Laboratório de Ecologia Molecular e Parasitologia Evolutiva, Setor de Ciências Biológicas, Departamento de Zoologia, Universidade Federal do Paraná, Caixa Postal 19073, CEP 81531-980, Curitiba, PR, Brazil,
Parasitol Res. 2014 Feb;113(2):481-90. doi: 10.1007/s00436-013-3677-8. Epub 2013 Nov 13.
Using network analysis, we looked for broad patterns of distribution of Monogenoidea gill parasites on Neotropical freshwater fishes within a host phylogenetic framework. We analyzed a database of Monogenoidea parasitizing fishes from Neotropical rivers, from 23 watersheds, based on species descriptions published until 2011. Host-parasite interactions were organized into five matrices grouping species at different taxonomic levels. The network of interactions between host families and parasite genera was significantly modular and revealed that each fish order has a unique composition of parasite genera. Hence, interactions between lower taxa were analyzed separately for the largest fish orders (Perciformes, Siluriformes, and Characiformes). Networks tended to be loosely connected and organized in modules. Despite the putative high host specificity of monogenoids, some have a wider host range that includes distantly related host species. Among the hosts, the clade composed by the piranhas (Serrasalmus spp. and related species, Serrasalmidae) stands out in terms of parasite richness per host species, resulting in a more connected network. The history of the lineages of each host order within Neotropical freshwaters seems to have a great influence on the extent of parasite sharing. The observed modularity was influenced by both spatial structure and phylogenetic relatedness of species. In average, 37 % of modules of networks between host species and parasite genera were associated with a particular river basin and 63 % of modules were associated with a host family. Hence, spatial structure determines the co-occurrence of host and parasite species, but their evolutionary history is the main factor defining which interactions are possible.
利用网络分析，我们在宿主系统发育框架内，寻找新热带淡水鱼类单殖吸虫类鳃寄生虫的广泛分布模式。我们分析了一个新热带河流鱼类单殖吸虫数据库，这些寄生虫来源于 23 个流域，基于截至 2011 年出版的物种描述。宿主-寄生虫相互作用被组织成五个矩阵，将不同分类水平的物种分组。宿主科与寄生虫属之间的相互作用网络具有显著的模块性，表明每个鱼类目都有独特的寄生虫属组成。因此，对最大的鱼类目（鲈形目、鲇形目和脂鲤目）分别分析了较低分类群之间的相互作用。网络往往连接松散，组织成模块。尽管单殖吸虫类被认为具有高度的宿主特异性，但有些寄生虫的宿主范围更广，包括亲缘关系较远的宿主物种。在宿主中，由食人鱼（Serrasalmus spp. 和相关物种，锯脂鲤科）组成的分支在每个宿主物种的寄生虫丰富度方面表现突出，导致网络更加连接。每个新热带淡水鱼类目谱系的历史似乎对寄生虫共享的程度有很大影响。观察到的模块性受到物种的空间结构和系统发育关系的影响。平均而言，宿主种间和寄生虫属间网络的 37%模块与特定的流域有关，63%的模块与宿主科有关。因此，空间结构决定了宿主和寄生虫物种的共存，但它们的进化历史是确定哪些相互作用是可能的主要因素。
