We surveyed infection by Trypanosoma spp. and Leishmania spp. in small wild mammals from Cumari, Goiás State aiming to investigate the diversity of trypanosomatid in a modified landscape of the Brazilian Cerrado (and possible infection overlapping with canids from the same area). Blood, skin, spleen, and liver samples were collected for parasitological, serological, and molecular assays. Gracilinanus agilis was the most abundant species (N = 70; 48.6%) and it was the only one with patent parasitemia. Characterization by mini-exon and 18SrDNA targets were achieved in 7/10 hemocultures with positive fresh blood examination, which confirmed the T. cruzi infection by Discrete Typing Units (DTU) TcI in single (N = 2) and mixed infections with other DTUs (N = 5). T. rangeli and T. dionisii were detected in skin fragments from Didelphis albiventris and Oecomys cleberi, respectively. G. agilis were found to be infected by L. braziliensis and L. guyanensis, while Leishmania sp. DNA was detected in the liver of Oligoryzomys nigripes and Calomys expulsus. Subpatent infection by T. cruzi and Leishmania sp. was serologically detected in 15% and 9% of the small mammal fauna, respectively. Small mammals from Cumari are included in T. cruzi and Leshmania spp. transmission cycles, showing a higher diversity of trypanosomatid species and/or genotypes than that observed in canids of the same agroecosystem.

The echimyid rodents of the genus Thrichomys vary considerably in their behavior and feeding ecology, reflecting their occurrence in environments as different as the Caatinga, Cerrado, Pantanal, and Chaco biomes. While the genus was originally classified as monospecific, a number of Thrichomys species have been recognized in recent decades, based on morphometric, cytogenetic, and molecular analyses. While Thrichomys is well studied, the variation found in its cranial morphology is poorly understood, given the taxonomic and ecological complexities of the genus. Using a geometric morphometric approach, we characterized the differences found in the cranial morphology of four Thrichomys taxonomic units, including three established species, Thrichomys apereoides, Thrichomys fosteri, and Thrichomys laurentius, and one operational taxonomic unit (OTU), Thrichomys aff. laurentius. No significant differences were found among these units in cranium size, but significant variation was found in skull shape. The Procrustes distances provided a quantification of the differences in the shape of the skull, with the largest distances being found between T. aff. laurentius and T. fosteri in the dorsal view, and between T. aff. laurentius and T. apereoides in the ventral view. A Discriminant Function Analysis (DFA) with cross‐validation determined that the pairings with the highest correct classification were T. aff. laurentius vs. T. apereoides and T. aff. laurentius vs. T. fosteri, in both views. The principal variation in skull shape was found in the posterior region and the zygomatic arch, which may be related to differences in diet.

We tested the water conservation ability of three species of the genus Trichomys that occur in localities with very different climatic regimes, T. fosteri (Pantanal -seasonal wetlands), T. aff. laurentius (Cerrado -savanna) and T. laurentius (Caatinga -shrub land). Individuals were submitted to laboratory urinary concentration experiments using two treatments: one where food and water ad libitum were offered (control experiment -I) and the other of food and water deprivation (test experiment -II). Experiments were conducted during 24 hours and urine volume was collected and measured every 6 hours. We compared the differences in body mass, body mass loss (BML), urine volume (UV), relative urine volume (UVr) and urine osmolality (UO) between treatments for each species and between species for the test experiment (II). The patterns of temporal variation in urine concentration were also analyzed during the experiments. T. fosteri has significantly higher body mass than the other species. Significant differences were found in UV, UVr and UO but not in BML when experiments I and II were compared. Interspecific comparisons showed no differences between species, except for UV, which was correlated with body mass and was higher for T. fosteri. All species presented low mean urine concentration values (T. aff. Laurentius = 1226.14±608.03 mOsmol/kg, T. laurentius = 1210.02±662.68 mOsmol/kg, T fosteri = 1301±541 mOsmol/kg) compared to other South American rodents. All species showed high intraspecific variability. Some individuals of T. laurentius reached values of UO higher than 3000mOsmol/Kg. The temporal patterns of urine concentration from experiments I and II were very similar for all species. Changes in the pattern of urine concentration over time were not observed when comparing experiments I and II. The Thrichomys species studied here seem not to have efficient mechanisms for urine concentration. However, based on the high individual variability and the lack of changes in the short-term temporal variation, this question has to be better analyzed.

Since 1984, the Laboratory of Biology and Parasitology of Reservoir Wild Mammals (LABPMR) has been establishing a scientific collection, intending to carry out studies on taxonomy, biogeography, and ecology of mammals in Brazil, aiming to understand their role in zoonotic agents transmission cycles. In this context, the LABPMR also acts as a reference laboratory for the Ministry of Health, providing taxonomic reports of species involved in transmission cycles, based on integrative taxonomy (morphological/morphometric, karyotypic, and molecular analyses). The objective of this work was to offer an overview of the LABPMR Mammal Collection, including its taxonomic and geographic scope, and an account of the research carried out. Over the years, we have collected approximately 18 thousand specimens in all biomes and regions of Brazil, with a large part being deposited in the LABPMR collection. The collection consists mainly of the orders Rodentia and Didelphimorphia, but Carnivora, Chiroptera, Cingulata, Lagomorpha, and Primates are also represented. The collection consists of dry skins and skeletons and fluid-preserved specimens (11,818 specimens), tissues (12 thousand samples), and cell suspensions (four thousand samples). Our database also contains information on zoonotic agents associated with these specimens. Based on taxonomic, biogeographic, and host-parasite relationships, the collection was established and fostered studies on mammalian hosts of Trypanosoma cruzi, Leishmania spp., Orthohantavirus, Mammarenavirus, Schistosoma mansoni, and multi-host bacteria. Data generated enabled the solution of complex issues in the study of zoonoses and served as a subsidy for public health policies and eco-epidemiological surveillance of zoonoses in different regions of Brazil.

Locomotion, as a fundamental function in mammals directly associated with the use of ecological resources, is expected to have anatomical structures functionally committed that evolved under intense selective pressure, possibly carrying specializations for different locomotor habits. Among caviomorph rodents, the family Echimyidae stands out for having the greatest species richness, with relatively well-resolved phylogenetic relationships, wide variation in body mass, and remarkable diversity of locomotor habits, including arboreal, scansorial, semi-aquatic, semifossorial, and terrestrial forms. Thus, Echimyidae constitutes a promising model for understanding how phylogenetic, allometric, and ecological factors affect the evolution of postcranial structures directly linked to locomotor function. We investigated the influence of these three factors on scapular and humeral morphological variation in 38 echimyid species using two-dimensional geometric morphometry and phylogenetically informed comparative methods. Scapular and humeral shape variation had a low correlation with body mass and structure size, conveying a small or negligible allometric effect. Conversely, a significant moderate to strong phylogenetic signal was detected in both structures, suggesting that an important part of their morphometric variation results from shared evolutionary history. Notably, morphological variation of the scapula was extensively structured by phylogeny, without the marked influence of locomotor habits, suggesting that its shape may be a suitable taxonomic marker. Finally, locomotor habits were important in structuring the morphological variation of the humerus. Our results suggest that the morphologies of the scapula and humerus, despite being anatomically and functionally interconnected, were differentially shaped by ecological factors associated with locomotor habits.

During our visits to the main Brazilian collections of echimyid rodents to conduct a study relating scapula and humerus morphometry with locomotor habits, we found a large number of specimens with absent postcranium or in a poor state of conservation, compromising our sampling and hindering our work. As a result, the scapulae accounted for only 35% and the humerus 32% of the total skulls present in mammalogy collections. We, therefore, alert all fellow mammalogists to the importance of preserving postcranial structures for deposit in zoological collections.

Os roedores constituem a ordem mais rica em espécies de mamíferos. Na América do Sul, dentre os roedores caviomorfos, a família Echimyidae possui uma história taxonômica confusa e apesar de várias revisões, ainda permanecem lacunas de estudos sistemáticos para esta família que é compreendida pelos ratos-de-espinho, as hutias e o coypu. Esta família destaca-se por possuir um elevado número de espécies (ca. 100 spp.), larga variação na massa corporal e, ainda, uma grande diversidade de hábitos locomotores, os quais incluem espécies arborícolas, escansoriais, semi-aquáticas, semifossoriais e terrestres. Assim, a função esquelética dos roedores equimiídeos juntamente com a sua organização filogenética, fornecem um modelo de estudo promissor e de particular interesse para a compreensão de como fatores alométricos, ecológicos e filogenéticos afetam a evolução do esqueleto pós-craniano. Assim, o objetivo principal desta tese foi analisar a influência destes três fatores sobre a diferença da forma e do tamanho na morfologia pós-craniana em um contexto filogenético, possibilitando a compreensão da evolução e da divergência nas características morfológicas e ecológicas. Para a realização destas análises, fotografamos 186 escápulas e 181 úmeros de 38 espécies de 15 gêneros equimiídeos (ca. 37% e 54% respectivamente do total de equimiídeos). Posteriormente, para a resolução deste problema, utilizamos a morfometria geométrica, uma ferramenta de baixo custo e precisa para identificação de sutis diferenças morfológicas digitalizando 31 marcos anatômicos bidimensionais (2D) para a escápula (14 landmarks e 17 semilandmarks) enquanto para o úmero, foram utilizados 23 marcos (19 landmarks e 4 semilandmarks). A partir das coordenadas destes pontos, foi possível eliminar o efeito do tamanho das espécies possibilitando testarmos as diferenças de forma entre os grupos filogenéticos e os hábitos locomotores. A variação morfológica da escápula e do úmero mostraram uma baixa correlação com a massa e o tamanho corporal evidenciando um efeito alométrico pequeno ou desprezível. Os resultados demonstraram ainda um sinal filogenético significativo, mas baixo, para ambas as estruturas. A variação morfológica da escápula foi extensamente estruturada pela filogenia dos equimiídeos podendo tornar-se um relevante marcador taxonômico e filogenético em estudos futuros. Por outro lado, a variação morfológica do úmero foi estruturada pelos hábitos locomotores tornando-se útil para áreas de estudo como a paleontologia que buscam reconstruir hábitos locomotores sobre uma perspectiva ecomorfológica. Assim, estes resultados sugerem que estruturas pós-cranianas como escápula e úmero foram moldadas por restrições e adaptações evolutivas e por estarem envolvidas com a locomoção, estas estruturas são bem adequadas para os estudos ecomorfológicos por integrarem uma parte essencial da diversificação ecomorfológica e filogenética. Embora existam vários trabalhos com a escápula e o úmero de caviomorfos utilizando abordagens morfológicas e morfofuncionais, este é o primeiro estudo morfométrico a abordar uma ampla diversidade de gêneros equimiídeos utilizando a escápula e o úmero. Este trabalho fornece uma visão sobre a função e a evolução do sistema esquelético dos equimiídeos sugerindo ainda que a diversidade dos membros anteriores seja uma parte essencial da diversificação ecomorfológica e filogenética desta família de roedores.