Biodiversity of non-marine ostracods (Crustacea, Ostracoda) in the alluvial valley of the upper Paraná River, Brazil

Abstract

In the present study, we test the relevance of a number of environmental factors on alpha and beta ostracod diversities, at species and family level. Ostracods were sampled from several substrates, including sediment and root systems of various floating aquatic macrophytes, from 48 environments (both lentic and lotic habitats, ranging from the river itself, over connecting channels linking with open lakes, and, finally closed lakes), belonging to four different systems (Paraná, Ivinheima, Baía and Taquaruçu), in the alluvial valley of the Upper Paraná River. The faunistic survey recorded the presence of 54 species of Ostracoda, belonging to the families Cyprididae, Candonidae, Limnocytheridae and Darwinulidae. Various diversity estimators indicated that these recorded levels of specific diversity should be close to true values. Higher values of ostracods species richness (alpha diversity) were observed in the Baía and Ivinheima systems, while lotic habitats were richer than lentic ones. In addition, open lakes appeared to be more affected by the variable 'system' than closed ones, which can to some extend be explained by the putative effects of flood pulse on benthic communities. The two investigated factors have different effects on the four ostracod families. The present study also indicated that there is a large homogeneity within and between systems, as exemplified by the low beta-diversity levels.Keywords: Ostracoda, diversity, floodplain, Paraná River, South America. Biodiversidade de ostrácodes (Crustacea, Ostracoda) no vale aluvial do Alto Rio Paraná, Brasil ResumoNo presente estudo foi testada a relevância de fatores ambientais sobre a diversidade alfa e beta de ostrácodes, bem como, sobre a diversidade de um nível taxonômico mais elevado (família sity of Brazilian floodplain. Besides, we test for the relevance of environment type and fluvial system on alpha and beta ostracod diversities, as well as on a higher level taxonomic diversity (family). Material and Methods Study areaThe Upper Paraná River consists of a large braided channel, with an extensive floodplain and high sediment accumulation in its bed, creating sand bars and islands of diverse sizes . The floodplain, apart from the main channel of the Paraná River, comprises several secondary channels, lakes and tributaries (including Ivinheima and Baía Rivers) (Agostinho et al., 2007). Further away from the main channel, and not connected to it, is the Taquaruçu system which comprises exclusively closed lakes (Souza Filho and Stevaux, 2004) (Figure 1). Field sampling and laboratory analysisOstracods were collected during March, July and November of 2004 throughout the alluvial valley of the Upper Paraná River. In total, 132 samples from 48 environments were collected. These were divided over 4 fluvial systems (Paraná, Ivinheima, Baía and Taquaruçu) and 5 environment types (closed lake, open lake, river, channel and stream).Ostracods were sampled using a rectangular net (28 × 14 cm, mesh size c 160 µm) hauled close to sediment-water interfac...

The genus Chlamydotheca Saussure (Crustacea: Ostracoda) in northeastern Argentina

“…Remarks: Chlamydotheca iheringi was recorded in Río Grande do Sul, Brazil (Higuti et al, 2009). It also has been recorded in temporary ponds in Buenos Aires province (Laprida, 2006).…”

Checklist de ostrácodes (Crustacea, Ostracoda) dulcícolas do Pantanal Sul Mato-grossense, Brasil

“…Entre os crustáceos de água doce, cladóceros e copépodos têm sido relativamente bem explorados em nosso país, tanto em termos ecológicos como em estudos sobre taxonomia. Por outro lado, a despeito de os ostrácodes serem abundantes na maioria dos corpos de água, ainda existem poucos estudos em ambientes aquáticos continentais brasileiros (Würdig & Freitas, 1988;Higuti, 2006;Higuti et al, 2007Higuti et al, , 2009bHiguti et al, , 2010Miranda, 2008;Mormul et al, 2010;Pereira, 2010;Matsuda, 2011;Chaves 2012;Matsuda et al 2015a,b;Higuti & Martens, 2016).…”

“…As recentes adições à fauna brasileira de ostrácodes realizadas nos estados do Rio Grande do Sul (Würdig & Pinto, 2001); São Paulo (Pinto et al, 2003(Pinto et al, , 2004(Pinto et al, , 2005a(Pinto et al, ,b, 2008 e Paraná/Mato Grosso do Sul (Higuti et al, 2009a;Higuti & Martens, 2012a, b, 2014, Higuti et al, 2013 elevaram esse número para 117 espécies em 37 gêneros. No entanto, novos gêneros e novas espécies ainda aguardam descrições nos diferentes ambientes (Higuti, 2006;Pinto, 2007;Higuti et al, 2009bHiguti et al, , 2010. No Apêndice I consta a lista de espécies de ostrácodes de água doce registradas no Pantanal Sul Mato-grossense.…”

Five new species of Candoninae (Crustacea, Ostracoda) from the alluvial valley of the Upper Paraná River (Brazil, South America)

“…The collections made to study the ecology of the ostracods in the pleuston in the alluvial valley of the Upper Paraná River (Higuti et al 2007(Higuti et al , 2009b(Higuti et al , 2009cMormul et al 2010) also served for taxonomic revisions and several new species and genera of ostracods have meanwhile been described from lakes, river beds and channels of this floodplain (Higuti et al 2009a(Higuti et al , 2013Higuti & Martens 2012a, 2012b. Most of these new taxa belong to the family Cyprididae; only one paper thus far treated two species of Candonidae from this floodplain in detail (Higuti & Martens 2012b), describing a new genus and species, Candobrasilopsis rochai Higuti & Martens, 2012, and redescribing and generically transferring another species, Candobrasilopsis brasiliensis (Sars, 1901).…”

“…Close to 300 of these species have been described and reported from South America and more than 100 species are now known from Brazil (Martens & Behen 1994;Higuti et al 2009aHiguti et al , 2013Higuti & Martens 2012a, 2012b. Recent work on the alluvial valley of the Upper Paraná River (Higuti et al 2007(Higuti et al , 2009b(Higuti et al , 2009cMormul et al 2010) has contributed significantly to the general knowledge of ecology and biogeography of Brazilian freshwater ostracods, especially those occurring in the pleuston of floating plants. Floating plants such as species in the genera Eichhornia, Pistia and Salvinia are typical of South American (floodplain) lakes, and pleuston, the animal communities living in the root systems of such plants, are thus typical of such lakes.…”