Optimum Temperatures and Temperature Ranges for Growth of Snow Algae

Abstract

Blooms of algae are known to occur in snow when air temperatures remain above freezing for extended periods of time. However, hard freezes may occur after snow algae make their appearance, and some species may survive this environmental stress more easily than others. × Three species of snow algae, Raphidonema nivale, Chloromonas pichinchae, and Cylindrocystis brébissonii, were isolated into axenic culture for optimum temperature studies under set laboratory conditions. In those temperatures tested (1, 5, 10, 15, and 20°C), it was found that optimum growth for R. nivale occurred at 5°C, for C. pichinchae at 1°C, and for C. brébissonii at 10°C. Three other species of snow algae, Chlainomonas kolii, Chlainomonas rubra, and Chlamydomonas nivalis (from Washington snow), did not grow in defined medium for extended periods of time. Vegetative cells of C. kolii and C. rubra lose their flagella at temperatures above 4°C as observed on a cooling stage, and optimum growth for these species probably occurs at a temperature below 5°C. C. nivalis resting spores cleave into daughter cells at temperatures from 0 to 2°C, and perhaps this observation may be used as an indicator for optimum growth in this species.

Species of snow algae used in this study and in previous studies are compared with respect to their optimum temperature and temperature range for growth.* Species that do not grow at temperatures above 10°C and have optimum growth at lower temperatures are classified here as true snow algae. This list of species includes Chlainomonas kolii, Chlainomonas rubra, Chlamydomonas nivalis (cultures of Hoham from Washington snow), Chloromonas pichinchae, Chloromonas sp., Raphidonema tatrae, Chromulina chionophila (cultures of Stein), and Cryptomonas frigoris.

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Erratum Vol. 7, No.1, p. 20.