Gamophyceae:
Zygnematales: Desmidiaceae
Cosmarium pachydermum
var. aethiopicum W. et G.S. West
Species [var. pachydermum]:
Cell body 78-117 μm long, 60-87 μm wide, isthmus 25-34 μm wide,
semicells semielliptical in shape, corners rounded.
[var. aethiopicum W. et G.S. West ]: Semicells nearly half-circle; cellwall thin;
cell body 64-107 μm long, 56-80 μm wide, isthmus 28-34 μm wide.
[var. ellipticum Hinode ]: Semicells rectangular at base; curvature of lateral margins weak compared to var. pachydermum;
cell body 94-100 μm long, 67-74 μm wide, isthmus 28-34 μm wide.
[var. heptagonum Grönblad ]: Semicells irregular pentagon in shape;
posterior half of lateral margins nearly straight;
cell body 94-100 μm long, 67-74 μm wide, isthmus 28-34 μm wide
(Illustrations of The Japanese Fresh-water Algae, 1977).
|
Similar species -->>
C. lundellii;
Cosmarium pachydermum var. aethiopicum W. et G.S. West,
cell body 77 μm long, 54 μm wide, isthmus 23 μm wide,
x 640, Nakagawa Kahan Park, Nasu-shiobara city (formerly Kuroiso city), Tochigi Pref., Japan, August 2003 by Y. Tsukii
31 μm
63 μm
94 μm; x 640
Cosmarium pachydermum P. Lundell var. pachydermum:
Cell body 78-117 μm long, 60-87 μm wide, constriction (isthmus) 25-34 μm wide;
semicells broad half-ellipsoidal, each corner rounded; side view nearly circular, apical view ellipsoidal;
cell wall densely puncatated
(Illustrations of the Japanese Fresh-water Algae, 1977)
Cosmarium lundellii P. Lundell var. circular:
Cell body 53-73 μm long, 48-56 μm wide, constriction (isthmus) 17-25 μm wide;
semicells broad semicircular, each corner rounded; apex narrowly straight; side view nearly circular,
apical view elongated ellipsoidal; cell wall puncatated
(Photomicrographs of the Fresh-water Algae, vol. 5, 1986).
Please click on images for viewing enlarged.
Copyright
Protist Information Server