Ceratium
Ceratium spp. · Phytoplankton
Under the microscope · Photo: Don Loarie / CC BY
Also called Horned dinoflagellate, Ceratium hirundinella
How to identify Ceratium
- Under the microscope: large armored cell with one long front horn and two or three back horns
- Groove around the middle with a spinning swim
- Golden brown to brownish red color
- In the water: blooms make the water brown or coffee colored and can smell fishy or septic
Similar species
Peridinium is round without long horns; Gymnodinium has no armor plates.
Profile
| Season | Mid to late summer and fall. |
|---|---|
| Starts | About 60 F and up |
| Light | Moderate to full sun; migrates up and down daily |
| Depth | Moves through the water column; often near the surface in daytime |
| How it spreads or reproduces | Cell division and thick walled resting cysts in the sediment |
| Habitat | Lakes, reservoirs and larger ponds, often stratified water; frequent in Pacific Northwest reservoirs. |
Why it matters in a lake
Not toxic, but dense blooms cause brown water, fishy odors and clog filters. When blooms crash and decay they can drop oxygen and cause fish kills.
Where it is found
- Idaho: Common
- Oregon: Common
- Wyoming: Common
Classification
| Kingdom | Chromista |
|---|---|
| Phylum | Myzozoa |
| Class | Dinophyceae |
| Order | Gonyaulacales |
| Family | Ceratiaceae |
| Scientific name | Ceratium spp. |
Peridinium
Gymnodinium
Microcystis
Dolichospermum (Anabaena)
Fragilaria
CryptomonasNeed 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