The evolutionary history of prey specialisation differs among spider species, particularly among active wandering species which have evolved a variety of prey-capture tactics. Here, we conducted a comparative analysis of prey specialisation and prey capture behaviour in Gnaphosidae. We used nine species each representing a different genus and investigated their acceptance of spiders and ants as prey, on which they may specialise, and their attack behaviour. Then we collected such data for another about 20 species from literature. The studied species used only either biting or silk (followed by biting) to constrain prey during attack. For each species, we measured selected morphological characteristics—specifically, the relative sizes of cheliceral fangs and spinnerets as well as the number of spigots on spinnerets—and related them to the ability to catch spiders (araneophagy) and ants (myrmecophagy) and mode of attack behaviour. We found the relative fang size to be significantly shorter for myrmecophagous species. Other traits were not related to prey specialisation or attack behaviour. They used silk particularly for larger prey. Use of silk was a conditional strategy in some species. We reconstructed the phylogenetic relationships among the studied genera using molecular and morphological data. We found that araneophagy was frequent but myrmecophagy was rare among recent taxa. Comparative analysis revealed that araneophagy is an ancestral state, while myrmecophagy was less likely and repeatedly lost. The use of silk for prey immobilisation was also as likely as unlikely for ancestors and has been repeatedly lost.

中文翻译：

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追踪地蛛科 Gnaphosidae 的营养特化和攻击行为模式的演变

猎物特化的进化史因蜘蛛物种而异，特别是在已经进化出各种猎物捕获策略的活跃游荡物种中。在这里，我们对 Gnaphosidae 的猎物专业化和猎物捕获行为进行了比较分析。我们使用了 9 个物种，每个物种代表一个不同的属，并调查了它们对蜘蛛和蚂蚁作为猎物的接受程度，它们可能专门针对它们，以及它们的攻击行为。然后我们从文献中收集了另外大约 20 个物种的此类数据。所研究的物种仅使用咬人或丝绸（随后是咬人）来限制攻击期间的猎物。对于每个物种，我们测量了选定的形态特征——特别是，螯肢和喷丝头的相对大小以及喷丝头上的龙头数量 - 并将它们与捕捉蜘蛛（食蛛）和蚂蚁（食蚁兽）的能力以及攻击行为模式相关联。我们发现食虫物种的相对尖牙大小明显更短。其他特征与猎物特化或攻击行为无关。他们特别使用丝绸来捕食较大的猎物。在某些物种中使用丝绸是一种有条件的策略。我们使用分子和形态学数据重建了研究属之间的系统发育关系。我们发现在最近的分类群中，araneophy 很常见，但 myrmecophagy 很少见。比较分析表明，食肉动物是一种祖先状态，而食肉动物的可能性较小且反复丢失。