Synurophytes in the lakes and ponds of Kenmin-no-mori, Yamagata, Japan

The synurophytes from 10 lakes and ponds in Kenmin-no-mori (Yamagata, Japan) were collected between May and July 2011 and identified by light and scanning electron microscopy, and included 4 species of Synura and 18 species of Mallon2onas. Mallomonas was present in all of the lakes and ponds, whereas Synura was absent in two of the lakes, including Lake Arenuma, which was sampled on ten separate occasions and was characterized by a Dinobiyon bloom. Two species of Synura (S. petersenii and S. sphagnicola) and 2 species of Mallomonas (M caudata, M crassisquama) were found in 6 and 7 of the ponds, respectively. On the other hand, 10 species (S. spinosa, M insignis, M.flora, M heterospina, M leboimei, M papillosa, M punctifera, M striata, M tonsurata and Mallomonas sp.) were found only in one lake or pond. Mallomonas lebohnei, which was previously found in Europe, Russia and North America, has now been observed in Kenmin-no-mori, so may be distributed throughout the Northern Hemisphere.