ABSTRACT
In the interstitial environment, the food web is simple, based on detritus and its decomposers, with a certain number of detritivorous consumers and some carnivores. In the surface environment, the basis of the food webs is more diversified, and three levels of consumers can be distinguished. The first is that of omnivores with a detritivorous or phytophagous tendency. The second are omnivore-carnivores, and the third strict carnivores. Fish are located at the top of the food webs. The functioning of ecosystems is generally understood through the study of energy flow and its distribution in the food webs. It involves knowledge of the cycling time of nutrients, carbon, nitrogen, phosphorus, and other elements assimilated by organisms and entering into the composition of their tissues, subsequently de-assimilated and mineralized. Energy flow is a basic canvas for the development of communities rather than just a limiting factor of their biomass and its production.
