Hydrurus
Hydrurus foetidus · Algae
Underwater · Photo: Jan Vršovský / CC BY-SA
Also called Golden algae, Hydrurus foetidus, Stinky algae, Brown slime
How to identify Hydrurus
- Brown to golden, slimy, branching tufts streaming from rocks
- Strong rotten or foul smell when handled
- Soft gelatinous texture
- Grows in fast, very cold water
Similar species
Didymo is woolly and not smelly; Lemanea is stiff and dark.
Growth profile
| Season | Grows in winter and spring during cold flows, peaks during snowmelt and fades as water warms in summer. |
|---|---|
| Starts | Very cold water, near 32 to 45 F |
| Light | Moderate to bright light |
| Depth | Attached to rocks in fast water |
| How it spreads or reproduces | Swimming cells and fragments |
| Habitat | Cold, fast mountain streams and snowmelt fed rivers, attached to rocks. |
Why it matters in a lake
A cold water alga typical of clean mountain streams. Its bad smell is distinctive.
Where it is found
- Idaho: Occasional
- Oregon: Occasional
- Wyoming: Occasional
Classification
| Kingdom | Chromista |
|---|---|
| Phylum | Ochrophyta |
| Class | Chrysophyceae |
| Order | Hydrurales |
| Family | Hydruraceae |
| Scientific name | Hydrurus foetidus |
Didymo
Frog spawn alga
Lemanea
Compsopogon
Red crust alga
SpirogyraNeed a hand?
Is it taking over your lake?
We identify what is growing, map how much of it there is and build a control plan that targets it without harming the rest of the lake.
Idaho / Wyoming (208) 501-4531Oregon (541) 280-0596