Ulothrix
Ulothrix spp. · Algae
Where it grows · Photo: Jamie O'Neill / CC BY
Also called Green slime, Filamentous algae, Ulothrix zonata
How to identify Ulothrix
- Bright green, short, slippery threads coating rocks
- Forms a green fringe on rocks at or just below the waterline
- Unbranched, with a band shaped green body in each cell under a hand lens
- Most noticeable in cold water
Similar species
Cladophora is coarse and branched; Spirogyra floats and has spiral bands.
Growth profile
| Season | Peaks in late winter and early spring, fades in summer and returns in fall. |
|---|---|
| Starts | Cold water, about 35 to 50 F |
| Light | Moderate to bright light |
| Depth | Attached to rocks at the waterline to a few feet |
| How it spreads or reproduces | Swimming spores and fragments |
| Habitat | Cold streams, lake shorelines with waves and spring fed water, attached to rocks and hard surfaces. |
Why it matters in a lake
A cold water alga that often forms the green fringe on rocks in early spring. Usually fades on its own as water warms.
Where it is found
- Idaho: Occasional
- Oregon: Occasional
- Wyoming: Occasional
Classification
| Kingdom | Plantae |
|---|---|
| Phylum | Chlorophyta |
| Class | Ulvophyceae |
| Order | Ulotrichales |
| Family | Ulotrichaceae |
| Scientific name | Ulothrix spp. |
Spirogyra
Cladophora
Horsehair algae
Oedogonium
Rhizoclonium
Water net
Water felt
Mougeotia
Zygnema
MicrosporaNeed a hand?
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