Department of Mycology, Real Jardín Botánico, RJB-CSIC, Madrid, Spain.
Department of Veterinary Medical Sciences Alma Mater Studiorum, University of Bologna, Ozzano dell'Emilia, Italy.
PLoS One. 2023 Oct 13;18(10):e0292679. doi: 10.1371/journal.pone.0292679. eCollection 2023.
European crayfish species are a clear example of the drastic decline that freshwater species are experiencing. In particular, the native species of the Iberian Peninsula, the white clawed-crayfish (WCC) Austropotamobius pallipes, is listed as "endangered" by the IUCN and included in Annex II of the EU Habitat Directive and requires especially attention. Currently, implemented conservation management strategies require a better understanding of the genetic diversity and phylogeographic patterns, as well as of its evolutionary history. For this purpose, we have generated the largest datasets of two informative ribosomal mitochondrial DNA regions, i.e., cytochrome oxidase subunit I and 16S, from selected populations of the WCC covering its geographical distribution. These datasets allowed us to analyze in detail the (i) genetic diversity and structure of WCC populations, and (ii) divergence times for Iberian populations by testing three evolutionary scenarios with different mtDNA substitution rates (low, intermediate, and high rates). The results indicate high levels of haplotype diversity and a complex geographical structure for WCC in the Iberian Peninsula. The diversity found includes new unique haplotypes from the Iberian Peninsula and reveals that most of the WCC genetic variability is concentrated in the northern and central-eastern regions. Despite the fact that molecular dating analyses provided divergence times that were not statistically supported, the proposed scenarios were congruent with previous studies, which related the origin of these populations with paleogeographic events during the Pleistocene, which suggests an Iberian origin for these WCC. All results generated in this study, indicate that the alternative hypothesis of an introduced origin of the Iberian WCC is highly improbable. The result of this study, therefore, has allowed us to better understand of the genetic diversity, structure patterns, and evolutionary history of the WCC in the Iberian Peninsula, which is crucial for the management and conservation needs of this endangered species.
欧洲螯虾物种是淡水物种急剧减少的一个明显例子。特别是伊比利亚半岛的本地物种，白螯螯虾（WCC） Austropotamobius pallipes，被 IUCN 列为“濒危”物种，并被列入欧盟栖息地指令的附件 II，需要特别关注。目前，实施的保护管理策略需要更好地了解遗传多样性和系统地理学模式，以及它的进化历史。为此，我们从 WCC 的选定种群中生成了两个信息丰富的核糖体线粒体 DNA 区域（细胞色素氧化酶亚基 I 和 16S）的最大数据集，以覆盖其地理分布。这些数据集使我们能够详细分析（i）WCC 种群的遗传多样性和结构，以及（ii）通过测试三种具有不同 mtDNA 替代率（低、中和高速率）的进化情景，对伊比利亚种群的分歧时间。结果表明，伊比利亚半岛的 WCC 具有高水平的单倍型多样性和复杂的地理结构。发现的多样性包括来自伊比利亚半岛的新独特单倍型，并且表明大多数 WCC 遗传变异性集中在北部和中东部地区。尽管分子年代测定分析提供的分歧时间没有得到统计支持，但提出的情景与先前的研究一致，这些研究将这些种群的起源与更新世期间的古地理事件联系起来，这表明这些 WCC 起源于伊比利亚半岛。本研究产生的所有结果表明，伊比利亚 WCC 的引入起源的替代假设极不可能。因此，这项研究的结果使我们能够更好地了解伊比利亚半岛 WCC 的遗传多样性、结构模式和进化历史，这对于管理和保护这种濒危物种的需求至关重要。
