The effects of fossil taxa, hypothetical predicted ancestors, and a molecular scaffold on pseudoextinction analyses of extant placental orders.

Pseudoextinction analyses, which simulate extinction in extant taxa, use molecular phylogenetics to assess the accuracy of morphological phylogenetics. Previous pseudoextinction analyses have shown a failure of morphological phylogenetics to place some individual placental orders in the correct superordinal clade. Recent work suggests that the inclusion of hypothetical ancestors of extant placental clades, estimated by ancestral state reconstructions of morphological characters, may increase the accuracy of morphological phylogenetic analyses. However, these studies reconstructed direct hypothetical ancestors for each extant taxon based on a well-corroborated molecular phylogeny, which is not possible for extinct taxa that lack molecular data. It remains to be determined if pseudoextinct taxa, and by proxy extinct taxa, can be accurately placed when their immediate hypothetical ancestors are unknown. To investigate this, we employed molecular scaffolds with the largest available morphological data set for placental mammals. Each placental order was sequentially treated as pseudoextinct by exempting it from the molecular scaffold and recoding soft morphological characters as missing for all its constituent species. For each pseudoextinct data set, we omitted the pseudoextinct taxon and performed a parsimony ancestral state reconstruction to obtain hypothetical predicted ancestors. Each pseudoextinct order was then evaluated in seven parsimony analyses that employed combinations of fossil taxa, hypothetical predicted ancestors, and a molecular scaffold. In treatments that included fossils, hypothetical predicted ancestors, and a molecular scaffold, only 8 of 19 pseudoextinct placental orders (42%) retained the same interordinal placement as on the molecular scaffold. In treatments that included hypothetical predicted ancestors but not fossils or a scaffold, only four placental orders (21%) were recovered in positions that are congruent with the scaffold. These results indicate that hypothetical predicted ancestors do not increase the accuracy of pseudoextinct taxon placement when the immediate hypothetical ancestor of the taxon is unknown. Hypothetical predicted ancestors are not a panacea for morphological phylogenetics.

New records of fleas and ticks in armadillos (Xenarthra: Chlamyphoridae) br /from the Espinal and Monte ecoregions of La Pampa province, Argentina.

La Pampa province is divided into two clearly distinguishable fractions: a small northeastern humid sector corresponding to the Pampas ecoregion and a drier western sector, represented by the Monte de Llanuras y Mesetas (termed Monte region in this paper) and Espinal ecoregions (sensu Brown et al. 2006). These three ecoregions are visibly distinguishable from an edaphological and phytogeographic point of view, while the mammalian fauna composition is homogeneous. The study area was located in the central part of the province, comprising the Monte and Espinal ecoregions (Fig. 1). In that area three species of armadillos are recorded (Soibelzon et al. 2015). Two of these (Zaedyus pichiy Desmarest, 1804 and Chaetophractus villosus Desmarest, 1804) (Xenarthra: Chlamyphoridae) are the most common and widely distributed armadillos both in the province and in the country, while the third species, Chlamyphorus truncatus Harlan, 1825, has a more restricted distribution and is one of the most cryptic and least known armadillos in the country. For this reason, in our fieldwork ectoparasites were obtained only from the first two species mentioned.

Anatomia macroscópica interna e avaliação elétrica do coração de Bradypus variegatus / Internal macroscopic anatomy and electrical evaluation of the Bradypus variegatus heart

The Bradypus variegatus species presents peculiar anatomophysiological properties and many aspects of its organic systems still need to be clarified, especially regarding the cardiovascular system, given its participation in vital activities. Disorderly anthropic action has had drastic consequences in sloth populations and the need to treat sick and injured animals is increasingly common. To this end, the importance of knowing its characteristics is emphasized. Therefore, this study proposed to describe the internal macroscopic structures of the sloth's heart, as well as to measure the ventricular walls and indicate the electrical activity of the organ. For the dissections, 15 Bradypus variegatus cadavers were used (1 young female, 9 adults females and 5 adult males) belonging to the Área de Anatomia of the Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco (UFRPE), Recide, PE, Brazil. After they were fixed and preserved, the specimens received a midsagittal incision in the chest, followed by soft tissue folding and removal of ribs to access the heart. The organ was derived from the cavity and sectioned sagittal medially to identify its internal anatomy. Ventricular walls and interventricular septum were measured with a steel caliper (150 mm / 0.02 mm). An electrocardiogram was performed to determine the electrical profile on 5 healthy B. variegatus sloths, living under semi-livestock conditions at the Recife Zoo, PE, Brazil. The electrodes were taken from the regions, scapular and glutes of the animals that were called hugging a keeper during the procedure, carried out in the Zoo itself, using a portable device. Based on the data obtained, sloths have cardiac chambers separated by septa, however between atria and ventricles, in both antimeres, there are atrioventricular ostia, where valves are found, consisting of 3 valves on the right and 2 on the left. The atria are practically smooth inside and have their cavity enlarged by the atria, the right being larger than the left, these having a greater amount of pectineal muscles in relation to the atria. The ventricles have trabeculae and papillary muscles, 3 on the right and 2 on the left. These muscles hold the tendinous chords that connect the valves. The existence of trabeculae marginal septum was not evidenced. The thickness of the wall of the left ventricle, as well as that of the interventricular septum, proved to be greater than the thickness of the wall of the right ventricle, regardless of the age or sex of the animals. Based on the electrocardiographic recordings, the sloths presented sinus rhythm, with a heart rate between 67 and 100 bpm. The electrical axis ranged from -60º to -90º. The P wave is smoother than the QRS complex. While the S-T segment was classified as isoelectric. The T wave was shown to be + and predominantly > or = at 25% of the S wave, which characterized an rS type QRS deflection in both females and males. The general characteristics of the cardiac chambers in sloths are similar to those observe in other domestic and wild mammals. However, the presence of pectineal muscles associated with the atria and auricles differs from that observed in mammals such as the paca and raccoon and in birds such as the ostrich, which have trabecular structures in these cavities. The number of valves in sloths is equal to the anteater. However, it has a marginal trabeculae septum, not seen in Bradypus variegatus. According to the electrocardiographic findings, the rhythm was sinus, but much lower than that observed in the capuchin monkey, which also maintains arboreal habits.(AU)

Gregariousness in the giant sloth Lestodon (Xenarthra): multi-proxy approach of a bonebed from the Last Maximum Glacial of Argentine Pampas.

Megamammals constituted an important component in the Pleistocene faunal communities of South America. Paleobiological and paleoecological studies involving different megamammal taxa have increased significantly in the last years, but there are still several poorly-known issues of its life history. In this work, we analyze an assemblage composed of 13 individuals of different ontogenetic stages, and possibly different sex, belonging to the giant ground sloth Lestodon armatus (Xenarthra, Folivora), recovered from Playa del Barco site (Pampean Region, Argentina). A dating of 19,849 years Cal BP allows assigning this assemblage to a period of the MIS (Marine Isotope Stage) 2 related to the end of the Last Glacial Maximum. Based on multiple lines of research (e.g. taphonomy, paleopathology, osteohistology, isotopy), we interpret the origin of the assemblage and diverse paleobiological and paleoecological aspects (e.g. social behavior, ontogenetic changes, sexual dimorphism, diseases, resource and habitat use, trophic relationships) of L. armatus. Evidence suggests that the assemblage was formed by a local single event of catastrophic mortality, which affected different members of a social group. This record represents the first accurate evidence of gregariousness for this ground sloth, providing new data on a poorly-known behavior among extinct Folivora.

Fecal progesterone and estrogen metabolite monitoring for cyclicity and pregnancy in southern tamandua (Tamandua tetradactyla).

Reproductive management of the southern tamandua (Tamandua tetradactyla) should include timed introductions for breeding to minimize aggression and pregnancy monitoring. Since serial blood sampling could cause unnecessary stress, and urinary progesterone metabolites are found in very low concentrations, this study sought to validate progesterone and estradiol enzyme immunoassays for measuring fecal progesterone metabolite (FPM) and fecal estrogen metabolite (FEM) concentrations in two females. Peaks in FEM concentrations coincided with breeding and conception, were 5-6 times higher than baseline concentrations, and were followed by clear luteal phases distinguished by FPM concentrations 5-6 times higher than baseline concentrations. FPM concentrations during the first 30-53 days of gestation overlapped with luteal phase concentrations, thereafter increasing to 8-25 times higher than baseline concentrations. FEM concentrations during the first 41-44 days of gestation remained near basal values for one female, whereas concentrations were 1.8 times higher than baseline for the second. FEM concentrations became elevated for the former by 44 days of gestation and increased further for the latter after 53 days, ultimately averaging four times higher than baseline for both females. The biphasic increase in FPM and FEM concentrations, follicular and luteal phase durations (follicular: 7 ± 1 days, luteal: 25 ± 1 days), total cycle length (41 ± 1 days), and gestation (161-165 days) documented in this study were consistent with previous reports from serum and urine analyses. Monitoring FPM and FEM is a reliable noninvasive method for tracking reproductive cycles and pregnancy in southern tamandua that overcomes the challenges associated with serum or urinary hormone analysis.

Morphological description of smell glands in Cyclopes didactylus.

A macroscopic and microscopic study of the mandibular organ of the silky anteater (Cyclopes didactylus) was carried out. The organ extends from below the zygomatic bone line to the middle of the mandible body, between the skin and the masseter muscle, on both sides of the animal. It has an average length of 11.7 mm and a width of 6.3 mm. In the mesoscopic analysis, it was observed that the organ presents in yellowish color due to the high amount of sebaceous content. In the histological analysis, the mandibular organ was observed to be composed of innumerable alveoli of the specialized sebaceous gland, surrounded by a layer of adventitia tunica. Scanning electron microscopy (SEM), revealed an apparent alveolar division with what appeared to be a sulcus at its center. The information here presented regarding the constitution and location of this structure has not been previously explored for other species and differs with respect to other descriptions for anteaters. Based on the present study, it is suggested that the mandibular organ is involved in social interaction in this species.

The lesser anteater (Tamandua tetradactyla) is not tetradactyla, but pentadactyla.

The name of the species tetradactyla means "four digits." In the literature, the hand of the lesser anteater (Tamandua tetradactyla) is described as having four digits (I, II, III and IV) with the absence of a fifth digit. The purpose of this study was to carry out an update adequately proposing an anatomical description of the T. tetradactyla hand. The present findings were analysed on the validation of Morse's law for this species. In total, seven male cadavers were radiographed and dissected. We observed that the hand of the T. tetradactyla was formed by a carpus containing four bones in the proximal row, which in the medium lateral direction was the radial, intermediate, ulnar and accessory bones of the carpus, and the distal row was formed by carpal bones I, II, III and IV. There were five metacarpal bones (I, II, III, IV and V). The presence of five digits was verified but not confirmed with the literature. Digit I had two phalanges, the proximal and distal; digits II, III and IV had three phalanges: proximal, middle and distal. Digit five had only one phalanx, the proximal, but it was not externally visible. According to the findings of this study, the presence of the fifth digit raises the question of whether the term tetradactyla is the most appropriate to describe this species. This rudimentary fifth digit and the presence of a functional first digit show that the Morse's law does not applies for the T. tetradactyla species.

Single- or Pair-Housed: Which Is Better for Captive Southern Tamanduas?

The captive environment can limit some important behavioral options for nonhuman animals, which often results in decreased welfare. The companion of a conspecific can be a source of complexity in captivity, but this aspect has received little attention for solitary species. This study investigated the effects of two different housing conditions on the behavior of a solitary species, the Southern tamandua (Tamandua tetradactyla). Six individuals housed singly and four housed in pairs in two Brazilian zoological institutions were observed for 10 days from 09:00h to 17:00h during the rainy season. Each individual was observed for 26:40 hours. Compared with singly housed tamanduas, paired animals were less inactive (single = 74.62 ± 5.2%, paired = 28.51 ± 0.04% of the records), foraged and explored more (single = 11.07 ± 3.0%, paired 31.48 ± 0.01% of the records), and exhibited a diversity of behaviors 102.56% greater than single tamanduas. These results suggest that interactions with conspecifics in captivity, even for solitary animals, can promote the performance of desirable behaviors, which in several species has been correlated with improved welfare.

Functional morphology and paleoecology of Pilosa (Xenarthra, Mammalia) based on a two-dimensional geometric Morphometrics study of the Humerus.

The relationship between humerus shape and the modes of exploring substrate among extinct and extant Pilosa (especially anteaters and ground sloths) were investigated here. We used geometric morphometrics and discriminant analyses to relate morphological patterns and their possible ecological categories. Our results suggest that plesiomorphic taxa such as Nothrotheriidae, most Megalonychidae and basal Megatheriidae tend to have more slender humerus, associated to generalist habitus (climbing, swimming and digging activities), and while Mylodontidae developed specialized digging habitus. Additionally, we inferred ground sloths which inhabited the Brazilian territory during the Quaternary likely occupied at least four different niches. Mammals display morphofunctional adaptations on the limbs which are reflected on their modes of substrate exploration. Herein, we analyzed the humerus morphology of ground sloths and anteaters. Our results suggest that most of the Pleistocene Mylodonts were fossorial taxa, while most of the Santacrucian sloths plus extant anteaters were semiarboreal or semiaquatic taxa. The Pleistocene Megatheriidae should be ambulatory.

In-house monitoring of steroid hormone metabolites in urine informs breeding management of a giant anteater (Myrmechophaga tridactyla).

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.

Which Wild Aardvarks Are Most Suitable for Outdoor Enclosures in Zoological Gardens in the European Union?

The aardvark is popular in many zoological gardens in the European Union. These creatures are nocturnal, and aardvarks in the wild are known to walk distances of 4 km to 7 km per night. Despite what is known about their biology, most aardvarks are kept in zoological gardens in indoor enclosures with little space for movement. This lack of space leads to a tendency toward obesity and compromised welfare. With their wide distribution in Sub-Saharan Africa, aardvarks are perceived as thermophilic nonhuman animals. Nevertheless, some records suggest they may be able to adapt to colder climates and can be active outside their burrows when temperatures fall to 2°C. These findings suggest there may be a wild African population that is suitable for partial outdoor keeping under European climatic conditions. Therefore, a climate match was computed between the source area with aardvark occurrence and a target area of the European Union. Data revealed that the Free State, a South African province, was the area with the best climate similarity, and aardvarks from this area are recommended as suitable for the aforementioned purpose.

Anatomy description of cervical region and hyoid apparatus in living giant anteaters Myrmecophaga tridactyla Linnaeus, 1758 / Descrição anatômica da região cervical e aparato hioide em espécimes vivos de tamanduá-bandeira, Mymercophaga tridactyla Linnaeus, 1758

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.(AU)

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.(AU)

SERIAL ULTRASOUND TO ESTIMATE FETAL GROWTH CURVES IN SOUTHERN TAMANDUA (TAMANDUA TETRADACTYLA).

From 2012 to 2015, 16 pregnancies were monitored by ultrasonography in nine tamanduas ( Tamandua tetradactyla ) housed in three zoological facilities. Sonographic measurements were recorded to establish fetal growth curves using thoracic and skull landmarks described for giant anteaters ( Myrmecophaga tridactyla ). All pregnancies resulted in the uncomplicated delivery of healthy offspring, thus gestational development was considered normal. These data may be used as a reference for normal fetal development with potential for estimating parturition date in the absence of breeding data.

Feeding Asian pangolins: An assessment of current diets fed in institutions worldwide.

Pangolins are ant specialists which are under intense threat from the illegal wildlife trade. Nutrition has notoriously been their downfall in captivity and is still an issue in regards to rescue and rehabilitation. We analyzed the nutrient content of diets used by institutions that are successfully keeping Asian pangolins and to assess the variety of the ingredients and nutrients, compared these with the nutritional requirements of potential nutritional model species. We performed intake studies at five institutions and also had data from three other institutions. We also analyzed five different wild food items to use as a proxy of wild diet. We observed two categories of captive diets: those mostly or completely composed of insects and those high in commercial feeds or animal meat. Nutrient values were broad and there was no clear rule. The non-protein energy to protein energy ratio of the diets were much higher than the wild food items, more so for those which receive less insects. The average contribution of carbohydrate, fat and protein energy were also further away from the wild samples the less insects they contained. The previously suggested nutritional model for pangolins is the domestic dog which is supported by our relatively large nutrient ranges of apparently successful diets, however due to their highly carnivorous nature; the upper most nutrient intake data are not consistent with this and favor the feline nutrient recommendations. We are unable to render a conclusion of what model is more appropriate based on our data collected.

Sound at the zoo: Using animal monitoring, sound measurement, and noise reduction in zoo animal management.

A clear need for evidence-based animal management in zoos and aquariums has been expressed by industry leaders. Here, we show how individual animal welfare monitoring can be combined with measurement of environmental conditions to inform science-based animal management decisions. Over the last several years, Disney's Animal Kingdom® has been undergoing significant construction and exhibit renovation, warranting institution-wide animal welfare monitoring. Animal care and science staff developed a model that tracked animal keepers' daily assessments of an animal's physical health, behavior, and responses to husbandry activity; these data were matched to different external stimuli and environmental conditions, including sound levels. A case study of a female giant anteater and her environment is presented to illustrate how this process worked. Associated with this case, several sound-reducing barriers were tested for efficacy in mitigating sound. Integrating daily animal welfare assessment with environmental monitoring can lead to a better understanding of animals and their sensory environment and positively impact animal welfare.

CONJUNCTIVAL BACTERIAL FLORA, ANTIBIOGRAM, AND LACRIMAL PRODUCTION TESTS OF COLLARED ANTEATER (TAMANDUA TETRADACTYLA).

The collared anteater ( Tamandua tetradactyla ) is adapted to a variety of habitats. It is a solitary species for which no reference values for ophthalmic tests have been established. Eight animals ranging from 1 to 4 yr of age, two males and six females, were manually restrained for assessment. Ophthalmic tests included evaluation of tear production by Schirmer tear test 1 (STT1), endodontic absorbent paper point tear test (EAPPTT), palpebral fissure length (PFL), culture of the conjunctival bacterial flora, and antimicrobial susceptibility test. Median ± semi-interquartile range (S-IQR) STT1, EAPPTT, and PFL were 8.50 ± 4.13 mm/min, 14.13 ± 3.24 mm/min, and 15.91 ± 2.51 mm, respectively. Bacterial growth was present in 100% of the samples, with predominance of Gram-positive bacteria (70.27%). Staphylococcus spp. was the most frequently isolated genus. Antimicrobial susceptibility test showed sensitivity of Staphylococcus epidermidis and Staphylococcus spp. to neomycin, tobramycin, and gentamicin. The results in this study can benefit the determination of reference values for different diagnostic techniques, and may be used as a guide for diagnosis and treatment of ocular diseases in collared anteaters.

Morphological convergence in the pubis of slow-moving primates and xenarthrans.

OBJECTIVES: Determining the functional significance of pubic rami is important for reconstructing locomotor behavior of fossil species. The slow loris pelvis, characterized by long pubic rami, is unusual among primates. Long pubic rami may be related to increasing the moment arm of the abdominal musculature during ventroflexion after the termination of hindlimb suspension, which is a common component of slow arboreal quadrupedalism (AQ). Some extant xenarthran species are also slow AQ taxa, and provide an ideal group to test hypotheses of morphologically convergent adaptations to slow AQ. MATERIALS AND METHODS: A model relating abdominal moment arms to pubic morphology is tested in three genera of slow-moving xenarthrans (Bradypus, Choloepus, and Cyclopes) and two species of slow loris (Nycticebus coucang and Perodicticus potto), using a comparative sample of 37 species of primates and xenarthrans. Phylogenetic analyses of variance and regression were performed on pubic dimensions (superior and inferior pubic ramus length, pubic symphysis length). RESULTS: As a locomotor group, slow-moving xenarthrans and lorises share superior pubic rami that are longer than all other locomotor groups; at the species level, there is some overlap among slow AQ and non-slow-AQ taxa. Inferior pubic ramus and pubic symphysis lengths also differ according to locomotor category, but multiple comparisons among locomotor groups are non-significant. DISCUSSION: These results support the hypothesis that superior pubic ramus length is functionally related to slow, suspensory locomotion by increasing the leverage of the ventral abdominal musculature, and demonstrates morphological convergence among two phylogenetically distant groups of mammals that have evolved adaptations for slow, suspensory locomotion.

Semen characteristics and refrigeration in free-ranging giant anteaters (Myrmecophaga tridactyla).

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.

GAIT ANALYSIS IN GIANT ANTEATER (MYRMECOPHAGA TRIDACTYLA) WITH THE USE OF A PRESSURE-SENSITIVE WALKWAY.

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.