Our team studies free-living marine nematodes. Among multicellular animals inhabiting marine sediments, nematodes are considered to be the most numerous. Their quota in meiobenthic communities usually accounts 60-100%, and their density can amount to more than one million individuals per one square meter of sea floor.
Species diversity of marine free-living nematodes is immense. About 5.000 species of marine nematodes are known to date, but, the total number of marine nematode species is estimated at several hundred thousand. Besides, the local diversity of marine nematodes is very high. For instance, among 1.000 examined deep-sea nematode individuals, about 100-200 species can be found, and most of them are new, unknown. This shows clearly that deep-sea nematodes as the most common and most dominate meiobenthic taxon are greatly understudied.