Changes in deep-sea metazoan meiobenthic communities and nematode assemblages along a depth gradient (North-western Sea of Japan, Pacific)

摘要: Abstract The Sea of Japan is a very young sea which has been newer connected with the deep Pacific. In this connection, big portion shallow-water taxa are expected to inhabit part sea. Meiofaunal communities were investigated for first time on 13 stations at depths from 500 3700 m within four deep-sea transects in north-western densities low ranging 4.80±1.17 ind./10 cm 2 177.42±14.3 ind./10 cm . There was significant decrease density meiofauna depth all locations. Taxonomic structure metazoan meiobenthos plentiful whole area and totaled 20 groups. Nematodes numerically dominant taxon, constituting 49.6–84.1% total abundance. At below 3000 m, polychaetes taxon nematodes only 12–36.9% meiofaunal density. On portions polychaetes, quite unique comparison surrounding regions. total, 92 different nematode species, belonging 75 genera 32 families found. number species strongly reduces depth. Species richness evenness assemblages greatly decreased than 2000 m. No specific fauna