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Gamophyceae: Zygnematales: Desmidiaceae or Closteriaceae

Closterium acerosum
var. minus Hantzsch

Closterium acerosum Genus: Cell body crescent in shape (long, curved, tapered at both ends); cross section rounded; cell wall smooth or with longitudinal lines, bands on the cell wall in some species; chloroplast laminae ridged and radially arranged, which makes cross section star-shaped; pyrenoids aligned or scattered (Illustrations of The Japanese Fresh-water Algae, 1977).
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).


Chlosterium acerosum var. minus Hantzsch ?, cell body 375 μm long, 61 μm wide, L/W = 6, 10 pyrenoids (5 in each semicell), x 100, x 200, x 400, Japan, 199? by Y. Tsukii
scale 50 μm scale 100 μm scale 150 μm; x 400 : scale 31 μm scale 63 μm scale 94 μm; x 640
Closterium Closterium Closterium Closterium Closterium

* 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).


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