Kingdom Protoctista Hogg, 1860
   Phylum Microspora Sprague, 1977 - microsporans see Phylum Microsporida Balbiani, 1882
     Class Microsporea Levine & Corliss, 1963 see Class Microsporidea Corliss & Levine, 1963
       Order Microsporida Balbiani, 1882
         Suborder Apansporoblastina Tuzet et al., 1971
           Family Nosematidae Labbé, 1899
             1 Genus Nosema Nägeli, 1857
             2 Genus Ichthyosporidium Caullery & Mesnil, 1905
             3 Genus Hirsutosporos Batson, 1983