Investigating the effects of temperature on Euglena gracilis growth rate


  • H. Kim
  • J. Villareal
  • K. Liu
  • M. Ling


Algal blooms are occurring more frequently due to anthropogenic activities, in which rising water temperatures is one of the leading causes (Paerl et al., 2001). In the present study, the relationship between temperature and growth rate of Euglena gracilis, a single-celled alga, was investigated to further correlate rising temperatures with more frequent algal blooms in freshwater systems. E. gracilis was prepared and incubated at three different temperatures (17℃, 20℃ , and 30℃ ). The cells were then counted on a hemocytometer slide under a microscope at days 1, 4, 7, 10, and 12 following the day of initial preparation and a growth rate curve was plotted for each of the treatments and replicates. The growth rate was found to be the greatest at 30℃ and lowest at 17℃ (p<0.01). This demonstrates that rising temperatures play a role in increasing the rate of algae division and ultimately resulting in algal blooms