The extinction of fish species can direct and indirectly affect many groups of associated species, among which parasite communities can be the most susceptible. However, the intensity of this effect depends on the structure interaction networks. This study evaluated whether networks constituted of fish ectoparasites or endoparasites differed in their robustness to the loss of host species and to what extent these potential differences are explained by the network structures. We used path models to evaluate the direct and indirect effects of host and parasite richness, connectance, and nestedness on the robustness of ecto- and endoparasite-based networks. In most cases, nestedness was the descriptor that best explained the robustness of the fish-parasite networks, and co-extinctions are less likely when the fish species act mainly as hosts of the generalist parasites. Both the richness of the host species and connectance in the networks have an essential indirect influence on robustness. Regardless of the extinction sequence, the ectoparasite-based networks showed higher vulnerability to host species loss when compared to endoparasite-based networks. These findings highlight the importance of considering both ecto- from endoparasites to better understand the structure and vulnerability of host–parasite networks.

中文翻译：

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外寄生虫比同时发生的内寄生虫更容易受到宿主灭绝的影响：来自淡水和海水鱼类后生寄生虫的证据

鱼类物种的灭绝可以直接和间接地影响许多相关物种，其中寄生虫群落可能最容易受到影响。然而，这种效应的强度取决于结构相互作用网络。这项研究评估了由鱼类外寄生物或内寄生物构成的网络在对宿主物种丧失的稳健性方面是否存在差异，以及网络结构在多大程度上解释了这些潜在差异。我们使用路径模型来评估宿主和寄生虫丰富度、连接性和嵌套性对基于体外和体内寄生虫的网络的稳健性的直接和间接影响。在大多数情况下，嵌套性是最能解释鱼类寄生虫网络稳健性的描述符，当鱼类主要作为通才寄生虫的宿主时，共同灭绝的可能性较小。宿主物种的丰富度和网络中的连接对稳健性有重要的间接影响。无论灭绝顺序如何，与基于内寄生虫的网络相比，基于外寄生虫的网络对宿主物种损失的脆弱性更高。这些发现强调了考虑体外寄生虫以更好地了解宿主 - 寄生虫网络的结构和脆弱性的重要性。与基于体内寄生虫的网络相比，基于体外寄生虫的网络对宿主物种损失的脆弱性更高。这些发现强调了考虑体外寄生虫以更好地了解宿主 - 寄生虫网络的结构和脆弱性的重要性。与基于体内寄生虫的网络相比，基于体外寄生虫的网络对宿主物种损失的脆弱性更高。这些发现强调了考虑体外寄生虫以更好地了解宿主 - 寄生虫网络的结构和脆弱性的重要性。