gig did not spawn, so the effect (if any) of <br /> <br />this accumulated selenium residue from the high selenium diet (11.8 I1g/g) on reproduction could <br /> <br />not be determined, Consequently, the hazard posed by parental exposures to dietary selenium <br /> <br />concentrations :512 l1g/g and waterborne selenium concentrations :58 I1g/L to wild Colorado <br /> <br />pikeminnow cannot be adequately assessed from the reproduction data obtained in this study and <br /> <br />additional research is needed to determine the dietary selenium threshold concentration for <br /> <br />reproductive impainnent in these fish, <br /> <br />Xl <br />