The Thermotolerance of Dinoflagellate Endosymbiont Algae in Culture
Open Access
- Author:
- Snyder, Jacob
- Area of Honors:
- Biology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Monica Medina, Thesis Supervisor
Benoit A Dayrat, Thesis Honors Advisor - Keywords:
- algae
coral
bleaching
stress
oceans
reef
Symbiodiniaceae
mutualism
cryptic
tolerance
resilience - Abstract:
- Most reef-building corals form intracellular mutualisms with dinoflagellate endosymbiont algae in the family Symbiodiniaceae, which fulfill a majority of their energetic budget and partly define their response to environmental change. Warming ocean temperatures disrupt coral-symbiont mutualisms during coral bleaching events, triggering mass mortality in reefs and depriving humans of an economically and ecologically significant resource. This investigation monitors the population growth and photochemical efficiency of five cultured species of Symbiodiniaceae, spanning three genera, under ambient and elevated temperatures to derive thermotolerance ratios. Here, I confirm the thermal tolerance of Symbiodinium microadriaticum and the thermal sensitivity of Symbiodinium tridacnidorum, as established in prior literature; yet, I characterize Durusdinium trenchii as thermally susceptible, challenging its status as an extremophile. Significantly, our results suggest that Breviolum aenigmatum and Breviolum pseudominutum – largely understudied species – exhibit thermal sensitivity and moderate thermal tolerance, respectively. This study provides insight into the within- and between-genera differences in symbionts’ susceptibility to heat stress to characterize their potential capacity to confer tolerance to a symbiotic host in the face of environmental change.