Search

The structure of the heart and the coronary blood supply of wild mammals, including that of threatened species, are poorly understood. This study set out to describe the heart, aortic arch branching and coronary distribution of Myrmecophaga tridactyla, and to compare it with anatomical descriptions of other Xenarthra given elsewhere. Eight adult giant anteater cadaveric specimens were used in this study. Morphological features of the heart and coronary blood supply were examined using gross dissection as well as latex and cast preparations. The heart lied in the median plane of the thoracic cavity and corresponded to a cone-shape structure with a rounded apex facing left. The internal chambers of the heart comprised the same structures described in other mammals. Two different patterns of coronary blood supply were observed in the giant anteater. Hence, it can be concluded that the three species of Xenarthra share the same heart structure described in other mammals to date. Aortic arch branches and variations in coronary blood supply in this study have been described in carnivores, particularly the cat and the galea. The branching pattern of the coronary artery differed from that of other mammals and may be specific to Myrmecophaga tridactyla. Morphological description of the heart of the giant anteater and comparison with morphological features of other mammals, especially Xenarthra, may assist in phylogenetic analysis and provide significant contributions to clinical anatomy of practical procedures.

In general, large mammal species with highly specialized feeding behavior and solitary habits are expected to suffer genetic consequences from habitat loss and fragmentation. To test this hypothesis, we analyzed the genetic diversity distribution of the threatened giant anteater inhabiting a human-modified landscape. We used 10 microsatellite loci to assess the genetic diversity and population structure of 107 giant anteaters sampled in the Brazilian Central-Western region. No genetic population structuring was observed in this region suggesting no gene flow restriction within the studied area. On the other hand, the moderate level of genetic diversity (Ho = 0.54), recent bottleneck detected and inbreeding (Fis, 0.13; p ≤ 0.001) signatures suggest potential impacts on the genetic variation of this Xenarthra. Additionally, a previous demographic reduction was suggested. Thus, considering the increased human-promoted impacts across the entire area of distribution of the giant anteater, our results can illustrate the potential effects of these disturbances on the genetic variation, allowing us to request the long-term conservation of this emblematic species.

The giant anteater (Myrmecophaga tridactyla) is a vulnerable species from Central and South America, and is considered possibly extinct in Belize, Guatemala, El Salvador, and Uruguay. Due to the species’ conservation and reproductive importance, this research aimed to characterize the morphology, histochemical, immunohistochemical, and ultrastructural feature of the giant anteater prostate gland. For this, we collected 11 giant anteater prostate glands and performed macroscopic, morphological, histochemical, immunohistochemical, and ultrastructural analysis. Nine prostate glands from an adult subject and two from young subjects were studied. Grossly, the adult giant anteater prostate gland is divided in two distinct zones, the central zones (composed mainly of ducts) and the peripheral zones (of acini formed by secretory cells). The secretory cells showed positive periodic acid–Schiff staining. Furthermore, the immunohistochemical characterization revealed a similar human prostate pattern, with p63 staining basal cells, uroplakin III (UPIII) superficial cells of prostatic urethra, androgen receptor (AR) expressing nucleus of secretory and stromal cells, and prostatic specific antigen (PSA) staining prostatic epithelial cells. Overall, our research provided an in-depth morphological description of the giant anteater’s prostate gland, providing valuable information for futures studies focused on giant anteater conservation.

Made available in DSpace on 2021-06-25T10:54:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 The aim of this study was to identify the anatomical structures in the head region of the giant anteater (Myrmecophaga tridactyla) using computed tomography. For this, three giant anteater corpses, adult and female, were used. The tomographic analysis was performed in sequential order in rostrocaudal direction. Subsequently, the heads of these animals were sectioned in cross sections of approximately 1.5 cm each. Tomographic images were compared with anatomical sections. The association between computed tomography and anatomical sections allowed the visualization of anatomical structures found in the nasal, oral, cranial, pharyngeal and ear cavities. An elongated oral cavity delimited by the elongated mandible was observed. The oral cavity was mainly occupied by a thin and elongated tongue formed mainly by the union of the sternoglossal muscles. The nasopharynx and oropharynx extended up to the neck at the level of the fifth cervical vertebra. The findings of this study suggest that the giant anteater has a head with structures morphologically adapted to its feeding habits, such as an elongated skull, tongue, styloid bones and mandible. In addition, based on the results of this study, it is possible to suggest that computed tomography is a pivotal tool for the veterinary routine of wild animals, since it allowed the identification of anatomical structures found in the head of the giant anteater. School of Veterinary Medicine and Animal Science Graduate Program in Wild Animals São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science Department of Animal Reproduction and Veterinary Radiology São Paulo State University (UNESP) Laboratory of Wildlife Anatomy São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science Graduate Program in Wild Animals São Paulo State University (UNESP) School of Veterinary Medicine and Animal Science Department of Animal Reproduction and Veterinary Radiology São Paulo State University (UNESP) Laboratory of Wildlife Anatomy São Paulo State University (UNESP)

An adult, female, 31kg body weight, free range Myrmecophaga tridactyla was referred for medical consultation due to apathy, dehydration, intense flatulence and fetid stools. The animal was submitted to chemical restraint and physical examination, blood count, fecal analysis, and vaginal cytology and abdominal ultrasonography were performed. Good nutritional status and clinical variables within the normal range were observed at physical examination. At vaginal cytology leukocytes, spermatozoa and a large proportion of cornified cells (superficial) were observed, indicating estrus and recent copula. At ultrasound examination it was possible to locate, identify, evaluate and measure the ovaries and the uterine structures, cervix, body, lumen, myometrium and endometrium, a fact never reported in the literature for this species. These data can be used as reference for clinical evaluation of the reproductive tract in Myrmecophaga tridactyla females considered vulnerable species, for the diagnosis of reproductive pathologies, biotechnologies application or estrous cycle evaluation. RESUMO Uma fêmea, com 31kg de peso corporal, de Myrmecophaga tridactyla, de vida livre, foi apresentada para consulta médica em razão de apatia, desidratação, flatulência intensa e fezes fétidas. O animal foi submetido à contenção química e foram realizados exame físico, hemograma, análise fecal, citologia vaginal e ultrassonografia abdominal. Ao exame físico, foi determinado bom estado nutricional e variáveis clínicas dentro da faixa de normalidade. Na citologia vaginal, foram observados leucócitos, espermatozoides e uma grande proporção de células cornificadas (superficiais), indicando estro e cópula recente. No exame ultrassonográfico, foi possível localizar, identificar, avaliar e mensurar os ovários e as estruturas uterinas, o colo do útero, o corpo do útero, o lúmen, o miométrio e o endométrio, fato nunca relatado na literatura para essa espécie. Esses dados podem ser utilizados como referência para avaliação clínica do trato reprodutivo de fêmeas de Myrmecophaga tridactyla considerada espécie vulnerável, para o diagnóstico de patologias reprodutivas, aplicação de biotecnologias ou avaliação do ciclo estral.

Made available in DSpace on 2020-12-10T20:04:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-06 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Background: The acupuncture points are considered a point in the skin of sensitivity to stimulation. The acupuncture meridians represent the communication between acupuncture points and internal organs. The giant anteater (Mirmecophaga tridactyla) is routinely attended in veterinary centers, and is pivotal to know its morphology and therapies such as acupuncture that, probably, can be used in medical practice. Thus, the aim of this study was to evaluate the morphological substrate in regions that correspond to the transposition of acupuncture points of the Bladder Meridian using radiography, ultrasonography, electrical impedance and histology in the giant anteater. Materials, Methods & Results: Seven giant anteaters (six males and one female) were used. The animals were from the Center of Medicine and Research in Wild Animals (CEMPAS), School of Veterinary Medicine and Animal Science, UNESP, Botucatu, Sao Paulo. The acupoints of Bladder Meridian evaluated were Bladder 11 (B-11), Bladder 18 (B-18), Bladder 23 (B-23), Bladder 25 (B-25), and Bladder 28 (B-28). The locations of the acupoints were transposed based on the location of these acupuncture points in dogs. Four animals were live and were used for radiographic, ultrasonographic, and electrical impedance analysis. Three animals were died and the fragments of this acupoints were destined to histological routine with hematoxylin and eosin (HE) and Masson's Trichrome stains. The giant anteaters studied had fifteen thoracic vertebrae, three lumbar vertebrae, and five sacral vertebrae fused in a single bone. The acupuncture points were characterized by presence of abundant connective tissue at the superficial and intermuscular level, muscular fascia, and many neurovascular bundles in the dermal layer. These bundles consisted of nerves, arteries and veins of various calibers. The spaces between the nerves and blood vessels were filled by loose connective tissue containing adipose cells, capillaries, and sweat glands. Discussion: The network of acupuncture points can be seen as a representation of a network formed by interstitial connective tissue. This hypothesis is supported by ultrasound imaging that demonstrated plans for cleavage of connective tissue at acupuncture points in normal humans. It seems that the anatomical relationship of acupoints and meridians with connective tissue planes is relevant to the mechanism of action of acupuncture and suggests an important integrative role for interstitial connective tissue. The presence of connective tissue was observed in the transposition areas studied in the giant anteater using ultrasound. The main histological structures found in the transposition regions of the acupoints in the giant anteater were the nerve and connective tissue, similar to other studies, who claimed that the nerve is the main histological component of an acupoint. Therefore, there are reports suggesting that the network of acupoints and meridians can be seen as a representation of a network formed by interstitial connective tissue and that this relationship is important for the therapeutic mechanism of acupuncture. Based on the results of this study, it is possible to infer that the studied regions present a morphological substrate that is consistent with the characteristics of an acupuncture point. Thus, it is suggested that there are probably acupuncture points in these regions in the giant anteater, which makes possible the use of this alternative medical therapy for the treatment of these animals. Univ Estadual Paulista UNESP, Fac Med Vet & Zootecnia FMVZ, Programa Posgrad Anim Selvagens, Botucatu, SP, Brazil Univ Estadual Paulista UNESP, Dept Anat, Inst Biociecias Botucatu IBB, Botucatu, SP, Brazil Univ Estadual Paulista UNESP, Fac Med Vet & Zootecnia FMVZ, Programa Posgrad Anim Selvagens, Botucatu, SP, Brazil Univ Estadual Paulista UNESP, Dept Anat, Inst Biociecias Botucatu IBB, Botucatu, SP, Brazil CAPES: 001

Giant Anteater (Myrmecophaga tridactyla) is a vulnerable species because of progressive habitat destruction, mostly affected by wildfires and car accidents. The increasing number of animals that are attended by wildlife rescue centres reinforces the need of knowledge about haematological parameters, especially for those that inhabit Brazilian cerrado biome. For this purpose and in order to establish reference values for this species and also to compare them with previous studies, haematological analysis of captive giant anteaters from Brazilian cerrado were performed. Moreover, the alterations of blood samples after 24 and 48 hours of storage at refrigeration temperatures (4oC) and preserved with two different EDTA concentrations (5% and 10%) were studied. Means and standard deviations of haematological parameters analysed immediately after collection were: RBC: 2,07 x106/μL ± 0,40; hematocrit: 38,08%± 5,93; haemoglobin: 11.33g/dL±2.15; MCV:186.52 fL±21.72; MCHC: 29.68g/dL±2.56; MCH: 55.08pcg±5,94; total leucocytes: 8.142/μL±2.441; neutrophils: 5.913/μL±2.168; lymphocytes: 1.460/μL±740; eosinophil: 522/μL±385; monocytes: 247/μL±176; thrombocytes: 123.458/μL±31.362 and total plasma protein: 6.23g/dL±0.49. This data shows evidence of the existence of important differences between these values and others from other areas, either from Brazil or from other South American countries. Those variations might be connected to environment, genetic, nutritional and/or management factors. Regarding the storage effect analysis, it can be concluded that in giant anteaters, haematological analysis can be performed until 24h after collection without any significant alterations on the haematological parameters, except for thrombocytes. Concerning the different EDTA concentrations, it can be concluded that there are no quantitative differences in haematological variables. Nevertheless, relevant morphologic alterations in blood cells can be observed after a 24h storage period, being most noticeable in the leucocytes. Those alterations can lead to misinterpretation of the results, interfering diagnosis, prognosis and treatment. RESUMO: O tamanduá-bandeira (Myrmecophaga tridactyla) é uma espécie vulnerável devido à destruição progressiva do seu habitat natural, sendo afetado por queimadas e atropelamentos. O aumento na casuística de atendimentos de animais silvestres reforça a necessidade de se ter conhecimento dos parâmetros hematológicos, em especial para os que vivem no bioma do cerrado. Por isso, este trabalho teve por objetivos realizar o hemograma de tamanduás-bandeiras de cativeiro localizados no cerrado brasileiro, a fim de estabelecer valores de referência para essa espécie e compará-los a estudos prévios. Além disso, verificar quais alterações podem ser encontradas em amostras armazenadas por 24 e 48 horas após a colheita, em temperatura de refrigeração (4oC) e tratadas com duas concentrações distintas de EDTA (5% e 10%). A média e o desvio padrão das variáveis hematológicas encontradas nas amostras processadas logo após a colheita foram: hemácias (2,07x106/μL±0,40); volume globular (38,08%± 5,93); hemoglobina (11,33g/dL±2,15); VCM (186,52 fL±21,72); CHCM (29,68g/dL±2,56); HCM (55,08pcg±5,94); leucócitos totais (8.142/μL±2.441); neutrófilos (5.913/μL±2.168); linfócitos (1.460/μL±740); eosinófilos (522/μL±385); monócitos (247/μL±176); plaquetas (123.458/μL±31.362) e proteínas plasmáticas totais (6,23g/dL±0,49). Tais dados permitem afirmar que existem importantes diferenças entre os valores hematológicos destes em relação aos animais provenientes de outras regiões, tanto do Brasil quanto de outros países da América do Sul. Provavelmente, tais divergências estão associadas a fatores ambientais, genéticos, nutricionais e/ou de manejo. Quanto à análise das amostras estocadas, conclui-se que, em tamanduás-bandeiras, as amostras para a realização de hemograma podem ser processadas até 24 horas após a colheita, sem alteração significativa das variáveis hematológicas, com exceção das plaquetas. Com relação às duas concentrações de EDTA, pode-se inferir que não há diferença quantitativa entre ambas para as variáveis hematológicas. Contudo, é possível constatar que o EDTA promove alterações morfológicas relevantes nas células sanguíneas após 24 horas de armazenamento, sendo os leucócitos os mais afetados. Tais alterações, quando relatadas, podem induzir interpretações equivocadas, interferindo no diagnóstico, prognóstico e tratamento.

The giant anteater (Mymercophaga tridactyla) is a highly specialized insectivore for which nutrient requirements are not clearly established, making diet formulation challenging for this species. Multiple clinical reports suggest anteaters have an obligate dietary taurine (TAU) requirement. Sulphur amino acid (SAA) metabolism in adult anteaters was evaluated using noninvasive methods to measure TAU synthesis potential from dietary methionine (MET) and a basal diet containing on a dry matter (DM) basis 1.7 mg TAU/kg DM and 6.9 g MET/kg DM. Urinary equilibrium times for TAU excretion were determined by feeding the basal diet with or without 1.5 g/kg DM supplemental TAU (crossover design; n = 4). Effects of supplemental dietary TAU (1.7, 2.0, 2.4, 2.7, 3.0, 3.3 g/kg DM) or MET (6.9, 9.0, 11.2 g/kg DM) on urinary TAU were evaluated (randomized block trials; n = 5 or 4 respectively). All urinary values (TAU, MET, unbound inorganic sulphate) were normalized to creatinine (CRT). Results indicate urinary TAU equilibrium in anteaters requires at least 2 weeks of feeding. Urinary ratio of TAU to CRT (TAU:CRT) increased as dietary TAU content increased from 1.7 to 3.0 g/kg DM, consistent with renal homoeostatic modulation of TAU excretion. Our data indicate that TAU needs were met by TAU in the basal diet or by de novo synthesis. Supplemental MET resulted in ~five- to eightfold increases in urinary TAU:CRT excretion, further supporting existence of mechanisms for TAU synthesis from dietary SAA in anteaters. Adult anteaters appear able to synthesize TAU when diets contain adequate SAA, but dietary TAU may be critical if protein intakes are low or of poor quality. This study may provide guidance on choice of domestic canids vs. felids as suitable physiologic models for improved nutrition in giant anteaters, and also outlines a noninvasive method for assessing TAU status/metabolism that may be useful across species.

This study aimed to describe the number of thoracic, lumbar and sacral vertebrae in tridactyla through radiographic examinations associated with gross anatomy determination. For this purpose, 12 adult specimens of M. tridactyla were analyzed, assigned to the Screening Center of Wild Animals (CETAS), IBAMA-GO, and approved by the Ethics Committee on the Use of Animals (Process CEUA-UFG nr 018/2014). In the radiographic examinations the following numbers of thoracic (T) and lumbar (L) vertebrae were observed: 16Tx2L (n=7), 15Tx2L (n=3), and 15Tx3L (n=2). In contrast, the numbers of vertebrae identified by anatomical dissection were as follows: 16Tx2L (n=4), 15Tx2L (n=3), and 15Tx3L (n=5). This difference occurred in cases of lumbarization of thoracic vertebrae, as seen in three specimens, and was explained by changes in regional innervations identified by anatomical dissection and the presence of floating ribs (right unilateral=1, left unilateral=1 and bilateral=1), which were not identified by radiographic exams. Regarding the sacral vertebrae there was no variation depending on the methods used, which allowed the identification of 4 (n=1) or 5 (n=11) vertebrae. Thus, we concluded that there is variation in the number of thoracic, lumbar and sacral vertebrae, in addition to lumbarization, which must be considered based on the presence of floating ribs, in this species. RESUMO: Este estudo teve como objetivo descrever o número de vértebras torácicas, lombares e sacrais em Myrmecophaga tridactyla por meio de exames radiográficos e por contagem anatômica. Foram analisados doze espécimes adultos de M. tridactyla oriundos do Centro de Triagem de Animais Silvestres (CETAS), IBAMA-GO, após aprovação pela Comissão de Ética no Uso de Animais (Processo CEUA-UFG no. 018/2014). Nos exames radiográficos, foram observados os seguintes números de vertebras torácicas (T) e lombares (L): 16Tx2L (n=7), 15Tx2L (n=3), e 15Tx3L (n=2). Em contraste, o número de vértebras identificados através de dissecção anatómica foram como se segue: 16Tx2L (n=4), 15Tx2L (n=3), e 15Tx3L (n=5). Essa diferença ocorreu em casos de lombarização da vertebra torácica, como visto em três exemplares e, foi explicada por mudanças nas inervações regionais identificadas por meio de dissecção anatômica e a presença de costelas flutuantes (unilateral direita=1, unilateral esquerda=1 e bilateral=1) que não foram identificados por meio de exame radiográfico. Em relação ao número de vértebras sacrais não houve variação dos métodos utilizados, sendo que ambos permitiram a identificação de quatro (n=1) ou 5 (n=11) vértebras. Assim, concluiu-se que há variação no número de vértebras torácicas, lombares e sacrais, devido à lombarização, que devem ser consideradas com base na presença de costelas flutuantes nesta espécie.

In view of the scarcity of data about the topography and syntopy of abdominopelvic viscera of the giant anteater (Myrmecophage tridactyla - Linnaeus, 1758), the present study aimed to elucidate these characteristics and to compare them with the other animal species, especially the domestic ones. Three specimens, two males and one female, were donated by the Environmental Military Police of Franca to the Anatomy Veterinary Laboratory of the University of Franca, after death by road killings. The animals were fixed and maintained in aqueous 10% formaldehyde solution, followed by conventional dissection of the abdominopelvic cavities for subsequent direct inspection and topographic description of the viscera, aiming at comparative analyzes with other species, whose positioning and particularities are already established in the literature. It was observed that most of the viscera of these cavities have similar location and syntopy to domestic animals, except for the kidneys and testicles. In view of the established methodology and the results obtained, it is accepted that more specimens of anteater, both genera, should be evaluated and registered scientifically to confirm the data of the current research and anatomical preconization of the abdominopelvic cavity, inasmuch anatomical individual variation are possible between animals of the same species.

Made available in DSpace on 2019-10-04T12:36:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-04-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) The giant anteater (Myrmecophaga tridactyla) and the collared anteater (Tamandua tetradactyla) are widespread in Brazil and found in all Brazilian biomes. These hosts frequently use domestic animal environments such as pastures, where tick and related microorganism interchange may occur between hosts. Reports of tick infestations of these animals are scattered and refer to small samples and/or are geographically restricted. We herein present data on a wide geographic distribution of ticks and their Rickettsia collected from 72 giant and 30 collared anteaters, mostly road killed, over a period of 18 years, from Southeast and Central-West Brazil encompassing four States and 46 Municipalities. Overall nine tick species (Amblyomma auricularium, A. calcaratum, A. nodosum, A. ovale, A. parvum, A. sculptum, A. triste, Rhipicephalus microplus and R. sanguineus sensu lato) were collected from anteaters. Amblyomma sculptum, A. nodosum, and A. calcaratum were the most prevalent corresponding to, respectively, 48.8%, 39.3% and 2.7% of all ticks (n = 1775). However, A. nodosum tick numbers on collared anteaters were significantly higher (P < 0.001) than those on giant anteaters. At the same time, an abundance of A. sculptum adults on giant anteaters was significantly higher (Z = 2.875; P = 0.004) than that of A. nodosum and only eight A. sculptum nymphs were found on collared anteaters. DNA samples from 20 ticks from nine different animals yielded a visible amplicon in PCR targeting gltA. The PCR products targeting spotted-fever Rickettsia gene (ompA) from five adults of A. nodosum were sequenced and were shown to be 100% identical to Rickettsia parkeri strain NOD (MF737635.1). The product of one nymph and one adult of A. sculptum yielded a sequence 99% identical to R. parkeri strain NOD. Further, Rickettsia bellii genes were found in three A. nodosum adults. Ecological, behavioral and anatomical traits of anteaters are discussed to explain reported tick infestations and Rickettsia DNA found. Univ Fed Uberlandia, Fac Med Vet, Lab Ixodol, Av Para 1720,Campus Umuarama Bloco 2T, BR-38400902 Uberlandia, MG, Brazil Inst Fed Goiano, Campus Urutai,Rod Geraldo S Nascimento Km 2,5, BR-75790000 Urutai, Go, Brazil Univ Fed Uberlandia, Inst Ciencias Biomed, Lab Virol, Av Para 1720,Campus Umuarama Bloco 2B, BR-38400902 Uberlandia, MG, Brazil Univ Brasilia, Lab Patol Vet, Av L4 Norte,Hosp Vet Campus Univ Darcy Ribeiro, BR-70910970 Brasilia, DF, Brazil Univ Sao Paulo, Fac Med Vet & Zootecn, Dept Med Vet Prevent & Saude Anim, Av Prof Orlando Marques de Paiva 87,Cidade Univ, BR-05508270 Sao Paulo, SP, Brazil Univ Estadual Paulista, Dept Patol, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal, SP, Brazil Inst Estadual Florestas, Praca Tubal Vilela 03, BR-38400186 Uberlandia, MG, Brazil Univ Estadual Paulista, Dept Patol, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal, SP, Brazil

Hypervitaminosis D was diagnosed in a giant anteater (Myromecophaga tridactyla) and a large hairy armadillo (Chaetophractus villosus) being fed a commercial insectivore diet. Clinical findings included weight loss, reduced appetite, vomiting, and suspected abdominal discomfort. Hypercalcemia (3.68 and 2.04 mmol/L total and ionized calcium, respectively) was detected in the anteater, and plasma 25(OH)D levels were measured and found to be 808.7 and 379.4 nmol/L for the anteater and armadillo, respectively. Dietary change resulted in a reduction of 25(OH)D levels in both animals and resolution of hypercalcemia in the giant anteater. Dietary analysis of the commercial insectivore food revealed levels of vitamin D3 higher than the data-sheet values. This case report demonstrates that hypervitaminosis D in Xenarthra can be associated with significant clinical signs.

The neural system plays an important role in understanding some features of animals. Anatomical complexity correlates with the increase of functional capacity. Xenarthrans include anteaters (Vermilingua), armadillos (Cingulata) and sloths (Folivora). This group is the base of eutherian mammals, and understanding the anatomy of its neural system could provide data for functional and evolutionary interpretations. The gross anatomy of the xenarthran brain is recorded. Four extant families of Pilosa and two families of Cingulata were sampled. Usual dissection procedures were used, and the brains were analysed macroscopically. The brain of two-toed sloth, three-toed sloth, six-banded armadillo, giant anteater and collared anteater are gyrencephalic. Pygmy anteater, nine-banded armadillo, great long-nosed armadillo, southern naked-tailed armadillo and giant armadillo are lissencephalic. In most species, the rhinal fissure presents two segments, rostral and caudal (except in Vermilingua and three-toed sloth). The diencephalon and brainstem present similar anatomy. The cerebellum is wide and presents four lobes (rostral, central, caudal and floccular). Its average volume is 12.16% (Folivora), 14.26% (Vermilingua) and 18.61% (Cingulata). Among these groups, there is a statistical difference between Folivora/Cingulata concerning the cerebellum average. The general pattern of the brain of the xenarthrans is similar to that of other mammals.

The monospecific giant anteater, Myrmecophaga tridactyla Linnaeus, 1758, is the largest of the 4 species of New World vermilinguans. A feeding specialist on ants and termites, it occupies a broad range of lowland habitats, from dry scrub and savannah to rainforests. Its geographic range extends throughout southern Central America and northern South America, from Honduras in the north to Bolivia and northern Argentina in the south. M. tridactyla is listed on Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and is identified as " Vulnerable " on the International Union for Conservation of Nature and Natural Resources Red List. Fil: Gaudin, Timothy. University of Tennessee; Estados Unidos Fil: Hicks, Patrick. University of Tennessee; Estados Unidos Fil: Di Blanco, Yamil Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina. Centro de Investigaciones del Bosque Atlántico; Argentina

The giant anteater (Myrmecophaga tridactyla) is classified as a vulnerable species on Brazil’s list of species at risk of extinction mainly due to deforestation and forest fires. This has contributed to a considerable increase in detailed clinical case records of the treatment of wild species at veterinary institutions. However, the paucity of serum biochemical profiles of healthy giant anteaters has made it difficult to evaluate these animals, preventing diagnosis, treatment and prognosis. The objective of this work was to collect data about the biochemical profile of healthy giant anteaters from the Brazilian Cerrado raised in captivity, in order to better understand the physiological characteristics inherent to this species. Eighteen analytes from 12 healthy giant anteaters were measured. The following means and standard deviations were found in the biochemical analyses: albumin 3.29±0.33g/dL, ALT 15.49±7.98 IU/L, amylase 1037.92±149.04 IU/L, AST 21, 12±7.50 IU/L, total cholesterol 62.79±20.08mg/dL, HDL cholesterol 14.73±4.98mg/dL, LDL cholesterol 26.60±11.05mg/dL, VLDL cholesterol 2.14±1.06mg/dL, CK 111.61±70.16 IU/L, creatinine 1.05±0.37mg/dL, iron 194.64±81.17μg/dL, GGT 65.18±54.57 IU/L, glucose 103.71±29.63mg/dL, globulins 2.76±0.36g/dL, lipase 28.80±5.11 IU/L,TSP 6.05±0.56g/dL, triglycerides 10.71±5.29mg/dL, and urea 53.46±18.28mg/dL. The values found in this study can be used as references for the laboratory evaluation of giant anteaters living in conditions similar to those of this study. This is one of the first reports of biochemical examinations on giant anteaters of the Cerrado biome. RESUMO: O tamanduá-bandeira (Myrmecophaga tridactyla) está classificado como espécie vulnerável na lista brasileira de espécies ameaçadas de extinção devido principalmente ao desmatamento e aos incêndios florestais. Tal fato contribuiu com o aumento da casuística de atendimento de espécies silvestres em instituições veterinárias. Porém, a escassez de valores bioquímicos séricos em tamanduás-bandeiras hígidos tem dificultado a avaliação destes animais, impedindo o diagnóstico, tratamento e prognóstico. O objetivo deste trabalho foi fornecer dados sobre o perfil bioquímico de tamanduás-bandeiras saudáveis do cerrado brasileiro, criados em cativeiro, a fim de compreender melhor as características fisiológicas inerentes a esta espécie. Foram mensurados 18 analitos de 12 tamanduás-bandeiras hígidos. As médias e o desvio padrão correspondentes às análises bioquímicas foram: albumina 3,29±0,33g/dL; ALT 15,49±7,98 UI/L; amilase 1037,92±149,04 UI/L; AST 21, 12±7,50 UI/L; colesterol total 62,79±20,08mg/dL; colesterol HDL 14,73±4,98mg/dL; colesterol LDL 26,60±11,05mg/dL; colesterol VLDL 2,14±1,06mg/dL; CK 111,61±70,16 UI/L; creatinina 1,05±0,37mg/dL; ferro 194,64±81,17μg/dL; GGT 65,18±54,57 UI/L; glicose 103,71±29,63mg/dL; globulinas 2,76±0,36g/dL; lipase 28,80±5,11 UI/L; PST 6,05±0,56g/dL; triglicerídeos 10,71±5,29mg/dL; ureia 53,46±18,28mg/dL. Os valores encontrados neste estudo podem ser utilizados como referência para a avaliação laboratorial de tamanduás-bandeiras que vivam em condições similares ao do presente estudo. Este é um dos primeiros estudos a relatar exames bioquímicos em tamanduás-bandeiras do bioma cerrado.

Anteater forelimbs are morphologically adapted to obtain food and to provide defense and locomotion. Four species are known, but there are few anatomical studies presenting the morphologic features of each species. The aim of this study was to describe the skeletal morphology of the giant anteater (Myrmecophaga tridactyla) forelimb. Pictures and schematic drawings of six cadavers were created to show the bone morphology. In addition, radiographs and computed tomographs were obtained. The skeletal structure of the forelimb had several notable anatomical features. The scapula had two spines, with apparent differences between infant and adult animals. The humerus had a pectoral ridge, a pectoral tubercle, and a pronounced medial epicondyle that represent the origins of muscles important for fossorial activity. The radius had cranial, lateral, and caudal ridges that became more prominent in older animals, and the distal condyle joint provided enhanced support of the dorsal articulation for the manus. Knowledge of the bone morphology of the forelimb generates a better understanding of giant anteater habits and helps in the diagnosis of skeletal abnormalities and in the routine medical assessment of this species.

The aim of this study was to evaluate the kinetic and temporospatial parameters of clinically healthy juvenile giant anteaters (Myrmecophaga tridactyla) by using a pressure-sensing walkway. Three free-ranging clinically healthy giant anteaters (M. tridactyla), two males and one female, aged 5-7 mo, were used. There was no statistically significant difference between the right and left sides for the kinetic and temporospatial parameters for both forelimbs and hind limbs. Although the gait velocity was similar for all giant anteaters, the stride frequency was higher in the smaller anteaters. The difference in stride frequency is associated with body size, which also influenced other temporospatial parameters. The percentage of body distribution was higher on the forelimbs than the hind limbs. The contact surface and trajectory of the force of the forepaws differed from the hind paws. In conclusion, the anteaters have gait peculiarities associated with the anatomical differences between forelimbs and hind limbs.

The giant anteater has specific anatomical adaptations resulting from its ant and termite feeding habits. The unique arrangement of its hyoid apparatus is essential for the ingestion of food. However, its description in the literature is based on fragments and fossils, making it difficult to determine existing anatomical details in live animals. Imaging techniques, which enable the topographical anatomy of animals to be examined noninvasively, provide essential information for the diagnosis and prognosis of diseases. The aim of this study is to describe the bone contours in the hyoid apparatus of the giant anteater by means of radiographic and tomographic images. Giant anteaters of varying ages from the Wild Animal Screening Center (CETAS-GO) were used, seven for X-ray exams and two adults for CT exams. The hyoid elements in all the animals were evaluated using the two imaging techniques, and were visualized in the cervical region of C2 to C6, which comprises three paired bones (stylohyoid, epihyoid, ceratohyoid) and one unpaired bone (basihyoid). The presence of air in the oropharynx enabled the assessment of soft tissue structures in this region, such as the epiglottis and the soft palate. CT axial sections are of limited usefulness for evaluating the hyoid bones, but enable assessments of the basihyoid bone and its characteristic V-shape. Thus, to analyze the hyoid region in anteaters based on radiographic and tomographic images, one must keep in mind that the stylohyoid, epihyoid and ceratohyoid bones are situated ventrally to the C2 to C5 vertebrae and that the basihyoid at the level of C5-C6 demarcates the transition between the nasopharynx and the trachea. The nasopharynx and oropharynx extend from C1 to C5, and the trachea begins at the level of C6. RESUMO: O Tamanduá-Bandeira possui adaptações anatômicas específicas, devido aos hábitos alimentares de ingestão de formigas e cupins. O arranjo singular do aparato hioide dos tamanduás é fundamental para a ingestão de alimentos. Sua descrição na literatura é baseada em peças e fósseis, o que dificulta a determinação de detalhes anatômicos existentes em animais vivos. As técnicas de imagem permitem a avaliação da anatomia topográfica dos animais, de maneira não invasiva, e o conhecimento desta é fundamental para o diagnóstico e prognóstico de afecções. O objetivo desse trabalho foi descrever o contorno ósseo do aparato hioide do tamanduá-bandeira, por meio de imagens radiográficas e tomográficas. Foram utilizados tamanduás-bandeiras provenientes do Centro de Triagem de Animais Silvestres (CETAS-GO), sendo sete, de variadas idades, para os exames radiográficos e dois adultos para os tomográficos. Os elementos hioideos foram avaliados em todos os animais por meio de ambas as técnicas de imagem, sendo visibilizados na região cervical, de C2 até C6, composto por três elementos pares (estiloioide, epioide, ceratioide) e um elemento ímpar (basitireoide). A presença de ar na orofaringe permitiu a avaliação das estruturas de tecidos moles desta região, como a epiglote e o palato mole. Os cortes tomográficos axiais têm importância limitada na avaliação dos hioides, mas permitem a avaliação do basitireoide e de seu formato característico (V-bone). Desta forma, para avaliar a região hioidea por meio dos exames radiográficos e tomográficos em tamanduás-bandeira, deve-se considerar que os ossos estiloioide, epioide e ceratioide localizam-se ventral às vértebras C2 até C5 e o basitireoide, em C5-C6, delimita a transição entre a nasofaringe e a traqueia. A orofaringe e a nasofaringe estendem-se de C1 a C5, e a traqueia inicia-se a partir de C6.

Although numbers of giant anteaters within North American facilities have been steadily increasing for the last 15 years, the population now exhibits an unstable age distribution with genetically valuable individuals nearing reproductive senescence. Contributing to this issue is the Association of Zoos and Aquariums (AZA) described lack of standardization of breeding introduction practices and high risk of female injury occurring during such pairings. This report describes the development of a successful breeding protocol at Cleveland Metroparks Zoo based on hormone monitoring and efficient communication between science and animal management teams that minimizes risk of female injury. By training a female giant anteater for urine sample and body weight data collection, staff members accurately predicted estrus, and timed breeding introductions to facilitate positive interactions between the male and female. Such training also allowed for careful monitoring of two pregnancies through parturition (169-184 days from breeding) and post-partum return to estrus (114-129 days from parturition). Urinary hormone monitoring revealed a sharp progestogen increase averaging >five-fold over basal levels (0.52 ± 0.05 ng/mg creatinine) which was sustained throughout the second half of pregnancy. Mean regular estrous cycle length (n = 14 cycles), was calculated as 46.17 ± 1.39 days, measured as days between estrogen peaks of mean concentration 2.27 ± 0.19 ng/mg creatinine. This report summarizes impressive collaborative efforts among multiple zoological departments to achieve extensive hormonal and body weight monitoring from a female giant anteater, adding valuable information on reproductive parameters, and specifics for novel hormone assay techniques.

O tamanduá-bandeira (Myrmecophaga tridactyla) é uma mamífero silvestre, da superordem Xenarthras, nativo das Américas Central e do Sul e que está, atualmente, classificado como vulnerável na lista de espécies ameaçadas de extinção, fato que pode ter como causas, desde o avanço territorial das atividades agropecuárias às construções de estradas e queimadas Pesquisas científicas são de suma importância para a conservação de espécies inclusas nessa lista e existe uma escassez de dados acerca dos tamanduás-bandeira. Dentre essas informações a serem coletadas, existem poucas informações acerca do exame ultrassonográfico nesta espécie. A ausência de um padrão de referência para a realização e avaliação do exame ultrassonográfico para espécies específicas pode limitar a aplicação deste exame e impedir o estabelecimento de um diagnóstico preciso. Por estes motivos, objetivou-se nesse estudo estabelecer um padrão de referência para a avaliação ultrassonográfica do abdômen de tamanduás-bandeira machos e fêmeas. Para isso, foram utilizados 10 animais adultos, cinco fêmeas e cinco machos, clinicamente saudáveis, provenientes da Fundação Jardim Zoológico de Brasília. Os animais foram anestesiados utilizando protocolo da própria Fundação, os animais foram posicionados em decúbito dorsal e, em seguida, foi realizada a tricotomia ampla do abdômen para possibilitar a varredura abdominal. Foram estabelecidas as estruturas visíveis no exame ultrassonográfico abdominal dos tamanduás, bem como descritas: posição topográfica, relações anatômicas, ecotextura e ecogenicidade de vesícula urinária, útero, testículos, rins, baço, fígado, estômago e alças intestinais. Também foi descrita a presença de alterações em alguns animais, como: líquido intra-uterino; hepatomegalia; esplenomegalia; líquido-livre abdominal. Verificou-se que o exame ultrassonográfico abdominal de tamanduás-bandeira pode ser realizado segundo o que já é preconizado para cães e gatos e sua avaliação e interpretação podem ser comparadas tanto com os exames de mamíferos domésticos quanto com descrições já documentadas em outras espécies de mamíferos silvestres. The giant anteater (Myrmecophaga tridactyla) is a wild mammal of the superorder of Xenarthras, native to Central and South America, which is currently classified as vulnerable in the list of endangered species. A fact that can have as causes, from the territorial advance of the agricultural activities to the constructions of roads and fires. Scientific research is of great importance for the conservation of species included in this list and there is a dearth of data about the anteater. Among these information to be collected, there is little information about ultrasound examination in this species. The absence of a reference standard for performing and evaluating ultrasonographic examination for specific species may limit the application of this test and disrupt the establishment of an accurate diagnosis. For these reasons, the aim of this study was to establish a reference standard for the ultrasonographic evaluation of the abdomen of male and female giant anteaters. For this, 10 adult animals, five females and five males, clinically healthy, were used from the Fundação Jardim Zoológico de Brasília. The animals were anesthetized using the Foundation's own protocol, the animals were placed in dorsal decubitus position, and then a wide tricotomy of the abdomen was performed to allow abdominal scanning. The visible structures were established in the abdominal ultrasound examination of the anteaters, have also been established: topographic position, anatomical relationships, ecotexture and echogenicity of: urinary vesicle, uterus, testes, kidneys, spleen, liver, stomach and intestines. It has also been described the presence of alterations in some animals, such as: an animal with intrauterine fluid; an animal with hepatomegaly; an animal with splenomegaly; and thre animals with abdominal fluid. It has been verified that the abdominal ultrasound examination of anteater can be performed according to what is already recommended for dogs and cats and its evaluation and interpretation can be compared with the examinations of domestic mammals as well as descriptions already documented in other species of mammals Wild. Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES

Tunga penetrans (Siphonaptera, Tungidae) is a flea that infests humans and a variety of domestic and wild animals. Burrowing of the female flea under the skin causes tungiasis, a disease that manifests in skin lesions that if untreated, can progress to severe complications. In this paper, we report the first case of T. penetrans in a wild giant anteater (Myrmecophaga tridactyla) from Argentina. We describe the lesions and discuss the potential role of the giant anteater as a host or reservoir for this flea. Fil: Di Nucci, Dante L.. Fundación Temaikèn; Argentina Fil: Ezquiaga, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: Abba, Agustin Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina

The giant anteater (Myrmecophaga tridactyla, Pilosa, Linnaeus 1758) belongs to the mammalian order Pilosa and presents a large distribution along South America, occupying a great variety of habitats. It is listed in the IUCN Red List of threatened species as Vulnerable. Despite threatened, there is a lack of studies regarding its genetic variability. The aim of this study was to examine the genetic diversity and patterns of genetic structure within remaining populations. We analyzed 77 individuals from seven different populations distributed in four biomes across Brazil: Cerrado, Pantanal, Atlantic Forest and Amazon Forest. We sequenced two mitochondrial markers (control region and Cyt-b) and two nuclear markers (AMELY and RAG2). We found high genetic diversity within subpopulations from National Parks of Serra da Canastra and Emas, both within the Cerrado biome, with signs of population expansion. Besides, we found a notable population structure between populations from the Cerrado/Pantanal and Amazon Forest biomes. This data is a major contribution to the knowledge of the evolutionary history of the species and to future management actions concerning its conservation.

The reproductive behavior of giant anteaters is rarely seen and, as a consequence, hard to study. Most of the few reports that exist are based on observations in captivity. In July 2014, we witnessed what could be Myrmecophaga tridactyla courtship and mating behavior in Goias State, Brazil. Although the couple showed aggressive mating behavior, the offspring was able to stay on its mother's back throughout the entire ritual. This report clarifies how, behaviorally, wild giant anteaters mate and suggests that aggressiveness can be present during courtship at least when the female is carrying an offspring. This kind of observation is very difficult to obtain; without long-term monitoring studies, it simply becomes a matter of luck.

Although distal stifle joint nerve distribution has been well established in domestic animals, this approach is scarcely reported in wild animals. Therefore, the aim of this study was to describe the nerves of the leg and foot of Myrmecophaga tridactyla with emphasis on their ramification, distribution, topography and territory of innervation. For this purpose, six adult cadavers fixed and preserved in 10% formalin solution were used. The nerves of the leg and foot of the M. tridactylawere the saphenous nerve (femoral nerve branch), fibular and tibial nerves and lateral sural cutaneous nerve (branches of the sciatic nerve) and caudal sural cutaneous nerve (tibial nerve branch). The saphenous nerve branches to the skin, the craniomedial surface of the leg, the medial surface of the tarsal and metatarsal regions and the dorsomedial surface of the digits I and II (100% of cases), III (50% of cases) and IV (25% of cases). The lateral sural cutaneous nerve innervates the skin of the craniolateral region of the knee and leg. The fibular nerve innervates the flexor and extensor muscles of the tarsal region of the digits and skin of the craniolateral surface of the leg and dorsolateral surface of the foot. The tibial nerve innervates the extensor muscles of the tarsal joint and flexor, adductor and abductor muscles of the digits and the skin of the plantar surface. The caudal sural cutaneous nerve innervates the skin of the caudal surface of the leg. The nerves responsible for the leg and foot innervation were the same as reported in domestic and wild animals, but with some differences, such as the more distal division of the common fibular nerve, the absence of dorsal metatarsal branches of the deep fibular nerve and a greater involvement of the saphenous nerve in the digital innervation with branches to the digits III and IV, in addition to digits I and II.

Myrmecophaga tridactyla, popularly known as giant anteater, is a member of Xenarthra magnorder which is under the threat of extinction. Herein, we describe the complete mitochondrial genome of M. tridactyla. The circular DNA molecule is 16,546 bp long, contains 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and a non-coding Control Region of 1110 bp. All protein-coding genes are on the heavy strand, except for Nd6. Ten of the 13 PCGs contained an ATG start codon.

A tetratrichomonad flagellate found in the diarrhoeic faeces of a 5 years-old male giant anteater (Myrmecophaga tridactyla) was characterised by morphological and genetic analysis. This protozoan presents four anterior flagella of unequal length and a recurrent flagellum attached to the undulating membrane without a free end portion, and a broad axostyle projection. Numerous vacuoles of different sizes containing bacteria and digestion products were found. The complete sequence of the DNA coding for the 16S rRNA-ITS1-5.8S rRNA-ITS2 region was also obtained in order to compare this isolate with other tetratrichomonad species. The sequence obtained was identical to others previously obtained by other researchers from bovines and turtles (Geochelone sp.). It is not easily explainable how the same organism could be found in such different hosts and locations; however these results indicate that some tetratrichomonad species could have a wide host range and could survive in a wide range of environmental conditions.

Background: Anaplasma marginale is a well-known cattle pathogen of tropical and subtropical world regions. Even though, this obligate intracellular bacterium has been reported in other host species different than bovine, it has never been documented in Myrmecophaga tridactyla (giant anteater) or Hippocamelus antisense (taruca), which are two native endangered species. Methods: Samples from two sick wild animals: a Myrmecophaga tridactyla (blood) and a Hippocamelus antisense (blood and serum) were studied for the presence of A. marginale DNA through msp5 gene fragment amplification. Further characterization was done through MSP1a tandem repeats analysis and MLST scheme and the genetic relationship among previously characterized A. marginale sequences were studied by applying, eBURST algorithm and AMOVA analysis. Results: Anaplasma marginale DNA was identified in the Myrmecophaga tridactyla and Hippocamelus antisense samples. Through molecular markers, we identified an identical genotype in both animals that was not previously reported in bovine host. The analysis through eBURST and AMOVA revealed no differentiation between the taruca/ anteater isolate and the bovine group. Inst. de Biotecnología Fil: Guillemi, Eliana Carolina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina Fil: De La Fourniere, Sofia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina Fil: Orozco, Maria Marcela. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Ecologia, Genetica y Evolucion. Laboratorio de Eco - Epidemiologia; Consejo Nacional de Invest. Científ.y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina; Fil: Peña Martínez, Jorge. Conservation Land Trust; Argentina Fil: Correa, Elena. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales. Reserva Experimental Horco Molle; Argentina Fil: Fernández, Javier. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales. Reserva Experimental Horco Molle; Argentina Fil: Lopez Arias, Ludmila Sol. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina Fil: Paoletta, Martina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina Fil: Corona, Belkis. Centro Nacional de Sanidad Agropecuaria; Cuba Fil: Wilkowsky, Silvina Elizabeth. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina Fil: Farber, Marisa Diana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina Fil: Pinarello, Valérie. Institut National de la Recherche Agronomique. Contrôle des Maladies Animales Exotiques et Emergentes Centre; Francia

Giant anteaters (Myrmecophaga tridactyla) are among those mammals for which a particularly low metabolism has been reported. In order to verify presumably low requirements for energy, we used eight anteaters (two males, six females; aged 1-14 years; body mass between 46 and 64 kg) in a total of 64 individual trials, in which a variety of intake levels was achieved on various diets. Digestible energy (DE) intake was quantified by measuring food intake and faecal excretion and analysing representative samples for gross energy, and animals were weighed regularly. Maintenance DE requirements were calculated by regression analysis for the DE intake that corresponded to zero weight change. Differences between individuals were significant. Older anteaters (n = 3 animals aged 12-15 years in 29 trials) had lower relative requirements than younger ones (n = 5 animals aged 1-7 years in 35 trials); thus, giant anteaters resemble other mammals in which similar age-specific differences in energy requirements are known. However, estimated maintenance requirements were 347 kJ DE/kg(0.75)/day in the anteaters, which is low compared to the 460-580 kJ DE/kg(0.75)/day maintenance requirements of domestic dogs. The lack of knowledge that metabolic requirements are below the mammalian average could make species particularly susceptible to overfeeding, if amounts considered adequate for average mammals were provided. Non-scientific reports on comparatively fast growth rates and high body masses in captive giant anteaters as compared to free-ranging animals suggest that body mass development and feeding regimes in captivity should be further assessed.

The presacral vertebra of anteaters was examined by three-dimensional CT image analysis of the xenarthrous processes peculiar to the Order Xenarthra. The anteater is equipped with two following articulations in addition to the normal zygapophysial articulation. The dorsal xenarthrous process of the former vertebra articulates to the ventral area of the base of the mammillary process in the later vertebra. The pocket-like structure in the ventral area of the mammillary process receives the dorsal and ventral xenarthrous processes of the former vertebra. The complicated articulations do not obstruct the ability of the giant anteater to flex dorsally and laterally, however aids flexibility and strengthens the caudal thoracic and lumber regions of the animal. The xenarthrous processes and articulations may function as a supporter of the body weight during the bipedal standing posture when the anteater destroys the nests of ants and termites and protects itself from the enemies.

Interpreting the evolution of neuronal types in the cerebral cortex of mammals requires information from a diversity of species. However, there is currently a paucity of data from the Xenarthra and Afrotheria, two major phylogenetic groups that diverged close to the base of the eutherian mammal adaptive radiation. In this study, we used immunohistochemistry to examine the distribution and morphology of neocortical neurons stained for nonphosphorylated neurofilament protein, calbindin, calretinin, parvalbumin, and neuropeptide Y in three xenarthran species-the giant anteater (Myrmecophaga tridactyla), the lesser anteater (Tamandua tetradactyla), and the two-toed sloth (Choloepus didactylus)-and two afrotherian species-the rock hyrax (Procavia capensis) and the black and rufous giant elephant shrew (Rhynchocyon petersi). We also studied the distribution and morphology of astrocytes using glial fibrillary acidic protein as a marker. In all of these species, nonphosphorylated neurofilament protein-immunoreactive neurons predominated in layer V. These neurons exhibited diverse morphologies with regional variation. Specifically, high proportions of atypical neurofilament-enriched neuron classes were observed, including extraverted neurons, inverted pyramidal neurons, fusiform neurons, and other multipolar types. In addition, many projection neurons in layers II-III were found to contain calbindin. Among interneurons, parvalbumin- and calbindin-expressing cells were generally denser compared to calretinin-immunoreactive cells. We traced the evolution of certain cortical architectural traits using phylogenetic analysis. Based on our reconstruction of character evolution, we found that the living xenarthrans and afrotherians show many similarities to the stem eutherian mammal, whereas other eutherian lineages display a greater number of derived traits.

Appeals to synapomorphic features of the wrist and hand in African apes, early hominins, and modern humans as evidence of knuckle-walking ancestry for the hominin lineage rely on accurate interpretations of those features as adaptations to knuckle-walking locomotion. Because Gorilla, Pan, and Homo share a relatively close common ancestor, the interpretation of such features is confounded somewhat by phylogeny. The study presented here examines the evolution of a similar locomotor regime in New World anteaters (order Xenarthra, family Myrmecophagidae) and uses the terrestrial giant anteater (Myrmecophaga tridactyla) as a convergence test of adaptation for purported knuckle-walking features of the Hominidae. During the stance phase of locomotion, Myrmecophaga transmits loads through flexed digits and a vertical manus, with hyperextension occurring at the metacarpophalangeal joints of the weight-bearing rays. This differs from the locomotion of smaller, arboreal anteaters of outgroup genera Tamandua and Cyclopes that employ extended wrist postures during above-branch quadrupedality. A number of features shared by Myrmecophaga and Pan and Gorilla facilitate load transmission or limit extension, thereby stabilizing the wrist and hand during knuckle-walking, and distinguish these taxa from their respective outgroups. These traits are a distally extended dorsal ridge of the distal radius, proximal expansion of the nonarticular surface of the dorsal capitate, a pronounced articular ridge on the dorsal aspects of the load-bearing metacarpal heads, and metacarpal heads that are wider dorsally than volarly. Only the proximal expansion of the nonarticular area of the dorsal capitate distinguishes knuckle-walkers from digitigrade cercopithecids, but features shared with digitigrade primates might be adaptive to the use of a vertical manus of some sort in the stance phase of terrestrial locomotion. The appearance of capitate nonarticular expansion and the dorsal ridge of the distal radius in the hominin lineage might be indicative of a knuckle-walking ancestry for bipedal hominins if interpreted within the biomechanical and phylogenetic context of hominid locomotor evolution. Am J Phys Anthropol, 2005. © 2005 Wiley-Liss, Inc.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:04:53Z No. of bitstreams: 1 S1415-47572004000300014.pdf: 89107 bytes, checksum: 96cb764255096749257a2e233ab23329 (MD5) Made available in DSpace on 2013-08-22T19:04:53Z (GMT). No. of bitstreams: 1 S1415-47572004000300014.pdf: 89107 bytes, checksum: 96cb764255096749257a2e233ab23329 (MD5) Previous issue date: 2004-01-01 Made available in DSpace on 2013-09-30T20:08:20Z (GMT). No. of bitstreams: 2 S1415-47572004000300014.pdf: 89107 bytes, checksum: 96cb764255096749257a2e233ab23329 (MD5) S1415-47572004000300014.pdf.txt: 14841 bytes, checksum: 22d0fd44852c92a62ebc94b86364b41c (MD5) Previous issue date: 2004-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:17:27Z No. of bitstreams: 2 S1415-47572004000300014.pdf: 89107 bytes, checksum: 96cb764255096749257a2e233ab23329 (MD5) S1415-47572004000300014.pdf.txt: 14841 bytes, checksum: 22d0fd44852c92a62ebc94b86364b41c (MD5) Made available in DSpace on 2014-05-20T15:17:27Z (GMT). No. of bitstreams: 2 S1415-47572004000300014.pdf: 89107 bytes, checksum: 96cb764255096749257a2e233ab23329 (MD5) S1415-47572004000300014.pdf.txt: 14841 bytes, checksum: 22d0fd44852c92a62ebc94b86364b41c (MD5) Previous issue date: 2004-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Anteaters belong to the Order Xenarthra / Family Myrmecophagidae and are the only members without teeth. There are three genera with four living species in the family Myrmecophagidae: Myrmecophaga tridactyla (giant anteater), Tamandua tetradactyla (southern lesser anteater), Tamandua mexicana (northern lesser anteater), and Cyclopes didactylus (silky anteater). The karyotypes of M. tridactyla (2n = 60), T. tetradactyla (2n = 54) and C. didactylus (2n = 64) have already been described. In the present paper, three female and two male specimens of giant anteater and one lesser anteater male were analyzed. The results indicate the existence of a new karyotype in the genus Tamandua, with 2n = 56 chromosomes, which can represent a new lesser anteater species. The karyotype of M. tridactyla was also described, supporting previous reports. Universidade Estadual Paulista Instituto de Biociências de Botucatu Universidade Federal de Minas Gerais Departamento de Biologia Geral Laboratório de Citogenética Fundação Zoobotânica de Belo Horizonte Departamento de Biologia Geral Laboratório de Citogenética Universidade Estadual Paulista Instituto de Biociências de Botucatu

The giant anteater (Myrmecophaga tridactyla) is considered vulnerable to extinction. Scientific data on the reproductive parameters of this species are scarce. Semen from eight free-ranging giant anteaters was collected to establish its characteristics and the effects of cooling and storage at 5 °C after dilution with the BotuCrio extender without cryoprotectant. The ejaculate presented two distinct sequential fractions, including a whitish fraction, which was milky and rich in sperm cells, and a gel fraction, which was colorless, viscous, and azoospermic. The mean ± standard error of the mean values of the seminal characteristics were as follows: volume of the first fraction, 0.75 ± 0.1 mL; motility, 75 ± 2.9%; vigor, 3.2 ± 0.3; sperm motility index, 68.8 ± 4.3; concentration, 108.5 ± 13.4 × 10(6)/mL; plasma membrane integrity index, 71 ± 4.0%; spermatic defects detected using modified Karras staining, 35.5 ± 3.3%; and spermatic alterations identified by differential interference contrast microscopy, 48.3 ± 6.8%. During refrigeration, the semen presented decreasing motility from 0 to 18 hours, sperm motility index decreased from 0 to 24 hours, and vigor did not change in the first 6 hours and then decreased to 18 hours.

The fatal outcome of a defensive attack by a giant anteater (Myrmecophaga tridactyla) is reported. The attack occurred while the victim was hunting, and his dogs cornered the adult anteater, which assumed an erect, threatening position. The hunter did not fire his rifle because of concern about accidentally shooting his dogs. He approached the animal armed with a knife, but was grabbed by its forelimbs. When his sons freed him, he had puncture wounds and severe bleeding in the left inguinal region; he died at the scene. Necroscopic examination showed femoral artery lesions and a large hematoma in the left thigh, with death caused by hypovolemic shock. A similar case is cited, and recommendations are made that boundaries between wildlife and humans be respected, especially when they coinhabit a given area.

Oestrogen and progestagen metabolites were measured in the faeces of five female giant anteaters (Myrmecophaga tridactyla), to characterise the oestrous cycle and pregnancy. Faecal samples were collected twice weekly for a minimum of 6 months, and immunoreactive progestagens and oestrogens were analysed using enzyme immunoassays (EIA). For progestagens, two antibodies that cross-reacted with 20alpha-hydroxy- or 20-oxo-progestagens were used. Both assays effectively monitored ovarian cyclicity; however, the concentrations obtained using the antibody for 20alpha-hydroxy-progestagens were higher, and the hormonal changes were more pronounced. Regular ovarian cycles were identified in three of the five females. Average (+/-SEM) length of the oestrous cycle (n=10) was 51.4+/-5.6 days. Peak concentrations of 20alpha-hydroxy-progestagens ranged from 80-660 ng/g of faeces and those of oestrogens from 20-100 ng/g. Hormone concentrations were measured during parts of two pregnancies and during four post-partum periods. The length of one gestation (from oestrous oestrogen peak until parturition) was 184 days. In the second half of gestation, progestagen concentration started to increase above luteal phase values; in the week before parturition it was approximately 20 times higher than those during the luteal phase. Concentrations of excreted oestrogens began to increase after two thirds of gestation and exceeded that of the follicular phase by approximately 2.5-fold in the week before parturition. Onset of ovarian cyclicity after parturition varied from 4-11 weeks. In conclusion, the measurement of faecal immunoreactive progestagens and oestrogens in the giant anteater indicated an ovarian cycle of approximately 7 weeks in length and provided potentially useful data for successful breeding management.