Variation of the ichthyofauna along the Goioerê River: an important tributary of the Piquiri-Paraná basin

Abstract

ABSTRACT. The construction of reservoirs is considered an important source of impacts on the fish fauna, severely altering the structure of the assemblage. This paper aimed to describe the structure of the fish assemblage of the Goioerê River, determining its longitudinal distribution and patterns of species dominance. The evaluation of its longitudinal variation in the diversity and abundance of the fish assemblage was conducted in July and October 2004 and January and May 2005. The collections were carried out near the headwaters (Gurucaia), middle stretch (Olaria), just above the falls (Paiquerê) and downstream (Foz). Forty-four species were captured. The Gurucaia fish assemblages differed significantly from Olaria, Paiquerê and Foz. The Olaria assemblages differed significantly from the Foz. Gurucaia showed the lowest diversity and abundance of species. Astyanax aff. paranae Eigenmann,1914 (78% of the total) was found to be dominant at this site. Almost the same species richness was found at Olaria and Paiquerê, although Olaria had the greatest abundance of individuals. Astyanax aff. paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 were the top three dominants and comprised over 71% of the total number of fish caught. At Paiquerê, Astyanax altiparanae, Hypostomus aff. ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 composed 58% of the catches. Thirty-one species were recorded at Foz, which presented the greatest richness. The most abundant species were Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A.altiparanae, which contributed to 50% of the total catches in this environment.These results record the fish biodiversity and how the community is longitudinally structured in the Goioerê River, and also demonstrate how this type of evaluation is important to understanding the fish community patterns and finding solutions to problems related to the conservation and management of the basin.

<b>Does riparian vegetation affect fish assemblage? A longitudinal gradient analysis in three Amazonian streams

“…A historical set of studies shows that the species diversity of streams increases from the source to the mouth (Vannote, Minshall, Cummins, Sedell, & Cushing, 1980;Poff & Allan, 1995;Matthews, 1998), because as the stream increases in size, it offers a variety of resources, shelters and physical conditions that favor the addition of species (Tos, Gomes, & Rodrigues, 2014). However, deforestation can lead to several changes in the structure and energy sources of streams (Allan, Erickson, & Fay, 1997;De Paula et al, 2013;Leal et al, 2016), directly or indirectly influencing the distribution of organisms along the longitudinal gradient (Perkin & Gido, 2012).…”

First record of Astyanax bifasciatus Garavello &amp; Sampaio, 2010 (Teleostei, Ostariophysi, Characidae) in the Piquiri river basin, upper Paran&aacute; river basin

“…Among those, the Piquiri river basin has the third largest drainage area, also with extensive stretches free of damming in the upper Paraná river basin (Affonso et al 2015;Cavalli et al 2018). Recent ichthyofaunistic inventories in Piquiri river basin recorded a high diversity of fishes (152 species), mainly represented by small species belonging to the Loricaridae and Characidae (Gubiani et al 2010;Delariva and Silva 2013;Dei Tos et al 2014;Cavelli et al 2018). However, those studies did not record A. bifasciatus.…”