Aulacoseira
Aulacoseira spp. · Phytoplankton
Under the microscope · Photo: Petr Knotek / CC BY
Also called Melosira (old name), Aulacoseira granulata
How to identify Aulacoseira
- Under the microscope: cylinder shaped diatoms linked end to end into straight or curved chains
- Side walls show rows of tiny dots, and chain ends may have spines
- Golden brown color
- In the water: blooms give a muddy brown color in turbid, mixed reservoirs
Similar species
Melosira chains look similar but the cells are wider and smoother walled; Fragilaria ribbons are flat, not round.
Profile
| Season | Spring and fall, and in summer when wind keeps the water mixed. |
|---|---|
| Starts | About 45 to 65 F |
| Light | Tolerates low light and turbid water |
| Depth | Needs mixing to stay up; sinks in calm water |
| How it spreads or reproduces | Cell division |
| Habitat | Turbid, nutrient rich lakes, reservoirs and slow rivers; very common in irrigation reservoirs and the Snake River system. |
Why it matters in a lake
Heavy diatoms that sink fast, so they thrive in windy, mixed reservoirs. Large numbers can clog irrigation filters and drip systems.
Where it is found
- Idaho: Common
- Oregon: Common
- Wyoming: Common
Classification
| Kingdom | Chromista |
|---|---|
| Phylum | Bacillariophyta |
| Class | Coscinodiscophyceae |
| Order | Aulacoseirales |
| Family | Aulacoseiraceae |
| Scientific name | Aulacoseira spp. |
Fragilaria
Cyclotella
Asterionella
Navicula
Ulnaria (Synedra)
Nitzschia
Stephanodiscus
Tabellaria
Melosira
GomphonemaNeed a hand?
Want to know what is in your water?
Lab counts of the algae in your lake show what is growing, how much and whether a bloom is coming.
Idaho / Wyoming (208) 501-4531Oregon (541) 280-0596