Spatial distribution of nematode communities along the salinity gradient in the two estuaries of the Sea of Japan

摘要

Spatial distribution and structure of nematode assemblages in two estuaries (long lowland Razdolnaya and mountain Sukhodol rivers, the Sea of Japan) were investigated. Sampling was conducted from freshwater to marine benthic habitats. The meiobenthiccommunity was strongly dominated by nematodes. In both estuaries, the spatial distribution of nematode density, composition and feeding types related to the salinity gradient. From a total of 57 nematode species, 42 and 40 nematode species were identified in each estuary, respectively. The changes in the taxonomic structure of nematode fauna were found along the salinity gradient. Differences in nematodes community observed along each estuarine gradient were much lower than between the two estuaries. Only four species Anoplostoma cuticularia, Axonolaimus seticaudatus, Cyatholaimus sp. and Parodontophora timmica, were present in all sampling zones of both estuaries. Most of the recorded species were euryhaline, described previously in shallow coastal bays; only five freshwater species have been described previously from the freshwater habitat of Primorsky Krai.