Nematode assemblages of deep-sea and shelf break sites in the North Atlantic and Mediterranean Sea

Abstract

The nematode community structure of several shelf break and deep-sea stations is compared using data from the literature. Samples from two Mediterranean deep-sea canyons have a unique fauna of predatory and scavenging nematodes (eg Synonchiella, Halichoanolaimus, Gammanema) which comprise some 20 to 30% of the community. The nematode generic composition of the other sites reveals a gentle transition from the shelf break over the slope towards the continental rise, abyssal plain and hadal depths. At all these sites predators and omnivores are less abundant while bacterial feeders predominate. With increasing water depth, the genus Sabatieria becomes less dominant, while the genera Theristus, Acantholaimus and Halalaimus gain in importance. It is suggested that this is caused by the growing importance of the oxic mineralization pathway at greater depth. -from Authors