When the psbB-psbF sequence of S. maritima from the Paracel Islands was compared to the psbB-psbF sequence (673 bp) of S. maritima from the USA (obtained from GenBank), the similarity of two sequences was 100%. When the trnL intron sequence of S. maritima from the Paracel Islands was compared to the trnL intron sequence (472 bp) of S. maritima from South Africa (obtained from GenBank), two base insertions were detected (GA, in 239–240 bp) in the Paracel Islands sequence, and the similarity of the two sequences was 99.6%.