PUB - Publikationen an der Universität Bielefeld

The nematode Caenorhabditis elegans (Maupas) was exposed in a sediment bioassay to 26 different unpolluted freshwater sediments varying in particle size distribution (2.5-18% clay, 25.7-68.2% silt, 18.7-70.9% sand) and organic content (2.5-77.1%). We examined the variation of the test endpoints body length, eggs per worm, and percentage of gravid worms. Caenorhabditis elegans tolerated all investigated sediments, with at least 80% (total mean 96.6%) of the worms reaching the stage of reproductive adults. Variation in body length was small (total mean 1,235 +/- 97.8 mu m), but significant differences among the various sediments were found. We found a weak correlation of body length with particle size distribution, indicating that the nematodes grew better in coarser sediments. The number of eggs per worm showed relatively high variation among treatments (total mean 12.4 +/- 4.8) and also within treatments (mean +/- 5-95%). C. elegans is a suitable test organism for freshwater sediment bioassays, using body length and percentage of gravid worms as test endpoints.