The Effect of Temperature on Food Vacuole Formation in Tetrahymena thermophila

  • Cindy Pham
  • Kattereya Kennedy
  • Nicola Popper
  • Ravneet Ghotra


Through the process of phagocytosis for food vacuole formation, Tetrahymena thermophila can fulfill its nutritional needs for growth. This study aims to determine the effect of temperature on the number of vacuoles produced in T. thermophila over time as they possess a relationship with zooplankton, an important food source for salmon.  Our null hypothesis states that there is no change in vacuole production due to temperature change.  Next, our first alternative hypothesis states that vacuole production will be highest at 30°C.  Lastly, our second alternative hypothesis states that food vacuole production will be highest at 10°C.  T. thermophila was observed every 20 minutes over a 2-hour interval at temperature groups 10°C, 23°C, and 30°C. Three replicates were made at every 20-minute interval consisting of counting the number of vacuoles in 10 randomly selected cells.  Our research showed that T. thermophila formed more food vacuoles at lower temperatures, 10°C and 23°C, than at 30°C. This contradicts our initial prediction, but supports the second alternative hypothesis.   Statistical analysis was performed using two-way ANOVA and 95% confidence intervals.  The P-value is consistently lower than our confidence level of 0.05, thus our results are statistically significant.