Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park, Johannesburg, 2006, South Africa.
Centre for Aquatic Genomics, Forensics and Bioinformatics, Kenya Marine and Fisheries Research Institute, P.O. Box 81651-80100, Mombasa, Kenya.
Sci Rep. 2021 Feb 18;11(1):4205. doi: 10.1038/s41598-021-83754-4.
Historical demographic events shape genetic diversity that remains evident in the genomes of contemporary populations. In the case of species that are of conservation concern, this information helps to unravel evolutionary histories that can be critical in guiding conservation efforts. The Knysna seahorse, Hippocampus capensis, is the world's most endangered seahorse species, and it presently survives in only three estuaries on the South African south coast. Factors that contributed to the species becoming endangered are unclear; additionally, the lack of information on whether the three populations should be managed separately because of potential long-term isolation hampers effective management efforts. In the present study, we reconstructed the seahorses' demographic history using a suite of microsatellite loci. We found that the largest population (Knysna Estuary) has colonised the other estuaries relatively recently (< 450 years ago), and that its population size is comparatively large and stable. Neither of the other two populations shows signs of long-term reductions in population size. The high conservation status of the species is thus a result of its limited range rather than historical population declines. Our findings indicate that the long-term survival of H. capensis depends primarily on the successful management of the Knysna population, although the other estuaries may serve as reservoirs of genetic diversity.
历史人口事件塑造了遗传多样性，这种多样性在当代种群的基因组中仍然显而易见。对于受到保护关注的物种，这些信息有助于揭示进化历史，这对于指导保护工作至关重要。角海马（Hippocampus capensis）是世界上最濒危的海马物种，目前仅在南非南海岸的三个河口幸存。导致该物种濒危的因素尚不清楚；此外，由于长期隔离的潜在风险，缺乏关于三个种群是否应该分开管理的信息，这阻碍了有效的管理工作。在本研究中，我们使用一系列微卫星基因座重建了海马的种群历史。我们发现，最大的种群（Knysna Estuary）相对较近（<450 年前）才在其他河口殖民，其种群规模相对较大且稳定。另外两个种群都没有长期种群数量减少的迹象。因此，该物种的高度保护状况是由于其有限的分布范围，而不是历史上的种群减少造成的。我们的研究结果表明，角海马的长期生存主要取决于对 Knysna 种群的成功管理，尽管其他河口可能是遗传多样性的储备库。
