Trophic interactions between ciliates and nematodes from an intertidal flat
| Autor: | Tom Moens, Koenraad Muylaert, Wim Vyverman, Ilse Hamels |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Belgium
Schelde R Nematoda [Nematodes] Interactions Intertidal zone Aquatic Science Biology ANE Netherlands Westerschelde Molenplaat Trophic levels Predation Sediments Benthos Tidal flats Sand Ciliophora Ecology Evolution Behavior and Systematics Trophic level Ciliate ANE Netherlands Westerschelde Biomass (ecology) Ciliates Microbial food web Ecology biology.organism_classification Food web Predators Benthic zone Trophic relationships |
| Zdroj: | Aquatic Microbial Ecology. 26:61-72 |
| ISSN: | 1616-1564 0948-3055 |
| DOI: | 10.3354/ame026061 |
| Popis: | The present study investigated the possibility of a trophic link between ciliates and nematodes in fine sandy sediments of the Molenplaat intertidal flat (Schelde estuary, SW Netherlands). Grazing experiments were conducted under controlled laboratory conditions, with ciliate species isolated from enrichment cultures and nematodes collected directly from the field. Significant reductions in ciliate numbers were found in the presence of the predatory nematode Enoploides longispiculosus, a prominent species (and genus) in fine to medium sandy sediments of the North Sea and adjacent estuaries. No such effects were found when ciliates were inoculated with a mix of mainly deposit-feeding nematodes from the same sampling site. On the basis of these results, ciliate predation by E. longispiculosus was tested for several benthic ciliate species and abundances, at a range of predator abundances and temperatures, and in the presence of alternative prey (in casu nematodes). E. longispiculosus significantly reduced the densities of 5 out of 6 ciliate species offered as prey. Depending on the experimental conditions and the prey species, predation rates ranged from 0.19 to 10.8 ciliates predator-1 h-1, corresponding to a biomass consumption of 0.001 to 0.33 µg C predator-1 d-1. An overall positive relation between available ciliate biomass and predation rate was found. Comparison of experimental data with field conditions suggests that a considerable part of the ciliate production in fine sandy sediments of the Molenplaat is likely to be consumed by E. longispiculosus, which largely dominates meiofaunal biomass there. Estimated carbon requirements for the predator and production estimates of ciliate and nematode prey at the study site strongly suggest that ciliates are probably a far more important carbon source for E. longispiculosus than nematode prey, at least between late spring and autumn. This implies that carbon transfer from primary producers and bacteria to predatory nematodes may to a large extent be mediated through the microbial food web. In view of the generally high densities and biomasses of ciliates as well as predacious nematodes in fine sandy sediments, similar patterns are to be expected in many other estuarine and marine sediments. |
| Databáze: | OpenAIRE |
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