The Astyanax scabripinnis complex is composed of a large number of almost morphological indistinguishable species, including Astyanax paranae and Astyanax rivularis, which exist in the Paraná and São Francisco Basins, respectively, and sometimes are considered subspecies of the A. scabripinnis group or even are cited just as A. scabripinnis. The two river basins are separated by the Upper Paranaíba Arc, likely the main cause of the isolation of these species. We used geometric morphometric tools and DNA analyses of populations of both species to identify the differences between them. Geometric morphometrics separated the two species into distinct groups, whose main difference was the body depth. This is generally related to the speed of the water flow in the river basins. The maximum likelihood phylogram based on mitochondrial DNA sequences formed two main clades: one composed of the population of A. rivularis and the other, of A. paranae. In the haplotype network, the species were similarly separated into two groups from the same ancestral haplotype, with A. rivularis dispersing into two lineages in the São Francisco River Basin. The distribution of A. paranae is a consequence of a secondary dispersion event in the Paraná River Basin. It forms two lineages from a haplotype derived from the ancestor. The vicariant effect of separate basins, through the elevation of the Upper Paranaíba Arc, led to the allopatric speciation of the populations originating the present species. The results of geometric morphometrics and molecular data of the fish show the importance of this geological event in the biogeography and evolutionary history of the ichthyofauna of the region and indicate that the isolation of these species seems to be effective.

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The genus Psalidodon Eigenmann, 1911 (Characiformes Characidae) is a fish group with great diversity, expressed at the chromosomal, genetic and taxonomic level. The genus is markedby events of allopatric and vicariant evolution, by the formation of complexes of species andby wide geographical distribution. Both in these fish and other organisms, the association ofstudies with molecular markers and geometric morphometric techniques are useful in delimitingsignificantly evolutionary units (ESU). In this work, we performed maximum likelihood esti-mates (MLE) from mitochondrial Cyt b gene sequences and canonical variables (CVA) from13 landmarks in eight populations of P. aff. paranae Eigenmann, 1914. The analysis of Max-imum likelihood resulted in the structuring of populations in two different clades, one of whichwas composed only of individuals from a small population inhabiting a stream with approxi-mately two km of length, demonstrating their clear distinction from the other populations. Theanalysis of canonical variation demonstrated the complete structuring of this population, andthe position of each clade in the morpho-space was congruent with the topography observedin the MLE. Based on the results found, the existence of a new endemic species of the genusPsalidodon is evident.

Baird et Girard, 1854 (Teleostei Characiformes) is one of the most well characterized of the neotropical ichthyofauna and is composed of fish with great ability to adapt to different environmental conditions and a wide spectrum of interaction in fish assemblages due to its structure and population density. This study presents the geographical distribution and morphological diversity of Astyanax rivularis Lütken, 1874, a fish historically complex and extremely diverse, in tributary streams of the left side of upper São Francisco River.

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The Hypostomini tribe comprises a single genus, Hypostomus, which possibly contains several monophyletic groups because of significant morphological variation and a variety of diploid numbers and karyotype formulas. The objective of this study was to infer evolutionary relationships among some species of Hypostomus found in the Paraná River basin and subsequently to identify chromosomal synapomorphies in the groupings formed. Two nuclear genes, rag1 and rag2, and two mitochondrial genes, mt-co1 and mt-cyb, were used to establish evolutionary relationships. Phylogenetic trees were inferred using the maximum likelihood (ML) method for mt-co1 and Bayesian analysis (BA) for all genes concatenated. Both phylogenetic trees showed two large monophyletic clades within Hypostomus. These clades are based on chromosome number, where haplogroup I contains individuals with 66–68 chromosomes, and haplogroup II contains species with 72–80 chromosomes. A third monophyletic haplogroup was also observed using ML, formed by H. faveolus and H. cochliodon, which present 2n = 64, reinforcing the separation of groups in Hypostomus by diploid number. Robertsonian rearrangements were responsible for forming the different diploid numbers and for the diversity of karyotype formulas. The groups based on traditional morphological taxonomy are considered artificial in this study; the staining pattern, which separates the two large groups morphologically and is supported by little chromosomal evidence, was instead determined to show homoplasy. Ag-NORs are predominantly multiple and located on st/a chromosomes, along with 18S rDNA sites; 5S rDNA sites are often seen in an interstitial position, following the trend already described for vertebrates.

Com a crise sanitária instaurada no início de 2020, foi proposta, por membros da comunidade acadêmica da Universidade Federal de Viçosa - Campus Rio Paranaíba (UFV-CRP), a criação de um laboratório de diagnóstico do SARS-CoV-2 por RT-qPCR. O objetivo deste artigo é relatar como o esforço conjunto entre universidade e instituições públicas e privadas promoveu, com sucesso, a instalação de um laboratório de testagem em um campus novo e fora de sede universitária e contribuiu no enfrentamento da COVID-19. Nos quase dois anos de atividade, o Laboratório de Diagnósticos Moleculares (LDM) atendeu 22 municípios da região do Alto Paranaíba/MG, e liberou 25.201 exames. Além dos exames, o LDM também realizou o treinamento de estudantes de graduação e pós-graduação nas técnicas moleculares de diagnóstico do coronavírus, além do combate contra a propagação de informações falsas nas redes sociais e a disseminação de métodos profiláticos da COVID-19. A instalação do LDM também proporcionou a criação de uma disciplina teórica e prática sobre a doença, e fortaleceu a pesquisa no campus, permitindo que projetos de iniciação científica relacionados a COVID-19 fossem executados e seus resultados publicados em periódicos científicos indexados internacionalmente.