Methodology by organism type:

M.elongata:
Tagged colonies were sampled in May 2015 (before bleaching), September 2015 (during bleaching), and after bleaching - November 2015, March 2016, May 2016, September 2016, November 2016, March 2017 and August 2017. Tissue was preserved in 95% ethanol. DNA was extracted from symbiont cells following Coffroth et al. (1992) and re-suspended in TE buffer (5-15µl, diluted to a concentration of 5ng/µl). Symbionts were characterized using four polymorphic microsatellite loci, B7SYM15, B7SYM34, B7Sym8, and SYM 155 following the protocols of Pettay and LaJeunesse (2007) and Andras et al (2009). Cp-type were determined following the protocols outline in Santos et al (2003). Putative species identity was based on cp-type or Breviolum microsatellites as noted above.

P. dichotoma:
Tagged colonies were sampled in May 2015 (before bleaching), September 2015 (during bleaching), and after bleaching - November 2015, March 2016, May 2016, September 2016, November 2016, March 2017 and August 2017. Tissue was preserved in 95% ethanol. DNA was extracted from symbiont cells following Coffroth et al. (1992) and re-suspended in TE buffer (5-15µl, diluted to a concentration of 5ng/µl). Symbionts were characterized using four polymorphic microsatellite loci, B7SYM15, B7SYM36, B7Sym9, and CA6.38 following the protocols of Pettay and LaJeunesse (2007), Andras et al (2009) and Santos et al (2003a) Cp-type were determined following the protocols outline in Santos et al (2003b). Putative species identity was based on cp-type were available.

M. atlantica:
Tagged colonies were sampled in September 2015 (during bleaching), and after bleaching - November 2015, March 2016, May 2016, September 2016, November 2016, March 2017 and August 2017 and tissue preserved in 95% ethanol. DNA was extracted from symbiont cells following Coffroth et al. (1992) and re-suspended in TE buffer (5-15µl, diluted to a concentration of 5ng/µl). Symbionts were characterized using four polymorphic microsatellite loci, B7SYM15, B7SYM34, B7Sym8, and SYM 155 following the protocols of Pettay and LaJeunesse (2007) and Andras et al (2009). Cp-type were determined following the protocols outline in Santos et al (2003). Putative species identity was based on cp-type or Breviolum microsatellites as noted above.

Location:
Two patch reefs in the vicinity of Long Key in the Florida Keys (CMF-N24.44.704, W 80 46.793 and SC2- N24 49.478 W80 41.187)

Coral taxonomic identifiers (Genus species, LSID):
Muricea atlantica, urn:lsid:marinespecies.org:taxname:287554
Muricea elongata, urn:lsid:marinespecies.org:taxname:287559
Plexaurella dichotoma, urn:lsid:marinespecies.org:taxname:290812

Endosymbiont taxonomic identifiers (Genus species, LSID):
Breviolum, urn:lsid:marinespecies.org:taxname:1391356
Cladocopium, urn:lsid:marinespecies.org:taxname:1491877