Nucleic acid, protein content, and growth of larval fish sublethally exposed to various toxicants.

Larval fathead minnows Pimephales promelas were exposed for 96-h to several concentrations of benzophenone, ethyl acetate, hexavalent chromium, hydrogen cyanide, or p-cresol. The range of 'safe' concentrations determined from 96-h macromolecular content (RNA, DNA, and protein) and growth was within or very near the range of 'safe' concentrations determined by concomitant longer term exposure (28- to 32-d early life stage toxicity test). Larval RNA content appeared to be the 96-h measurement most responsive to toxicant exposure. Measurement of growth and macromolecular content after a 96-h larval exposure provided a physiologically relevant measurement of toxicity that was predictive of longer term sublethal toxicity. -from Authors