Laserfiche WebLink
<br />become, the less sensitive their response to toxicants. Consequently, the estimated median lethal <br />concentration for razorback sucker at 27 days after hatching may be slightly higher than the value <br />at 10 days. This test will be repeated during future investigations to assess the influence of age <br />on sensitivity of razorback sucker. <br />Conclusions <br />Description of adverse effects as functions of dietary exposure were not possible because <br />toxic selenium concentrations in diet were not achieved. However, results do confirm that <br />exposure to dietary selenium below 1.4 µg/g dry weight do not adversely effect survival and <br />growth of larval razorback sucker. The 96-hour median lethal concentrations and 95% <br />confidence limits for razorback sucker and fathead minnow exposed to dissolved selenium were <br />40.8 (37.0, 44.9) and 33.3 mg/L (29.8, 37.1), respectively. <br />Recommendations <br />No recommendations can be made at this time. Useful recommendations should be <br />provided by ongoing investigations that will extend results of research presented in this report. <br />Ongoing investigations <br />Two ongoing investigations being conducted by the authors will provide data that will <br />expand this research and allow evaluation of its predictive accuracy. One study entitled <br />"Evaluation of interspecific sensitivity to dietary selenium exposure: razorback sucker versus <br />flannelmouth sucker" will provide data that will extend the dissolved and dietary exposure <br />24 <br />