Five new species of genus Astyanax Baird & Girard, 1854 from Rio Iguaçu, Paraná, Brazil (Ostariophysi, Characiformes, Characidae)

Abstract

This article concerns an inventory of the ichthyofauna from the main channel of the mid-Tocantins River and studies on fisheries in this region including an evaluation of activities from Colônia de Pesca Z-35 of Estreito and Carolina in Tocantins and Maranhão States, Brazil, during 1999 and 2000. This study includes taxonomy and fishery data obtained from field collections and from interviews with the fishermen, carried out in March and July of 2001. The systematic record and fishery data were obtained from the most common species of the ichthyofauna of the mid-Tocantins River. A critical examination of fish resources from this area allows us to conclude that the large commercial species have decreased in number and are qualitatively reduced in that area of Tocantins. This fact may be a result of breaking the main channel of Tocantins, first by the hydroelectric power dam of Tucurui, twenty years ago, followed by the formation of the hydroelectric reservoirs of Lageado, Peixe Angical and Serra da Mesa, that transformed the main channel of Tocantins into a successive cascade of reservoirs. Those events may perhaps modify the profile of the fish community in that area. The obtained data also permit an examination of fisheries in the area, providing an appraisal on forthcoming problems that will be faced by fishermen of Colônia de Pesca Z-35.

A new species of Astyanax (Ostariophysi: Characiformes: Characidae) from the upper rio Iguaçu basin, southern Brazil

“…Members of this clade were characterized by the presence of hooks on fin rays, absence of supraorbital, presence of two unbranched plus eight branched dorsal fin rays, and presence of four teeth in the inner premaxillary row. This clade was latter supported by molecular and morphological phylogenetic studies (Calcagnoto et al, according to Melo & Buckup (2006); A. burgerai (according to the original description in Zanata & Camelier, 2009); A. turmalinensis (according to Triques & Queiroz, 2010); and A.bifasciatus Garavello & Sampaio, 2010 (according to the original description). Among Bryconamericus species this variation was reported for B. pyahu Azpelicueta, Casciotta & Almirón (according to original description in Azpelicueta et al, 2003); B. orinocensis and B. singularis Román-Valencia (according to Román-Valencia et al, 2008), B. cf.…”

“…5), A. paranae sensu Eigenmann (1927) and A. gymnogenys may be assigned to both middle and upper portions of the river basin. Despite of this new information given by Garavello & Sampaio (2010), they did not make it clear if all type specimens of A. paranae from the rio Iguaçu are A. gymnogenys or just some. They also did not measure those specimens and did not left clear the reasons to take that decision.…”

“…Although Garavello & Sampaio (2010) did not indicate relationships among the species studied by them with existing species groups, analysis of specimens of A. serratus let us to allocate that species in the A. scabripinnis species complex. Otherwise, we had no access to specimens of A. gymnogenys during our studies, but we tentatively assign that species to A. scabripinnis species complex.…”

“…leonidas and A. troya & Garavello (2010) recently informed that part of the type specimens of A. paranae from Porto União da Vitória (actually Porto União and União da Vitória cities) and Serrinha were composed by specimens of A. gymnogenys. Once Serrinha is located in the upper rio Iguaçu basin, very close to the boundary of its upper and medium sections (25º35'55.9''S 49º42'45.0''W, Fig.…”

“…They also did not measure those specimens and did not left clear the reasons to take that decision. As Garutti & Britski (2000) restricted the type locality of A. paranae to Castro, rio Tibagi drainage, and Garavello & Sampaio (2010) did not inform the exactly number or size of comparative material analyzed by them, it is difficult to take any conclusions about the presence or synonymies of Astyanax paranae in the rio Iguaçu without examination of the original specimens studied by Eigenmann (1914Eigenmann ( , 1921Eigenmann ( , 1927.…”