Diversification in ancient Lake Biwa: integrative taxonomy reveals overlooked species diversity of the Japanese freshwater snail genus Semisulcospira (Mollusca: Semisulcospiridae)
Diversification in ancient Lake Biwa: integrative taxonomy reveals overlooked species diversity of the Japanese freshwater snail genus Semisulcospira (Mollusca: Semisulcospiridae)
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DOI：
10.1163/18759866-bja10035
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发表时间：
2022-08
影响因子：
2.2
通讯作者：
Naoto Sawada;Yusuke Fuke
中科院分区：
文献类型：
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作者：
Naoto Sawada;Yusuke Fuke
日本古代琵琶湖淡水螺属半沟螺属已适应性辐射。尽管日本半沟螺的壳形态存在显著的地理变异，但其系统分类仍不确定。本文对S. niponica及其同源属S. biwae和S. fuscata通过形态学和遗传学研究。全基因组snp s被用来估计他们的遗传关系。随机森林算法探索了命名类型和新收集的标本的贝壳的形态变化。我们的研究结果检测到5个遗传簇，并揭示了成年壳形态与遗传关系的一致性，加强了基于壳形态的属种划分的鲁棒性。目前的系统学将S. biwae隶属于S.尼波尼卡。这5个遗传簇分别对应于两个已描述的种S. niponica和S. fuscata和3个新种，即渡部半沟螺Semisulcospira watanabei sp. nov.，nov.中野半沟螺，和Salebrosa半沟螺（Semisulcospira salebrosa sp. nov.）尼波尼卡。所观察到的相似性基板的偏好和物种之间的分布格局的差异表明，地理隔离后，最初的生态位分化加速了该属的多样化。我们认为，半沟螺种的分布可能受到它们之间的竞争排斥的影响，并且多个物种形成事件以类似的模式发生。
The freshwater snail genus Semisulcospira has adaptively radiated in the ancient Lake Biwa, Japan. Although significant geographical variations have been known in the shell morphology of Semisulcospira niponica, their systematics remain uncertain. We evaluated the systematic status of the geographical variations in S. niponica and its congenerics S. biwae and S. fuscata through morphological and genetic investigations. Genome-wide snp s were used to estimate their genetic relationships. Random Forest algorithms explored the morphological variation of the shells of the name-bearing types and newly collected specimens. Our results detected five genetic clusters and revealed the consistency of adult shell morphology with genetic relationships, reinforcing the robustness of shell morphology-based species delimitation of the genus. The present systematics synonymized S. biwae under S. niponica. The five genetic clusters corresponded to the two described species, S. niponica and S. fuscata, and three new species, Semisulcospira watanabei sp. nov., Semisulcospira nakanoi sp. nov., and Semisulcospira salebrosa sp. nov. discovered among the geographical variations of S. niponica. The observed similarities in substrate preference and differences in distribution patterns among species suggest that the diversification of the genus was accelerated by geographical isolation after the initial ecological niche differentiation. We suggest that the distributions of Semisulcospira species may have been influenced by competitive exclusion among them, and that multiple speciation events have occurred in similar patterns.