Benthic invertebrate fauna of a forest spring on the Muravyov- Amursky Peninsula (Primorsky Krai, Southern Russian Far East)

The fi rst data on spring macroinvertebrate fauna of the Southern Russian Far East are presented. Macrobenthos of a small forest spring classifi ed as helocrene includes at least 21 species from 20 genera and 17 families in Arthropoda and Platyhelminthes. Main groups of benthic organisms are amphipods, planarians, larvae of dipterous insects, caddisfl ies, stonefl ies and mayfl ies, small water beetles. The following invertebrates are defi ned to the species level: planaria Phagocata sibirica, stonefl y Skwala compacta, caddisfl y Glossosoma angarensis, aquatic beetles Hydraena riparia (imago) and Heterlimnius gapyeongensis (larvae), amphipods Gammarus koreanus and hypogean Procrangonyx primoryensis. The macrobenthos of the spring is also ecologically diverse. Here, rheo- and stagnophiles, highly specialized stygo- and crenobionts, and species with wide ecological niches, sharply diff ering in their preferences, closely coexist.