Janet Higuti, Eliezer dO Conceição, Ramiro Campos, Vitor G Ferreira, Jonathan Rosa, Márian BdO Pinto, and Koen Martens (2017)
Periphytic community structure of Ostracoda (Crustacea) in the river-floodplain system of the Upper Paraná River
Acta Limnologica Brasiliensia, 29(120):17.
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.
Peer Review, Open Access, International Redaction Board
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