Data from: High stakes species delimitation in eyeless cave spiders (Cicurina, Dictynidae, Araneae) from central Texas

A remarkable radiation of completely eyeless, cave-obligate spider species (Cicurina) has been described from limestone caves of Texas. This radiation includes over 50 described species, with a large number of hypothesized single-cave endemics, and four species listed as US Federally Endangered. Because of this conservation importance, species delimitation in the group is “high stakes” - it is imperative that species hypotheses are data-rich, objective, and robust. This paper focuses on a complex of four cave-dwelling Cicurina distributed on the northwestern edge of Austin, Texas. Several of the existing species hypotheses in this complex are weak, based on morphological comparisons of small samples of adult female specimens; one species description (for C. wartoni) is based on a single adult specimen. Species limits in this group were newly assessed using morphological, mitochondrial, and nuclear DNA sequence data evidence, analyzed using a variety of approaches. All data support a clear lineage separation between C. buwata versus the C. travisae complex (including C. travisae, C. wartoni, and C. reddelli). Observed congruence across multiple analyses indicate that the C. travisae complex represents a single species, and the formal species synonymy presented here has important conservation implications. The integrative framework utilized in this study serves as a potential model for other Texas cave Cicurina, including US Federally Endangered species. More generally, this study illustrates how and why taxon-focused conservation efforts must prioritize modern species delimitation research (if the existing taxonomy is weak), before devoting precious downstream resources to conservation efforts. The study also highlights the issue of taxonomic type II error that diversity biologists increasingly face as species delimitation moves into the genomics era.

得克萨斯州石灰岩洞穴中已报道过一类极为特殊的演化辐射类群——完全无眼的专洞栖卷叶蛛属（Cicurina）蜘蛛。该演化辐射类群包含50余个已描述物种，存在大量推测的单洞特有种，另有4个物种被列为美国联邦濒危物种。鉴于其极高的保护价值，该类群的物种界定工作堪称“高风险任务”：构建具备充足数据支撑、客观且可靠的物种假说至关重要。本研究聚焦于分布于得克萨斯州奥斯汀市西北边缘的4个洞穴栖居卷叶蛛属物种复合体。该复合体中数个现有物种假说依据不足，仅基于少量成年雌性标本的形态比较；其中C. wartoni的物种描述仅基于单头成年标本。研究人员通过多种分析方法，整合形态学、线粒体DNA及核DNA序列数据，重新评估了该类群的物种界限。所有数据均表明，C. buwata与C. travisae物种复合体（包含C. travisae、C. wartoni及C. reddelli）之间存在清晰的谱系分化。多项分析结果的一致性证实，C. travisae复合体实为单一物种，本文正式提出的物种同物异名处理方案具备重要的保护学意义。本研究采用的整合研究框架，可为得克萨斯州其他洞穴卷叶蛛类群（包括美国联邦濒危物种）提供参考范式。总体而言，本研究阐明了为何以类群为核心的保护工作，若现有分类体系存在缺陷，必须优先开展现代物种界定研究，再将宝贵的后续资源投入保护行动。此外，本研究还凸显了生物多样性学家在物种界定迈入基因组学时代时，日益面临的分类学II类错误问题。