Blastocerus Research Articles

Osteology and radiographic anatomy of the hind limbs in Marshdeer (Blastocerus dichotomus)

Abstract: The knowledge of anatomical structures found in wild animals is important for the practice of medical and surgical clinic. Thus, the aim of this study was to describe the osteology and radiographic anatomy of the femur, patella, tibia, fibula, tarsal, metatarsal and phalanges of the Marshdeer Blastocerus dichotomus as a reference for clinical use and species identification. Most structures were similar to those found in domestic animals, with special features of this species. Noteworthy is, for example, the absence of the third trochanter of the femur. Although a ruminant, the Marshdeer has a fibuyla similar to the one described for the horse. B. dichotomus has four fingers on each limb, formed through three phalanges, only the third and fourth finger touch the ground, and the second and fifth finger is rudimentary. It has four proximal and two distal sesamoid bones, and sesamoid bones near the gastrocnemius muscle do not exist.

Occurrence of antibodies anti -Toxoplasma gondii, Neospora caninum and Leptospira interrogans in a captive deer herd in Southern Brazil.

A large number of Brazilian zoos keep many endangered species of deer, however, very few disease surveillance studies have been conducted among captive cervids. Blood samples from 32 Brazilian deer (Blastocerus dichotomus, Mazama nana and Mazama americana) kept in captivity at Bela Vista Biological Sanctuary (Foz do Iguaçu, Brazil) were investigated for 10 ruminant pathogens, with the aims of monitoring deer health status and evaluating any potential zoonotic risk. Deer serum samples were tested for Brucella abortus, Leptospira (23 serovars), Toxoplasma gondii, Neospora caninum, bovine viral diarrhea virus, infectious bovine rhinotracheitis virus, foot-and-mouth disease virus, western equine encephalitis virus, eastern equine encephalitis virus and Venezuelan equine encephalitis virus. Antibodies against T. gondii (15.6%), N. caninum (6.2%) and L. interrogans serogroup Serjoe (3.1%) were detected. The serological results for all other infectious agents were negative. The deer were considered to be clinically healthy and asymptomatic regarding any disease. Compared with studies on free-ranging deer, the prevalences of the same agents tested among the captive deer kept at the Sanctuary were lower, thus indicating good sanitary conditions and high-quality management practices at the zoo.

Patrones de consumo final de cérvidos en el Paraná medio: el caso del sitio Cerro Aguará

Los cérvidos fueron amplia y regularmente explotados por los cazadores-recolectores que habitaron la macroregión del Paraná-Plata durante el Holoceno tardío. En la cuenca media del Paraná, sin embargo, muy pocos estudios han enfocado sobre las estrategias empleadas para su obtención, procesamiento y consumo. El objetivo de este trabajo es explorar dichos aspectos a partir del análisis de los conjuntos de cérvidos provenientes del sitio arqueológico Cerro Aguará, localizado en el departamento General Obligado (provincia de Santa Fe). La perspectiva seleccionada propone al consumo como factor preponderante en la configuración del registro zooarqueológico dentro del continuum de actividades que componen la explotación faunística. Desde este marco de referencia, y tomando en consideración que las carcasas de los cérvidos proveen distintos tipos de recursos alimenticios con diferentes costos de extracción (carne, médula y grasa ósea), se evalúan diferentes indicadores para establecer si existió diferente intensidad en su procesamiento. Los resultados indican que las dos especies de cérvidos identificadas en el sitio, Blastocerus dichotomus y Ozotoceros bezoarticus, ocuparon un rol preponderante en la dieta, aunque las carcasas del primero fueron empleadas más intensivamente probablemente en correlación con su mayor disponibilidad de nutrientes internos.

Morfologia do estômago do cervo-do-pantanal (Blastocerus dichotomus, Illiger 1815)

Em razão da falta de informações sobre a morfologia do cervo-do-pantanal, objetivou-se apresentar a morfologia das câmaras gástricas desse cervídeo. Macroscopicamente, o estômago do cervo-do-pantanal é formado pelo rúmen, retículo, omaso e abomaso, assemelhando-se aos ruminantes domésticos. Microscopicamente, o rúmen e o abomaso são semelhantes aos animais domésticos, já o retículo e o omaso apresentam características específicas, como acentuada queratinização no ápice das pequenas projeções epiteliais do retículo e pregas omasais revestidas por discretas papilas.

Detection of Ehrlichia chaffeensis in a naturally infected elk (Cervus elaphus) from Missouri, USA

Introduction: Ehrlichia chaffeensis is an emerging zoonotic tick‐borne rickettsial pathogen that has been detected in a wide range of vertebrate hosts, including ruminants, canids and primates. Although white‐tailed deer (Odocoileus virginianus) are considered the primary reservoir of E. chaffeensis, this pathogen was also reported in other naturally infected cervids, including Korean spotted or sika deer (Cervus nippon) and Brazilian marsh deer (Blastocerus dichotomus). Case presentation: A captive adult bull elk (Cervus elaphus) from east‐central Missouri was submitted for post‐mortem analysis. The elk was in poor body condition with easily palpable ribs and vertebral spinal processes. Excoriations were noted on the occipital region of the head and on the left scapula, which had moderate amounts of maggots within the lesions. Large numbers of ticks were scattered over the body. Novel and established PCR assays were used to detect E. chaffeensis in blood and spleen samples from this elk, but the pathogen was not detected in Dermacentor albipictus ticks collected at necropsy. Portions of several gene sequences were analysed from the infecting agent. Conclusion To the best of our knowledge this is the first report of E. chaffeensis infection in an elk. It was not determined whether the pathogen contributed to cause of death. Notably, the pathogen was not detected in D. albipictus ticks collected from the elk.

Rickettsial Infection in Animals, Humans and Ticks in Paulicéia, Brazil.

A previous study in Paulicéia Municipality, south-eastern Brazil, reported 9.7% of the Amblyomma triste ticks to be infected by Rickettsia parkeri, a bacterial pathogen that causes spotted fever in humans. These A. triste ticks were shown to be associated with marsh areas, where the marsh deer Blastocerus dichotomus is a primary host for this tick species. During 2008-2009, blood serum samples were collected from 140 horses, 41 dogs, 5 opossums (Didelphis albiventris) and 26 humans in farms from Pauliceia Municipality. Ticks were collected from these animals, from vegetation and from additional wildlife in these farms. Overall, 25% (35/140) of the horses, 7.3% (3/41) of the dogs, 3.8% (1/26) of the humans and 100% (5/5) of the opossums were seroreactive (titre ≥64) to spotted fever group (SFG) Rickettsia spp. Multivariate statistical analysis indicated that horses that were allowed to forage in the marsh were 4.8 times more likely to be seroreactive to spotted fever group (SFG) Rickettsia spp than horses that did not forage in the marsh. In addition, horses that had been living in the farm for more than 8.5 years were 2.8 times more likely to be seroreactive to SFG Rickettsia spp than horses that were living for ≤8.5 years. Ticks collected from domestic animals or from vegetation included Amblyomma cajennense, Amblyomma coelebs, Amblyomma dubitatum, Dermacentor nitens and Rhipicephalus microplus. By PCR analyses, only one pool of A. coelebs ticks from the vegetation was shown to be infected by rickettsiae, for which DNA sequencing revealed to be Rickettsia amblyommii. Ticks (not tested by PCR) collected from wildlife encompassed A. cajennense and Amblyomma rotundatum on lizards (Tupinambis sp), and A. cajennense and A. triste on the bird Laterallus viridis. Our results indicate that the marsh area of Paulicéia offers risks of infection by SFG rickettsiae.

Evaluation of the Marsh Deer Stifle Joint by Imaging Studies and Gross Anatomy

This study aimed to evaluate the stifle joint of marsh deer using imaging studies and in comparison with gross anatomy. Ten hindlimbs from 5 marsh deer (Blastocerus dichotomus) were used. Radiography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed in each stifle joint. Two hindlimbs were dissected to describe stifle gross anatomy. The other limbs were sectioned in sagittal, dorsal or transverse planes. In the craniocaudal radiographic view, the lateral femoral condyle was broader than the medial femoral condyle. The femoral trochlea was asymmetrical. Subsequent multiplanar reconstruction revealed in the cranial view that the external surface of the patella was roughened, the medial trochlea ridge was larger than the lateral one, and the extensor fossa at the lateral condyle was next to the lateral ridge. The popliteal fossa was better visualized via the lateral view. Sagittal MRI images identified lateral and medial menisci, caudolateral and craniomedial bundles of cranial cruciate ligament, caudal cruciate ligament, patellar ligament and common extensor tendon. In conclusion, the marsh deer stifle presents some anatomical characteristics of the ovine stifle joint.

Dating human occupation at Toca do Serrote das Moendas, São Raimundo Nonato, Piauí-Brasil by electron spin resonance and optically stimulated luminescence

Excavation of Toca do Serrote das Moendas, in Piauí state, Brazil revealed a great quantity of fossil wild fauna associated with human remains. In particular, fossils of a cervid (Blastocerus dichotomus) were found, an animal frequently pictured in ancient rock wall paintings. In a well-defined stratum, two loose teeth of this species were found in close proximity to human bones. The teeth were independently dated by electron spin resonance (ESR) in two laboratories. The ages obtained for the teeth were 29 ± 3 ka (thousands of years) and 24 ± 1 ka. The concretion layer capping this stratum was dated by optically stimulated luminescence (OSL) of the quartz grains to 21 ± 3 ka. As these values were derived independently in three different laboratories, using different methods and equipment, these results are compelling evidence of early habitation in this area.

Plants from deer diet in the Brazilian Pantanal Wetland as potential source of antiviral and antioxidant compounds

The major part of plants foraged by endangered pampas and marsh deer at the Brazilian Pantanal Wetland belongs to botanical genera containing medicinal species used mainly for healing infectious and inflammatory diseases. In this study, extracts and fractions of 19 plant species from deer diet were in vitro screened against bovine and suid herpesviruses, avian reovirus and infectious bursal disease virus (IBDV). At non-cytotoxicity concentrations, the extract and/or fractions from 14 plant species presented antiviral activity against at least one of these viruses except IBDV. Cecropia pachystachya, Melochia villosa and Polygonum acuminatum presented the most relevant results against bovine and suid herpesviruses while Andira cuyabensis was the most active plant against avian reovirus. C. pachystachya extract and fractions showed virucide effect, and kept their inhibitory activity towards both herpesviruses independent of the addition time in cell culture. Considering the benefit of the antioxidant activity of food and medicinal plants for the health balance, and its important role in viral infections, the extracts were also screened in a DPPH assay. Our findings show that several plants foraged by pampas and marsh deer possess antiviral activity against some pathogenic viruses for mammals. This study proposed an innovative strategy by adopting plants consumed in the diet of wild non-primate mammals for the search of potentially therapeutic substances. DOI: http://dx.doi.org/10.17525/vrrjournal.v19i2.95

Spatiotemporal variation in human-wildlife conflicts along highway BR-262 in the Brazilian Pantanal

The Pantanal of Brazil, the world’s largest freshwater wetland, supports a large diversity of species and is under continually increasing pressure from human development, including vehicle collisions with wild animals. We examined decadal, annual, and spatial variation in wildlife-vehicle collisions along highway BR-262 in the southern Pantanal, and specifically: (1) what is the rate of roadkill along BR-262, and did it increased over the previous decade, (2) which species are frequently victims of collisions and does this vary annually along the highway’s length, and (3) what anthropogenic or environmental factors may influence this variation and how can the context of collisions inform mitigation? We sampled the highway monthly, between April 2011 and June 2012, stopping when roadkill was observed to identify species and collect GPS coordinates and a photographic record. Data was analyzed temporally and in relation to traffic volume and precipitation, and imported into a GIS and analyzed spatially and in relation to elevation. We recorded 518 carcasses from 40 species over the 15 sampling periods. The rate of roadkill incidents was 1 every 6.2 km, a tenfold increase since 2002, and is now one of the highest in Brazil. IUCN Red List species were observed, including lowland tapir, giant anteater, and marsh deer. At the lowest elevations, during seasonal wetland inundation the causeway embankment is sought for refuge, increasing collision probability. Mitigation measures tied to seasonal flood pulse variation along the causeway may reduce the high rate of wild animal mortality and loss of biodiversity.

Severe population decline of marsh deer, Blastocerus dichotomus (Cetartiodactyla: Cervidae), a threatened species, caused by flooding related to a hydroelectric power plant

Balancing power production and environmental conservation can be problematic. The objective of this study was to investigate the abundance of marsh deer in the Paraná River Basin, above the Sergio Motta (Porto Primavera) Dam, before and after the impact of the dam closure. A fixed-wing, flat window aircraft was used to survey study transects. Observations were recorded based on the distance sampling line transect method, assuming that the detection probability decreases with increased distance. The abundance of marsh deer in the survey region prior to flooding was estimated to be 974 individuals (CV = 0.23). The overall abundance dropped from 974 to 444 (CV = 0.26) individuals after flooding, an overall reduction of 54%. This reduction can be attributed to the direct impact of the flooding process, but it was likely exacerbated by indirect effects, such as increased disease, hunting, and reduction in food availability. Prior to flooding, the marsh deer was distributed widely throughout the dam's catchment area; however, the marsh deer habitat was almost completely destroyed by the flooding process. This situation highlights the need to implement management strategies that ensure the survival of the remaining fragmented population.

Potential Effects of Climate Change on the Water Level, Flora and Macro-fauna of a Large Neotropical Wetland

Possible consequences of climate change in one of the world’s largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a long-term negative trend in water-level. To explore the possible response of biota to such water-level changes, species-area relationships of flora and aerial censuses of macro-fauna were analysed during an extraordinary dry period. Plant species richness at the basin scale was found to be highly resistant to hydrological changes, as the large dimension of the wetland acts to buffer against the water-level variations. However, local diversity decreased significantly with low water levels, leading to the loss of ecosystem resilience to additional stressors. The analysis of macro-fauna populations suggested that wetland provides refuge, in low water periods, for the animals with high dispersal ability (aquatic and migratory birds). On the contrary, the abundance of animals with low dispersal ability (mainly herbivorous species) was negatively impacted in low water periods, probably because they are required to search for alternative resources beyond the wetland borders. This period of resource scarcity was also related to increased mortality of large mammals (e.g. marsh deer) around water bodies with high anthropogenic enrichment and cyanobacteria dominance. The synergy between recurrent climatic fluctuations and additional stressors (i.e. biological invasions, eutrophication) presents an important challenge to the conservation of neotropical wetlands in the coming decades.

Epizootic Hemorrhagic Disease in Brocket Deer, Brazil

Epizootic Hemorrhagic Disease in Brocket Deer, Brazil

A PCR/RFLP methodology to identify non-Amazonian Brazilian deer species

Due to the necessity of using noninvasive samples to study animals as elusive as the deer that occur in Brazil, we realized it was important to develop a PCR/RFLP protocol to assist in identifying such samples. Thus we developed a protocol in which a fragment of the cytochrome b gene is digested with two enzymes: SspI, which distinguishes species of the genus Mazama from Blastocerus dichotomus and Ozotoceros bezoarticus, and TAQα1 which permits differentiation between the species B. dichotomus and O. bezoarticus.

Isotopic values of diet of Blastocerus dichotomus (marsh deer) in Paraná Basin, South America

The marsh deer (Blastocerus dichotomus, Illiger, 1815) is the largest contemporary South American deer, and its habitat includes the floodplains and wetlands of eastern South America. Throughout the Holocene these deer were widely used by indigenous societies, from the southern banks of the Amazon River to the Río de la Plata River, and from the Andean foothills to the Atlantic Ocean. However, despite the enormous ecological and archaeological importance of this ungulate in the region, our knowledge of the isotopic values of their diet is almost nonexistent. This paper is the first systematic approach to the study of the isotopic values of this mammal's diet, using archaeological and present-day samples from interconnected watersheds of the Paraná and Uruguay rivers in east-central Argentina. The results obtained from 24 measurements indicate an average value of −21.09 ± 1.46‰ in δ13C collagen, with a low coefficient of variation (6.92%). The data indicate a marked preference for consumption of plants with a C3 photosynthetic pathway. Most of the observed variability in the isotopic values corresponds to the period 900–1430 14C years BP, a time range during which the values show higher consumption of C4 plants. This it could be related with a period where temperature and associated humidity increased, synchronous in the area with the Medieval Climate Anomaly.

Flavonoids from Mimosa xanthocentra (Leguminosae: Mimosoideae) and molecular modeling studies for isovitexin-2″-O-α-l-rhamnopyranoside rotamers

Phytochemical investigation of Mimosa xanthocentra Mart. (Leguminosae: Mimosoideae), an herb comprising the diet of marsh deer and pampas deer in the Brazilian Pantanal, led to the isolation of flavones isovitexin-2″-O-α-l-rhamnopyranoside 1 and vitexin-2″-O-α-l-rhamnopyranoside 2, and a mixture of flavonols avicularin 3a and reynoutrin 3b. At room temperature, compound 1 was observed in the 1H and 13C NMR spectra as a mixture of two rotamers in equilibrium in a DMSO-d6 solution. Molecular modeling using MM2 calculations led to the first proposal of three-dimensional solution structure of both observed conformers. The energy barrier between both rotamers was evaluated theoretically by molecular modeling and experimentally by variable-temperature NMR studies and calculation of ΔG‡ of rotation using Eyring equation. This is the first report on flavonoids from M. xanthocentra.

Densities of the Vulnerable marsh deer Blastocerus dichotomus in Bolivia's northern savannahs

AbstractAerial surveys have been used successfully to estimate vertebrate populations in open habitats. The marsh deer Blastocerus dichotomus, categorized as Vulnerable on the IUCN Red List, lives in such habitats and is suitable for aerial counting because it is conspicuous. This species, the largest South American deer, is native to Argentina, Boliva, Brazil, Paraguay and Peru but no reliable information has previously been available on its populations in Bolivia. From May to August 2007 we conducted aerial transects to survey marsh deer in three large areas of savannah. We used a modified mark–recapture method to improve the accuracy of the counts and estimated density and abundance. The corrected, estimated density of the marsh deer was 0.24 km−2 in the northern La Paz Department, 0.12 km−2 in Mamoré and 0.15 km−2 in Iténez. These densities are similar to the mean density of the species on other South American savannahs. This is the first large-scale survey of the marsh deer in Bolivia and the first to provide information about the density of the species in the Amazon. We recommend the creation of protected areas in these savannahs, and wildlife and domestic health programmes to conserve the marsh deer of this region.

Prevalence and molecular characterization of Anaplasmataceae agents in free-ranging Brazilian marsh deer (Blastocerus dichotomus)

Anaplasmataceae organisms comprise a group of obligate intracellular gram-negative, tick-borne bacteria that can infect both animals and humans. In the present work we investigate the presence of Ehrlichia, Anaplasma, and Neorickettsia species in blood samples from Brazilian marsh deer (Blastocerus dichotomus), using both molecular and serologic techniques. Blood was collected from 143 deer captured along floodplains of the Paraná River, near the Porto Primavera hydroelectric power plant. Before and after flooding, marsh deer were captured for a wide range research program under the financial support of São Paulo State Energy Company (CESP), between 1998 and 2001. Samples were divided into four groups according to time and location of capture and named MS01 (n=99), MS02 (n=18) (Mato Grosso do Sul, before and after flooding, respectively), PX (n=9; Peixe River, after flooding), and AGUA (n=17; Aguapeí River, after flooding). The seroprevalences for Ehrlichia chaffeensis and Anaplasma phagocytophilum were 76.76% and 20.2% in MS01, 88.88% and 5.55% in MS02, 88.88% and 22.22% in PX, and 94.12% and 5.88% in AGUA, respectively. Sixty-one animals (42.65% of the total population) were PCR-positive for E. chaffeensis PCR (100.0% identity based on 16S rRNA, dsb, and groESL genes). Seventy deer (48.95% of the total population) were PCR-positive for Anaplasma spp. (99.0% of identity with A. platys, and in the same clade as A. phagocytophilum, A. bovis, and A. platys based on 16S rRNA phylogenetic analysis). Our results demonstrate that Brazilian marsh deer are exposed to E. chaffeensis and Anaplasma spp. and may act as reservoirs for these rickettsial agents, playing a role in disease transmission to humans and other animals.

Molecular Detection of Tick-Borne Pathogens of the Family Anaplasmataceae in Brazilian Brown Brocket Deer (Mazama gouazoubira, Fischer, 1814) and Marsh Deer (Blastocerus dichotomus, Illiger, 1815)

Deer are important natural reservoir hosts of Anaplasmataceae. The present study used nested PCR and nucleotide sequencing to evaluate the occurrence of Anaplasmataceae species in 23 free-living and six captive specimens of the cervids Mazama gouazoubira and Blastocerus dichotomus in Minas Gerais State, Brazil. Blood samples were tested for the presence of Ehrlichia and Anaplasma spp. using nPCR assays and sequencing of the msp4, msp1 and 16S rRNA genes. The identity of each sequence was confirmed by comparison with sequences available from GenBank using BLAST software. Of the animals investigated, 93.1% (27/29) were infected with haemoparasites including Anaplasma marginale (79.3%), Ehrlichia chaffeensis (3.4%), Anaplasma bovis (3.4%) and Anaplasma spp. (assigned to A.platys and A.phagocytophilum) (17.2%). Co-infection occurred in 20% (6/29) of the deer examined. Four (13.8%) were infected with A.marginale and Anaplasma sp., one (3.4%) was infected with A.marginale and E.chaffeensis, and one (3.4%) was infected with A.marginale and A.bovis. The results of the present study suggest that cross-protection does not occur in these deer. Immunological cross-reaction occurs when sera are tested diagnostically because these bacteria are closely related taxonomically, reinforcing the importance of molecular diagnosis followed by nucleotide sequencing.

Prevalence and Molecular Characterization of Mycoplasma ovis in Selected Free-Ranging Brazilian Deer Populations

Mycoplasma ovis is a hemoplasma that may cause anemia and mortality in small ruminants. Our aim was to determine whether M. ovis infects populations of free-ranging deer in Brazil. Buffy coat samples from 64 Blastocerus dichotomus from Porto Primavera, 18 Ozotocerus bezoarticus from Pantanal, and 21 O. bezoarticus from Emas National Park were tested. Using a M. ovis PCR protocol to amplify extracted DNA, 46/64 (72%) of deer from Porto Primavera, 10/18 (56%) from Pantanal, and 4/21 (19%) from Emas National Park were positive, giving an overall positive rate of 58% for hemoplasma in these wild deer. Sequencing and phylogenetic analysis of the 16S rRNA gene revealed 3 genetically distinct hemoplasmas including M. ovis, 'Candidatus Mycoplasma erythrocervae', and a hemoplasma most closely related to M. ovis. Phylogenetic analysis of the 23S rRNA gene from selected sequences confirmed these relationships.