Local Hotspots of Endemism or Artifacts of Incorrect Taxonomy? The Status of Microendemic Pill Millipede Species of the Genus Glomeris in Northern Italy (Diplopoda, Glomerida)

Local endemic species with their unique evolutionary history always stirred the interest of scientists. One such area especially rich in endemics is northern Italy. In case of pill millipedes of the genus Glomeris Latreille, 1803, only a single species is found in northern Europe, while 22 country-endemics alone are known from Italy. Many of these endemics, however, have not been studied in several decades; therefore we aimed to determine whether this diversity is the result of overlooked synonymies or natural processes. A focus was placed on the local endemics that are in some aspects morphologically similar to the widespread and variable G. klugii Brandt, 1833. The local endemics Glomeris larii Verhoeff, 1921, G. primordialis Verhoeff, 1930, G. oblongoguttata Verhoeff, 1894, G. oropensis Verhoeff, 1936, G. transalpina Koch, 1836, G. romana Verhoeff, 1900, G. ligurica Latzel, 1884 and G. apuana Verhoeff, 1911 were included in a molecular analysis incorporating ribosomal nuclear (28S) and mitochondrial (COI) genes. Individuals were sequenced and compared to 31 specimens from 18 localities of G. klugii. The final dataset included 657 base pairs for 56 terminals in the COI, and 14 terminals with 1068 base pairs in the combined 28S and COI analysis. Our analysis shows intraspecific distances of up to 5% in the COI gene in G. klugii that are not strictly correlated to geography or color pattern. G. larii is discovered to be genetically and morphologically identical to G. klugii and is synonymised with the latter. Interspecific distances in our dataset vary between 6.7 to 15.9%, with the lowest (6.7–9.0%) between G. primordialis and G. klugii. Our analysis confirms the species status of the local endemics G. primordialis, G. oblongoguttata, G. oropensis, G. transalpina, G. ligurica and G. apuana. We also confirm the synonymy of G. undulata Koch, 1844 under G. klugii. G. genuensis Latzel, 1886 is indistinguishable from G. ligurica.

拥有独特演化历史的地方特有物种始终备受科学家关注。物种特有性尤为丰富的区域之一当属意大利北部。以1803年拉特雷伊尔（Latreille）定名的球马陆属（Glomeris）丸马陆为例，北欧仅分布有1个该属物种，而意大利一国已知的国家特有种就多达22种。然而其中多数特有物种已有数十年未被系统研究，因此本研究旨在探明这类物种多样性究竟源于被忽视的同物异名，还是自然演化过程的产物。我们重点关注了在部分形态特征上与广布且具形态变异的G. klugii Brandt, 1833相似的地方特有种。本研究将以下地方特有种纳入分子分析：Glomeris larii Verhoeff, 1921、G. primordialis Verhoeff, 1930、G. oblongoguttata Verhoeff, 1894、G. oropensis Verhoeff, 1936、G. transalpina Koch, 1836、G. romana Verhoeff, 1900、G. ligurica Latzel, 1884以及G. apuana Verhoeff, 1911，分析涵盖核核糖体（28S）与线粒体（COI）基因。研究人员对个体样本进行测序，并与采自18个样点的31份G. klugii标本进行比对。最终数据集包含56个终端分类单元的COI基因序列（长度为657碱基对），以及14个终端分类单元的28S与COI基因联合序列（长度为1068碱基对）。分析结果显示，G. klugii的COI基因存在最高达5%的种内遗传距离，且该距离与地理分布或体色模式并无严格关联。研究发现G. larii在遗传与形态特征上均与G. klugii完全一致，因此将其归为后者的同物异名。本数据集的种间遗传距离介于6.7%至15.9%之间，其中G. primordialis与G. klugii之间的遗传距离最低（6.7–9.0%）。分析结果证实了G. primordialis、G. oblongoguttata、G. oropensis、G. transalpina、G. ligurica以及G. apuana这些地方特有种的物种独立地位。本研究同时确认G. undulata Koch, 1844为G. klugii的同物异名。G. genuensis Latzel, 1886与G. ligurica无法通过现有数据区分。