Spirogyra
Spirogyra spp. · Algae
A bloom in the water · Photo: Bogdan / CC BY-SA 3.0 (Wikimedia Commons)
Also called Water silk, Frog spit, Filamentous algae, Pond moss, Pond scum
How to identify Spirogyra
- Bright green, very slimy and slippery strands that slide through fingers
- Unbranched threads that form cottony clouds or floating mats
- Under a hand lens, a spiral green band inside each cell
- Floating mats often trap bubbles and turn yellow when old
Similar species
Cladophora feels coarse like wet wool; Mougeotia and Zygnema are also slimy but lack the spiral band.
Growth profile
| Season | Appears early in spring, often peaks in late spring before the heat, can return in fall and overwinters as resting spores. |
|---|---|
| Starts | About 45 to 55 F water, often one of the first algae in spring |
| Light | Full sun in shallow water |
| Depth | Starts on the bottom, then rises to float at the surface |
| How it spreads or reproduces | Fragments and thick walled spores; carried by waterfowl and gear |
| Habitat | Ponds, lakes, ditches and slow canals, especially warm shallow water with extra nutrients. |
Why it matters in a lake
Mats rise when trapped oxygen bubbles lift them off the bottom. Often signals nutrient enrichment from runoff or fertilizer.
Where it is found
- Idaho: Common
- Oregon: Common
- Wyoming: Common
Classification
| Kingdom | Plantae |
|---|---|
| Phylum | Charophyta |
| Class | Zygnematophyceae |
| Order | Spirogyrales |
| Family | Spirogyraceae |
| Scientific name | Spirogyra spp. |
Cladophora
Horsehair algae
Oedogonium
Rhizoclonium
Water net
Water felt
Mougeotia
Zygnema
Microspora
StigeocloniumNeed a hand?
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