Laboratory of Insect Biosystematics, Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea.
Laboratory of Insect Phylogenetics and Evolution, Department of Plant Protection & Quarantine, Jeonbuk National University, Jeonju, Republic of Korea.
Sci Rep. 2022 Sep 15;12(1):15528. doi: 10.1038/s41598-022-18666-y.
Leptonetidae are tiny, rarely encountered spiders that mainly inhabit moist environments, such as caves, leaf litter, and rock piles. Because they are microhabitat specialists, most leptonetid species have short-range endemism, and rarely occur in sympatry. Their small size, relatively simple habitus features and reproductive organ structure increase the difficulty of identification. The identification of leptonetids and other spiders may also be time-consuming due to their sexual dimorphism, polymorphism, and lack of diagnostic characteristics in juveniles. DNA barcoding has been used as an effective tool for species identification to overcome these obstacles. Herein, we conducted a test of DNA barcoding based on 424 specimens of Korean Leptonetidae representing 76 morphospecies. A threshold of 4.2% based on maximum intraspecific genetic divergence was estimated to efficiently differentiate the morphospecies. The species assignments tested by five species delimitation methods (ABGD, ASAP, GMYC, PTP, and bPTP) were consistent with the morphological identifications for only 47 morphospecies (61.8%), indicating many cases of cryptic diversity among the remaining morphospecies. Furthermore, sympatry in leptonetids, which are known to be rare, was revealed to be common in South Korea, especially in epigean species. Our results showed that sympatries within families, congeners, and intraclades potentially occur throughout the entire region of Korea.
瘦蛛科是一类体型微小、罕见的蜘蛛，主要栖息于潮湿环境中，如洞穴、落叶层和石堆。由于它们是微生境的专家，大多数瘦蛛科物种具有短距离特有性，很少发生同域现象。它们体型小，形态特征和生殖器官结构相对简单，增加了鉴定的难度。瘦蛛科和其他蜘蛛的鉴定可能也很耗时，因为它们存在性二态性、多态性和幼体缺乏诊断特征。DNA 条形码已被用作物种鉴定的有效工具，以克服这些障碍。在此，我们对代表 76 个形态种的 424 个韩国瘦蛛科标本进行了 DNA 条形码测试。基于最大种内遗传分歧估计的 4.2%的阈值可有效区分形态种。五种物种界定方法（ABGD、ASAP、GMYC、PTP 和 bPTP）测试的物种分配与形态鉴定仅一致 47 个形态种（61.8%），表明其余形态种存在许多隐存多样性。此外，瘦蛛科已知罕见的同域现象在韩国很常见，尤其是在地面物种中。我们的结果表明，在整个韩国地区，科内、同属种和内群之间的同域现象可能普遍存在。
