Molecular and spatial evaluation of small rodents and Didelphimorphis infected with Mycobacterium leprae in the southern Amazon, Brazil.

BACKGROUND: The high levels of recent transmission of leprosy worldwide demonstrate the necessity of epidemiologic surveillance to understand and control its dissemination. Brazil remains the second in number of cases around the world, indicating active transmission of Mycobacterium leprae (M. leprae) in the population. At this moment, there is a consensus that the bacillus is transmitted by inter-human contact, however, different serologic, molecular, and histopathological approaches indicate the existence of non-human transmission sources. METHODS AND RESULTS: The qPCR assay was used to amplify the molecular targets 16S RNAr and RLEP, in samples of liver, spleen, and ear of wild animals belonging to Didelphimorphia and Rodentia orders, in highly endemic areas of Mato Grosso, Brazil. The RLEP repetitive sequence was positive in 202 (89.0%) samples, with 96 (42.3%) of these also being positive for the 16S gene. Regarding the collection sites, it was observed that the animals were found in areas profoundly deforested, close to urban areas. CONCLUSIONS: Our results suggest that wild animals can play an important role in the maintenance of M. leprae in endemic regions with major anthropic action in Brazil. Therefore, integrating human, animal, and environmental health care with the One Health initiative is highly efficient for the development of effective strategies to contain and control leprosy in Brazil.

Expanding the universe of Piroplasmids: morphological detection and phylogenetic positioning of putative novel piroplasmids in black-eared opossums (Didelphis aurita) from southeastern Brazil, with description of "South American Marsupialia Group" of Piroplasmida.

The growing proximity of wildlife to large urban niches arouses greater interest in understanding wild reservoirs in the epidemiology of diseases of importance to animal and human health. The aim of the present study was to investigate the presence of piroplasmids in opossums rescued from the metropolitan region of Rio de Janeiro state, Brazil. Blood and bone marrow samples were collected from 15 Didelphis aurita and subjected to DNA extraction and PCR using primers for the 18S rRNA, cox1, cox3, and hsp70 genes of piroplasmids. Clinical and hematological evaluation of the animals was also performed. Five (33.3%) of the 15 opossums tested positive for piroplasms in the nested PCR based on the 18S rRNA, and in two animals, it was possible to observe intra-erythrocytic structures compatible with merozoites. One of the positive animals showed clinical signs of infection such as jaundice, fever, and apathy. Anemia, low level of plasma protein, leukocytosis, and regenerative erythrocyte signs were observed in positive animals. Phylogenetic analysis based on both 18S rRNA and cox-3 genes demonstrated that the piroplasmids detected in D. aurita formed a unique sub-clade, albeit related to piroplasmids previously detected in Didelphis albiventris and associated ticks from Brazil. This study proposes the novel Piroplasmida Clade, namely "South American Marsupialia Group," and reinforces the need for new clinical-epidemiological surveys to understand the dynamics of these infections in didelphids in Brazil.

Urban biodiversity: Cuterebriasis in free-ranging Robinson's mouse opossum (Marmosa robinsoni) in the suburbs of Barranquilla, Colombia.

The tropical dry forest is one of the world's most threatened ecosystems and is the habitat of the Robinson's Mouse Opossum (Marmosa robinsoni), a small marsupial within the Didelphidae family. This study aimed to describe cases of cuterebriases in free-ranging M. robinsoni by examining individuals caught in live animal traps. Sherman traps were deployed in four different sites over three different periods in five days. All animals passed through biometry, weighing, sampling parasites, and sampling feces. Only animals captured in the study site located close to the city were anesthetized and examined. The evaluation included blood samples and a clinical examination. Animals received anesthesia under physical restraint by intramuscular injections of ketamine and xylazine. For anesthetic reversion, the protocol was Yohimbine administered before release. In total, 8% (5/60) of all captured animals had fly larvae extracted from wounds. The molecular Barcode of the mitochondrial Cytochrome Oxidase I gene showed no match with any recognized species of Cuterebra. The animals weighed from 35 to 80 g and had lesions in the scapular region with parasites under their skin in sizes ranging from 1.3 to 2.2 cm. The animals with parasites were in good physical condition without evidence of disturbances in health conditions. This is compatible with literature, reporting little effect on population dynamics of other host species infected with Cuterebra larvae. The study included 24 animals captured in three areas far from any city, which showed no evidence of cuterebrid infection, suggesting that proximity to the city could increase exposure to cuterebriasis. There are reports of cuterebrids in M. robinsoni in Brazil; however, this is the first report of cuterebriasis in M. robinsoni in Colombia.

Morphological and Molecular Data Reveal Two New Species of Viannaia (Nematoda: Viannaiidae), Parasitizing Opossums (Mammalia: Didelphidae) in Mexico.

Two new species of Viannaia from the intestine of the North American opossums, Didelphis virginiana (Virginia opossum), and Philander opossum (gray four-eyed opossum), are described based on morphological and molecular data, through an integrative taxonomic approach. Maximum likelihood and Bayesian inference analyses for each dataset and the concatenated dataset were performed using a mitochondrial cytochrome c oxidase subunit 1 (COI) gene, and the nuclear ribosomal internal transcribed spacer region (ITS1-5.8S-ITS2). The phylogenetic analyses revealed 2 new species that occur in Mexico, one from the western state of Colima and another from the southern state of Chiapas. Our phylogenetic trees for both molecular markers and concatenated datasets yielded similar topologies with high bootstrap values and posterior probabilities. Viannaia is recovered as a monophyletic group, but the family Viannaiidae appears as non-monophyletic, due to the position of Travassostrongylus scheibelorum, similar to previous studies. Finally, the morphology of Viannaia and Hoineffia is discussed.

Topografia dos órgãos abdominais em Didelphis albiventris / Topography of abdominal organs in Didelphis albiventris

O conhecimento da localização dos órgãos nas diferentes regiões do corpo do animal é essencial para a prática clínica, cirúrgica e para o diagnóstico por imagem. O objetivo do estudo foi descrever a anatomia topográfica abdominal do Didelphisalbiventris. Foram utilizados quatro cadáveres (animais jovens), dois destes destinados para o estudo macroscópico em peças a fresco e os outros fixados em solução aquosa de formaldeído a 10%. Os cadáveres foram dissecados e as estruturas anatômicas identificadas, analisadas e fotografadas. A maioria dos órgãos localizados na região abdominal dos cadáveres da espécie D. albiventris apresentou posição similar aos dos caninos, porém, alguns órgãos e a localização de determinadas estruturas apresentaram particularidades importantes, como a presença dos ossos epipúbicos, a ausência do lobo hepático quadrado, a presença de um ceco desenvolvido e o cólon dividido em três segmentos.

The knowledge about localization of organs in different regions of the animal's body is essential for clinical, surgical and diagnostic imaging practice. The purpose of this study was to describe the abdominal topographic anatomy of Didelphis albiventris. Was used four dead bodys (young animals), two of these was intended for the macroscopic study of fresh pieces and the others fixed in 10% aqueous formaldehyde solution. The corpses was dissected and the anatomic structures was identified, analyzed and photographed. Most of the organs located in the abdominal region of cadavers from species D. albiventris presented structure and position similar to canines, however some of these organs and localization of structures presented important particularities, like the presence of epipubic bones, absence of square hepatic lobe, presence of an developed cecum and colon divided into three segments.

Topografia dos órgãos abdominais em Didelphis albiventris / Topography of abdominal organs in Didelphis albiventris

O conhecimento da localização dos órgãos nas diferentes regiões do corpo do animal é essencial para a prática clínica, cirúrgica e para o diagnóstico por imagem. O objetivo do estudo foi descrever a anatomia topográfica abdominal do Didelphisalbiventris. Foram utilizados quatro cadáveres (animais jovens), dois destes destinados para o estudo macroscópico em peças a fresco e os outros fixados em solução aquosa de formaldeído a 10%. Os cadáveres foram dissecados e as estruturas anatômicas identificadas, analisadas e fotografadas. A maioria dos órgãos localizados na região abdominal dos cadáveres da espécie D. albiventris apresentou posição similar aos dos caninos, porém, alguns órgãos e a localização de determinadas estruturas apresentaram particularidades importantes, como a presença dos ossos epipúbicos, a ausência do lobo hepático quadrado, a presença de um ceco desenvolvido e o cólon dividido em três segmentos.

The knowledge about localization of organs in different regions of the animal’s body is essential for clinical, surgical and diagnostic imaging practice. The purpose of this study was to describe the abdominal topographic anatomy of Didelphis albiventris. Was used four dead bodys (young animals), two of these was intended for the macroscopic study of fresh pieces and the others fixed in 10% aqueous formaldehyde solution. The corpses was dissected and the anatomic structures was identified, analyzed and photographed. Most of the organs located in the abdominal region of cadavers from species D. albiventris presented structure and position similar to canines, however some of these organs and localization of structures presented important particularities, like the presence of epipubic bones, absence of square hepatic lobe, presence of an developed cecum and colon divided into three segments.

Descriptive morphometry and stereology in accessing the testis structure and function of the marsupial Philander frenatus (Olfers, 1818) (Didelphimorphia: Didelphidae).

Philander frenatus is an important marsupial for the maintenance and conservation of the Atlantic Rainforest, however, it has biological characteristics that are still little explored. The study of the reproductive biology is an important key to understand the species reproductive strategies and to improve the development of conservation and management activities. The present study aimed to conduct a histological and morphometric investigation of the testis structure and function of P. frenatus. The average body and testicular weight were 445 g and 0.74 g, respectively, with a gonadosomatic index of 0.17%. The seminiferous tubules occupying 64.95% of the organ, totalising 9.26 m per gram of testis. The tubulesomatic and epitheliumsomatic indexes were 0.10% and 0.07%, respectively. Philander frenatus showed cell loss of approximately 98% during the proliferative phase and the spermatogenic yield was 10.3 cells. The high loss during the mitotic phase contributed to the low spermatogenic yield. The testicular parenchyma was composed of 35% of intertubular components, one of the highest proportions observed in mammals. Leydig cells were responsible for approximately 25% of the testes, followed by lymphatic space (6.44%), blood vessels and connective tissue (4% together). The organisation of the intertubular components resembles the Fawcett III category. The volume and number of Leydig cell per gram of testis were 2,627.12 µm3 and 91.28 × 106 cells, respectively. High investment in the intertubular compartment, specifically number and volume of Leydig cells in P. frenatus is consistent with territorial behaviour and polygynic mating system, which have greater androgenic capacity.

Molecular Detection of Human Adenovirus and Rotavirus in Feces of White-Eared Opossums.

The white-eared opossums (Didelphis albiventris) is the largest Brazilian marsupial and a great example of animal synanthropy. Considering the high potential as a carrier of viruses originating from environmental contamination, the presence of Human adenovirus (AdV) and rotavirus was investigated in the feces of rescued white-eared opossums, which were in the process of rehabilitation. The feces of 49 animals were initially investigated by immunochromatography, with three samples positive for AdV and one sample positive for rotavirus. When submitted to PCR and nested PCR, the samples of six animals were positive for AdV and three animals were positive for group A rotavirus. Two positive samples in the immunochromatographic assay were not confirmed by PCR. After sequencing and phylogenetic analysis of AdV samples, all were identified within the genus Mastadenovirus, one being HAdV-C, four HAdV-E, and one being similar to a Mastadenovirus found in primates. This is the first report of molecular confirmation of human adenovirus and rotavirus in white-eared opossums. These data could be important of anticipation some emerging diseases and their effects on ecosystems health.

Use of highway culverts by the water opossum (Chironectes minimus) in southeastern Brazil / Uso de drenagens fluviais sob rodovias pela cuíca dagua (Chironectes minimus) no sudeste do Brasil

Abstract The water opossum (Chironectes minimus) is a semi-aquatic mammal that is infrequently sampled in Atlantic rainforest areas in Brazil. Here we report on new records of C. minimus in the state of São Paulo, southeastern Brazil, and comment on its behavior and ecology. We placed nine camera traps in culverts and cattle boxes under a highway, between 2017 and 2019. From a total of 6,750 camera-trap-days, we obtained 16 records of C. minimus (0.24 records/100 camera-trap-days) in two cameras placed in culverts over streams. Most of the records were made between May and August, in the dry season and in the first six hours after sunset. The new records are from a highly degraded area with some riparian forests. The records lie approximately 30 km away from the nearest protected area where the species is known to occur. We suggest that C. minimus has some tolerance to degraded habitats, as long as the water bodies and riparian forests are minimally preserved. The new records presented here also fill a distribution gap in western São Paulo state.

Resumo A cuíca d'agua (Chironectes minimus) é um mamífero semiaquático pouco amostrado em áreas de Mata Atlântica do Brasil. Neste estudo apresentamos novos registros de C. minimus no estado de São Paulo, sudeste do Brasil, e comentamos sobre seu comportamento e ecologia. Nós instalamos nove armadilhas fotográficas em drenagens fluviais e passagens de gado sob uma rodovia, entre 2017 e 2019. De um total de 6.750 armadilhas-fotográficas-dia, obtivemos 16 registros de C. minimus (0,24 registros/100 armadilhas-fotográficas-dia) em duas armadilhas fotográficas instaladas em drenagens fluviais. A maioria dos registros foram feitos entre maio e agosto, na estação seca, e nas seis primeiras horas da noite. Os novos registros são de uma área altamente degradada que possui algumas matas ciliares. Os registros estão a aproximadamente 30 km da área protegida mais próxima onde a espécie já foi registrada. Nós sugerimos que C. minimus possui certa tolerância a hábitats degradados, contanto que os corpos d'agua e as matas ciliares estejam minimamente preservados. Os novos registros aqui apresentados também preenchem uma lacuna amostral no oeste de São Paulo.

Helminth Community Structure of the Gray Four-Eyed Opossum Philander opossum (Mammalia: Didelphidae) in the Neotropical Portion of Mexico.

Studies on helminth communities associated with didelphids are scarce; the majority of works have focused at taxonomic level. To increase the ecological knowledge of these host-parasite associations, during March (dry season) of 3 consecutive years (2013-2015) a total of 49 adults of the gray four-eyed opossum (Philander opossum) was collected in the Neotropical portion of Mexico (Agua Fría, Chiapas State) and examined for helminths. The main objectives of this study were to describe the infra- and component communities of helminths associated with P. opossum and to compare the helminth fauna of the Mexican population of this host species with those studied in French Guiana and in other Mexican terrestrial didelphids. The helminthological record of this host consisted of 12 species: 7 taxa of Nematoda, 3 of Trematoda, 1 Cestoda, and 1 Acanthocephala. Eight of the 12 taxa have been previously recorded in Didelphidae and 4 represent accidental infections ( Glossocercus sp., Stomylotrema vicarium, Spirura mexicana and Acanthocephala gen. sp.). Diet of hosts is the main structuring factor of the communities (92% of the helminth species were recruited through ingestion). Forty-eight hosts were parasitized by at least 1 helminth species; Rhopalias coronatus was the most prevalent and abundant species in the hosts sampled. No significant differences were found in global prevalence among the helminth species present in all samplings, considering host sex and year. The dominance exerted by R. coronatus led to low values of evenness and diversity at both community levels. No significant differences were observed in composition of helminth species among the 3 sampling years regarding sex. The results of our study showed changes in helminth abundance at infracommunity level; during the first sampling these changes are explained by species with direct life cycle ( Viannaia sp. and Cruzia tentaculata), whereas in last 2 surveys the explanation can be attributed to species with heteroxenous life cycles (particularly R. coronatus, Duboisiella proloba, and Turgida turgida). Thirty-three percent of the helminth species recorded in P. opossum in Agua Fría is shared with the other 2 terrestrial species of didelphids sampled in different sites of Mexico: Didelphis marsupialis and Didelphis virginiana. In contrast, samples from French Guiana and Agua Fría, differ in terms of helminth fauna, confirming that the helminth communities of opossum species inhabiting the same locality show higher levels of taxonomic similarity than communities of conspecific marsupials allopatrically distributed.

The impact of botfly parasitism on the health of the gracile mouse opossum (Gracilinanus agilis).

Fragmented habitats generally harbour small populations that are potentially more prone to local extinctions caused by biotic factors such as parasites. We evaluated the effects of botflies (Cuterebra apicalis) on naturally fragmented populations of the gracile mouse opossum (Gracilinanus agilis). We examined how sex, food supplementation experiment, season and daily climatic variables affected body condition and haemoglobin concentration in animals that were parasitized or not by botflies. Although parasitism did not affect body condition, haemoglobin concentrations were lower in parasitized animals. Among the non-parasitized individuals, haemoglobin concentration increased with the increase of maximum temperature and the decrease of relative humidity, a climatic pattern found at the peak of the dry season. However, among parasitized animals, the opposite relationship between haemoglobin concentration and relative humidity occurred, as a consequence of parasite-induced anaemia interacting with dehydration as an additional stressor. We conclude that it is critical to assess how climate affects animal health (through blood parameters) to understand the population consequences of parasitism on the survival of individuals and hence of small population viability.

Seasonal changes of faecal cortisol metabolite levels in Gracilinanus agilis (Didelphimorphia: Didelphidae) and its association to life histories variables and parasite loads.

The aim of this study was to evaluate the role of environmental (dry versus wet season) and individual (sex, body mass and reproductive status) factors in the levels of faecal cortisol metabolites (FGCs) in Gracilinanus agilis faecal samples as an index of stress levels in this species; as well as its association with abundance of Eimeria spp, as an indicator of immunocompetence against parasites. Our study found that FGCFGCs are a reliable indicator of adrenal activity in G. agilis. We found that FGCFGCs increase considerably by environmental stressors like the dry season. Moreover, the observed positive association between FGCs and body mass is the result of the effect of season and reproduction in both variables. We also demonstrated that an increase in FGC levels among G. agilis during the dry season is associated with a rise in the probability of being infected by Eimeria spp. Hence, our finding supports the corticosteroid-fitness hypothesis, which predicts that increased glucocorticoids as a response to stressors usually results in decreased fitness of individuals, translated into low future survival and reproductive success, and higher parasite infection. To our knowledge, this is the first study that integrates environmental changes, hormone responses and parasite loads in a US marsupial in both empirical and experimental approaches.

Detection of antibodies against Leptospira spp in free-living marsupials caught in the Eastern Amazon

Abstract INTRODUCTION: Serological surveys are important to assess the health status of wild animals. In this study, antibodies against Leptospira spp, causal agents of leptospirosis, were detected in free-living marsupials in the State of Pará, Brazil. METHODS: Nineteen blood samples collected from marsupials in the municipalities of Peixe-Boi, Viseu, and Castanhal were subjected to microscopic agglutination tests. RESULTS: In total, 36.8% (7/19) of samples were positive, and two exhibited co-agglutination. The most frequent serovars were Icterohaemorrhagiae (60%; 3/5), Panama (20%; 1/5), and Nupezo (20%; 1/5). CONCLUSIONS: Anti-Leptospira spp antibodies currently circulate in free-living marsupials in Northeastern Pará.

A checklist of chiggers from Brazil, including new records (Acari: Trombidiformes: Trombiculidae and Leeuwenhoekiidae).

A checklist of the family Trombiculidae and Leeuwenhoekiidae is presented, containing 63 species in 30 genera of chiggers from 80 different hosts and 146 localities in Brazil. The type locality and depository are provided, including new locality and host records for the country.

A checklist of chiggers from Brazil, including new records (Acari: Trombidiformes: Trombiculidae and Leeuwenhoekiidae)

A checklist of the family Trombiculidae and Leeuwenhoekiidae is presented, containing 63 species in 30 genera of chiggers from 80 different hosts and 146 localities in Brazil. The type locality and depository are provided, including new locality and host records for the country.

Orbit orientation in didelphid marsupials (Didelphimorphia: Didelphidae).

Usually considered a morphologically conservative group, didelphid marsupials present considerable variation in ecology and body size, some of which were shown to relate to morphological structures. Thus, changes on orbit morphology are likely and could be related to that variation. We calculated orbit orientation in 873 specimens of 16 Didelphidae genera yielding estimates of orbits convergence (their position relative to midsagittal line) and verticality (their position relative to frontal plane). We then compared similarities in these variables across taxa to ecological, morphological and phylogenetic data to evaluate the influencing factors on orbit orientation in didelphids. We found an inverse relation between convergence and verticality. Didelphids orbits have low verticality but are highly convergent, yet orbit orientation differs significantly between taxa, and that variation is related to morphological aspects of the cranium. Rostral variables are the only morphological features correlated with orbit orientation: increasing snout length yields more convergent orbits, whereas increase on snout breadth imply in more vertical orbits. Size and encephalization quotients are uncorrelated with orbit orientation. Among ecological data, diet showed significant correlation whereas locomotion is the factor that less affects the position of orbits. Phylogeny is uncorrelated to any orbital parameters measured. Ecological factors seemingly play a more important role on orbit orientation than previously expected, and differentiation on orbit orientation seems to be more functional than inherited. Thus, despite the apparent homogeneity on didelphid morphology, there is subtle morphological variability that may be directly related to feeding behavior.

Morfologia e histoquímica das glândulas sexuais acessórias de Metachirus nudicaudatus, Didelphidae-Marsupialia / Morphology and histochemistry of accessory sex glands of Metachirus nudicaudatus, Didelphidae-Marsupialia

São descritas a morfologia e a distribuição de glicogênio e mucossubstâncias na próstata e nas glândulas bulbouretrais de Metachirus nudicaudatus (Geoffroy, 1803), única espécie do gênero. A próstata é envolvida pelas túnicas adventícia e muscular, e o estroma é formado pelo conjuntivo da mucosa uretral. O parênquima é constituído pelos túbulos secretores, disseminados na mucosa uretral, e que diferem histológica e histoquimicamente nos segmentos cranial, médio e caudal. Essas diferenças morfo-histoquímicas também são observadas nas partes externa, média e interna de cada túbulo. De um modo geral, os três segmentos prostáticos secretam mucossubstâncias neutras, porém o segmento caudal produz também glicogênio. Os três pares de glândulas bulbouretrais (laterais, intermédias e mediais) do Metachirus são envolvidas por uma cápsula conjuntiva e músculo estriado esquelético. O maior par é a bulbouretral lateral que é constituída por longos túbulos secretores de mucossubstâncias neutras. As bulbouretrais intermédias são formadas por túbulos ramificados, que produzem mucossubstâncias neutras, ácidas carboxiladas e ácidas sulfatadas. Os túbulo-ácinos ramificados das bulbouretrais mediais secretam mucossubstâncias neutras. O Metachirus não possui glândulas ampulares, vesículas seminais nem glândulas de coagulação.(AU)

This paper describes the morphology and distribution of glycogen and mucous substances in the prostate and the bulbourethral glands of Metachirus nudicaudatus (Geoffroy, 1803), the only species of the genus. The prostate is surrounded by the tunica adventitia, and muscle and stroma is formed by connective urethral mucosa. The glandular parenchyma consists of secretory tubules, scattered throughout the connective tissue of the urethral mucosa which differs histologically and histochemically in cranial, middle, and caudal segments of the prostate. These morpho-histochemical differences are also observed in the outer, middle and inner parts of the tubular epithelium of each prostatic segment. In general, prostatic segments secrete neutral mucous substances, and the caudal segment also produces glycogen. The three pairs of bulbourethral glands (lateral, intermediate and medial) are surrounded by a capsule of dense connective tissue and skeletal striated muscle. The glandular parenchyma is formed by tubules or branched tubuloacinar, covered by simple epithelium which is characteristic for each pair of glands. The lateral bulbourethral glands and the medial bulbourethral glands produce neutral mucous substances and the secretion of the intermediate bulbourethral glands consists of neutral mucous substances, carboxylated acids, and sulfated acids. The M. nudicaudatus does not have ampullary glands, seminal vesicles or coagulating glands.(AU)

Morfologia do escroto, do testículo e das vias espermáticas de Metachirus nudicaudatus (Geoffroy, 1803), Didelphidae-Marsupialia / Morphology of scrotum and testicle, and spermatic pathways of Metachirus nudicaudatus (Geoffroy, 1803), Didelphidae-Marsupialia

Foram utilizadas as gônadas e vias espermáticas de cinco animais machos, adultos em fase reprodutiva, da espécie Metachirus nudicaudatus Geoffroy 1803, única espécie do gênero, para descrever a morfologia do escroto, do testículo e das vias espermáticas. O Metachirus possui escroto pré-peniano e que contém os testículos permanentemente. A pele escrotal é não pigmentada e com poucos pelos e glândulas. A lâmina parietal da túnica vaginal apresenta-se pouco pigmentada. Os testículos são ovais e ligados ao epidídimo através do pedículo testículo-epididimário. Eles são envolvidos, externamente, pela cápsula testicular e sustentados por um estroma de natureza conjuntiva. As células intersticiais são os elementos predominantes no abundante tecido intertubular. Os túbulos seminíferos são largos, enovelados e envolvidos por uma túnica própria fibroelástica, contendo células mióides. O epitélio seminífero é formado pelas células espermatogênicas e de Sertoli intercaladas. Os túbulos seminíferos convergem em direção à extremidade capitata do testículo, ficando revestidos por apenas células de sustentação, caracterizando uma região de transição entre túbulos seminíferos e túbulos retos, ocupada por uma estrutura tipo "válvula" que obstrui parcialmente o lume tubular. Os túbulos retos reúnem-se para formar um único dúctulo eferente, que percorre uma pequena extensão intratesticular, atravessa a albugínea e penetra no pedículo testículo-epididimário. A parte flexuosa do dúctulo eferente forma um lóbulo separado na parte medial do corpo do epidídimo. O epidídimo é envolvido pela cápsula epididimária e constituído pelo ducto epididimário, que se encontra bastante enovelado. O ducto epididimário é revestido por epitélio simples colunar pseudoestratificado apresentando células principais, basais, apicais e de "halo claro". As células principais são predominantes e apresentam características morfológicas e histoquímicas que diferem ao longo do ducto, possibilitando a caracterização de nove diferentes zonas epididimárias. É no lume da zona sete (início da cauda) que começa o pareamento de espermatozoides. Esse fenômeno coincide com alterações morfológicas bem evidentes e uma maior quantidade de mucossubstâncias neutras é secretada nessa zona.O ducto deferente apresenta-se dividido em três partes: justa-epididimária, funicular e abdominal, baseando nas variações histológicas e histoquímicas de seu epitélio e componentes envolventes. O ducto deferente não apresenta ampola e nem cruza o ureter antes de desembocar na uretra. O funículo espermático contém o ducto deferente, artéria e veias testiculares, vasos linfáticos, nervos e um desenvolvido músculo cremáster. Seus componentes apresentam modificações estruturais nas regiões proximal, média e distal, sendo notável a peculiar rede admirável.(AU)

Gonads and sperm pathways of five adult male Metachirus nudicaudatus in the reproductive phase were used to describe the morphology of scrotum, testicle, and spermatic tract. M. nudicaudatus has a scrotum pre-penis which contains the testicles permanently. The scrotal skin is not pigmented and has few hairs and glands. The parietal vaginal tunic is slightly pigmented. The testicles are oval and connected to the epididymis by testicular-epididymal pedicle; they are surrounded externally by the testicular capsule and supported by a stroma of connective nature. Interstitial cells are the predominant elements in abundant intertubular tissue. The seminiferous tubules are wide, meandering and surrounded by a fibro-elastic coat, containing myoid cells. The seminiferous epithelium is composed of spermatogenic cells and Sertoli cells interspersed. The seminiferous tubules converge toward the end of the testis capitata, getting coated only support cells, featuring a transition region between the seminiferous tubules and straight tubules, occupied by a type "valve" structure that partially blocks the tubular lumen. Straight tubules together to form a single efferent ductule, which runs a small intra-testicular extent, penetrates through the tunica and the pedicle testis-epididymis. The flexuosa part of the efferent ductule forms a separate lobe in the medial part of the body of the epididymis. The epididymis is enveloped by a capsule and epididymal comprising the epididymal duct, which is quite entangled. The epididymal duct is lined by pseudostratified columnar epithelium with simple principal, basal, apical and "clear halo" cells. The main cells are prevalent and have morphological and histochemical differing characteristics along the duct, enabling to characterize nine different epididymal areas. In the lumen of the seventh area (top of tail) that starts the pairing of sperm. This phenomenon coincides well with morphological change and a larger amount of neutral muco-substances is secreted in that area. Vas deferens has three parts: fair-epididymal, abdominal and funicular part, based on histological and histochemical changes of the epithelium and surrounding components. The vas deferens has no bulb and even crosses the ureter before flowing into the urethra. The spermatic cord contains the vas deferens, testicular artery and veins, lymphatic vessels, nerves and developed cremaster muscle. Its components have structural changes in the proximal, middle and distal region, with a peculiar admirable network.(AU)

Morphological and ultrastructural analysis of the tongue of Gracilinanus microtarsus (Wagner, 1842) / Análise morfológica e ultraestrutural da língua da Gracilinanus microtarsus (Wagner, 1842)

The G. microtarsus is a small marsupial belonging to the Didelphidae family and may be found mainly in the Atlantic Rainforest of the Brazilian Southeastern region. G. microtarsus has important ecological importance in the dispersion of seeds of several plant species. Current research characterizes morphologically six tongues of adult male and female specimens, which are fixed in 10% formaldehyde. The tongues were analyzed, measured and photographed "in situ" and "ex situ". Anatomy, light microscopy and ultrastructural analysis were performed. Macroscopically the tongue has root, a fixed body and a free apex. The tongue has fungiform papillae and high conical and acute filiform papillae across the dorsal surface. It also featured three vallate papillae located at the root and marginal fungiform papillae at the apex. Microscopically, the tongue is composed of longitudinal and transversal muscle fibers. Blood vessels, nerves, serous, mucous and mixed acini are found in non-modeled connective tissue. Ventrally, the tongue is lined by a keratinized stratified pavement epithelium. The morphology of the tongue of G. microtarsus resembles that described in carnivores and marsupials Didelphidae regarding its microscopic structure, differing only in the distribution and number of papillae.

O G. microtarsus é um pequeno marsupial pertencente à família Didelphidae, que pode ser encontrado principalmente na Mata Atlântica da região sudeste brasileira. O G. microtarsus possui importância ecológica na dispersão de sementes de diversas espécies de plantas. A pesquisa atual caracteriza morfologicamente as línguas de seis animais adultos, fixados em formol a 10%. As línguas foram analisadas, mensuradas e fotografadas. Foram realizadas análises anatômicas, microscópicas de luz e ultraestruturais. Macroscopicamente a língua possui raiz, um corpo fixo e um ápice livre. A língua possui papilas fungiformes, filiformes cônicas altas e agudas em toda a superfície dorsal. Também possui três papilas valadas localizadas na raiz e papilas fungiformes marginais no ápice da língua. Microscopicamente, a língua é composta por fibras musculares longitudinais e transversais. Os vasos sanguíneos, nervos e ácinos serosos, mucosos e mistos são encontrados em tecido conjuntivo não modelado. Ventralmente, a língua é revestida por um epitélio pavimentoso estratificado queratinizado. A morfologia da língua de G. microtarsus se assemelha ao descrito em carnívoros e marsupiais Didelphidae quanto à sua estrutura microscópica, diferindo apenas na distribuição e número de papilas.

The Araguaia River as an Important Biogeographical Divide for Didelphid Marsupials in Central Brazil.

The riverine barrier model suggests that rivers play a significant role in separating widespread organisms into isolated populations. In this study, we used a comparative approach to investigate the phylogeography of 6 didelphid marsupial species in central Brazil. Specifically, we evaluate the role of the mid-Araguaia River in differentiating populations and estimate divergence time among lineages to assess the timing of differentiation of these species, using mitochondrial DNA sequence data. The 6 didelphid marsupials revealed different intraspecific genetic patterns and structure. The 3 larger and more generalist species, Didelphis albiventris, Didelphis marsupialis, and Philander opossum, showed connectivity across the Araguaia River. In contrast the genetic structure of the 3 smaller and specialist species, Gracilinanus agilis, Marmosa (Marmosa) murina, and Marmosa (Micoureus) demerarae was shaped by the mid-Araguaia. Moreover, the split of eastern and western bank populations of the 2 latter species is consistent with the age of Araguaia River sediments formation. We hypothesize that the role of the Araguaia as a riverine barrier is linked to the level of ecological specialization among the 6 didelphid species and differences in their ability to cross rivers or disperse through the associated habitat types.