Espécies raras e seu papel na estruturação funcional de assembleias de peixes estuarinos tropicais

Abstract

Species rarity in estuaries is often related to the lack of distinct features that allow abundant species to explore the estuarine ecosystem despite its constant shifts in physical-chemical parameters throughout its dynamics. In this respect, it is expected that rare species would present different traits in comparison to abundant species. However, little is known about the functional role played by these species in these areas. Using two different scenarios of species loss (removal happening at random and from rarest to the most common species), we evaluated the contribution of rare species to the functional structure of estuarine fish assemblages in a tropical region. Our results show that although rare species play redundant functions in estuaries, these species have a crucial role in increasing niche differentiation within functional groups, enhancing response diversity inside groups and, hence, keeping key functions.