Cryptomonas

Idaho: Common
Oregon: Common
Wyoming: Common

Cryptomonas spp. · Phytoplankton

Under the microscope · Photo: zookanthos / CC BY

NativePlanktonic algae (in the water)

Also called Cryptomonads, Cryptophytes

How to identify Cryptomonas

Under the microscope: bean or slipper shaped single cells with a groove (furrow) on one side
Two flagella from the groove and a jerky, wobbling swim
Olive, brown or reddish brown color with one or two large plastids
In the water: not seen by eye except in rare blooms that tint the water brownish

Rhodomonas is much smaller and reddish with a pointed tail end; dinoflagellates have a groove around the middle and a spinning swim.

Season	Present year round; often most abundant in spring, fall and under ice when other algae are scarce.
Starts	Any temperature, even near 35 F under ice
Light	Low light tolerant; can feed on particles
Depth	Throughout the water column; often concentrated in cooler deep layers
How it spreads or reproduces	Cell division
Habitat	Almost every pond, lake and reservoir, including cold mountain lakes and shaded or ice covered water.