Mangroves are considered as ecosystems that provide shelter, food and breeding grounds for many groups of inhabiting fauna. Much of the fauna present are organisms in different stages of their life cycle, mostly juveniles. The three-dimensional structure of the mangrove roots and the combination of the aquatic and terrestrial environments are factors that bring together a great diversity. Such diversity within mangrove sites includes aquatic and terrestrial vertebrates and invertebrates such as fish, amphibians, reptiles, mammals and birds. Present within the fauna are representatives of different trophic guilds that perform key functions in the ecosystem, such as pollination, seed dispersal and nutrient recirculation. The food produced by the ecosystem is based on the production of detritus caused by leaf litter and its decomposition, where transformation of energy and accumulation of biomass for higher trophic levels begins with the invertebrates. With regard to breeding activity, many fish families spawn in the mangrove roots (e.g. Fundulidae), or nest in the canopy (herons and cormorants) that provides protection against predators and food for juvenile organisms. Undoubtedly, mangroves function as feeding and breeding grounds that are essential in maintaining populations of marine organisms, especially fish. Many fish species that grow in the mangroves are important for fisheries. Unequivocally, maintaining these breeding sites for marine and terrestrial fauna is crucial to the general functioning of adjacent ecosystems.