Exposure of Chironomus riparius larvae to 17 alpha-ethynylestradiol: effects on survival and mouthpart deformities

Evidence from field studies shows that mouthpart deformities in chironomid larvae are a sublethal response to pollution. Interest has been shown to us e this end-point in programs for monitoring sediment quality. During labora tory studies, however, deformities were induced in only a few single pollut ant exposures. These deformities develop at the endocrine regulated molting stage and disruption of this complex process is likely at the base of thei r ontogeny. Aiming to clarify the processes involved in the rise of such de formities, we tested the effects of ethynylestradiol (EE2) in an in vivo la b study. Chironomus riparius larvae were exposed to 1, 10 and 100 mug l(-1) EE2 (nominal concentrations). No adverse effects on the larvae, for the in vestigated end-points (survival and deformity induction), were found. (C) 2 001 Elsevier Science B.V. AII rights reserved.