The Effects of Nematodes on Bacterial Activity and Abundance in a Freshwater Sediment

• Published in: Oecologia Vol. 112; no. 1; pp. 118 - 122
• Main Authors: Walter Traunspurger, Matthias Bergtold, Goedkoop, Willem
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 01.09.1997; Springer
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Bacteria; Biological and medical sciences; Bioturbation; Community Ecology; Density; Fresh water; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; Grazing; Lakes; Microcosms; Nematoda; Nematodes; Population growth; Sediments; Synecology; Sweden; Europe; Microbial activity; Aphelenchus avenae; Animal microorganism relation; Microcosm; Bioturbation; Freshwater environment; Bacterivorous; Caenorhabditis elegans; Helmintha; Bacteria; Nemathelminthia; Invertebrata; Nematoda; Ecological abundance; Bacterial activity; Freshwater sediment; Microcosms; Key words Nematoda; BENTHIC NEMATODES; bacterial activity; nematoda; GROWTH RATES; microcosms; DISTURBANCE; OLIGOTROPHIC LAKE KONIGSSEE; freshwater sediment; COMMUNITY; NATIONAL-PARK BERCHTESGADEN; MEIOFAUNA; FRG; MARINE
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s004420050291

The effects of natural nematode communities on bacterial activity and abundance were investigated in a microcosm study. Nematodes were added at different densities to a freshwater sediment and bacterial parameters were measured after 1, 5, 9, and 17 days. Significant effects of nematode density on bacterial activity were noted on day 5. No long-term changes in bacterial activity were recorded. Bacterial abundance displayed an overall decrease in both treatments and controls. In a second experiment, the effect of nematode feeding-type on bacterial activity was studied. Microcosms were incubated with 100 individuals of a fungus-feeding (Aphelenchus avenae) or a bacteria-feeding nematode species (Caenorhabditis elegans) respectively, and bacterial activity was determined after 0, 1, 2, 4, and 7 days. Significant time and feeding-type effects were found, with consistently higher bacterial activity estimates in treatments with bacteria-feeding nematodes. These results suggest that grazing affects bacterial activity, and indicate that grazing by nematodes may be more important in stimulating bacterial activity than bioturbation or excretion. Combining these results, we conclude that natural nematode communities may have an impact on bacterial activity, and that the magnitude of this impact depends on the proportion of actively feeding bactivores within the community.