| Title: | Phenylpyrazole insecticide fipronil induces male infertility in the estuarine meiobenthic crustacean Amphiascus tenuiremis |
| Author(s): | Cary TL; Chandler GT; Volz DC; Walse SS; Ferry JL; |
| Address: | "Department of Environmental Health Sciences, Norman J. Arnold School of Public Health, University of South Carolina, Columbia, South Carolina 29208, USA" |
| ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
| Abstract: | "Copepods are the most abundant arthropods on earth and are often the most important secondary producers in estuarine/marine food webs. The new GABA (gamma-aminobutyric acid)-disrupting insecticide fipronil (FP) induces unique sex-specific reproductive dysfunction in male meiobenthic copepods, leading to trans-generational population depression at environmentally realistic concentrations (0.63 microg/L). Using a newly developed 96-well microplate lifecycle bioassay, more than 700 individual Stage-I juveniles were reared to adulthood in as short as 12 days in only 200 microL of control (CTL) or 0.63 microg-FP/L seawater solution. Individual virgin male: female pairs were then cross-mated for all possible combinations within and across rearing treatments and allowed to mate for an additional 12 days in CTL or 0.63 microg-FP/L solution. FP at 0.63 microg/L caused no significant lethality to any mating combinations but evoked 73% or 89% inhibition of reproduction when FP-reared males were mated with either a control- or FP-reared female in FP solution, respectively. In contrast, when CTL-reared males were mated with FP-reared females in FP solution, there was no difference in reproductive success compared to FP-free controls. When FP-reared males were mated with either female group in FP-free solution, these mating pairs displayed a 3-day delay in time to brood sac extrusion but ultimately did reproduce. As fipronil (1) has a high K(ow), (2) is persistent in sediments where meiobenthic copepods live, and (3) has been detected in estuarine waters >0.7 microg/L, it may pose high risk to copepod production in estuarine systems" |
| Keywords: | "Animals Biological Assay Copepoda/*physiology Female Infertility, Male/*chemically induced/*veterinary Insecticides/*toxicity Male Population Dynamics Pyrazoles/*toxicity Risk Assessment Water Pollutants, Chemical/*toxicity;" |
| Notes: | "MedlineCary, Tawnya L Chandler, G Thomas Volz, David C Walse, Spencer S Ferry, John L eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2004/01/31 Environ Sci Technol. 2004 Jan 15; 38(2):522-8. doi: 10.1021/es034494m" |
