Family: Unicells or cells loosely attached forming hyphae; cell body varied in shape, a constriction at the center in most species; cell walls consisting of two or more parts, with small pores and various ornaments (Illustrations of The Japanese Fresh-water Algae, 1977).
Genus: Variable in shape and in size; mostly longer than wide; strong constriction at center; semicell pyramid-shaped, apically flattened with indentation (or notch, some species lack this notch); laterally straight or wavy or indented; one chloroplast in each semicell; one pyrenoid for each chloroplast (Illustrations of The Japanese Fresh-water Algae, 1977).
Google Image Search
| Subgenus: Atomum (Apical area slightly depressed) | |||
| Section: Retusa (Cell body large; granulated dome(s) at the center of each semicell) | |||
E. turgidum 115 x 95 μm Yamagata, 1999 |
E. ceylanicum ? 77 x 56 μm Japan, 1999 |
E. verrucosum 16 samples 75-90 x 61-77 μm 1999-2008 |
|
E. spinulosum v. spinulosum 2 samples 74-83 μm 2001-2006 |
E. spinulosum v. inermius 7 samples 59-70 x μm 2001-2008 |
E. spinulosum v. ??? 2 samples 66-67 x μm 2001-2004 |
E. egregium & E. ceylanicum 2 samples μm Japan, 2008  |
E. gemmatum 55 x 44 μm Uruguay, 1999 |
E. substellatum μm Water field Kusu Oita, 2008 |
||
| Section: Simplicia (Cell body small, 10-40 μm; cell surface smooth) | |||
E. sublobatum 3 samples 26-28 μm 2005-2008 |
E. validum 4 samples 25-35 x μm 2003-2007 |
E. binale 14 samples 17-25 μm 1998-2008 |
E. binale 14 samples 17-25 μm 1998-2008 |
E. insulare μm Hachiman-numa m. Hachimantai Iwate, 2007 |
|||
| Section: Ornata (Cell body small, 10-40 μm; cell wall garanulated or dented) | |||
E. tenue 19 x μm near Yamakado m. Nishi-Azai Shiga, 2008 |
E. exile 27 x μm Kashibaru marsh Karatsu Saga, 2008 |
E. exile 28 x μm Ko-numa Minakami Gunma, 2008 |
|
| Subgenus: Entomum (Apical area deeply indented or notched) | |||
|
Section: Incisa (Cell surface smooth; apical area without spiny projections)
|
|||
E. crassum 16 samples 175-190 μm 2003-2008 |
E. oblongum 10 samples 130-172 x 63-80 2003-2008 |
E. humerosum 24 samples 98-117 μm L/W=1.8-1.9 2003-2008 |
E. humerosum 24 samples 98-117 μm L/W=1.8-1.9 2003-2008 |
E. affine ? 39 samples 100-157 x μm L/W=1.8-2.2 1999-2008 |
E. affine 39 samples 100-157 x μm L/W=1.8-2.2 1999-2008 |
E. didelta 4 samples 115-170 μm L/W=1.8-1.9 2003-2008 |
Euastrum sp. 131 x 69 μm Numappara marsh Kuroiso Tochigi, 2003 |
E. pinnatum 5 samples 120-130 x μm L/W=2.0 2005-2007 |
E. ozense 6 samples 122-146 μm L/W=2.1-2.4 Shiga highland Nagano, 2005-7 |
E. ampullaceum 18 samples 84-101 x 53-59 μm L/W=1.7-1.8 2005-2008 |
|
E. sinuosum 45 samples 50-107 μm 1999-2008 |
E. sinuosum 45 samples 50-107 μm 1999-2008 |
E. sinuosum 45 samples 50-107 μm 1999-2008 |
E. ansatum 33 samples 80-103 μm 1998-2008 |
E. cuneatum 38 samples 95-110 μm 2004-2008 |
E. gnathophorum 24 samples 57-78 μm 2003-2008 |
E. gnathophorum 24 samples 57-78 μm 2003-2008 |
E. indicum 73 x 35 μm Koigakubo marsh Tessei-cho Okayama, 2004 |
| Section: Excisa (Cell surface granulated or dented; apical area with spiny projections) | |||
E. crameri 52 x 42 μm Uruguay, 1999 |
E. turnerii 2 samples 46 x 28 μm 1999-2004 |
E. geometricum 3 samples 37-51 x μm 1999-2004 |
E. evolutum or E. divaricatum ? 2 samples 40-42 x 26-30 μm Chiba, 2004 |
E. bidentatum 4 samples 46-55 x 31-37 μm 2005-2006 |
E. pulchellum ? 2 samples 35-40 x μm 1999-2006 |
E. denticulatum 13 samples 21.5-30 x 18-22 μm 2005-2008 |
E. elegans var. elegans 32 x 22 μm Uruguay, 1999 |
E. subalpinum 4 samples 19-24 x μm 2003-2007 |
E. subamoenum 30 x 23 μm Shimo-no-koike Shiga highland Nagano, 2007 |
||
