Nematode Community Structure Along a Mediterranean Shelf-slope Gradient

Abstract. Nematode assemblages along a Mediterranean depth transect (160–1220 m) and vertically in the sediment were investigated. The station at the edge of the continental shelf (160 m) was distinctly different from those situated on the continental slope (280–1220 m). On the slope, nematode communities in the upper centimetre differed significantly from communities in the deeper sediment layers, which were dominated by fewer and larger species. Vertical segregation could be a factor explaining the coexistence of several species belonging to the genus Sabatieria , with larger species penetrating deeper into the sediment. Clear differences in buccal morphology suggest food resource partitioning as the dominant factor promoting coexistence of several species belonging to the other dominant genus, Acantholaimus .