Algae and cyanobacteria
Cyanobacteria threads
Oscillatoria and other filamentous cyanobacteria
Bacteria, not algae: thin blue-green threads that glide and sway slowly, which gave Oscillatoria its name.
What to look for
- Thin threads (trichomes) of short disc-shaped cells; no chloroplasts or nucleus to see.
- Colour blue-green to olive; the tips wave and the threads slide past each other.
- Some kinds (Anabaena, Nostoc) form beaded chains with larger empty-looking cells (heterocysts).
Size in the field
Thin: at 100× like fine hairs; 400× shows the cells.
Where to find it
Dark mats on mud and stones, and blooms in nutrient-rich water.
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