Redescription of Microsporidium takedai (Awakura, 1974) as Kabatana takedai (Awakura, 1974) comb. n.

Ultrastructural study of the microsporidian Microsporidium takedai from the muscles of masu salmon Oncorhynchus masou proved that this species can be assigned to the genus Kabatana Lom, Dykova and Tonguthai, 2000. The parasit es develop within disintegrated sarcoplasm without any delimiting boundary or cyst. Cylindrical multinucleate meronts proliferate by serial constricti ons into uninucleate stages which repeat the process. Eventually, the uninu cleate stages transform into uninucleate sporonts, which divide once to pro duce sporoblasts, thus functioning as sporoblast mother cells. Spores, with a subterminally located anchoring disc and 3 to 4 turns of the polar tube coil, average 3.3 by 1.9 mum in size. The exospore is divided into small fi elds; the endospore frequently makes small invaginations into the spore ins ide. Phylogenetic analysis using SSU rDNA sequence consistently placed Kaba tana takedai in a group consisting of Microgemma sp., Spraguea lophii and G lugea americanus. The K, takedai could easily be separated from the other s pecies in the same group by 2 inserts in the SSU rDNA sequence.