Nephrocystidium pickii Weissenberg, 1921 belongs to Myxozoa (Cnidaria) but is not conspecific with Myxidium lieberkuehni Bütschli, 1882 (Myxozoa: Bivalvulida: Variisporina: Myxidiidae): molecular-genetic evidence.
Sergey Sokolov, Ekaterina Volkova, Alexander Kudryavtsev, Aleksey Parshukov
Author Information
Sergey Sokolov: A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
Ekaterina Volkova: Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia.
Alexander Kudryavtsev: Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia.
Aleksey Parshukov: Institute of Biology of the Karelian Research Centre of the Russian Academy of Sciences, Petrozavodsk, Russia. aleksey.nik.parshukov@gmail.com. ORCID
We isolated and re-investigated Nephrocystidium pickii Weißenberg, 1921 (Myxozoa: Bivalvulida: Variisporina) using light microscopy and phylogenetic analysis of the small-subunit (SSU) ribosomal RNA gene. This species is a parasite of the northern pike Esox lucius L. (Actinopterygii: Esocidae) which localizes in the endothelial cells of the glomerular capillary. The results of the phylogenetic analysis including this species clarify its taxonomic status and show that although it is the closest relative to Myxidium lieberkuehni Bütschli, 1882, the two organisms are not conspecific, contrary to the earlier hypotheses. The data obtained highlight the necessity of a profound taxonomic revision of the Myxozoa and the need to clarify species affiliation of extrasporogonic developmental stages of these organisms that occur in different organs of fish.
