In ecology, interaction networks allow the investigation of how interactions among species affect community structure and functioning. The structure of interaction networks can be nested and/or modular. Ecologically, the nested structure minimizes competition and increases the number of coexisting species, creating high diversity, while the modular structure occurs when there are non-overlapping groups of highly interacting consumer-resource species. Despite the importance of gastropod shells to hermit crabs, currently, few studies explored the structure of hermit crabs communities through a resource-usage perspective. Therefore, network analyses appear as an important tool to unveil how the use of empty shell as a resource rules hermit crabs communities through competition among species and rules hermit crabs populations through competition among distinct ontogenetic groups. This study investigated the resource usage pattern of empty gastropod shells by distinct ontogenetic stages of the hermit crab Calcinus tibicen from two different locations, using a network approach and the “Shell Adequacy Index” (SAI) analysis. The present results show that the interaction network between ontogenetic groups and gastropod shells was non-nested and modular and the SAI reflected the differences between males and ovigerous females in both locations, regarding shell size adequacy. We suggest that the modular structure may be a result of resource partitioning, which, in turn, is favored in habitats with a high degree of heterogeneity. The modular network structure may indicate habitat heterogeneity and resource partitioning. Future studies including other hermit crab species from the same areas should help determine how shells are partitioned interspecifically.

在生态学中，相互作用网络可以研究物种之间的相互作用如何影响群落结构和功能。交互网络的结构可以是嵌套的和/或模块化的。从生态上讲，嵌套结构最大程度地减少了竞争并增加了共存物种的数量，从而创造了高度的多样性，而模块化结构则是在存在高度相互作用的消费资源物种的不重叠组时发生的。尽管腹足动物的贝壳对寄居蟹很重要，但目前很少有研究通过资源利用的角度探讨寄居蟹的群落结构。因此，网络分析似乎是揭示使用空壳资源如何通过物种之间的竞争来统治寄居蟹社区以及如何通过不同个体发育群体之间的竞争来统治寄居蟹种群的重要工具。本研究通过寄居蟹不同的发育阶段研究了空腹足纲贝壳的资源利用模式使用网络方法和“壳牌充足指数”（SAI）分析，从两个不同位置提取出的Calcinus tibicen。目前的结果表明，个体发育群体和腹足动物壳之间的相互作用网络是非嵌套的和模块化的，SAI反映了在壳大小适当性方面，两个位置的雄性和雌性雌性之间的差异。我们建议模块化结构可能是资源分配的结果，而资源分配又反过来在具有高度异质性的栖息地中受到青睐。模块化网络结构可以指示栖息地异质性和资源划分。未来的研究包括来自同一地区的其他寄居蟹物种，应有助于确定贝壳如何进行种间分配。