Effect of bacterivorous and predatory nematodes on macroalgal detritus decomposition

Nematodes may contribute to the decomposition of detritus in both aquatic and terrestrial ecosystems. in aquatic sediments,the most prominent role is expected for bacterial-feeding nematodes,since these may in several ways affect the activity and abundance of bacteria,the principal decomposers of organic matter. however,many free-living nematodes have other feeding strategies,and it is unclear whether they may also affect decomposition processes. predatory nematodes,for instance,may affect the abundance of bacterivores and hence indirectly also of bacteria (i.e. a trophic cascade). this study focuses on the short-term (9 days) effects of the rhabditis bacteriovorous nematodes rhabditis (pellioditis) marina and panagrolaimus paetzoldi and of the predatory nematode enoploides longispiculosus in single-species as well as in combination treatments on the decomposition rate of brown algae (fucus vesiculosus l.) detritus through laboratory microcosm experiments. remarkably,all treatments with the predatory nematode showed higher decomposition rates than treatments without e. longispiculosus. howeve,the mechanism behind this effect remain unclear. in addition,a combination treatment with both bacterivorous species had a higher decomposition rate than treatments with single bacterivore species,inline with other recent studies demonstrating interactions effects between different bacterivore species. © pakistan academy of sciences.