Steindachnerina nigrotaenia is resurrected from the synonym of S. brevipinna and considered a valid species. The previous designation of the lectotype of S. nigrotaenia is considered invalid and a new lectotype is designated herein. Steindachnerina nigrotaenia and S. insculpta are redescribed based on ty...
Schizodon dissimilis is redescribed on the basis of syntypes and non-type specimens from the Parnaíba, Jaguaribe and Mearim rivers, and lectotype and paralectotypes are designated. Schizodon dissimilis is distinct from the Amazonian and southeastern Brazil congeners by having four dark brown vertical ba...
Brycon orbignyanus is an endemic species from La Plata basin whose stocks have been presenting significant reductions throughout the Paraná River. Brycon orbignyanus is categorized as an endangered species. This study evaluated aspects of the bio-ecology of this species that may be related to this threa...
Ontogenetic development of the tetra Astyanax lacustris was studied under laboratory conditions. Larvae obtained by induced reproduction were maintained individually in tissue-culture plates, at 25°C. Daily observations and morphometric measurements were performed. Larvae hatched with a total length (TL...
The mucous cells (MC) of traíra, Hoplias malabaricus, and jeju, Hoplerythrinus unitaeniatus, two ecologically distinct erythrinid species, were analyzed in fish exposed to deionized (DW) and high ion concentration (NaCl and Ca2+) water (HIW) during 15 days to evaluate the MC responses to ion challenge. ...
Spermatozoa and spermiogenesis ultrastructure were studied in the serrasalmine species Piaractus mesopotamicus, Mylossoma duriventre, Serrasalmus maculatus, and Metynnis mola and two distinct patterns may be recognized: the first common to Mylossoma, Serrasalmus and Metynnis, and the other, characteristi...
The Paraná-Paraguay basin encompasses central western Brazil, northeastern Paraguay, eastern Bolivia and northern Argentina. The Pantanal is a flooded plain with marked dry and rainy seasons that, due to its soil characteristics and low declivity, has a great water holding capacity supporting abundant f...
The species Hoplias malabaricus is a predator fish found in nearly all cis-Andean basins. From a cytogenetic point of view, this species comprises, at least, seven differentiated karyomorphs. Several localities have been formerly analyzed in Brazil, however, some regions, such as Bahia State, remain unde...
