Seasonal Dynamics of the Population Density of Mass Species and Trophic Groups of Free-living Marine Nematodes

Seasonal changes in the distribution density and trophic-group composition of marine nematodes were studied in a strait between Reineke and Popova islands (Amurskii Bay, Sea of Japan). Four nematode species dominated throughout the observation period, constituting altogether over 60% of the total nematode population density. Temperature indirectly affected the population composition of mass nematode species. The nine dominant species from Amurskii Bay (Sea of Japan) were classified into three trophic groups. In the spring, the nematode taxocene was dominated by predators; in the autumn, by nonselective detrivorous species; and in the winter and summer, by bottom feeders. Within each season, the trophic structure of the nematode taxocene was almost constant, with the number of species constituting the trophic group being the only variable.