Species belonging to the toxic dinoflagellate genus Ostreopsis are widespread, occurring from tropical to temperate waters. As mainly benthic/epiphytic species, they would be expected to show distinct geographical patterns. In this study, ribosomal DNA (rDNA) sequences from partial nuclear LSU D8-D10, 5.8S, and ITS regions were determined for 169 isolates of Ostreopsis species collected from three coastal sites (i.e., Jeju Island, Chuja Island, and Pohang) within Korea. The phylogenetic tree inferred from the LSU rDNA D8-D10 sequences showed that Korean Ostreopsis species corresponded to either Ostreopsis sp. 1 or sp. 6, with Ostreopsis sp. 1 being relatively predominant regarding their distribution. While Ostreopsis sp. 1 occurred throughout all the three sampling sites within Korea, Ostreopsis sp. 6 was confined to the northern part of Jeju Island. When further investigated, the genetic diversity of Ostreopsis sp. 1 in Korea based on ITS sequences showed a total of 21 haplotypes. The presumed ancestral haplotype H3, was also present in the Japanese and Russian populations of Ostreopsis sp. 1. Although the overall demographic history of all the Korean populations of Ostreopsis sp. 1 could not be clearly identified, probably due to a mixture of different regional demographic patterns within Korea, each Ostreopsis sp. 1 population showed a characteristic demographic pattern at a regional scale. While the Jeju Island Ostreopsis sp. 1 population showed a signal in agreement with population equilibrium, the Chuja Island and Pohang Ostreopsis sp. 1 populations showed distribution patterns that are expected in a sudden population expansion model. The results from this study provide a basis for a better understanding of the distribution and genetic structure of the Asian Ostreopsis sp. 1 populations.

属于毒性鞭毛藻属（Ostreopsis）的物种分布广泛，从热带到温带水域都有。作为主要的底栖/表生物种，预计它们将显示出独特的地理格局。在这项研究中，确定了部分LSU D8- D10、5.8S和ITS区域的核糖体DNA（rDNA）序列，这些序列来自于三个沿海地点（济州岛，丘贾岛和浦项）收集的169种分离的兽疫菌。韩国。从LSU rDNA D8-D10序列推论出的系统发育树表明，韩国Ostreopsis物种对应于任一Ostreopsis sp。1或sp。6，与骨质疏松症。1在其分布方面相对占优势。而Ostreopsis sp。在韩国的三个采样地点中，有1个发生在Ostreopsis sp.。6只限于济州岛北部。当进一步调查时，Ostreopsis sp。的遗传多样性。韩国基于ITS序列的1个显示总共21个单倍型。在日本和俄罗斯的Ostreopsis sp。种群中也存在推测的祖先单倍型H3 。1.虽然所有韩国Ostreopsis sp。人口的总体人口历史。可能由于韩国内部不同区域人口模式的混合，每种骨质疏松症无法明确识别1个sp。1个人口在区域范围内表现出典型的人口统计学特征。而济州岛的骨质疏松症。1个种群的信号与种群平衡，丘贾岛和浦项Ostreopsis sp。一致。1个种群显示了突然的种群扩张模型中预期的分布模式。这项研究的结果为更好地了解亚洲Ostreopsis sp。的分布和遗传结构提供了基础。1人口。