Abstract
The aim of the present study was to examine acute and delayed effects of pulse exposure of the pyrethroid pesticide, permethrin, on precopulatory pairs of Hyalella azteca. Pairs of H. azteca were exposed to a single 1. h pulse of different nominal concentrations of permethrin: 0, 0.3, 0.9 or 2.7. μg/L. During exposure, pairing behavior was observed, and during a 56 day post-exposure period the treatments were monitored for pairing behavior, survival and reproductive output. All permethrin-exposed pairs separated within minutes during exposure and shortly thereafter became immobile; however they regained mobility after transfer to clean water. The time to re-form pairs was significantly longer in all tested concentrations compared to the control, although all surviving pairs re-formed within the 56 day test period. Nevertheless not all pairs exposed to 0.9 and 2.7. μg/L reproduced. Furthermore the numbers of juveniles produced by pairs exposed to 0.9 and 2.7. μg/L, but not 0.3. μg/L, were lower throughout the entire post-exposure period compared to the control groups, and the total numbers of juveniles produced during 56 days were significantly lower in organisms exposed to 0.9 and 2.7. μg/L, but not 0.3. μg/L, compared to the control groups. The long-term effects of short-term exposure on reproductive behavior of pairs could potentially have consequences for the population dynamics of H. azteca. However, since individual-level responses can both overestimate and underestimate effects at the population level, appropriate population models are needed to reduce the uncertainty in extrapolating between these levels of biological organization.
Original language | English (US) |
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Pages (from-to) | 59-65 |
Number of pages | 7 |
Journal | Aquatic Toxicology |
Volume | 144-145 |
DOIs | |
State | Published - Nov 15 2013 |
Bibliographical note
Funding Information:This study was financed by Roskilde University , the Danish Agency for Science, Technology & Innovation and Syngenta Ltd . We thank Anne-Grete Winding, Klara Jensen, Anja Holden Damsholt and Linus Malmquist for technical assistance and guidance during laboratory work.
Keywords
- Amphipod
- Delayed toxicity
- Permethrin
- Pulse exposure
- Pyrethroids