Knowing how cave lithology influences the benthic macroinvertebrate fauna is important for conservation and management of subterranean aquatic systems. However, those influences are still poorly understood, especially in the Neotropics. This study aimed to understand how cave lithology can influence benthic EPT assemblages by assessing the differences in the EPT genera structure in caves of two distinct lithologies (quartzite and limestone) and determining possible differences in the lithology habitats. To achieve this, hydrochemistry data and biological samples were collected in six allogenic cave streams from the two aforementioned lithologies. Results showed that both the assemblages from different lithologies and within the same lithology are statistically different, thus indicating probable regional influences beyond local ones. Our results also pointed out an effect of lithology on the substrate parameters, which in turn affected the EPT composition. Cave lithology affects water chemical and physical characteristics, thus supporting different EPT assemblages. The results of this study provide a foundation for future investigation on how the lithology can influence the benthic macroinvertebrate fauna and should lead to means of predicting such fauna on the basis of the cave lithology and water chemistry.

了解洞穴岩性如何影响底栖大型无脊椎动物群对于保护和管理地下水生系统非常重要。然而，这些影响仍然知之甚少，尤其是在新热带地区。本研究旨在通过评估两种不同岩性（石英岩和石灰岩）洞穴中 EPT 属结构的差异并确定岩性栖息地的可能差异，了解洞穴岩性如何影响底栖 EPT 组合。为了实现这一目标，从上述两种岩性中收集了六个同种异体洞穴流中的水化学数据和生物样品。结果表明，来自不同岩性和同一岩性内的组合在统计上是不同的，因此表明可能存在超出局部影响的区域影响。我们的结果还指出了岩性对基底参数的影响，这反过来又影响了 EPT 组成。洞穴岩性影响水的化学和物理特性，从而支持不同的 EPT 组合。这项研究的结果为未来研究岩性如何影响底栖大型无脊椎动物群提供了基础，并应导致基于洞穴岩性和水化学预测此类动物群的手段。