Genus: Colonies of 4 (or 2, 8, 16) cells attached side by side, arranged linearly or zigzag; cell body elliptical or spindle or crescent in shape; terminal cells with spiny projections in many species; cell wall usually smooth, but in some species granulated or dented or ridged (Illustrations of The Japanese Fresh-water Algae, 1977).
Species [ var. ellipsoideus ]: (Illustrations of The Japanese Fresh-water Algae, 1977).
S= length of Spines; L=Body length; W=Body width (terminal cells)
Google Image Search
L/W = about 2, terminal cells ellipsoidal
S. ellipsoideus
4-cells type
cell 24 x 12 μm
L/W=2
S/L=
Uruguay, 1999
S. ellipsoideus
cell 20 x 7 μm
L/W=2.9
S/L=0.8
Nasu
Tochigi, 2001
S. ellipsoideus
8-cells type
cell 18 x 9 μm
L/W=2
S/L=
Uruguay, 1999
S. ellipsoideus
stock Tnk-1, axenic
cell 17 x 8 μm
L/W=2.1
S/L=
Tochigi, 2001
S. ellipsoideus
cell 15 x 6.5 μm
cell 19 x 8 μm
L/W=2.3, 2.4
S/L=0.87, 0.79
Urawa
Saitama, 2001
S. ellipsoideus
stock Smt-1
cell 17 x 8 μm
Urawa
Saitama, 2001
S. ellipsoideus
cell 27 x 11 μm
L/W=2.5
S/L=0.67
Saitama, 1999
S. ellipsoideus ??
stock Smt-1, axenic
cell 18 x 11 μm
L/W=1.6
S/L=
Urawa
Saitama, 2001
S. ellipsoideus ??
stock Smt-1, axenic
dividing cells
Urawa
Saitama, 2001
S. ellipsoideus
cell 12 x 6 μm
L/W=2.0
Ageo Maruyama Park
Saitama, 2002
S. ellipsoideus
9-11 x 4-6 μm
L/W=
Senganpi suigo p.
Sakura-ku
Saitama, 2005
S. ellipsoideus
cell 9 x 5 μm
L/W=1.8
Kasuga
Fukuoka, 2001
S. ellipsoideus
cell 18 x 7 μm
L/W=2.6
S/L=0.7
Ushiroya Park
Toda
Saitama, 2002
S. ellipsoideus
cell μm
L/W=
Numappara marsh
Kuroiso
Tochigi, 2003
S. ellipsoideus
cell μm
L/W=
Iruma River
Tsurugashima
Saitama, 2003
S. ellipsoideus
cell μm
L/W=
Kamisuwa r.w.st.
Suwa
Nagano, 2005
S. ellipsoideus
cell 10-13 x 7 μm
L/W=
Omoi river
Oyama
Tochigi, 2006