Barriers to gene flow in common seadragons (Syngnathidae: Phyllopteryx taeniolatus)

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• 作者：Nerida G. Wilson ; Josefin Stiller ; Greg W. Rouse
• 关键词：Bassian Isthmus ; Phylogeography ; Syngnathid ; Weedy seadragon
• 刊名：Conservation Genetics
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：18
• 期：1
• 页码：53-66
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Conservation Biology/Ecology; Ecology; Biodiversity; Evolutionary Biology; Plant Genetics & Genomics; Animal Genetics and Genomics;
• 出版者：Springer Netherlands
• ISSN：1572-9737
• 卷排序：18

文摘

The common seadragon is an iconic fish with presumed limited dispersal, because juveniles hatch directly from the tail of the male parent. Nothing is presently known of their phylogeographic structure, despite conservation concerns and a distribution spanning southern Australia. Here, we sequenced mitochondrial genes from 201 common seadragons in Western Australia, South Australia, Victoria, Tasmania and New South Wales. We show that common seadragon populations are highly structured geographically, and that genetic variation varies significantly. The historical Bassian Isthmus appears to have left a strong imprint on population structure. Populations east of the Bassian Isthmus are low in diversity and appear more connected than those in the west, although this is likely caused by a recent expansion from a common source after the Last Glacial Maximum. All individuals from Eden, Bicheno and Hobart are represented by only two haplotypes. Populations west of the Bassian Isthmus are more diverse, with the highest diversity indices shown by Western Australian and Spencer Gulf populations. A large sampling gap across the Great Australian Bight is yet to be resolved; the west versus east break here may be an artifact of this gap. Almost all sampled populations can be inferred to have limited gene flow among them, which has implications for recovery after local extinction. Populations thought to be in decline (Sydney, Hobart) showed low genetic diversity, which may make them vulnerable to further reductions.