Data from: Evolution of stenophagy in spiders (Araneae): evidence based on the comparative analysis of spider diets

Stenophagy (narrow diet breadth) represents an extreme of trophic specialization in carnivores, but little is known about the forces driving its evolution. We used spiders, the most diversified group of terrestrial predators, to investigate whether stenophagy 1) promoted diversification, 2) was phylogenetically conserved and evolutionarily derived state, and 3) was determined either by geographical distribution and foraging guild. We utilized published data on the prey of almost 600 species. Six categories of stenophagy were found: myrmecophagy, araneophagy, lepidopterophagy, termitophagy, dipterophagy and crustaceophagy. We found that the species diversity of euryphagous genera and families was similar to stenophagous genera and families. At the family level, stenophagy evolved repeatedly and independently. Within families, the basal condition was oligophagy or euryphagy. Most types of stenophagy were clearly derived: myrmecophagy in Zodariidae; lepidopterophagy in Araneidae; dipterophagy in Theridiidae. In contrast, araneophagy was confined to basal and intermediate lineages, suggesting its ancestral condition. The diet breadth of species from the tropics and subtropics was less diverse than species from the temperate zone. Diet breadth was lower in cursorial spiders compared to web-building species. Thus, the evolution of stenophagy in spiders appears to be complex and governed by phylogeny as well as by ecological determinants.狭食性（Stenophagy，即狭窄的食性宽度）是食肉动物营养特化的极端形式，但目前学界对推动其演化的驱动因素仍知之甚少。本研究以陆生捕食类群中多样性最高的蜘蛛为研究对象，旨在探究狭食性是否具备以下特征：1）促进物种分化；2）具有系统发育保守性且属于演化衍生状态；3）由地理分布与觅食功能群共同决定。本研究利用了已发表的近600种蜘蛛的猎物数据，共识别出6类狭食性类型：食蚁性、食蛛性、食鳞翅目性、食白蚁性、食双翅目性以及食甲壳类性。研究发现，广食性属与科的物种多样性与狭食性类群并无显著差异。在科的分类阶元上，狭食性经历了多次独立演化。在各科内部，祖先状态多为寡食性或广食性。多数狭食性类型均为明确的衍生状态：蚁蛛科（Zodariidae）的食蚁性、园蛛科（Araneidae）的食鳞翅目性以及球蛛科（Theridiidae）的食双翅目性均属此类。与之相反，食蛛性仅分布于基部与中间演化支系中，提示其为祖先状态。热带与亚热带地区蜘蛛物种的食性宽度多样性低于温带地区物种。游走型蜘蛛的食性宽度低于结网型蜘蛛。综上，蜘蛛狭食性的演化过程较为复杂，同时受系统发育与生态决定因素共同调控。