Nematodes and their food: difficult customers in the deep sea?

Nematodes represent the most abundant metazoan taxon in deep-sea sediments. Also in terms of total biomass per surface area they surpass larger size groups at depths below 3000m. Therefore they are assumed to represent a major component of deep-sea food webs despite their small size. Nonetheless, unraveling the trophic interactions of nematodes remains a big challenge, both in terms of prey and predators. We applied several approaches in order to unravel deep-sea nematode diets at different parts of the world and various deep-sea habitats. Natural biomarker analysis using lipids and stable isotope signatures revealed an undeniable link with sulphide oxidizing bacteria in chemosynthetic driven habitats. These thiobiotic species were also not responding to photosynthetic derived food sources in an experimental approach and seems therefore quite specific in their feeding behavior . Other deep-sea sediments exclusively depending on surface derived organic matters clearly reflect phytoplankton dependency in their fatty acids, but have shown a rather delayed response to natural and induced POC fluxes, suggesting an intermediate response by feeding on short-term responding microbiota. Enrichment experiments combined with colonization, however do not unequivocally confirm the bacterial feeding preference for deep-sea nematodes. Alternative suggestions for future approaches are presented here.

Jaar van publicatie:2011

Toegankelijkheid:Closed