Note
Symbiotic dinoflagellates belonging to the genus Symbiodinium (Freudenthal) are found worldwide in association with shallow-water tropical and subtropical marine invertebrates. Most phylogenetic studies of Symbiodinium have used nuclear rRNA (nrDNA) genes to infer relationships among members of the genus. In this report, we present the first phylogeny of Symbiodinium based on DNA sequences from a mitochondrial protein-coding gene (cytochrome oxidase subunit I [cox1]).