Snow and ice are considered extreme environments, but some green algae are well adapted to survival in these harsh conditions. The snow in the picture to the left appears pink because of red pigments found in the green algae growing in the snow. Click below to read more about the green algae you can find in snow and ice.
Some green algae are adapted to survival in snow and ice (cryophilic). When algal cells reach a high density, they impart a green or red color to the snow. Generally, both red and green snow contain green algae. The algae appear red because of the high concentration of carotenoids in their cytoplasm.
The most common snow algae are Chlamydomonas species (red zygote pictured below) and the green flagellate Chloromonas. Many conjugating green algae, including Ancylonema, Cylindrocystis and Mesotaenium, are also well adapted to life among snow and ice. With the exception of Ancylonema, other members of these genera are also found in warmer water.
Zygote of Chlamydomonas sp.