image_list image_listE

Chlorophyceae: Chlorococcales: Scenedesmaceae

Scenedesmus armatus
(Chodat) G. M. Smith var. armatus
= Desmodesmus armatus (Chodat) E. Hegewald

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. arumatus ]: Colonies of 2, 4, 8 cells arranging linearly or slightly sigzag; cell body ovoid or elongated ellipsoidal, both ends rounded, 10-20 μm long, 3.5-8 μm wide; each cell with longitudinal ridges on both sides, ridges distinct at both ends but unclear at the center; outer cells with spiny projections (8-15 μm long) at both ends (Illustrations of The Japanese Fresh-water Algae, 1977).

Longitudinal ridges present in all cells but obsucured at central region
Scenedesmus armatus
v. armatus
11 x 3, 12 x 4 μm
Tane-ike
Togakushi highland
Nagano, 2005
Scenedesmus
v. armatus ?
μm
Maimeno-ike
Norikura highland
Nagano, 2007
Scenedesmus
v. armatus
or v. boglariensis ?
cell μm
O-ike park
Yabuki
Fukushima, 2003
Scenedesmus armatus
v. armatus
or v. boglariensis
f. crassicaudatus ?
cell 14 x 3.5 μm
spines 14 μm
Ichikawa
Chiba, 2001
Scenedesmus armatus
v. armatus
or v. boglariensis
f. crassicaudatus ?
cell μm
O-ike park
Yabuki
Fukushima, 2003
Scenedesmus armatus
v. armatus
cell 12 x 5.5 μm
Shiba river
near Owada Park
Saitama, 2005
Scenedesmus
v. longispina
stock Tnk-2
cell 11 x 3-5 μm
Nishi-nasuno
Tochigi, 2001
Scenedesmus
v. longispina
stock Tnk-2
cell 11 x 6 μm
Nishi-nasuno
Tochigi, 2001
Outer cells with only one spiny projection
Scenedesmus brasiliensis
v. bicaudatus ?
cell μm
L/W=
Kazo
Saitama, 2003
Scenedesmus armatus
v. bicaudatus
cell 18 x 5-6 μm
spines 18 μm
Shiba river
near Owada Park
Saitama, 2005
Scenedesmus
v. bicaudatus
cell 12 x 4.5 μm
spines 9 μm
Sue-machi
Fukuoka, 2001
Scenedesmus
v. bicaudatus
9 x 2.5 μm
spines 8 μm
Umi-no-nakamichi
Fukuoka, 2001
Scenedesmus brasiliensis
v. bicaudatus ?
cell μm
L/W=
Akebono-yama A.P.
Kashiwa
Chiba, 2002
Spiny projections short, curving inward
Scenedesmus
v. chodatii ?
inner 11 x 4 μm
outer 9 x 4 μm
Abukuma river
Fukushima, 2005
Scenedesmus
v. chodatii ?
inner μm
outer μm
Itakura
Gunma, 2003
Scenedesmus
v. chodatii ?
inner 13 x 5 μm
outer 10 x 4 μm
Umi-no-nakamichi
Tochigi, 2001
Misc.
Scenedesmus
S. armatus ?
μm
Uruguay, 1999
Scenedesmus armatus
S. armatus ?
μm
Kayoicho-ike
Fukuoka, 2001
Scenedesmus
S. armatus ?
μm
Iruma river
Sayama
Saitama, 2004
Scenedesmus
S. armatus ?
12-13 x 4 μm
Hasu-ike
Shiga highland
Nagano, 2005
Similar species -->> S. quadricauda; S. longispina;

Please click on species name for more images.
Scenedesmus
Copyright Protist Information Server