Abstract The relationship between chromosomal and morphological variation in mammals is poorly understood. We analyzed the cranial size and shape variation in Ctenomys lami concerning to the geographic variation in their chromosome numbers. This subterranean rodent occurs in a narrow range of sand-dunes in the Coastal Plain of southern Brazil. This species presents a high karyotypic variation with diploid numbers varying from 2n = 54 to 2n = 58, involving the fission and fusion of chromosome pairs 1 and 2. Due to different chromosome rearrangement frequencies along their geographic distribution, four karyotypic blocks were proposed. This study, explored cranium shape and size variation in geographical, chromosomal polymorphism, and chromosome rearrangements contexts to test whether the four karyotypic blocks reflect morphologically distinct units. For this, we measured 89 craniums using geometric morphometrics and used uni and multivariate statistics to discriminate the predicted groups and test for an association among chromosomal and morphological variation. Our results show the size and shape of sexual dimorphism, with males larger than females, and support the existence of four karyotypic blocks for Ctenomys lami based on morphological variation. However, our results do not support a direct relationship between chromosomal and cranial morphological variation in C. lami.

Abstract In order to monitor the effects of anthropogenic pressures in ecosystems, molecular techniques can be used to characterize species composition. Among molecular markers capable of identifying species, the cytochrome c oxidase I (COI) is the most used. However, new possibilities of biodiversity profiling have become possible, in which molecular fragments of medium and short-length can now be analyzed in metabarcoding studies. Here, a survey of fishes from the Saint Peter and Saint Paul Archipelago was barcoded using the COI marker, which allowed the identification of 21 species. This paved the way to further investigate the fish biodiversity of the archipelago, transitioning from barcoding to metabarcoding analysis. As preparatory steps for future metabarcoding studies, the first extensive COI library of fishes listed for these islands was constructed and includes new data generated in this survey as well as previously available data, resulting in a final database with 9,183 sequences from 169 species and 63 families of fish. A new primer specifically designed for those fishes was tested in silico to amplify a region of 262 bp. The new approach should guarantee a reliable surveillance of the archipelago and can be used to generate policies that will enhance the archipelago’s protection.

Abstract We tested the association between chromosomal polymorphism and skull shape and size variation in two groups of the subterranean rodent Ctenomys. The hypothesis is based on the premise that chromosomal rearrangements in small populations, as it occurs in Ctenomys, produce reproductive isolation and allow the independent diversification of populations. The mendocinus group has species with low chromosomal diploid number variation (2n=46-48), while species from the torquatus group have a higher karyotype variation (2n=42-70). We analyzed the shape and size variation of skull and mandible by a geometric morphometric approach, with univariate and multivariate statistical analysis in 12 species from mendocinus and torquatus groups of the genus Ctenomys. We used 763 adult skulls in dorsal, ventral, and lateral views, and 515 mandibles in lateral view and 93 landmarks in four views. Although we expected more phenotypic variation in the torquatus than the mendocinus group, our results rejected the hypothesis of an association between chromosomal polymorphism and skull shape and size variation. Moreover, the torquatus group did not show more variation than mendocinus. Habitat heterogeneity associated to biomechanical constraints and other factors like geography, phylogeny, and demography, may affect skull morphological evolution in Ctenomys.

Abstract Domestic turkeys present several color phenotypes controlled by at least five genetic loci, but only one of these has been identified precisely: the bronze locus, which turned out to be the melanocortin-1 receptor (MC1R) gene. MC1R variation is important for breeders interested in maintaining or developing different color varieties. In this study, we sequenced most of the MC1R gene from 16 White Holland (the main commercial turkey variety) and 19 pigmented turkeys from southern Brazil with two purposes. The first was to describe the MC1R diversity in White Holland turkeys, which may serve as reservoirs of genetic diversity at this locus. The second was to test whether the traditional color classification used by Brazilian breeders is related to previously known MC1R alleles. White Holland turkeys had four different haplotypes corresponding to the bronze (b+) and black-winged bronze (b1) alleles. Pigmented turkeys also had four haplotypes corresponding to the b+ and b1 alleles, but different haplotypes represent the most common b+ allele in these two groups. The black (B) allele was absent from our samples. Overall, our results suggest that white and pigmented individuals form two different populations, and that the traditional color classification used by Brazilian breeders cannot accurately predict the genotypes at the bronze locus.

The puma is an iconic predator that ranges throughout the Americas, occupying diverse habitats. Previous phylogeographic analyses have revealed that it exhibits moderate levels of genetic structure across its range, with few of the classically recognized subspecies being supported as distinct demographic units. Moreover, most of the species' molecular diversity was found to be in South America. To further investigate the phylogeographic structure and demographic history of pumas we analyzed mtDNA sequences from 186 individuals sampled throughout their range, with emphasis on South America. Our objectives were to refine the phylogeographic assessment within South America and to investigate the demographic history of pumas using a coalescent approach. Our results extend previous phylogeographic findings, reassessing the delimitation of historical population units in South America and demonstrating that this species experienced a considerable demographic expansion in the Holocene, ca. 8,000 years ago. Our analyses indicate that this expansion occurred in South America, prior to the hypothesized re-colonization of North America, which was therefore inferred to be even more recent. The estimated demographic history supports the interpretation that pumas suffered a severe demographic decline in the Late Pleistocene throughout their distribution, followed by population expansion and re-colonization of the range, initiating from South America.

Entre janeiro de 2007 e dezembro de 2010 a abundância de mamíferos de médio porte foi estudada, com especial ênfase no zorrilho Conepatus chinga (Molina, 1782) em quatro locais no sul do Brasil. Neste estudo, foi utilizada a metodologia de transectos lineares de forma a obter dados para análises de densidade com uso do software Distance. Os transectos foram percorridos de carro, à noite, procurando por animais na periferia de estradas secundárias, com o uso de holofotes de longo alcance. Em 1.811 km percorridos, foram obtidos 620 registros de 20 espécies de mamíferos. A espécie mais comum foi a lebre européia Lepus europaeus (Pallas, 1778), para a qual, em uma das áreas estudadas, foi obtida a maior estimativa de abundância já registrada para a América do Sul, com uma densidade estimada de 32 indivíduos por km². Carnivora foi a ordem mais comumente registrada, representada por 10 espécies que, juntas, compreenderam 51% de todas as visualizações. O zorrilho ocorreu em todas as áreas estudadas, embora só tenha sido registrado em número suficiente para a obtenção de estimativas de densidade em duas destas áreas. A densidade do zorrilho foi estimada em 1,4 a 3,8 indivíduos por km², sendo esta a primeira estimativa por transectos lineares do gênero Conepatus na região Neotropical. Estes valores são similares aos observados para mefitídeos norte-americanos. No Brasil, C. chinga é aparentemente mais abundante no Pampa do que nos campos de altitude da Mata Atlântica. Para outras duas espécies, Lycalopex gymnocercus (Fisher, 1814) e Cerdocyon thous (Linnaeus, 1766), foram feitas estimativas preliminares de densidade que apontaram valores semelhantes aos de outras regiões de ocorrência das espécies.

Between January 2007 and December 2010, the abundance of medium-sized mammals was studied, with special focus on the Molina's hog-nosed skunk, Conepatus chinga (Molina, 1782), at four locations in southern Brazil. In this study, transect line methodology was used to obtain data for Distance Analyses. Transects were traveled by car at night, searching with spotlights along the edges of secondary roads in agricultural landscapes. Along 1,811 km, we obtained 620 observations of 20 mammal species. The most common species was the exotic European hare, Lepus europaeus (Pallas, 1778); the highest abundance estimated for South America was observed in one of the study areas, where its density was estimated as 32 individuals/km². Carnivores were the most commonly recorded mammals, represented by 10 species and comprising 51% of all observations. Molina's hog-nosed skunk occurred in all study areas, but occurred in sufficient numbers to obtain density estimates in only two of the areas. We estimated 1.4 to 3.8 individuals/km², in the first density estimate made by the transect method for a member of Conepatus in the Neotropics. These values are similar to those estimated for North American species of Mephitidae. In Brazil, C. chinga is apparently more abundant in the Pampa biome than in the grasslands of the Atlantic Forest. For two other carnivores, Lycalopex gymnocercus (Fisher, 1814) and Cerdocyon thous (Linnaeus, 1766), we estimated preliminary densities that were similar to those previously cited for different regions.

Grazing and fire, used in pasture regeneration practices, are inter-related activities in livestock management. Both activities affect habitat characteristics by changing the structure of the herbaceous and shrubby vegetation, reducing their biomass and litter cover. This study evaluated the effect of fire and livestock grazing on the assemblage of non-flying small mammals in grassland-Araucaria forest ecotones in southern Brazil. We compared four areas frequently affected by livestock management with four protected areas. Surveys were carried out in four sampling periods, one in each season of 2004. We captured a total of 325 individuals from 12 species of rodents - Akodon montensis Thomas, 1913, Akodon paranaensis Christoff, Fagundes, Sbalqueiro, Mattevi e Yonenaga-Yassuda, 2000, Akodon sp. 1, Akodon sp. 2 (2n = 34), Brucepattersonius iheringi (Thomas, 1896), Delomys dorsalis (Hensel, 1872), Oligoryzomys flavescens (Waterhouse, 1837), Oligoryzomys nigripes (Olfers, 1818), Oxymycterus nasutus (Waterhouse, 1837), Scapteromys sp. (2n = 34), Sooretamys angouya (Fischer, 1814) and Thaptomys nigrita (Lichtenstein, 1829) - and two species of marsupials - Monodelphis dimidiata (Wagner, 1847) and Philander frenatus (Olfers, 1818) -, in a total effective effort of 5254 traps.day-1. The abundance, biomass and diversity of non-flying small mammals were significantly higher in the protected areas than in those affected by fire and livestock grazing. Species strictly associated with grassland habitats were not found in the impacted area. These results indicate that the presence of herds of domestic ungulates negatively affect the assemblage of non-flying small mammals in grassland and Araucaria forest areas in southern Brazil.

Esse estudo documenta os danos causados por Euryzygomatomys spinosus (G. Fischer, 1814) em plantações de Pinus taeda Linnaeus (Pinaceae) localizadas em Cambará do Sul, Estado do Rio Grande do Sul, Brasil. Em laboratório foi testada positivamente a utilização de troncos de Pinus como recurso por E. spinosus, mas não para os outros roedores sigmodontíneos ocorrentes na área: Akodon montensis Thomas, 1913, Oligoryzomys nigripes (Olfers, 1818) e Delomys dorsalis (Hensel, 1872).

Feeding damage caused by Euryzygomatomys spinosus (G. Fischer, 1814) (Echimyidae) is documented for a Pinus taeda Linnaeus (Pinaceae) plantation located in Cambará do Sul, Rio Grande do Sul State, Brazil. Under laboratory conditions, feeding acceptance of P. taeda trunk sections was tested with positive results for E. spinosus, but not for other three co-occurring sigmodontine rodents: Akodon montensis Thomas, 1913, Oligoryzomys nigripes (Olfers, 1818) and Delomys dorsalis (Hensel, 1872).

Polygenis (Polygenis) platensis s. l. (Jordan & Rothschild) foi assinalada pela primeira vez no Brasil nos municípios de Capão da Canoa, Tramandaí e Osório, RS. Novos registros de hospedeiros são dados para a espécie, com a inclusão de Ctenomys flamarioni (Travi) e Ctenomys minutus (De Blainville). Variações morfológicas foram também observadas entre os espécimes coletados sobre mesma espécie de hospedeiro e em mesma localidade, evidenciando alguma hibridização entre as duas subspécies e impossibilitando a determinação do status subespecífico. O número de espécies de pulgas conhecidas para o Brasil é aumentado para 60.

Polygenis (Polygenis) platensis s. l. (Jordan & Rothschild) is recorded for the first time from Brazil in the municipalities of Capão da Canoa, Tramandaí and Osório, RS. New host records for this flea include Ctenomys flamarioni (Travi) and Ctenomys minutus (De Blainville). Morphological variations were also observed among the flea specimens collected on the same species of host at the same municipality, evidencing some hybridization between the two subspecies and disabling the determination of the subspecific status. The number of known species of Brazilian Siphonaptera is now 60.

Uma amostra de 101 exemplares de Ctenomys minutus foi coletada ao longo de sua distribuição geográfica e apresentou oito cariótipos (2n = 42, 45, 46a, 46b, 47,48, 49 e 50). Os polimorfismos cromossômicos deveram-se a rearranjos Robertsonianos e fusões in tandem. A distribuição dos polimorfismos evidenciou três blocos populacionais: ao norte (2n = 49 e 50), no centro (2n = 46a, 47 e 48) e ao sul (2n = 42, 45 e 46b). Estes dados sugerem que esta espécie está passando por um processo de especiação devido ao isolamento geográfico.

A sample of 101 specimens of Ctenomys minutus was collected along its geographic range. Eight karyotypes (2n = 42, 45, 46a, 46b, 47, 48, 49 and 50) were found. The chromosome polymorphisms were due to Robertsonian rearrangements and tandem fusions. The distribution of polymorphisms indicated three population blocks: northern (2n = 49 and 50), central (2n = 46a, 47, and 48) and southern (2n = 42, 45, and 46b). These findings suggest that this species is undergoing a speciation process due to geographic isolation.