Fauna of Freshwater Harpacticoida (Copepoda) in the Lena River Delta

Abstract

Abstract: The first description/overview of the freshwater copepod fauna of the order Harpacticoida from the Lena River delta is presented. Various habitats and regions were studied. As a result, we identified 18 species belonging to two families: Canthocamptidae and Harpacticidae. Eight of the identified species are new to the study area; five species belonging to the genera Bryocamptus, Canthocamptus, Moraria, and Maraenobiotus, presumably represent new species for science. We provide brief ecological descriptions of the species identified in the Lena River delta and analyze their differences from the typical populations. The harpacticoid fauna of the Lena delta consists of three main components including Palaearctic species, Holarctic species, and species with “Beringian” distribution patterns. We provide a morphological description of Bryocamptus umiatensis Wilson 1958. This species is quite similar to Bryocamptus jejuensis Lee and Chang 2016, recently described from Korea. The main character distinguishing these species is the ornamentation of the anal operculum. This character in our region reveals considerable interpopulation variations. We also provide an identification key to the freshwater Canthocamptidae of the Lena delta.