School of Biosciences, Cardiff University, Cardiff, UK.
Institute of Zoology, Zoological Society of London, London, UK.
Sci Rep. 2022 May 24;12(1):8740. doi: 10.1038/s41598-022-12422-y.
Erymnochelys madagascariensis is a Critically Endangered turtle endemic to Madagascar. Anthropogenic activity has depleted the wild population by 70% in the last century, and effective conservation management is essential to ensuring its persistence. Captive breeding was implemented to augment depleted populations in the southern part of Ankarafantsika National Park (ANP), when no genetic data were available for E. madagascariensis. It is unknown how much of the natural population's diversity is encapsulated in captivity. We used eight microsatellite loci and fragments of two mitochondrial genes to identify the genetic structure of E. madagascariensis in the wild. Captive bred turtles were compared with wild populations in order to assess the representativeness of this ex situ conservation strategy for ANP. Six microsatellite clusters, ten cytochrome b, and nine COI haplotypes were identified across wild populations, with high genetic divergence found between populations in two groups of watersheds. Captive bred individuals represent three out of six sampled microsatellite clusters found in the wild and just one mitochondrial haplotype, possibly due to genetic drift. To improve genetic representation, the strategy of frequent interchange between captive and wild breeders within ANP should be revitalised and, as originally planned, hatchlings or juveniles should not be released beyond ANP.
马达加斯加蛛网龟是一种极度濒危的龟，仅分布于马达加斯加。在上个世纪，人为活动使野生种群减少了 70%，因此有效的保护管理对于确保其生存至关重要。在安卡拉法特斯加国家公园（ANP）南部，由于缺乏马达加斯加蛛网龟的遗传数据，曾实施过圈养繁殖以补充已枯竭的种群。目前尚不清楚圈养种群中包含了多少自然种群的遗传多样性。我们使用了 8 个微卫星基因座和 2 个线粒体基因的片段，以确定野生马达加斯加蛛网龟的遗传结构。我们将圈养繁殖的龟与野生种群进行了比较，以评估这种圈养保护策略对 ANP 的代表性。在野生种群中发现了 6 个微卫星聚类、10 个细胞色素 b 和 9 个 COI 单倍型，两组流域的种群间存在高度的遗传分化。圈养繁殖的个体代表了在野外发现的 6 个微卫星聚类中的 3 个，以及仅 1 个线粒体单倍型，这可能是由于遗传漂变造成的。为了提高遗传代表性，应该恢复在 ANP 内频繁交换圈养和野生繁殖者的策略，并且按照最初的计划，不应将幼龟或幼龟释放到 ANP 之外。
