Diversity and Abundance of Symbiodiniaceae and Bacteria in Corals Sarcophyton trocheliophorum and Euphyllia ancora Under Thermal Stimulation

Coral Symbiodiniaceae and bacteria maintain a symbiotic relationship that is essential for coral survival. The symbiotic communities component in the polyps host that could affect coral resistance and the ability to recover from stress. In this study, we increased the cultured range temperature (26 ± 1 ℃) of Sarcophyton trocheliophorum and Euphyllia ancora at 32 ℃ for 12 hours, and then amplified the ITS2 sequence of Symbiodinium and the bacterial 16S rRNA sequence in the sample, respectively to compare Symbiodiniaceae and bacteria diversity and abundance with normal culture temperature. The results showed that there was no change in the dominant species of Symbiodinium in these two corals in the heat treatment group, but the diversity of Symbiodinium of the two corals was significantly different. On the other hand, after thermal treatment, the endophytic bacteria of S. trocheliophorum represented more aerobic bacteria Delfitia, while the E. ancora was infected with more pathogenic endosymbiotic bacteria. This difference observation can be attributed to the different tolerance of corals.