ИСТИНА

Two microsporidia from freshwater crustaceans were discovered during the ongoing survey for microsporidia in the river Karasuk basin (Novosibirsk Region, Western Siberia). The first species, tentatively a new species of the genus Alfvenia, parasitizes Cyclops sp. (Maxillopoda, Copedoda). The second one infects a cladoceran Daphnia magna (Branchiopoda, Phyllopoda), and basing on ultrastructure, was identified as Agglomerata (Glugea) cladocera (Pfeifer, 1895) Larsson, Dieter, Vavra, 1996, comb. n. Siberian isolate of A. cladocera shares 99% SSU rRNA gene sequence similarity to Binucleata daphniae Refardt et al., 2008 from Belgium. No sequences belonging to representatives of genera Alfvenia or Agglomerata have been available so far through public databases. New information sheds light on phylogenetic bonds within the Aquasporidia group of the Clade I (Vossbrinck, Debrunner-Vossbrinck, 2005). Both parasites fell in the “Aquatic outgroup” (AOG), a sister to the Amblyospora clade. Agglomerata cladocera clusters with Binucleata daphniae, while Alfvenia sp. – with Trichouzetia guttata. Interestingly, two major well supported branches can be identified within AOG: members of the first, the Alfvenia-Trichotuzetia lineage parasitize predominantly copepods-cyclopids, and representatives of the second, the Agglomerata-Gurleya-Larssonia-Berwaldia lineage are mainly associated with cladocerans. AOG clade also includes a few taxa with dipteran hosts suggesting that common ancestors of amblyosporids and AOG possessed polyxenous life cycles that probably involved a copepod as an intermediate host, like some extant amblyosporids. Given morphological and sequence similarity of Binucleata daphniae to Agglomerata spp., the genus Binucleata may be amended to a junior synonym of Agglomerata. Supported by RFBR 13-04-00693 and RF President grant MD-4284.2015.4.