Loch Gorm Algae 2003

? Aphanocapsa


Cyanobacterium (no chloroplast, cells frequently blue-green in colour). Colony spherical / subspherical (in aquatic species), with spherical cells irregularly arranged in mucilage. The sheath may have an indistinct boundary, but has an outer layer free of cells. The cells are quite densely packed, with pairs due to recent cell division, successive divisions in different planes.


Aphanothece microscopica
?Aphanothece stagnina


Cyanobacterium (no chloroplast, cells frequently blue-green in colour). Colony spherical / subspherical or irregular, with ovoid or cylindrical cells embedded in mucilage, closely packed, sometimes with individual sheaths. Cell division in 1 plane

Asterococcus limneticus


Chlorophyte (chloroplast present). Spherical cells embedded in a mucilage sheath which may be lamellate (concentric). Single chloroplast is stellate (arms sometimes expanded on reaching edge of cell), with a central pyrenoid.



Chlorophyte (chloroplast present, net-like with single pyrenoid, but usually hard to see). Colony usually composed of sub-colonies visibly connected by strings of mucilage, may be green, olive-green or orange. Cells closely packed in a tough wrinkled mucilage which makes them hard to see. Contain oil droplets which may be squeezed out under a coverslip, along with the cells.

Calothrix parietina


Cyanobacterium, forming filaments. May be single or in small colonies. Trichomes are tapering with a heterocyst at the base, occasionally showing false branching (see second picture above), and enclosed in a sheath. Cell dimensions, presence of intercalary heterocysts (between the cells), colour and lamellation of sheath are features which distinguish species.


Chroococcus dispersus
Chroococcus limneticus


Cyanobacterium, forming colonies of small groups of cells in mucilage. Cells spherical or subspherical, may have individual sheaths (not in the two species shown here).

Coelosphaerium sp.
Coelosphaerium sp.
? Coelosphaerium


Cyanobacterium, forming spherical colonies of tightly packed spherical or subspherical cells arranged around the periphery of the colony, forming a hollow ball. No stalks connecting cells. The mucilage sheath may be evident as a layer around the outside of the cells. The pictures show surface and equatorial views.

Coleochaete pulvinata


Chlorophyte, clearly evident parietal chloroplast with 1 or more pyrenoids. Plant is a branched filament which bears hair cells (NB not bulbous as in Bulbochaete). Branching repeated, colony spherical / subspherical, embedded in dense mucilage.


Cosmarium botrytis
Cosmarium botrytis



Colony in spherical or globular mucilage, cells in pairs at the ends of branched stalks. Dictyosphaerium is a chlorophyte, but the chloroplast may be hard to distinguish in smaller cells (compare with Snowella).


Dichotomococcus curvatus

Euastrum ansatum
Euastrum verrucosum
Eucapsis alpina


Cyanobacterium. Spherical cells forming colonies of 4 or multiples, in a cubic arrangement of regular rows. The mucilage sheath may be layered. Cells 2-7µm.


? Gomphonema
Gloeocystis vesiculosa
Gomphosphaeria aponina


Cyanobacterium (no chloroplast). Colony spherical. Cells packed around periphery of colony, usually heart-shaped, 4-10x8-12µm.



Merismopedia elegans


Cyanobacterium forming flat plates of cells arranged in regular rows.

Microcystis aeruginosa
Microcystis flos-aquae



Cyanobacterium, forming irregular or subspherical colonies in mucilage. Cells spherical / subspherical are crowded, irregularly arranged.
M. aeruginosa has cells 4-9µm diameter, colony becomes clathrate (divided) with age, usually has an outer layer free of cells.
M. flos-aquae is 2.5-5µm, forming spherical or irregular colonies, cells densely packed and no cell-free outer layer.


Oocystis sp.

Quadrigula closterioides
? Sphaerocystis

? Sphaerocystis

Spondylosium planum

Staurastrum cingulum
Staurodesmus mamillatus