Loch Gorm Algae 2003

    
    
? Aphanocapsa

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
 

Aphanothece

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

Asterococcus

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.

       
 
       
Botryococcus

Botryococcus

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
 
 

Calothrix

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
 

Chroococcus

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

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

Coleochaete

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
 
 
 

Dictyosphaerium

Dictyosphaerium

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

Eucapsis

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.

       
 
 
?Eudorina
   
 
 
 

? Gomphonema
 
 
 
 
     
Gloeocystis vesiculosa
 
   
Gomphosphaeria aponina

Gomphosphaeria

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

   
 
 



Gyrosigma
 
 

Merismopedia elegans

Merismopedia

Cyanobacterium forming flat plates of cells arranged in regular rows.

 
   
 
 
 
 
Microcystis aeruginosa
   
Microcystis flos-aquae

 

Microcystis

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.

 
 
 
 

Nostoc
 
 
 
     
Oocystis sp.

Quadrigula closterioides
 
 
 
     
 
 
  ?Snowella
 
 
 
       
 
 
? Sphaerocystis

? Sphaerocystis
 
 

Spondylosium planum
 
 
 
 

Staurastrum cingulum
     
Staurodesmus mamillatus
       
 
 
Woronichinia

?Woronichinia