Species:
250-(396-576)-790 μm long, 25-(33-84) μm wide;
cell body large, slightly curved; both termini tapered; pyrenoids 7-15 in each semicell
(Illustrations of The Japanese Fresh-water Algae, 1977).
Cell body slightly curved, gradually attenuated toward the truncated ends, which somewhat recurved
due to the covexity of the inner margin near the ends; inner margin straight or slightly concave,
outer margin convex, 300-500 μm long, 32-50 μm wide, L/W=9-14;
cell wall smooth and colorless or sometimes delicately striated and yellowish-brown in color;
chloroplasts with ridges containing 7-11 pyrenoids in central row
(Photomicrographs of the Freshwater Algae, vol. 1, 1984).
|
50 μm
100 μm
150 μm; x 400 :
31 μm
63 μm
94 μm; x 640
Closterium sp.,
475 μm long,
34 μm wide,
L/W = 14,
x 100, x 200, x 400, x 640, Saitama Pref., May-June 1999 by Y. Tsukii
* C. acerosum (Schrank) Ehrenberg var. acerosum: 250-(396-576)-790 μm long, 25-(33-84) μm wide; cell body large, slightly curved; both termini tapered; pyrenoids 7-15 in each semicell (Illustrations of The Japanese Fresh-water Algae, 1977).
C. acerosum var. elongatum Brébisson: 650-(773-780)-915 μm long, (30-38)-40 μm wide; L/W = 15-33 (Illustrations of The Japanese Fresh-water Algae, 1977).
C. acerosum var. minus Hantzsch: 200-300 μm long, 18-25 μm wide; L/W = 7-11 (Illustrations of The Japanese Fresh-water Algae, 1977).
C. acerosum var. tumidum Borge: Slightly swell at center; 336-(384-494) μm long, 35-(42) μm wide; L/W = 8-12 (Illustrations of The Japanese Fresh-water Algae, 1977).