Nine-banded Armadillo Dasypus Novemcinctus Research Articles

Fleas and lesions in armadillo osteoderms.

Armadillos are bitten by several species of flea. Females of the genus Tunga penetrate the epidermis and when in place are fertilised by males, after which the abdomen swells enormously to form a 'neosome'. Within the penetrans group, T. perforans, makes lesions that perforate the osteoderms within the integument to form ~3 mm diameter cavities occupied by a discoid neosome. We examined these lesions in carapace material from animals which had died in the wild to see whether we could recruit evidence as to how they may be generated, either by the insect or by the host. We studied one species without such lesions, the nine-banded armadillo Dasypus novemcinctus, and two species with, the greater hairy armadillo Chaetophractus villosus and the southern three-banded armadillo Tolypeutes matacus, both showing the characteristic 'flea bite' holes in the external surfaces of the osteoderms. Samples were studied by three-dimensional backscattered electron mode scanning electron microscopy and X-ray microtomography. Both methods showed resorption pit complexes in the external surfaces of the osteoderms characteristic of those made by osteoclasts in active bone resorption. Lesions involved both the syndesmoses (sutures) between adjacent bones and the central regions of the osteoderms. Many lesions showed extensive repair by infilling with new bone. We conclude that the T. perforans neosome creates a local host response which causes bone resorption, creating the space in which it can grow.

Phenotypic variability and environmental tolerance shed light on nine-banded armadillo Nearctic invasion

High phenotypic diversity is an intrinsic attribute of successful invaders, but remains poorly studied. Here, we investigate the role of phenotypic traits in biological invasions using one of the few Neotropical mammal lineages that has successfully invaded the Nearctic, the nine-banded armadillo Dasypus novemcinctus. Specifically, we analyzed cranial phenotypic variation of the nine-banded armadillo, comparing ecological associations throughout its native range with those experienced by invasive populations in the United States. We also compared the climatic conditions faced by native and invader armadillos to determine whether the species has broadened its environmental tolerance or remained within its native climatic pool. Our study shows that D. novemcinctus exhibits pronounced morphological variation through its range and that the phenotypic pattern in newly invaded areas departs from trends of the species in its native range. The morphological differences exhibited by invader armadillos can be related to their reduced reliance on myrmecophagy, with armadillos from temperate open areas in North America exploiting a broader range of dietary items. Moreover, we found the climatic conditions faced by alien armadillos during the initial phases of their Nearctic invasion fell within the native climatic range. In sum, high phenotypic variability and substantial environmental tolerance in the nine-banded armadillo help to explain its nearly ubiquitous distribution across contrasting ecosystems in its native range as well as its successful Nearctic invasion. Our findings underscore the importance of studying the covariation of morphology and climate across native and invasive ranges to understand biological responses in novel environments.

On The Evolutionary Origins Of Cd1d And The Type I, Semi-Invariant Natural Killer T Cells

Abstract The evolutionary origins of CD1d molecules and the T cell receptors (TCR) that recognize them currently remain unknown. CD1d molecules control the functions of a specialized subset of lymphocytes called semi-invariant natural killer T (type I NKT) cells. Type I NKT cells recognize both the self and non-self agonist —α-galactosylceramide (αGC) and related glycolipids— when presented by CD1d molecules. NKT cells express an invariant TCR α-chain (iTCRα) resulting from the mouse Vα14 or human Vα24 to Jα18 rearrangement. iTCRα pairs with the mouse Vβ8 (Vβ7, Vβ6, Vβ2) or the orthologous human Vβ11 TCR β-chain to create a functional NKTCR. Our phylogenetic analyses revealed that whilst the mouse Cd1 homologs have Mesozoic origin in they they evolved as far back asin the anole lizards, the orthologues of Cd1d and that of Vα14/Vα24 and Jα18 gene segments emerged with the decent of mammals. Moreover, the known avian CD1 orthologs lack the α3 domain and both the reptilian and the avian CD1 lack a functional endo/lysosomal-recycling motif critical for NKT cell development and function. As well, monotreme genomes lack Cd1d, Vα14/Vα24 and Jα18 orthologs and the marsupial Cd1d, Vα14/Vα24 and Jα18 orthologs harbor indels that would render the encoded proteins non-functional. Consistent with these findings, one of the most divergent Cd1d gene isolated from the nine-banded armadillo Dasypus novemcinctus and ectopically expressed in a cell line presented αGC and activated mouse NKT cell hybridomas. Hence, we conclude that the CD1d-restricted αGC-presentation in the immune system evolved more recently as an eutherian innovation.

Hunting of mammal species in protected areas of the southern Bahian Atlantic Forest, Brazil

AbstractTo investigate the practice of hunting by local people in the southern Bahia region of Brazil and provide information to support the implementation of the National Action Plan for Conservation of the Central Atlantic Forest Mammals, we conducted 351 interviews with residents of three protected areas and a buffer zone. Thirty-seven percent of respondents stated that they had captured an animal opportunistically, 16% hunted actively and 47% did not hunt. The major motivation for hunting was consumption but people also hunted for medicinal purposes, recreation and retaliation. The most hunted and consumed species were the paca Cuniculus paca, the nine-banded armadillo Dasypus novemcinctus and the collared peccary Pecari tajacu; threatened species were rarely hunted. Opinions varied on whether wildlife was declining or increasing; declines were generally attributed to hunting. Our findings suggest there is illegal hunting for consumption in and around protected areas of the region. Management efforts should prioritize fairness in the expropriation process for people who must be relocated, and adopt an approach to wildlife management that involves residents living around the protected areas, and considers their needs.

ATLANTIC-CAMTRAPS: a dataset of medium and large terrestrial mammal communities in the Atlantic Forest of South America.

Our understanding of mammal ecology has always been hindered by the difficulties of observing species in closed tropical forests. Camera trapping has become a major advance for monitoring terrestrial mammals in biodiversity rich ecosystems. Here we compiled one of the largest datasets of inventories of terrestrial mammal communities for the Neotropical region based on camera trapping studies. The dataset comprises 170 surveys of medium to large terrestrial mammals using camera traps conducted in 144 areas by 74 studies, covering six vegetation types of tropical and subtropical Atlantic Forest of South America (Brazil and Argentina), and present data on species composition and richness. The complete dataset comprises 53,438 independent records of 83 species of mammals, includes 10 species of marsupials, 15 rodents, 20 carnivores, eight ungulates and six armadillos. Species richness averaged 13 species (±6.07 SD) per site. Only six species occurred in more than 50% of the sites: the domestic dog Canis familiaris, crab-eating fox Cerdocyon thous, tayra Eira barbara, south American coati Nasua nasua, crab-eating raccoon Procyon cancrivorus and the nine-banded armadillo Dasypus novemcinctus. The information contained in this dataset can be used to understand macroecological patterns of biodiversity, community, and population structure, but also to evaluate the ecological consequences of fragmentation, defaunation, and trophic interactions.

Parental Risk-Taking at Natural Northern Bobwhite Nests

Parental risk-taking at the nest is critical to examining the trade-offs between current and future reproduction. Using Northern Bobwhites ( Colinus virginianus) at camera-monitored nests in the natural environment, we examined how parental and offspring characteristics, predator community, and predator type affected flush distance of incubating birds to approaching predators. During 1999–2006, we monitored 118 predation interactions at nests at two pairs of study sites in southern Georgia and northern Florida, USA where mesomammalian predators were experimentally reduced or not reduced. The results showed that incubating parent birds allowed closer approaches by predators that typically only consumed eggs ( e.g. Nine-banded Armadillos Dasypus novemcinctus, Virginia Opossums Didelphis virginiana, and snakes) than by predators that could harm the adults (including Bobcats Lynx rufus and Raccoons Procyon lotor) prior to flushing from the nest. Our data did not support the hypotheses that parent-offspring characteristics and predator community affect parental risk-taking at the nest. Our findings suggest that parent birds incorporate information about predator identity over parental and offspring characteristics or predator community into anti-predator decisions at the nest in systems with high predation risk.

Wild meat: a shared resource amongst people and predators

AbstractMillions of people throughout the tropics consume wild meat. Overhunting reduces food security for people and large predators, yet little is known of the impact of hunting in systems where people and predators target the same prey species. We collate published data on predator diet in Belize with interview data about the consumption of wild and domestic meat by Belizeans, to compare the wild-meat diets of humans, jaguarsPanthera oncaand pumasPuma concolorand assess the sustainability of the combined offtake by humans and jaguars. Six wild mammal species (nine-banded armadilloDasypus novemcinctus, pacaCuniculus paca, collared peccaryPecari tajacu, white-lipped peccaryTayassu pecari, red brocket deerMazama americanaand white-tailed deerOdocoileus virginianus) comprised 7% of the animal-protein meals eaten by Belizeans. Overall, 80% of these meals were eaten by 20% of interviewees, suggesting a necessary role of wild meat for the minority. The same species were found in 69 and 86% of jaguar and puma scats, respectively. We estimate a national annual harvest of c. 4,000 tonnes of these six wild mammals by humans and jaguars, of which 78% is hunted by people. Sustainability is difficult to evaluate because prey population data are lacking in Belize. However, simple models suggest that a sustainable harvest at this rate would require higher prey population densities than averages recorded in hunted Neotropical forests. We emphasize the need for robust regional estimates of game species densities, to improve assessments of sustainability and inform hunting regulations. We recommend that the requirements of predators as well as those of people be considered when assessing wild meat harvests.

Sporothrix schenckii sensu stricto Isolated from Soil in an Armadillo’s Burrow

Sporotrichosis is a polymorphic disease of man and animals caused by traumatic implantation of propagules into the skin and subcutaneous tissue. Pathogenic species includes S. brasiliensis, S. schenckii, S. globosa and S. luriei. The disease is remarkable for its occurrence as sapronoses and/or zoonosis outbreaks in tropical and subtropical areas; although, the ecology of the clinical clade is still puzzling. Here, we describe an anamorphic Sporothrix strain isolated from soil in an armadillo's burrow, which was located in a hyper endemic area of Paracoccidioidomycosis in Brazil. This isolate was identified as S. schenckii sensu stricto (Clade IIa) based on morphological and physiological characteristics and phylogenetic analyses of calmodulin sequences. We then discuss the role of the nine-banded armadillo Dasypus novemcinctus as a natural carrier of Sporothrix propagules to better understand Sporothrix sources in nature and reveal essential aspects about the pathogen's eco-epidemiology.

Occupancy estimation of jaguar Panthera onca to assess the value of east-central Mexico as a jaguar corridor

AbstractThe use of wildlife corridors to maintain landscape connectivity has become increasingly relevant to the conservation of wide-ranging species, including the jaguar Panthera onca. Jaguars are particularly threatened in Mexico, where corridor linkages are tenuous as a result of habitat fragmentation. Our study assessed a section of potential corridor south of the Sierra Madre Oriental in eastern Mexico. We conducted 245 interviews with local inhabitants in 140 36-km2 sampling units over a 5-month period and compiled detection histories for jaguars and five prey species: collared peccary Pecari tajacu, red brocket deer Mazama americana, white-tailed deer Odocoileus virginianus, spotted paca Agouti paca, and nine-banded armadillo Dasypus novemcinctus. These detection histories were then analysed using site occupancy modelling. Each sampling unit was assigned a probability of habitat use based on (1) the two smaller prey species (paca and armadillo) and (2) at least two of the larger prey species (collared peccary and two deer species) using habitat in that unit. This probability estimate was considered a proxy for the prey base of each sampling unit and therefore the unit's suitability as a jaguar corridor. Although the prey base in some areas appears adequate to support a jaguar population, large-scale development projects and the paucity of jaguar sign are major obstacles to this region's potential as a jaguar corridor. Our results suggest that the eastern coast of Mexico may not be a priority area for range-wide jaguar conservation.

A new species of Metathelazia (Nematoda: Pneumospiruridae) from the lungs of a nine-banded armadillo in Central Mexico

Twenty-four worms were collected from the bronchioles in both lungs of a male nine-banded armadillo Dasypus novemcinctus Linnaeus, 1758 captured in Teacalco, Morelos, Mexico. The worms, herein named Metathelazia mexicana n. sp., show a constriction in the esophagus at the level of the nerve ring; males of the species have 7 pairs of papillae, fewer than the other species in the genus. Metathelazia capsulata is the most similar species to Metathelazia mexicana; however, the latter has much shorter spicules. This is the fourth species in the genus known to occur in the New World.

Effects of habitat and landscape characteristics on medium and large mammal species richness and composition in northern Uruguay

The increasing world population and demand for food and other products has accelerated the conversion of natural habitats into agricultural lands, plantations and urban areas. Changes in habitat and landscape characteristics due to land-use change can have a significant effect on species presence, abundance, and distribution. Multi-scale approaches have been used to determine the proper spatial scales at which species and communities are responding to habitat transformation. In this context, we evaluated medium and large mammal species richness and composition in gallery forest (n = 10), grassland (n = 10), and exotic tree plantation (n = 10) in a region where grasslands have been converted into exotic tree plantations. We quantified mammal species richness and composition with camera traps and track surveys. The composition of the mammal community was related with local habitat variables, and landscape variables measured at seven spatial scales. We found 14 mammal species in forest, 11 species in plantation, and 7 mammal species in grassland. Two species are exotics, the wild boar Sus scrofa Linnaeus, 1758 and the European hare Lepus europaeus Pallas, 1778. The most common species are the crab-eating fox Cerdocyon thous Linnaeus, 1766, the nine-banded armadillo Dasypus novemcinctus Linnaeus, 1758 and the gray brocket deer Mazama gouazoubira G. Fischer, 1814 which are generalist species. Our results showed significant differences in mammal species richness and composition among the three habitat types. Plantations can have positive and negative effects on the presence of species restricted to grasslands. Positive effects are reflected in a wider local distribution of some forest species that rarely use grassland. The most important habitat and landscape variables that influenced mammal species richness and composition were vertical structure index, canopy cover, tree species diversity, percentage of grass, and the percentage of forest and grassland at the landscape scale of 0.1 km. We advise the following important measures for conservation of this mammal community: 1) reduce logging and cattle grazing in gallery forest, and 2) increase grassland buffer zones between plantation and forest.

Diversity in Paracoccidioides brasiliensis . The PbGP43 gene as a genetic marker

Paracoccidioides brasiliensis is a temperature-dependent dimorphic fungus and the agent of paracoccidioidomycosis (PCM), which is prevalent in rural workers of Latin American countries. Until a decade ago, most of the studies involving P. brasiliensis used clinical isolates, since environmental samples from soil are difficult to obtain. More recently, P. brasiliensis has been isolated from infected wild and domestic animals, especially from the nine-banded armadillo Dasypus novemcinctus in Brazil. Over the years, diversity within the species has been observed at several phenotypic levels. The present review will discuss the reports focusing on genetic polymorphism, which culminated with the detection of P. brasiliensis phylogenetic species as a result of a multilocus study. Polymorphism in the PbGP43 gene is detailed. This gene encodes fungal glycoprotein gp43, a dominant P. brasiliensis antigen largely studied in the last two decades for its importance in diagnosis, immune protection, and adhesive properties to extracellular matrix-associated proteins. Fungal traits associated with genetic groups are discussed.

Partial characterization of phagocytic activity in neutrophils of the nine-banded armadillo Dasypus novemcinctus

Though the armadillo is important as a research model in leprosy studies, the activity of armadillo's neutrophils is an aspect of little research. The aim of this study was carried out to partially characterize the chemotaxis, endocytosis and bacteriocidal ability of the neutrophils found in the nine-banded armadillo ( Dasypus novemcinctus) . Results showed that the chemotactic activity of the neutrophils, evaluated by the movement of the neutrophils through a nitrocellulose membrane (5 μm) in response to a chemo-attractive substance, was greater towards the armadillo serum (5.16 ± 1.35 migration index, p < 0.05) than towards the formil methionyl leucil phenylalanine (fMLP, 1.43 ± 0.18 migration index) or human serum (0.56 ± 0.18 migration index). Regarding endocytic capacity of the neutrophils and the monocytes against Escherichia coli was evaluated by a flow cytometry and using opsonized and non-opsonized E. coli-FITC at the following incubation times: 5, 10, 20, 30 and 60 min. The largest percentage of endocytosis by the neutrophils was 92.32 ± 0.12% with opsonized bacteria and 77.73 ± 14.33% with non-opsonized bacteria at 10 min incubation time, while the largest percentage of endocytosis by monocytes was 89.94 ± 1.40% with opsonized bacteria and 73.07 ± 15.6% with non-opsonized bacteria at 20 min incubation time. Evaluation of the bacteriocidal capacity of neutrophils using the methyl-thiazol-tetrazolium salts (MTT) reduction color-measurement assay showed an 89.0 ± 10% mortality rate of non-opsonized E. coli and 89.0 + 10% of opsonized E. coli. In conclusion, the armadillo neutrophils show a good phagocytosis and bacteriocidal activity; however, a deficiency in the migration towards the fMLP was observed. This deficiency could be a cause so that the armadillo neutrophils do not respond quickly to invading microorganism.

A Novel Abundant Family of Retroposed Elements (DAS-SINEs) in the Nine-Banded Armadillo (Dasypus novemcinctus)

About half of the mammalian genome is composed of retroposons. Long interspersed elements (LINEs) and short interspersed elements (SINEs) are the most abundant repetitive elements and account for about 21% and 13% of the human genome, respectively. SINEs have been detected in all major mammalian lineages, except for the South American order Xenarthra, also termed Edentata (armadillos, anteaters, and sloths). Investigating this order, we discovered a novel high-copy-number family of tRNA derived SINEs in the nine-banded armadillo Dasypus novemcinctus, a species that successfully crossed the Central American land bridge to North America in the Pliocene. A specific computer algorithm was developed, and we detected and extracted 687 specific SINEs from databases. Termed DAS-SINEs, we further divided them into six distinct subfamilies. We extracted tRNA(Ala)-derived monomers, two types of dimers, and three subfamilies of chimeric fusion products of a tRNA(Ala) domain and an approximately 180-nt sequence of thus far unidentified origin. Comparisons of secondary structures of the DAS-SINEs' tRNA domains suggest selective pressure to maintain a tRNA-like D-arm structure in the respective founder RNAs, as shown by compensatory mutations. By analysis of subfamily-specific genetic variability, comparison of the proportion of direct repeats, and analysis of self-integrations as well as key events of dimerization and deletions or insertions, we were able to delineate the evolutionary history of the DAS-SINE subfamilies.

The naked-tailed armadilloCabassous centralis(Miller 1899): a new host toParacoccidioides brasiliensis. Molecular identification of the isolate

The natural habitat of Paracoccidioides brasiliensis remains undefined but the repeated demonstration of infection by this fungus in the nine-banded armadillo Dasypus novemcinctus has opened interesting research avenues. We report here the isolation of this fungus from the spleen of a naked-tailed armadillo Cabassous centralis (Miller 1899) captured in a coffee farm localized in the Colombian endemic area for paracoccidioidomycosis. This particular isolate was identified by its dimorphism and also by comparison of the PbGP43 gene and ribosomal internal transcribed spacer regions (ITS) with recognized P brasiliensis strains. This finding extends the range of naturally acquired infections in mammals of the family Dasypodidae and confirms the existence of this human pathogen in areas where human paracoccidioidomycosis is known to occur.

Individual variation in metabolic traits of wild nine-banded armadillos (Dasypus novemcinctus), and the aerobic capacity model for the evolution of endothermy.

A fundamental assumption of the aerobic capacity model for the evolution of endothermy is that basal (BMR) and peak (PMR) metabolic rates are functionally linked at the intraspecific level. The purpose of this study was to use the nine-banded armadillo Dasypus novemcinctus as a model to test this assumption. Measurements of BMR, PMR, mass and rectal temperature were obtained over two summers from wild, adult individuals from a population in Louisiana, USA. BMR and PMR were positively correlated (r=0.62), and both were significantly higher (by 46% for BMR and by 35% for PMR) in 1999 than in 1998. Similar results were obtained whether metabolic rates were expressed in whole-animal or mass-independent units. These results suggest the existence of a functional link between BMR and PMR and are therefore consistent with the aerobic capacity model. In addition, this study confirmed that, compared with most eutherian mammals, the nine-banded armadillo exhibits low and highly variable basal and peak metabolic rates (20-60% the predicted values; 23% and 27% coefficients of variation) and rectal temperatures (range 32.7-35.3 degrees C). Such metabolic traits are, however, consistent with the general pattern previously observed for other members of the order Xenarthra and with the hypothesis that low metabolic rates in armored mammals evolved as a result of unbalanced selection in which, because of low predation risks, selection for a high aerobic capacity was much weaker than the opposing selection for energy conservation.

Distribution of Histoplasma capsulatum in Amazonian wildlife.

In a survey of 296 sylvatic animals captured from virgin forests in the north-eastern and south-western Amazon of Brazil, Histoplasma capsulatum was isolated, via the indirect hamster inoculation method, from the liver and spleen of four common opossums Didelphis marsupialis and two pacas Agouti paca. The infected animals did not show any clinical symptoms or histopathology. The known Amazonian mammalian species with natural histoplasmosis now total five, the previously reported species being the spiny rat Proechimys guyannensis, the two-toed sloth Choloepus didactylus and the nine-banded armadillo Dasypus novemcinctus.