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<br />1"-. <br />1;1 C:) <br />. ~~ <br />,a. ~.._ <br />r,-ry <br /> <br />] <br /> <br />II <br /> <br />-,I <br /> <br />J <br /> <br />I <br /> <br />11 <br /> <br />-~ <br />I <br />1 <br />-I <br />11 <br />11 <br />11 <br />1J <br />-- <br />I <br /> <br />Eggs and I-day posthatch larvae contained significantly greater selenium concentrations <br /> <br />than the female parent (about 2- to 5-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 /> <br />concentrations in larvae exposed to clean water and diet for 30 days were 20 to 76% lower than <br /> <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 /> <br />to interpret due to the lack of replicate spawns for three treatments and the small sample size. <br /> <br /> <br />Hatchability of eggs containing 1.8-11.6 !J.g/g selenium averaged 84% and the incidence of <br /> <br /> <br />deformities in the resulting larvae averaged 13%. Survival oflarvae containing 2.8-13.4 !J.g/g <br /> <br />selenium at hatch averaged 87% after 30 days. Overall survival of progeny from the 10 spawns <br /> <br /> <br />average 7.2%. Selenium concentrations in eggs (9.8 to 11.6 !J.g/g) produced by females with <br /> <br /> <br />muscle tissue selenium residues of2.5-3.0 !J.g/g fall in the low to moderate hazard category for <br /> <br /> <br />potential selenium-induced reproductive impairment in fish. However, the female with the <br /> <br /> <br />highest muscle plug selenium concentration of 5.2 !J.g/g did not spawn, so the effect (if any) of <br /> <br /> <br />this accumulated selenium residue from the high selenium diet (11.8 !J.g/g) on reproduction could <br /> <br /> <br />not be determined. Consequently, the hazard posed by parental exposures to dietary selenium <br /> <br /> <br />concentrations :S;12 !J.g/g and waterborne selenium concentrations :S;8 !J.g/L to wild Colorado <br /> <br /> <br />pikeminnow cannot be adequately assessed from the reproduction data obtained in this study and <br /> <br /> <br />additional research is needed to determine the dietary selenium threshold concentration for <br /> <br /> <br />reproductive impairment in these fish. <br /> <br />Xl <br />