Effects of Increasing Temperature on the Growth Rate of Tetrahymena thermophila: the impact of climate change and adaptation for survival


  • Tsewang Diki
  • Ishika Gill
  • Stephanie McPhail
  • Christine Sun


Tetrahymena thermophila is a unicellular complex ciliate organism that is able to undergo mitosis and meiosis. This protozoan makes up lower levels of the food web that includes salmon, a keystone species on the western coast of British Columbia. Increasing negative effects from climate change will have drastic consequences on marine ecosystems, altering the dynamics within and between populations. In order to test if temperature affected the cells’ growth rate, T. thermophila was cultured in temperature treatments of 25°C, 35°C and 39°C to observe their average population growth rate at each temperature. This research is essential to investigate the consequences of climate change on the components of the salmon food web. The experimental findings were that there was little to no growth rate for all three temperature treatments and the growth rates for the three temperatures were also not significantly different (p > 0.05); resulting in us being unable to reject the null hypothesis that temperature does not affect the cells’ growth rate. This finding contradicts our initial prediction that higher temperatures increase growth rate and implies that temperature does not have an overall effect on growth rate and that the cultured T. thermophila cells barely grew.