Abstract:
Caves have long been recognized as a window into the mechanisms of diversification and convergent evolution, due to the unique conditions of isolation and life in the dark. These lead to adaptations and reduce dispersal and gene flow, resulting in high levels of speciation and endemism. The Israeli cave arachnofauna remains poorly known, but likely represents a rich assemblage. In a recent survey, we found troglophilic funnel-web spiders of the genus Tegenaria in 26 caves, present mostly at the cave entrance ecological zone. In addition, we identified at least 14 caves inhabited by troglobitic Tegenaria, which are present mostly in the twilight and dark ecological zones. Ten of the caves, located in the north and center of Israel, are inhabited by both troglophilic and troglobitic Tegenaria. These spiders bear superficial phenotypic similarities but differ in the levels of eye reduction and pigmentation. To test whether these taxa constitute separate species, as well as understand their relationships to epigean counterparts, we conducted a broad geographic sampling of cave-dwelling Tegenaria in Israel and Palestine, using morphological and molecular evidence. Counterintuitively, our results show that the troglobitic Tegenaria we studied are distantly related to the troglophilic Tegenaria found at each of the cave entrances we sampled. Moreover, seven new troglobitic species can be identified based on genetic differences, eye reduction level, and features of the female and male genitalia. Our COI analysis suggest that the Israeli troglobitic Tegenaria species are more closely related to eastern-Mediterranean congeners than to the local sympatric troglophile Tegenaria species, suggesting a complex biogeographic history.
摘要:
长期以来,洞穴一直被认为是了解多样化和趋同进化机制的窗口,由于黑暗中的孤立和生活的独特条件。这些导致适应并减少传播和基因流动,导致高水平的物种形成和特有性。以色列洞穴蛛形纲动物仍然鲜为人知,但可能代表了一个丰富的组合。在最近的一项调查中,我们在26个洞穴中发现了Tegenaria属的嗜水漏斗蜘蛛,主要出现在洞口生态区。此外,我们发现至少有14个洞穴居住着Tegenaria,主要存在于黄昏和黑暗的生态区。十个洞穴,位于以色列的北部和中心,居住着嗜血和嗜血的Tegenaria。这些蜘蛛具有表面的表型相似性,但不同的水平的眼睛减少和色素沉着。为了测试这些分类群是否构成单独的物种,以及了解他们与epigean同行的关系,我们对以色列和巴勒斯坦的洞穴住宅Tegenaria进行了广泛的地理采样,使用形态学和分子证据。反直觉,我们的结果表明,我们研究的TeganticTegenaria与在我们采样的每个洞穴入口处发现的Tegenaria密切相关。此外,根据遗传差异,可以鉴定出七个新的管壳物种,眼睛减少水平,女性和男性生殖器的特征。我们的COI分析表明,以色列的Tegenaria物种与东地中海同类物的关系比与当地的同胞Tegenaria物种的关系更密切,暗示了一个复杂的生物地理历史。