Periphytic community structure of Ostracoda (Crustacea) in the river-floodplain system of the Upper Paraná River

Abstract

Cite as: Higuti, J. et al. Periphytic community structure of Ostracoda (Crustacea) in the river-floodplain system of the Upper Paraná River. Acta Limnologica Brasiliensia, 2017, vol. 29, e120. Abstract: Aim:We assessed the effect of environmental factors on the structure of periphytic ostracods communities along the river-floodplain system of the Upper Paraná River. We predict that the higher distance from Porto Primavera dam downstream would lead to higher diversity and density of the ostracods. Methods: Periphytic ostracods (associated with root systems of the floating Eichhornia spp) were sampled during November 2013 to May 2015. Three samples were collected at each sampling site (channel of the Paraná River, tributaries and lakes). Eichhornia plants were removed from the water by hand and the plants were placed in a plastic bucket. Roots were washed for the removal of ostracods, and samples were filtered through a hand net with 160 µm mesh size. Results: The faunistic survey recorded 44 ostracods species and richness estimators indicated that sampling effort appears to be suitable to reveal the diversity of ostracods in this studied area. The highest richness and density were observed in the stretch downstream of the dam in the main channel of Paraná River and in the lakes. Beta diversity was not significantly different along the longitudinal gradient downstream and higher similarity of ostracods species composition was observed in the lakes located in the stretch downstream of the dam. Conclusions: An increase in the richness and density of ostracods were recorded in the sections downstream of the Paraná River, evidencing the importance of undammed tributaries on the ostracods community. The similarity of beta diversity amongst sampling sites may be owing to permanent hydrological connectivity amongst these environments, favouring the exchange of organisms mainly through the drift of free-floating macrophytes, and owing to the passive dispersal of drought resistant eggs of ostracods. Local abiotic factors had significant effects on abundance and distribution of some ostracod species.

Geodiversity primarily shapes large-scale limnology and aquatic species distribution in the northern Neotropics

“…Comparatively, in South America, in flood plains of the Upper Parana River, species richness can be as high as 44 species (Higuti et al, 2017), interannually in this same system have been observed 38 species (Higuti et al, 2020), which is higher than that in lakes of Central America and comparable to richness of lakes in temperate regions. In Colombian aquatic systems, however, such as La Fé reservoir (Saldarriaga and Martínez, 2010) and River Magdalena basin (Roessler, 1990a, b) the number of species is again similar than that in Central America (⁓6 species per lake).…”

Geodiversity influences limnological conditions and freshwater ostracode species distributions across broad spatial scales in the northern Neotropics

“…Although we do not intend to deeply evaluate taxonomic and ecological aspects for the northern Neotropical ostracodes in this study, we detected low species richness in the study area compared to that in South America and Europe. In the flood plains of the Upper Parana River, South America, species richness can be as high as 44 (Higuti et al, 2017), whereas in Europe, a single lake may host 32 species (Sluys, 1981;Lorenschat et al, 2014). This pattern may be influenced by sampling effort, as sampling sites did not always cover the lake extent.…”

Species' traits and taxonomic distance can predict the hatching phenology of ostracod (Crustacea) resting eggs from tropical floodplain lakes

“…Freshwater ostracods are commonly found in temporary ponds and lakes, and their populations survive drought periods by producing resting eggs (Higuti et al, 2017;Rosa et al, 2021;Williams, 2006).…”