|   O. parvulum
 x 7 μm
 Akigase Park
 Saitama, 2002
 |   O. parvulum
 μm
 Omine-numa
 Tsukiyono
 Gunma, 2003
 |   O. parvulum
 μm
 Kejo-numa
 Furukawa
 Miyagi, 2003
 |   O. parvulum
 155 x 6.5 μm
 Watarase Wetland
 Fujioka
 Tochigi, 2005
 | 
|   O. parvulum ?
 117 x 7-8.5 μm
 Minuma-no-numa
 Omiya daisan p.
 Saitama, 2005
 |   O. parvulum
 70 x 7 μm
 Okubo Ryoke
 Akigase park
 Saitama, 2005
 |   O. parvulum
 60 x 5 μm
 near Akai wetland
 Aizuwakamatsu
 Fukushima, 2005
 |   O. parvulum
 x 5 μm
 near Karakemi marsh
 Omachi
 Nagano, 2005
 | 
|   O. parvulum
 70 x 5 μm
 Ichinose-enchi
 Norikura highland
 Nagano, 2005
 |   O. parvulum
 195 x 5 μm
 Shijuhachi-ike
 Shiga highland
 Nagano, 2005
 |   O. parvulum
 110 x 6 μm
 Azami-ike
 Norikura highland
 Nagano, 2006
 
  |   O. parvulum
 115 x 9 μm
 Tane-ike
 Togakushi highland
 Nagano, 2006
 
  |