Diversity of zooxanthellae from scleractinian corals of One Tree Island (The Great

The small subunit ribosomal gene (18S rDNA) of zooxanthellae from 19 species of Australian Pacific scleractinian corals was amplified using algae-specific PCR primers. Preliminary results of the restriction fragment length polymorphism (RFLP) profiles obtained by digestion of these PCR products by a single restriction enzyme, indicate that three recognised clades of zooxanthellae (A, B and C) are present. Clade C was detected in 18 species of corals but in two of these species, Acropora longicyathus and Pavona decussata, other clades were also found. Acropora longicyathus has either clade A or C depending on the colony. Pavona decussata produced an unusual RFLP profile indicating that it had a mixture of clade B and C. Plesiastrea versipora, which was the only coral species taken from a temperate region in our study, appears to host clade B zooxanthellae exclusively. Results from this preliminary study suggest that clade C is the predominant zooxanthella group in corals of One Tree Island