Stiller Josefin, Wilson Nerida G, Donnellan Stephen, Rouse Greg W
Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA.
Western Australian Museum, Perth, Australia.
J Hered. 2017 Mar 1;108(2):152-162. doi: 10.1093/jhered/esw075.
The leafy seadragon (Phycodurus eques, Syngnathidae), is a charismatic endemic of Australia’s temperate coast. The species exhibits remarkable camouflage in its kelp and seagrass habitat. These habitats have been retreating throughout the range of the species, leading to concerns about the persistence of leafy seadragons. Despite being a popular aquarium display and a flagship for coastal conservation, little is known about leafy seadragon biology. We used 7 microsatellite markers and 2 mitochondrial DNA fragments to investigate the population structuring and genetic diversity of 71 individuals. Bayesian cluster analysis identified 2 main genetic partitions, one in Western Australia and the other in South Australia. Shallower, yet significant, differentiation of mitochondrial DNA (φST) and microsatellites (FST, F′ST, D) was found on the smaller geographic scales in South Australia. Distinct groups were supported in Encounter Bay, on both shores of Gulf St Vincent, and in Spencer Gulf. Sample sizes were too small in the eastern Great Australian Bight and in the westernmost locality to address genetic differentiation in these regions. Overall genetic diversity was moderate to low, but particularly low levels were found in the Western Australian cluster. This latter point needs confirmation at other sites in Western Australia. In South Australia, signatures of demographic changes were detected, which may have been caused by a population expansion due to post-glacial reflooding of the gulfs. The Western Australian and South Australian clusters appeared as demographically independent units. Conservation actions should focus on preserving genetic diversity at local scales and maintaining habitat connectivity.
叶海龙（Phycodurus eques，海龙科）是澳大利亚温带海岸特有的极具魅力的物种。该物种在其海带和海草栖息地展现出非凡的伪装能力。这些栖息地在该物种的整个分布范围内一直在退缩，这引发了人们对叶海龙生存的担忧。尽管叶海龙是一种受欢迎的水族展示物种且是沿海保护的旗舰物种，但人们对其生物学特性知之甚少。我们使用了7个微卫星标记和2个线粒体DNA片段来研究71个个体的种群结构和遗传多样性。贝叶斯聚类分析确定了2个主要的遗传分区，一个在西澳大利亚，另一个在南澳大利亚。在南澳大利亚较小的地理尺度上，发现线粒体DNA（φST）和微卫星（FST、F′ST、D）存在较浅但显著的分化。在恩特湾、圣文森特湾两岸以及斯潘塞湾都发现了不同的群体。在澳大利亚大湾东部和最西部的地点，样本量太小，无法研究这些地区的遗传分化情况。总体遗传多样性为中度到低度，但在西澳大利亚的聚类中发现水平特别低。这一点需要在西澳大利亚的其他地点得到证实。在南澳大利亚，检测到了种群变化的特征，这可能是由于海湾后冰川期重新注水导致种群扩张引起的。西澳大利亚和南澳大利亚的聚类似乎是人口统计学上独立的单元。保护行动应侧重于在地方尺度上保护遗传多样性并维持栖息地的连通性。
