Caecidae is a species-rich family of microsnails with a worldwide distribution. Typical for many groups of gastropods, caecid taxonomy is largely based on overt shell characters. However, identification of species using shell characteristics is problematic due to their rather uniform, tubular shells, the presence of different growth stages, and a high degree of intraspecific variability. In the present study, a first integrative approach to caecid taxonomy is provided using light-microscopic investigation with microsculptural analyses and multi-marker barcoding, in conjunction with molecular species delineation analyses (ABGD, haplotype networks, GMYC, and bPTP). In total 132 specimens of Caecum and Meioceras collected during several sampling trips to Central America were analyzed and delineated into a minimum of 19 species to discuss putative synonyms, and supplement the original descriptions. Molecular phylogenetic analyses suggest Meioceras nitidum and M. cubitatum should be reclassified as Caecum, and the genus Meioceras might present a junior synonym of Caecum. Meiofaunal caecids morphologically resembling C. glabrum from the Northeast Atlantic are a complex of cryptic species with independent evolutionary origins, likely associated with multiple habitat shifts to the mesopsammic environment. Caecum invisibile Egger & Jörger, sp. nov. is formally described based on molecular diagnostic characters. This first integrative approach towards the taxonomy of Caecidae increases the known diversity, reveals the need for a reclassification of the genus Caecum and serves as a starting point for a barcoding library of the family, thereby enabling further reliable identifications of these taxonomically challenging microsnails in future studies.

中文翻译：

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用条形码发现壳类游戏：来自中美洲的淡紫色食蟹科蜗牛（Truncatelloidea，Caenogastropoda）的多样性

ec科是一个物种丰富的微蜗牛家族，分布在世界各地。盲肠分类法在许多种类的腹足动物中很典型，主要基于明显的壳特征。但是，由于它们的外壳是相当均匀的管状外壳，存在不同的生长阶段以及高度的种内变异性，因此使用外壳特征识别物种是有问题的。在本研究中，通过光学显微镜研究，显微雕刻分析和多标记条形码技术，以及分子种类描述分析（ABGD，单倍型网络，GMYC和bPTP），提供了一种针对盲肠分类的第一个综合方法。在对中美洲的几次采样旅行中收集的总共132株盲肠和短尾猿标本进行了分析，并划定为至少19种，以讨论假定的同义词，并补充原始说明。分子系统发育分析表明，应将针叶小球藻和肘分枝杆菌重新归类为盲肠，并且，鞘翅目属可能是盲肠的初级同义词。形态上类似于东北大西洋的麦角镰孢的盲肠是复杂的隐性物种的复合体，它们具有独立的进化起源，可能与向中渗环境的多次生境转移有关。Caecum invisibile Egger＆Jörger，sp。十一月 基于分子诊断特征正式描述。这是对尾科分类法的第一个综合方法，增加了已知的多样性，