Molecular diversity of symbiotic algae of the genus Symblodinium (Zooxanthellae) in cnidarians of the Mediterranean Sea

The molecular diversity of dinoflagellate algae of the genus Symblodinium in symbiosis with ten species of scleractinian coral, sea anemone and scyphomedusa in the Mediterreanean Sea was investigated by restriction analysis and sequencing of polymerase chain reaction-amplified fragments of SSU and LSU rRNA genes. All species bore Symblodinium of clade A, apart from Bunodeopsis strumosa, which had clade B. The clade A sequences clustered with a previously described group, 'temperate-A, known only from the Mediterranean and Atlantic coasts of the UK and France. It is concluded that clade temperate-A is prevalent, but not universal, in the Mediterranean.