Hybrids of the species Pseudoplatystoma corruscans vs. Pseudoplatystoma reticulatum are extensively traded because they are more docile and precocious compared to their parents. This study aimed to identify the occurrence of hybrid 'Surubim' in rivers of the State of Mato Grosso do Sul, applying molecular techniques. Pseudoplatystoma corruscans, Pseudoplatystoma reticulatum and hybrid 'Surubim' were detected using multiplex PCR and PCR-RFLP in RAG2, GLOBIN, EF1α, 18S rRNA nuclear genes, and mitochondrial 16S rRNA gene. The results revealed the presence of F 1 hybrids in rivers and the occurrence of genetic introgression, evidenced by the Post-F 1 hybrids. Furthermore, discrepancies between the morphological and genetic identification were observed, demonstrating the effectiveness of using different molecular markers for the correct identification of these hybrids. The necessity of implementation of management and conservation projects to maintain the genetic integrity of native species populations threatened by hybridization in the rivers of Mato Grosso do Sul State is evident.Híbridos envolvendo as espécies Pseudoplatystoma corruscans vs. Pseudoplatystoma reticulatum são amplamente comercializados por apresentarem maior docilidade e precocidade quando comparados aos parentais. Neste trabalho objetivou-se identificar, por meio de técnicas moleculares, a existência de surubins híbridos em rios do estado do Mato Grosso do Sul. Pseudoplatystoma corruscans, Pseudoplatystoma reticulatum e 'Surubim' híbrido foram identificados utilizando as técnicas de PCR multiplex e PCR-RFLP dos genes nucleares RAG2, GLOBINA, EF1α, 18S rRNA e mitocondrial 16S rRNA. Os resultados demonstraram a presença de híbridos F 1 em rios e a ocorrência da introgressão genética, evidenciada pelos híbridos Pós-F 1 . Além disso, foram observadas discrepâncias entre a identificação morfológica e genética, demonstrando a eficácia da utilização de diversos marcadores moleculares para identificação correta destes híbridos. Torna-se evidente a necessidade da implantação de projetos de manejo e conservação, a fim de manter a integridade genética de populações de espécies nativas em rios do estado do Mato Grosso do Sul, que encontram-se ameaçadas pela hibridação.

Plants growing in localities with more intense vehicular traffic had greater quantities of micronuclei as well as higher frequencies and average numbers of stomata than localities with less traffic, indicating the presence of atmospheric contaminants that damaged their DNA.

This study evaluated the mutagenicity, genotoxicity and cytotoxicity of water samples from the Arara Stream in the city of Rio Brilhante, MS, Brazil, by means of toxicological 118 Elisangela Bortoluci Maceda et al.

The presence of interspecific hybrid surubim (Pseudoplatystoma corruscans × Pseudoplatystoma reticulatum) in natural environments can put at risk the existence of the pure parental lineages. The aim of this study was to characterize the genetic variability of pure Pseudoplatystoma corruscans and Pseudoplatystoma reticulatum individuals from rivers in the Paraná and Paraguay basins in Brazil. Seventy-six pure individuals of P. corruscans and 16 of P. reticulatum were evaluated with six microsatellite loci for both species, along with one species-specific locus each for P. corruscans and P. reticulatum. Loss of heterozygosity was confirmed, and preservation measures for P. corruscans and P. reticulatum are needed in order not to lose further genetic variation. In addition, we confirmed that these markers are useful for the management of pure stocks in natural environments, for fish breeding, and in Biology Electronic supplementary material The online version of this article (

The dusky grouper, Epinephelus marginatus, is a well-known and widespread marine fish assessed as endangered by the International Union for the Conservation of Nature. Analyzing the genetic diversity of this species is, therefore, of utmost importance and necessary for conservation purposes. Microsatellites are molecular tools with advantages that are ideal for population analyses. This study provides the first set of species-specific microsatellite loci for E. marginatus that can be applied when assessing both intra- and interpopulation genetic variation. Twenty microsatellite loci were isolated and characterized for the dusky grouper by genotyping 20 individuals obtained from the North Eastern Atlantic Ocean (n = 4) and from the South Western Atlantic Ocean (n = 16). The number of alleles per locus varied from 2 to 11, while the observed and expected heterozygosities ranged from 0.25 to 0.94 and 0.34 to 0.89, respectively. The polymorphic information content varied from moderately to highly informative. This suite of markers provides the first specific nuclear tools for E. marginatus and, thus, allows to assess with more specificity different populations’ structures.

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large‐scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications.

RESUMO:Os procedimentos padrões para extração de DNA incluem o tratamento com proteinase k e posterior incubação em banho-maria por um determinado tempo. Sendo assim, avaliar métodos de extração de DNA que minimizem a quantidade de proteinase k e o tempo necessário para a realização das etapas, em que seja mantida a eficiência no que tange à quantidade, qualidade e a possibilidade de amplificação por PCR do DNA extraído, é de extrema importância para os estudos moleculares baseados em ácidos nucléicos. O objetivo deste estudo foi avaliar a eficiência de protocolos de extração de DNA, variando-se a concentração de proteinase k e tempo de incubação em banho-maria. O DNA foi extraído a partir de sangue periférico de bovinos. Para a extração do DNA genômico, utilizou-se oito protocolos que diferiam em concentrações de proteinase k (0,04 e 0,08µg mL-1) em intervalos de tempo variados (90, 180, 360 minutos e overnight). O DNA foi analisado quanto à sua qualidade, quantidade e viabilidade de amplificação. Foi possível obter DNA genômico de qualidade, com concentrações e pureza satisfatórias para amplificação. Com base nas análises estatísticas, as variações no protocolo tiveram efeitos isolados, ou seja, a qualidade do DNA foi suscetível à concentração de proteinase k e ao tempo no banho-maria, entretanto a quantidade de DNA das amostras foi suscetível ao tempo de incubação em banho-maria, não tendo interferência pela concentração de proteinase k. Apesar dos efeitos isolados, os parâmetros estudados influenciaram de maneira significativa na qualidade e quantidade de DNA. Palavras-chave: material genético; quantificação; sangue periférico; viabilidade de amplificação VARIATION IN CONCENTRATION OF PROTEINASE K FOR BOVINE DNA EXTRACTION PROTOCOLSABSTRACT: Standard procedures for DNA extraction include treatment with proteinase k and subsequent incubation in a water bath for a while. Thus, to evaluate methods of DNA extraction to minimize the amount of proteinase k and time required to perform the steps in which the efficiency is maintained relative to quantity, quality and the possibility of PCR amplification of DNA extracted, it is extremely importance for molecular studies based on nucleic acids. The objective of this study was to evaluate the efficiency of DNA extraction protocols, varying the concentration of proteinase k and incubation in a water bath. DNA was extracted from peripheral blood of cattle. For extraction of genomic DNA, we used eight protocols that differed in concentrations of proteinase K (0.04 and 0.08 mg mL-1) at various time intervals (90, 180, 360 minutes and overnight). We analyzed DNA´s quality, quantity and viability of amplification. It was possible to obtain high-quality genomic DNA, with concentrations and purity suitable for amplification. Based on statistical analysis, variations in the protocol had separated effects, in other words, the quality of DNA was susceptible to the concentration of proteinase k and to the time in water bath, however the amount of DNA samples was susceptible to the...

1. The dusky grouper Epinephelus marginatus is a large epinephelid species that occurs in the eastern and south-western Atlantic and western Indian Oceans. Late maturity, protogynous hermaphroditism, site fidelity, and overfishing have all contributed to its demographic decline.2. Connectivity and demography within a broad sampling of dusky grouper populations throughout its distribution were assessed. To do so, genetic variation at 11 polymorphic microsatellite loci and a partial sequence of the mitochondrial control region (mtCR) were evaluated.3. Two major mtCR lineages with a sequence divergence of 1.6% were found. The magnitude of genetic differentiation for mtCR among north and south Atlantic and Indian Ocean populations was high, with Φ ST = 0.528. 4. D EST and results of discriminant analysis of principal component revealed significant microsatellite genetic differentiation between all collection areas. Significant pairwise D EST showed moderate (0.084) to very great (0.603) differentiation. The effective population size was low for all localities, ranging between 25 (Azores Archipelago) and 311 (Rio Grande do Sul). The overall effective population size was estimated as 299 (confidence interval = 215-412), and there was no evidence of strong or recent bottleneck effects.5. Local and regional genetic structuring among dusky grouper populations is the consequence of the species' site fidelity, distribution across multiple oceanographic boundaries, and probably also of sequential hermaphroditism that contributes to the intensity of random genetic drift.6. The spatial pattern of genetic structuring of dusky groupers is such that fisheries management and conservation of population genetic integrity will have to be pursued at the local and regional scales.