Effects of Temperature Variance on Euglena Gracilis Growth Rate

  • Hamidreza Ayremlou
  • Molly Fu
  • Asana Khajavi
  • Min Jee Kim


Euglena gracilis, single-cell flagellate eukaryotes, are a diverse genus which can be found in both freshwater and saltwater. Salmon in freshwater depends on Euglena gracilis as a nutritious food source. To understand how various temperatures will impact the growth of salmon, we grew Euglena gracilis at different treatment temperatures. Four incubation temperature treatments were 13°C, 20°C, 25°C (optimal), and 30°C. Three replicates of each treatment, containing culture and Euglena gracilis were incubated for two weeks. Then, we collected data and calculated the growth rate of the species at 13°C, 20°C, 25°C, and 30°C and found 13111, 58921, 75998, 32685 cells/mL/day respectively. Our one-way ANOVA analysis shows that the f-calculated value equals 20.551, is greater than the f-critical value, 3.49 at ɑ=0.05. And the calculated p-value is less than 0.05, which indicates that there is a significant difference between the growth rates at the temperature treatments. Therefore, we rejected our null hypothesis. A Tukey-Kramer test concluded that the calculated p-values for 13°C treatment growth rate was less than the p-value of 0.05 in comparison to 20, 25, and 30°C treatments. There was no statistical difference among the 20, 25, and 30°C treatments. Therefore, 13°C is the only temperature treatment that has a growth rate that is significantly different from the other temperatures.