image_list image_listE

Gamophyceae: Zygnematales: Desmidiaceae

Cosmarium contractum
var. minutum (Delponte) W. et G.S. West

Cosmarium contractum Species [var. contractum]: Cell body 28-41 μm long, 18-31 μm wide, isthmus 5.3-8.7 μm wide, L/W=1.5; semicells broad ellipsoid, laterally circular; cellwall smooth or finely dotted, a single pyrenoid in each semicell.
[var. ellipsoideum (Elfving) W. et G.S. West]: Cell body 31-51 μm long, 24-42 μm wide, isthmus 7-12.5 μm wide, L/W=1.3; apex of semicells slightly flattened; cellwall smooth.
[f. jacobsenii (Roy) W. et G.S. West]: Semicells exactly ellipsoid, 28-47.6 μm long, 18-36.4 μm wide, isthmus 4.5-11.3 μm wide.
[var. minutum (Delponte) W. et G.S. West]: Cell body 19-28 μm long, 14-22 μm wide, isthmus 4.3-5.6 μm wide; semicells elongated ellipsoid, laterally circular, cellwall dotted.
(Illustrations of The Japanese Fresh-water Algae, 1977).
Similar species -- >> C. depressum; C. bioculatum; C. moniliforme;


Cosmarium contractum var. minutum (Delponte) W. et G.S. West, cell body 25 μm long, 16 μm wide, L/W=1.6, isthmus 5 μm wide, x 640, a pond near the entrance of climbing route to Omine mountain, Minakami town (formerly Tsukiyono town), Gunma Pref., Japan, April 15, 2007 by Y. Tsukii
scale 31 μm scale 63 μm scale 94 μm; x 640
Cosmarium contractum

Images of collecting locality: a pond near the entrance of climbing route to Omine mountain, Minakami town (formerly Tsukiyono town), Gunma Pref., Japan, April 15, 2007 by Y. Tsukii


Please click on images for viewing enlarged.
Copyright Protist Information Server