3 research outputs found
Deep-Sea Nematodes Actively Colonise Sediments, Irrespective of the Presence of a Pulse of Organic Matter: Results from an In-Situ Experiment
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 µm 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 cm−2) 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 support to the existence of a spatio-temporal mosaic
that emerges from highly localised, partially stochastic community dynamics