deep-sea nematodes actively colonise sediments, irrespective of the presence of a pulse of organic matter results from an in-situ experiment深海线虫积极开拓殖民地沉积物,无论一个脉冲的存在有机物的结果从一个现场试验.pdfVIP

Deep-Sea Nematodes Actively Colonise Sediments, Irrespective of the Presence of a Pulse of Organic Matter: Results from an In-Situ Experiment 1 2 3 1 Katja Guilini *, Thomas Soltwedel , Dick van Oevelen , Ann Vanreusel 1 Department of Biology, Marine Biology Section, Ghent University, Ghent, Belgium, 2 Department of Deep Sea Ecology and Technology, Alfred Wegener Institute, Bremerhaven, Germany, 3 Centre for Estuarine and Marine Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Yerseke, The Netherlands Abstract A colonisation experiment was performed in situ at 2500 m water depth at the Arctic deep-sea long-term observatory HAUSGARTEN to determine the response of deep-sea nematodes to disturbed, newly available patches, enriched with organic matter. Cylindrical tubes,laterally covered with a 500 mm mesh, were filled with azoic deep-sea sediment and 13C- labelled food sources (diatoms and bacteria). After 10 days of incubation the tubes were analysed for nematode response in terms of colonisation and uptake. Nematodes actively colonised the tubes,however with densities that only accounted for a maximum of 2.13% (51 ind.10 cm22) of the ambient nematode assemblages. Densities did not differ according to the presence or absence of organic matter, nor according to the type of organic matter added. The fact that the organic matter did not function as an attractant to nematodes was confirmed by the absence of notable 13C assimilation by the colonising nematodes. Overall, colonisationappears to be a process that yields reproducible abundance and diversity patterns, with certain taxa showing more efficiency. Together with the high variability between the colonising nematode assemblages, this lends experimental sup