The shape of Euglena gracilis in response to temperature


  • Jayd Adams
  • Raphael Roberto
  • Wendy Yang


Euglena gracilis is a photosynthetic single-celled eukaryote which can change its shape depending on the environmental conditions. Previous studies have shown the importance of unicellular photosynthetic organisms in the production of both atmospheric and aquatic O2, as well as the implications of E. gracilis’ shape on its photosynthetic capacity. This p resent study looks at the effects of temperature on the shape of Euglena, which has yet to be explored. To do this, we incubated E. gracilis culture at 10°C, 25°C, and 31°C (n=3 for each temperature treatment) for one hour before taking photos of the culture under a compound microscope. We quantified the results by counting the number of balled-up and elongated cells for all temperatures and replicates. We calculated a ratio of the counted number of balled-up cells divided by the total number of cells (balled up + elongated) for our statistical analysis. Our oneway ANOVA analysis shows that there is a statistically significant difference between the number of balled-up cells at 10°C and 31°C compared to the 25°C control treatment (p=0.0069). We therefore reject our null hypothesis that each temperature group will have the same mean ratio of balled-up cells/total cells counted, showing that temperature has an effect on the shape of E. gracilis