Biodiversidade de comunidades zooplanctônicas em lagoas salinas e de água doce do Pantanal Sulmatogrossense: aspectos taxonômicos, funcionais e ecológicos

Abstract

In an ecosystem its main components, biotic and abiotic, operate and somehow together reach functional stability. Not only the water body is the local where communities live, but these also transform the environment in what it is, making each aquatic ecosystem unique, especially regarding interactions. The zooplankton is considered one of the main links between planktonic primary producers and consumers of higher trophic levels in the food webs of aquatic ecosystems. In the present study the taxonomical composition and functional diversity of zooplankton communities of six saline lakes and one freshwater lake of Nhecolândia, Pantanal, MS, Brazil. The saline lakes are extreme environments with high salinity and alkaline pH. Their zooplankton community had low richness of species and high population densities of resistant species as the rotifer Brachionus dimidiatus. In 2017 samplings, during dry season species richness was very low in saline lakes, with exception of saline lake SR07 with lowest salinity and pH, which had higher richness similar to that observed in all saline lakes sampled in the rainy periods of 2018 and 2019. Analysis of zooplankton functional diversity in saline lakes allowed the identification of 7 functional groups, being groups G1 (herbivorous littoral suspensivorous C with sexual reproduction) and group 7 (herbivorous pelagic suspensivorous C with asssexual reproduction) those including more species. Considering the small sizes of the water bodies studied the occurrence of seven functional groups is relevant. Gerente Bay, a freshwater lake in the same region had a diversified zooplankton community with 58 species (23 Rotifera, 28 Cladocera and 3 Copepoda), of common occurrence in Pantanal freshwaters. The life cycle of four species, Chydorus nitidulus, C. eurynotus, Macrothrix spinosa and Metacyclops mendocinus were studied in the laboratory. DNA barcode of three species of Cladocera, the first for zooplankton species of Pantanal were characterized, deposited in Genbank and compared with species from the Neotropical region and from other regions in the world.