image_list image_listE

Gamophyceae: Zygnematales: Desmidiaceae

 Cosmarium pseudoexiguum
Raciborski var. pseudoexiguum

Cosmarium pseudoexiguum Species [ var. pseudoexiguum ]: Cell body small, L/W=2 or more, with deep constriction; semicells nearly rectangle in shape; apex and lateral margins slightly convexed; 18-25 μm long, 10-13.6 μm wide, isthmus 2-4 μm wide.
[ var. retusum Hirano ] Semicells trapezoid in shape; lateral margins nearly straight, narrowed toward apex; anterior half of the margins slanted and slightly concaved; 22-23 μm long, 12-13 μm wide, isthmus 3.4 μm wide.
[ var. hexagonum Grönblad ] Semicells hexagonal in shape, broadened toward apex; 18-19.6 μm long, 10.7-12.6 μm wide, isthmus 3-4.3 μm wide.
Similar species --> > C. succisum;

Cosmarium pseudoexiguum Raciborski var. pseudoexiguum (or var. retusum Hirano ?), cell body 26 μm long, 16 μm wide, L/W=1.6, isthmus 4.5 μm wide, x 640, a small pond at Obihiro University of Agriculture and Veterinary Medicine, Obihiro city, Hokkaido, Japan, October 13, 2005 by Y. Tsukii
scale 31 μm scale 63 μm scale 94 μm; x 640
Cosmarium

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