There is invreasing evidence that deep-sea nematodes, despite their numerical success in terms of biomass and diversity, do not respond rapidly to deposition of fresh food from the surface. To what extent the assumed high taxonomic diversity links with trphic diversity is crucial for our understanding of the implications of high biodivsity for ecosystem functioning. Therefore we will combine novel experimental and high-resolution analytical techniques to resolve precious assumptions on nematode respiration, diversity and their potential resources.