Hoess S et al. (1999) Environmental Toxicology and Chemistry "Growth and fertility of Caenorhabditis elegans (Nematoda) in unpolluted fresh-water sediments - Response to particle-size distribution and organic content."

Haitzer M, Hoess S, Steinberg CEW, Transpunger W

[Environmental Toxicology and Chemistry, 1999]

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.

Theriot JA (1996) Cell "Worm sperm and advances in cell locomotion."

Theriot JA

[Cell, 1996]

Across the animal kingdom, fertilization requires the encounter between a large stationary egg and small motile sperm. To maximize their likelihood of reaching the egg before their competition, sperm are extraordinarily specialized cells, generally consisting of little more than a haploid nucleus, mitochondria to generate energy, and a highly efficient movement engine. Almost all animal sperm are flagellated and seek the egg by swimming quickly through a liquid environment. Nematodes, however, produce sperm that move by crawling along solid substrates. These roundworm sperm extend pseudopods that look and behave like the actin-rich pseudopods of a wide variety of cells ranging from free-living soil amoebae to human white blood cells. The crawling sperm appear by most criteria to be exploiting classic actin-based cell motility, with one important difference: the sperm contain practically no actin (Nelson et al., 1982).