This project will investigate the influence of the quality, quantity and diversity of basal energy inputs on the biodiversity, structure and functionality of food webs in rivers with an underground path. The study will compare the influence of macronutrient (C, N and P) stocks in basal resources and their subsequent uptake by consumers on the characteristics of a river travelling through a cave. Important structural and functional changes are expected, as well as a decrease in biodiversity in direct proportion to the decrease in resource quality, quantity and diversity as the river flows through the cave. This decrease in basal energy is also expected to affect the mass of nutrients transferred between trophic levels, consumer homeostasis and secondary production. The decrease in the quality, quantity and diversity of basal resources will equally induce a simplifying effect on the architecture of the food web compared to the surface sectors, explaining the biodiversity of cave rivers. These aspects will include lower specific richness, increased overlap of trophic niches, increased omnivory of consumers, but also increased intraspecific competition for food compared to the surface sector. A