Patterns of species richness and composition of fish assemblages in streams of the Ivinhema River basin, Upper Paraná River

Abstract

AIM: The present study analyzed the spatial variation in fish species richness and composition in streams of the Ivinhema River basin, Upper Paraná basin, determining the relationship between local and regional descriptors of the fish assemblage organization; METHOD: From 2001 to 2011 we sampled 200 stream stretches, using different sampling methods. Local species richness and composition were analyzed using univariate and multivariate methods to detect patterns of variation in the fish assemblage organization; RESULTS: We identified 111 fish species in the streams, and estimated the occurrence of 117 fish species (CIα0.05 = 111 to 123) with lower species richness in headwater streams compared to the lower parts of the basin. The fish species recorded were predominantly of small size, and the mean size increased from the headwaters to the river mouth. The four most common species are widely distributed in the basin. However, 24 species are allocthonous to the Upper Paraná basin, and two species (Chaetobranchopsis australis and Apistogramma commbrae) are recorded here for the first time in the Upper Paraná basin. Altitude was the main determinant of local fish species richness and composition, and a discontinuity in assemblage organization (richness, composition, fish size) was detected at approximately 430 m a.s.l.; CONCLUSION: Streams of the Ivinhema River basin are inhabited mainly by small-sized fishes; and longitudinal variation, interacting with local characteristics, determines the fish assemblage patterns.

The fish fauna of the Jacaré-Guaçu River basin, Upper Paraná River basin

“…The existence of a higher floodplain area downstream the Gavião Peixoto Dam (Esguícero & Arcifa 2010b), and the free section downstream the Jacaré-Guaçu River confluence with the Tietê River (downstream the Ibitinga Dam), could support a higher number of fish species in that stretch. Another factor is that depth of the water body can positively influence the population size and the number of fish species (Súarez 2008), what was also observed in this study. Eutrophication and pollution affect negatively the fish fauna, what can be indicated by the negative correlation of fish diversity and water conductivity (Larkin & Northcote 1969, Bauer 1986, as observed in this study.…”

“…There is a clear difference between the fish fauna composition of habitats down-and upstream the dam, indicated by higher values of H' observed in the habitats downstream the dam, and a higher number of fish species captured in these habitats. According to some authors (Peres Neto et al 1995, Uieda & Barreto 1999, Súarez 2008, several ecological factors, such as food availability and habitat structure, can be responsible for the fish fauna composition and diversity. The existence of a higher floodplain area downstream the Gavião Peixoto Dam (Esguícero & Arcifa 2010b), and the free section downstream the Jacaré-Guaçu River confluence with the Tietê River (downstream the Ibitinga Dam), could support a higher number of fish species in that stretch.…”

Spatial distribution of fish assemblages along environmental gradients in the temporary ponds of Northern Pantanal, Brazil

“…Factors that influence the spatial distribution of fish species in streams (e.g., altitude, volume, flow and stream width: Oberdorff et al, 2001;Valério et al, 2007;Tondato and Súarez, 2010;Súarez et al, 2011) are different from those observed in floodplain ponds (Suarez et al, 2001(Suarez et al, , 2004. The composition of fish assemblages in temporary ponds of floodplains depends on multiple interactions with the environment: the occurrence of fish is uncommon during the isolation period because of drying out and limiting conditions (Baber et al, 2002) such as predation and competition for space (Okada et al, 2003).…”

“…In recent decades, several studies of the spatial organisation of fish assemblages have shown that ecological patterns vary depending on space (Jackson et al, 2001;Tejerina-Garro and Mérona, 2001;Valério et al, 2007;Súarez et al, 2011). This spatial variation can be determined by environmental characteristics and interactions among species, as advocated by the niche theory (Hutchinson, 1957;Chase and Leibold, 2003), or by stochastic processes through random combinations of colonisation, as assumed by the neutral theory (Hubbell, 2001).…”

Factors determining the structure of fish assemblages in an Amazonian river near to oil and gas exploration areas in the Amazon basin (Brazil): establishing the baseline for environmental evaluation

“…As well as many studies in the Neotropics (e.g., JUNK et al 1983, SAINT-PAUL & SOARES 1987, RODRÍGUES & LEWIS 1997, TEJERINA-GARRO et al 1998 SAINT-PAUL et al 2000, SÚAREZ et al 2001, HOEINGHAUS et al 2003, SIQUEIRA-SOUZA & FREITAS 2004, SÚAREZ et al 2004, 2011, FREITAS & GARCEZ 2004, FREITAS et al 2013, our results suggest that fish assemblages are influenced by seasonal variations and are ruled by the flood pulse, which causes changes in transparency, depth, water current velocity and dissolved oxygen. Although not detected evidence of environment changes associated to the activities of oil extraction, this study represents a baseline for future studies associated with evaluation of eventual or cronic environmental impacts in the area.…”