Clade ITS2 Type Genbank number B1 AF333511 B10 AF499787 B17 AY074987 B1j GU907637 C1 AF333515 Pseudonyms Symbiodinium pulchrorum; S. bermudense B C3 Symbiodinium goreaui C12 D1 AF499797 AF499801 C7a AF334660 Symbiodinium glynni AF499802 Symbiodinium trenchii, D1b, D5, D1a Previously reported in O. annularis Exuma Islands & Florida Keys; Barbados; Bahamas; US Virgin Islands; Bermuda LaJeunesse 2002; Savage et al. 2002; Thornhill et al. 2006; Correa et al. 2009; Thornhill et al. 2009; Finney et al. 2010 Florida Keys Thornhill et al. 2009 Belize Barbados; Belize; Curacao; Venezuela Bahamas; Cuba; Honduras; Tobago Belize; Columbia; Dominica Panama Eastern Caribbean Savage et al. 2002 LaJeunesse et al. 2009; Finney et al. 2010; Correa et al. 2009 Bahamas; Barbados; Cayman Islands; Cuba; Curacao; Dominica; Dominican Rep.; Jamaica; Nicaragua; US Virgin Islands; Tobago; Venezuela Bahamas; Barbados; Cuba; Curacao; Dominica; Dominican Rep.; Nicaragua; US Virgin Islands; Tobago; Venezuela n/a US Virgin Islands; Barbados Bahamas; Belize; Cuba; Dominica; Honduras; US Virgin Islands Exuma Islands; US Virgin Islands; South Yucatan; Florida Keys US Virgin Islands US Virgin Islands; Exuma Islands; Florida Keys LaJeunesse 2002; Thornhill et al. 2006; Warner et al. 2006; Correa et al. 2009; Thornhill et al. 2009 Warner et al. 2006; Correa et al. 2009; LaJeunesse et al. 2009; Finney et al. 2010 Eastern Caribbean; Exhuma Islands Thornhill et al. 2006; LaJeunesse et al. 2009; Thornhill et al. 2009; Finney et al. 2010; US Virgin Islands; South Yucatan; Exuma Islands; Florida Keys LaJeunesse et al. 2001; LaJeunesse 2002; Thornhill et al. 2006; Correa et al. 2009; LaJeunesse et al. 2009; Finney et al. 2010 LaJeunesse 2002; Thornhill et al. 2006; Correa et al. 2009; Finney et al. 2010; LaJeunesse et al. 2009 D D1-4 References Bahamas; Barbados; Belize; Cayman Islands; Columbia; Cuba; Curacao; Dominican Rep.; Honduras; Jamaica; Nicaragua; Tobago; US Virgin Islands; Venezuela Cayman Islands; Cuba AF499789 C C7 Locations detected in this study Table S1. Dominant Symbiodinium ITS2 types identified by DGGE analysis in this study, along with GenBank accession numbers and details on sampling locations from this and previous studies. References Correa A, McDonald M, Baker A (2009) Development of clade-specific Symbiodinium primers for quantitative PCR (qPCR) and their application to detecting clade D symbionts in Caribbean corals. Marine Biology 156:2403-2411 Finney J, Pettay D, Sampayo E, Warner M, Oxenford H, LaJeunesse T (2010) The relative significance of host–habitat, depth, and geography on the ecology, endemism, and speciation of coral endosymbionts in the genus Symbiodinium. Microbial Ecology 60:250-263 LaJeunesse TC (2001) Investigating the biodiversity, ecology, and phylogeny of endosymbiotic dinoflagellates in the genus Symbiodinium using the ITS region: In search of a "species" level marker. Journal of Phycology 37:866-880 LaJeunesse TC (2002) Diversity and community structure of symbiotic dinoflagellates from Caribbean coral reefs. Marine Biology 141:387-400 LaJeunesse TC, Smith RT, Finney J, Oxenford H (2009) Outbreak and persistence of opportunistic symbiotic dinoflagellates during the 2005 Caribbean mass coral 'bleaching' event. Proceedings Biological sciences: The Royal Society 276:4139-4148 Savage AM, Trapido-Rosenthal H, Douglas AE (2002) On the functional significance of molecular variation in Symbiodinium, the symbiotic algae of Cnidaria: photosynthetic response to irradiance. Marine Ecology Progress Series 244:27–37 Thornhill DJ, LaJeunesse TC, Kemp DW, Fitt WK, Schmidt GW (2006) Multi-year, seasonal genotypic surveys of coral-algal symbioses reveal prevalent stability or post-bleaching reversion. Marine Biology 148:711-722 Thornhill DJ, Xiang Y, Fitt WK, Santos SR (2009) Reef endemism, host specificity and temporal stability in populations of symbiotic dinoflagellates from two ecologically dominant Caribbean corals. PLoS ONE 4:e6262 Warner ME, LaJeunesse TC, Robison JD, Thur RM (2006) The ecological distribution and comparative photobiology of symbiotic dinoflagellates from reef corals in Belize: Potential implications for coral bleaching. Limnology and Oceanography 51:1887-1897