The Genus Zygogonium
Phylum Chlorophyta; sub-phylum Chlorophyceae; Order Zygnematales; Family Zygnemataceae.
Zygogonium is an unbranched filamentous green alga, related to Zygnema. At first glance it may appear like Microspora, as the cells can look bulbous or barrel-shaped, and the ends of filaments appear H-shaped.
However, the filament does not break up readily into H-pieces, and the (usually single) chloroplast is stellate. Occasional stretches with two chloroplasts prior to cell division can be mistaken for Zygnema.
The cell wall is usually thick, especially in aged filaments. In these, the shape of the chloroplast may not be visible and identification is especially difficult.
The cell width may vary, but only one species, Z. ericetorum, is reported from the British Isles:
These samples were
obtained from Loch Uigedail, Islay.
The loch is at an altitude of about 250m. and the pH was 4.8.