The species Moenkhausia australis was described based on two specimens from arroyos Trementina and Chagalalina, Rio Paraguai basin, Paraguay. Its taxonomic history is complex and for many years the species was considered a synonym of Moenkhausia sanctaefilomenae. Moenkhausia australis shares a reticulated color pattern with the Moenkhausia oligolepis/M. sanctaefilomenae complex, being more similar within the species included in the complex to M. oligolepis, M. sanctaefilomenae, and M. forestii, with which it shares a prepelvic region laterally compressed, a feature also observed in Bario steindachneri. The laterally compressed prepelvic region is inferred to be putatively synapomorphic for the subgroup herein denominated as Moenkhausia oligolepis group. Our results, based on both molecular and morphological data, support the validity of Moenkhausia australis, which can be readily distinguished from the other members of the group by possessing the following combination of characters: complete lateral line, 23–27 scales in the lateral line, and five scales series above and below the lateral line. Our analysis also indicates three genetic structured populations of M. australis, from Rio Paraguai, upper Rio Paraná, and Rio Madeira basins. Since they are not diagnosable by morphological characters, we conservatively maintain these three genetic lineages as a single species.

A new species of Hemigrammus is described from the upper Rio Negro, Amazon basin, Brazil. The new species is distinguished from all congeners by its unique color pattern consisting of a single humeral blotch clearly spaced from a conspicuous midlateral dark stripe, which extends from fifth or sixth anteriormost vertical scale row to the basis of the middle caudal-fin rays. Comments on its putative relationships are provided.

RESUMO:Os carnívoros são importantes componentes ecológicos dos ecossistemas, pois controlam a abundância, a distribuição e a diversidade das populações de suas presas. Desta forma, são considerados como espécies-chaves na manutenção e restauração da diversidade e da resiliência dos ecossistemas. Nesse grupo, a onça-parda (Puma concolor) é a espécie de mamífero silvestre mais amplamente distribuída do hemisfério ocidental, porém, suas exigências em tamanho de área de vida e alimentação mostram-se um fator de restrição para sobrevivência da espécie por fatores como pressão de caça, diminuição de presas e desmatamento. Este estudo teve como objetivo avaliar a dieta do P. concolor em uma paisagem silvicultural no Estado de São Paulo. A paisagem é formada pela presença de remanescentes de cerrado, plantações de eucalipto e áreas de pastagens. Para análise da dieta foram coletadas, triadas e analisadas 103 amostras de fezes de P. concolor. Os resultados indicam grande consumo de aves e mamíferos de pequeno porte, diferindo da alimentação da espécie em ambientes naturais onde os mamíferos são o principais itens alimentares. Esta variação na dieta confirma a onça-parda como predador generalista, que consume as presas disponíveis sem apresentar preferência por determinadas espécies.

The ribeirão Sucuri, a tributary of the rio Tietê, and part of the upper rio Paraná basin, is located in the municipality of Pongaí, São Paulo state. The ichthyofauna of ribeirão Sucuri was sampled at nine collection sites in May 2018. Our study captured 408 specimens representing five orders, 11 families, and 35 species. Among the species collected, two have not been previously reported from the rio Tietê basin: Eigenmannia guairaca Peixoto, Dutra & Wosiacki, 2015 and Hoplias misionera Rosso, Mabragaña, González-Castro, Delpiani, Avigliano, Schenone & Días de Astarloa, 2016. Additionally, four species were found that are non-native: Hoplias misionera, Poecilia reticulata Peters, 1859, Roeboides descalvadensis Fowler, 1932, and Satanoperca sp. This study represents the first fish inventory of a tributary on the left margin of the Tietê-Batalha sub-basin and only the second for this portion of the rio Tietê. Our results increase to 55 the number of species recorded from this sub-basin and add data on the putative morphological variation in several species.

The Neotropical family Heptapteridae comprises 228 valid species widely distributed in South America. Imparfinis is one of the most diverse genera of this family, with 25 valid species widely distributed, inhabiting streams from Costa Rica to Argentina. Old descriptions coupled with lack of recent systematic studies of the species of Imparfinis from the Upper Paraná river basin have led to a taxonomic impediment and hindered the advancement of studies in other areas, such as ecology, cytogenetic, phylogenetic, and evolution. We conducted the first integrative study analyzing both molecular and morphological data of Imparfinis from the Upper Paraná River basin. Our analyses strongly support the existence of four independent evolutionary lineages in this river system, three of them are the nominal species I. mirini, I. schubarti, and I. piperatus, and a new species from Goiás state described herein.

In the present study, we describe a new species of Neoplecostomus from central Brazil. The new species is known from Córrego Cachoeira a right tributary of the upper Rio Paraná basin. It can be distinguished from all congeners by absence of adipose fin or azygous plates on the dorsum surface of the caudal peduncle. Additionally, the new species differs from N. botucatu and N. paranensis by having a dark caudal fin with a unique v-shaped hyaline vertical area and a larger lower lip. A discussion on the morphological variation of adipose fin among species of Neoplecostomus is also provided.

In this study, a new species of Moenkhausia is described from the upper rio Juruena, rio Tapaj os basin, Brazil. It is distinguished from all congeners by the presence of minute bony hooks in all fins of both mature females and males and combination of a prepelvic region flattened, dorsal portion of the humeral blotch extending two scales horizontally and vertically, lateral line with 28-32 scales, five scale series above and below lateral line; circumpeduncular scales 13-14, anal-fin rays 16-19 and dorsal portion of eyes blue in live specimens. The new species is also supported by high divergence in the mitochondrial gene cytochrome c oxidase subunit I (COI). The presence of minute fin bony hooks in both females and males, population variations and late development of the lateral line in Moenkhausia andrica are discussed.