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1.
Sci Rep ; 12(1): 15251, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36085304

RESUMO

The eight species of bears world-wide consume a wide variety of diets. Some are specialists with extensive anatomical and physiological adaptations necessary to exploit specific foods or environments [e.g., polar bears (Ursus maritimus), giant pandas (Ailuropoda melanoleuca), and sloth bears (Melursus ursinus)], while the rest are generalists. Even though ursids evolved from a high-protein carnivore, we hypothesized that all have become low-protein macronutrient omnivores. While this dietary strategy has already been described for polar bears and brown bears (Ursus arctos), a recent study on giant pandas suggested their macronutrient selection was that of the ancestral high-protein carnivore. Consumption of diets with inappropriate macronutrient profiles has been associated with increased energy expenditure, ill health, failed reproduction, and premature death. Consequently, we conducted feeding and preference trials with giant pandas and sloth bears, a termite and ant-feeding specialist. Both giant pandas and sloth bears branched off from the ursid lineage a million or more years before polar bears and brown bears. We found that giant pandas are low-protein, high-carbohydrate omnivores, whereas sloth bears are low-protein, high-fat omnivores. The preference for low protein diets apparently occurred early in the evolution of ursids and may have been critical to their world-wide spread.


Assuntos
Bichos-Preguiça , Ursidae , Animais , Dieta com Restrição de Proteínas , Alimentos , Nutrientes
2.
3.
Environ Microbiol ; 24(7): 3148-3163, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35621042

RESUMO

Sloths have a dense coat on which insects, algae and fungi coexist in a symbiotic relationship. This complex ecosystem requires different levels of controls; however, most of these mechanisms remain unknown. We investigated the bacterial communities inhabiting the hair of two- (Choloepus Hoffmanni) and three-toed (Bradypus variegatus) sloths and evaluated their potential for producing antibiotic molecules capable of exerting control over the hair microbiota. The analysis of 16S rRNA amplicon sequence variants revealed that the communities in both host species are dominated by Actinobacteriota and Firmicutes. The most abundant genera were Brevibacterium, Kocuria/Rothia, Staphylococcus, Rubrobacter, Nesterenkonia and Janibacter. Furthermore, we isolated nine strains of Brevibacterium and Rothia capable of producing substances that inhibited the growth of common mammalian pathogens. The analysis of the biosynthetic gene clusters of these nine isolates suggests that the pathogen-inhibitory activity could be mediated by the presence of siderophores, terpenes, beta-lactones, Type III polyketide synthases, ribosomally synthesized and post-translationally modified peptides, non-alpha poly-amino acids like e-Polylysine, ectoine or non-ribosomal peptides. Our data suggest that Micrococcales that inhabit sloth hair could have a role in controlling microbial populations in that habitat, improving our understanding of this highly complex ecosystem.


Assuntos
Actinobacteria , Microbiota , Bichos-Preguiça , Animais , Antibacterianos/farmacologia , Bactérias/genética , Microbiota/genética , RNA Ribossômico 16S/genética , Simbiose
4.
J Exp Zool A Ecol Integr Physiol ; 337(7): 699-708, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35567440

RESUMO

A key characteristic of primate above-branch arboreal locomotion is hindlimb-biased weight support, subverting the typical mammalian condition in which the majority of the body weight is supported by the forelimb. This shift is thought to reflect an adaptation toward the arboreal niches exploited by early primates. However, above-branch quadrupedalism represents only one locomotor mode employed by primates in arboreal contexts. Inverted quadrupedal gaits, in which primates are suspended beneath branches by their hands and feet, have been documented in more than 50 primate taxa. This gait is characterized by a return to forelimb-biased weight distributions and a transition from peak vertical forces being greatest in the hindlimb to being greatest in the forelimb, which may occur to protect the hindlimb from high magnitudes of tensile loading when inverted. In this study, we compare kinetic and kinematic data during upright and inverted quadrupedalism in Lemur catta, Varecia variegata, Cebus capucinus, and Saimiri sciureus. These data are referenced against a classical inverted quadrupedal model: the two-toed sloth (Choloepus didactylus). Our findings show that inverted quadrupedalism in primates is differentiated from above-branch quadrupedalism by increases in forelimb weight support, forelimb contact times, and both forelimb and hindlimb joint excursions. Previously postulated biomechanical models outlining mechanisms relating to the control of weight support during upright walking do not translate well to inverted quadrupedal walking. We suggest that inverted primates may simply be adopting basal neuromuscular gait characteristics and applying them facultatively to this infrequent locomotor behavior.


Assuntos
Primatas , Bichos-Preguiça , Animais , Fenômenos Biomecânicos/fisiologia , Membro Anterior/fisiologia , Marcha/fisiologia , Primatas/fisiologia , Bichos-Preguiça/fisiologia , Árvores , Caminhada/fisiologia
5.
Anat Histol Embryol ; 51(4): 477-483, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35603530

RESUMO

Euphractus sexcinctus is a wild mammal native to the Americas; they have great diversity and are not in danger of extinction like other armadillo species. Despite the diversity, the morphology of several biological systems of this species has not been fully described. This study details the gross and microscopic anatomy of the urinary system in Euphractus sexcinctus, a six-banded armadillo, compared with other mammalian study models. Six animals were dissected in the study. In the anatomical analysis, the kidneys, ureters, urinary bladder and urethra were dissected and photographed; then, fragments were submitted to histological routine for staining with haematoxylin-eosin, toluidine blue and Masson's trichrome for visualization under light microscopy. The six-banded armadillo ureter is histologically composed of four concentric layers. The urinary bladder is presented with three tissue layers. The pattern of constitution and distribution of urinary system structures was compatible with that of most domestic like Canis familiaris and wild animals like Bradypus torquatus, with adaptations for the arid and semi-arid habitat. The description of the morphology of Euphractus sexcinctus presents great relevance both for its conservation and for its use as a model for clinical research.


Assuntos
Tatus , Sistema Urinário , Animais , Animais Selvagens , Tatus/anatomia & histologia , Cães , Bichos-Preguiça , Sistema Urinário/anatomia & histologia
6.
J Anim Physiol Anim Nutr (Berl) ; 106(4): 910-921, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35468240

RESUMO

We evaluated food intake, digestibility, digesta retention and digestible energy (DE) intake in four three-toed sloths (Bradypus variegatus, body mass 2.86 ± 0.10 kg) fed two leaf-based diets containing different neutral detergent fibre (NDF) and lignin contents. Total dry matter intake (DMI), and intake in relation to body mass and metabolic body weight were higher for the mixed diet with lower NDF content based on Pterondon sp. + Inga sp. (47 g day-1 , 16 g kg-1 day-1 and 21 g kg-0.75 day-1 ) compared to the treatment with higher content of NDF from only Cecropia pachystachya leaves (37 g day-1 , 14 g kg-1 day-1 and 18 g kg-0.75 day-1 ). The digestibility of dry matter (dDM) and neutral detergent fibre (dNDF) were higher in the mixed diet (60% and 61% respectively). There was a higher supply of DE and metabolisable energy (ME) on the mixed diet, at 221 and 199 kJ kg-0.75 day-1 , meeting the average energy requirement of 185 kJ ME kg-0.75 day-1 ME estimated for sloths in this study. In contrast, the diet with C. pachystachya generated a deficit of 31 kJ ME kg-0.75 day-1 . There was a correlation between DMI and dNDF (r2 = 0.89), and between dNDF and dDM (r2 = 0.98) across treatments. The mean retention times for a liquid and a particle marker were lower on the mixed diet with the higher intake at 133 h (passage rate = 0.75% h-1 ) and 181 h (0.55% h-1 ), and longer on the single-species diet with lower intake at 204 h (0.49% h-1 ) and 261 h (0.38% h-1 ). The results suggest that it may be beneficial for sloths to be offered a variety of browse from which they can choose low-NDF components. Further, we suggest that these sloths perform 'digesta washing' to increase the microbial yield in the stomach to maximise the digestion of NDF and dry matter.


Assuntos
Bichos-Preguiça , Ração Animal/análise , Animais , Detergentes , Dieta/veterinária , Fibras na Dieta/metabolismo , Digestão , Lignina
7.
Anat Histol Embryol ; 51(3): 400-410, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35285538

RESUMO

Paw pads are specializations of the integument and important shock absorbers of the locomotor system, as well as pressure, pain, temperature, storage and excretion sensors. Aiming to describe the paw pad morphology of the main arboreal xenarthras species in the Amazon, 16 animals were studied, Bradypus variegatus (6), Choloepus didactylus (5), Tamandua tetradactyla (3) and Cyclopes didactylus (2) that after death were donated to the Animal Morphological Research Laboratory (LaPMA / Ufra). The corpses were thawed and fixed with 10% aqueous formalin solution. The paw pads were measured, photographed and removed by skin incision dorsally to them. Fragments were used for routine histological processing, using two staining techniques: Hematoxylin-Eosin (HE) and Gomori's Trichrome, in sections of 6 to 8 µm. Choloepus didactylus, Tamandua tetradactyla and Cyclopes didactylus have digital paw pads, one in each digit, and one palm, as well as a plantar, whose shapes and colours are distinct from each other. Bradypus variegatus, however, has only one palmar and one plantar pad. Histologically, they have keratinized stratified squamous epithelium, supported by a large amount of collagen fibres and fibroblast cords in the dermis and hypodermis. Groups of eccrine sweat glands were observed in the reticular dermis of C. didactylus, B. variegatus, T. tetradactyla and only in the hypodermis of Cyclopes didactylus.


Assuntos
Bichos-Preguiça , Árvores , Animais , Extremidades , Pele/anatomia & histologia
8.
Sci Rep ; 12(1): 4119, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35260748

RESUMO

The Toca das Onças cave is one of the most important Quaternary mammal deposits of Brazil. Two different hypotheses have been proposed to explain the preservation mode of its skeletal remains: either the animals climbed down into the cave, or it could have functioned as a natural trap. Evaluation of pathological modifications on three articulated vertebrae of a single adult giant ground sloth Eremotherium laurillardi reveals a particular type of bone fracture caused by compressive force on the vertebral column, which split the vertebral bodies in the sagittal plane. This diagnosis suggests that the animal accidentally fell into the cave, in accordance with the second hypothesis proposed to the incorporation mode of skeletal remains into the cave.


Assuntos
Bichos-Preguiça , Fraturas da Coluna Vertebral , Acidentes , Animais , Restos Mortais , Fósseis , Vértebras Lombares/lesões , Fraturas da Coluna Vertebral/diagnóstico por imagem
9.
Sci Rep ; 12(1): 3943, 2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35273273

RESUMO

Sloth bears behave aggressively toward humans when threatened and are among the most dangerous wildlife in India. Safety messaging for those who live in sloth bear country must be accurate to be effective, and messaging may need to be modified to account for regional differences in human-bear relationships. The timing of sloth bear attacks on the Deccan Plateau of Karnataka, both by season and by time of day, deviated enough from those reported in other areas such that it warranted further investigation. We compared data from eight studies of human-sloth bear conflict from across the Indian subcontinent and explored possibilities as to why differences exist. Seasonally all studies reported that human-sloth bear conflict was highest when human activity in the forest was greatest, though the season of highest human activity varied significantly by region (χ2 = 5921, df = 5, P < 0.001). The time of day that the majority of attacks occurred also varied significantly by region (χ2 = 666, df = 5, P < 0.001), though human activity was relatively consistent. We speculated that the rate of day attacks on the Deccan Plateau was lower due to the reduced probability of encountering a sleeping bear as they are concealed and secure in shallow caves. Additionally, the rate of attacks was significantly higher at night on the Deccan Plateau because people often to work into nighttime. We concluded that slight differences, or different emphasis, to bear safety messaging may be necessary on a regional basis to keep the messaging accurate and effective.


Assuntos
Bichos-Preguiça , Ursidae , Animais , Animais Selvagens , Florestas , Humanos , Índia , Estações do Ano
10.
Vet Clin Pathol ; 51(1): 126-133, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35112370

RESUMO

The brown-throated sloth, Bradypus variegatus, is a common species endemic to South and Central America. Nonetheless, maintaining these animals in captivity can be challenging, and very few institutions manage to do so. The São Paulo Zoological Park Foundation is in a remnant of the Atlantic rainforest in the middle of São Paulo, the largest city in Brazil. This forest fragment has a population of B. variegatus that is geographically isolated and yet to be studied. Assessing the health status of individuals remains difficult due to the lack of reference intervals (RIs) for hematologic and biochemical variables for this species. We aimed to establish hematologic and biochemical RIs in a population of wild B. variegatus living in the largest remnant of Atlantic rainforest in São Paulo city, Brazil. Blood samples from 25 individuals of wild B. variegatus were collected and analyzed for 20 hematologic and 21 biochemical variables, using standard laboratory techniques. Each variable was statistically analyzed according to the American Society for Veterinary Clinical Pathology guidelines. The results obtained for each variable were statically analyzed, making it possible to obtain descriptive statistics for all hematologic and biochemical variables. RIs were determined for 16 hematologic variables. During the microscopic analysis, we observed anisocytosis, polychromatophils, Howell-Jolly bodies, macroplatelets, and reactive lymphocytes. The RIs and descriptive statistics described here establish important baseline numbers that could be essential for the management and treatment of both captive and wild B. variegatus sloths.


Assuntos
Bichos-Preguiça , Animais , Brasil , Contagem de Eritrócitos/veterinária
11.
J Exp Biol ; 225(5)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35142360

RESUMO

The material composition of vertebrate connective tissue is highly conserved across taxa. Existing data suggest that the compressive and tensile strength of limb bones are very similar despite marked variation in limb posture and locomotor patterns. However, the material properties of limb bone tissue from suspensory taxa have not been formally evaluated. Sloths are nearly obligatory in their use of below-branch suspensory locomotion and posture, thus placing their limb bones and associated soft tissue structures under routine tensile loading. It is possible that sloth limb bones are modified for enhanced tensile strength, perhaps at the expense of compressive strength. Forelimb and hindlimb bones of two-toed (Choloepus hoffmanni) and three-toed (Bradypus variegatus) sloths were tested in compression and bending to evaluate this hypothesis. Strength and elastic (Young's) modulus were similarly lower in sloth limb bones during both compression and bending, as compared with pronograde taxa. Ratios of peak bending strength to compressive strength additionally were elevated (sloths: 1.4-1.7; upright taxa: 0.6-1.2) for sloth limb bones. Overall, the material properties measured from the limb bones of tree sloths support our hypothesis of predicted function in a tensile limb system. Future studies should aim to directly test bones in tension to confirm indications of elevated axial tensile strength. Nevertheless, the results herein expand understanding of functional adaptation in mammalian tissue for a range of locomotor/postural behaviors that were previously unexplored.


Assuntos
Bichos-Preguiça , Animais , Extremidade Inferior , Postura , Resistência à Tração , Extremidade Superior
12.
J Anat ; 240(6): 1048-1074, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35037260

RESUMO

Tree sloths rely on their limb flexors for bodyweight support and joint stability during suspensory locomotion and posture. This study aims to describe the myology of three-toed sloths and identify limb muscle traits that indicate modification for suspensorial habit. The pelvic limbs of the brown-throated three-toed sloth (Bradypus variegatus) were dissected, muscle belly mass was recorded, and the structural arrangements of the muscles were documented and compared with the available myological accounts for sloths. Overall, the limb musculature is simplified by containing muscles with generally long and parallel fascicles. A number of specific and informative muscle traits are additionally observed in the pelvic limb of B. variegatus: well-developed hip flexors and hip extensors each displaying several fused bellies; massive knee flexors; two heads of the m. adductor longus and m. gracilis; robust digital flexors and flexor tendons; m. tibialis cranialis muscle complex originating from the tibia and fibula and containing a modified m. extensor digitorum I longus; appreciable muscle mass devoted to ankle flexion and hindfoot supination; only m. extensor digitorum brevis acts to extend the digits. Collectively, the findings for tree sloths emphasize muscle mass and organization for suspensory support namely by the hip flexors, knee flexors, and limb adductors, for which the latter two groups may stabilize suspensory postures by exerting appreciable medially-directed force on the substrate. Specializations in the distal limb are also apparent for sustained purchase of the substrate by forceful digital flexion coupled with strong ankle flexion and supination of the hind feet, which is permitted by the reorganization of several digital extensors. Moreover, the reduction or loss of other digital flexor and ab-adductor muscles marks a dramatic simplification of the intrinsic foot musculature in B. variegatus, the extent to which varies across extant species of two- and three-toed tree sloths and likely is related to substrate preference/use.


Assuntos
Bichos-Preguiça , Animais , Membro Posterior/fisiologia , Locomoção/fisiologia , Músculo Esquelético , Postura , Bichos-Preguiça/fisiologia
13.
Zoo Biol ; 41(1): 20-25, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34329484

RESUMO

Hoffmann's two-toed sloths (Choloepus hoffmanni) are unique animals popular in zoological settings. The role of vitamin D in the maintenance of calcium homeostasis in this species is unexplored, although disorders of calcium homeostasis have been reported in managed sloths, including urolithiasis and soft tissue mineralization. This study assessed cutaneous concentrations of 7-dehydrocholesterol (7-DHC) in nine indoor-housed Hoffmann's two-toed sloths, as a means of evaluating the potential for cutaneous photobiosynthesis of vitamin D3 . Samples were obtained from both abdominal and lumbar regions of the skin to assess for regional variation in 7-DHC concentration. The average concentration of 7-DHC in the sloth skin was low (0.197 ± 0.02 nmol/cm2 ). Location had a significant effect on 7-DHC level only when concentrations were expressed based on the wet weight of the sample (ng/g), but levels were similar when values were normalized to biopsy surface area (nmol/cm2 ).


Assuntos
Bichos-Preguiça , Animais , Animais de Zoológico , Desidrocolesteróis , Programas de Assistência Gerenciada
14.
Anat Rec (Hoboken) ; 305(6): 1394-1401, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34591370

RESUMO

Bone diseases are commonly found in the fossil record, especially in mammals of the Pleistocene megafauna, which exhibit signs of overload in the articulations. However, pathologies that affect soft tissues are not usually reported, even due to the nature of fossilization that rarely preserves such materials. In paleoneurological research using CT scan and three-dimensional reconstructions of Pleistocene sloths, an anomaly is discovered in the space that houses the pituitary gland, the sella turcica. The tomographic analysis of a Valgipes bucklandi skull revealed a great enlargement at the sella turcica, at the medial region in the body of the basisphenoid bone. The images delimit an enlarged dorsal-ventral projection, measuring approximately 15 mm height, at the tridimensional reconstructed endocranium. Taphonomic processes, such as the action of necrophagous agents, were discarded due to the shape and conditions of the structure, which also showed signs of bone remodeling. Thus, it is possible to affirm that a paleopathological process altered the size of the pituitary gland of the specimen MCT 3993-M, being probably a pituitary tumor.


Assuntos
Neoplasias Hipofisárias , Bichos-Preguiça , Animais , Hipófise , Neoplasias Hipofisárias/diagnóstico por imagem , Neoplasias Hipofisárias/patologia , Sela Túrcica/anormalidades , Sela Túrcica/patologia , Crânio
15.
Anat Histol Embryol ; 51(1): 85-90, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34820880

RESUMO

Bradypus variegatus, popularly known as common sloth or brown-throated sloth, is a species with wide geographical distribution in Brazil. Expand on the literature about the species, we aimed to describe the morphology of its eye and its main annexes. For this study, six frozen specimens donated to the Animal Morphological Research Laboratory of the Federal Rural University of Amazonia were used. The specimens were fixed in a 10% aqueous solution of formaldehyde. The structures that constitute the ocular apparatus were identified and described after dissection and histological analysis using light microscopy. The bulbar conjunctiva presented a stratified cuboidal epithelium, with a considerable number of serous glands. The stroma layer and the posterior limiting lamina were found well defined in the species. The corneoscleral meshwork possessed a large opening for drainage of aqueous humour, followed by a wide retinal region, in which a layer of photoreceptors was visualized. Cones and rods could not be discriminated from each other. Microscopy of the medial angle of the eye revealed the cartilage and glands of the third eyelid, and a well-developed lacrimal gland structure. Bradypus variegatus distinguishing features and similarities in comparison with other domestic and wild mammal and bird species already described were investigated, which expounded the limited knowledge that is presently available on the morphology of wild fauna. The data extend the limited knowledge that are presently available on the ocular histology of B. variegatus.


Assuntos
Bichos-Preguiça , Animais , Brasil , Microscopia/veterinária
16.
Anat Rec (Hoboken) ; 305(7): 1804-1819, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34779120

RESUMO

Two-toed (Choloepus sp.) and three-toed (Bradypus sp.) sloths possess short, rounded pisiforms that are rare among mammals and differ from other members of Xenarthra like the giant anteater (Myrmecophaga tridactyla) which retain elongated, rod-like pisiforms in common with most mammals. Using photographs, radiographs, and µCT, we assessed ossification patterns in the pisiform and the paralogous tarsal, the calcaneus, for two-toed sloths, three-toed sloths, and giant anteaters to determine the process by which pisiform reduction occurs in sloths and compare it to other previously studied examples of pisiform reduction in humans and orangutans. Both extant sloth genera achieve pisiform reduction through the loss of a secondary ossification center and the likely disruption of the associated growth plate based on an unusually porous subchondral surface. This represents a third unique mechanism of pisiform reduction among mammals, along with primary ossification center loss in humans and retention of two ossification centers with likely reduced growth periods in orangutans. Given the remarkable similarities between two-toed and three-toed sloth pisiform ossification patterns and the presence of pisiform reduction in fossil sloths, extant sloth pisiform morphology does not appear to represent a recent convergent adaptation to suspensory locomotion, but instead is likely to be an ancestral trait of Folivora that emerged early in the radiation of extant and fossil sloths.


Assuntos
Bichos-Preguiça , Xenarthra , Animais , Fósseis , Humanos , Mamíferos , Osteogênese , Bichos-Preguiça/anatomia & histologia
17.
J Zoo Wildl Med ; 52(3): 1030-1035, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34687521

RESUMO

Disorders of calcium homeostasis have been reported with some frequency in two-toed sloths, yet little investigation has been performed on vitamin D and mineral metabolism in these species. This study evaluates biomarkers involved in vitamin D and calcium metabolism in a group of nine managed Hoffmann's two-toed sloths (Choloepus hoffmanni), correlated with diet analysis. Serum was analyzed for both vitamin D2 and D3 metabolites, minerals (calcium [Ca], phosphorus [P], and magnesium [Mg]), parathyroid hormone (PTH), and ionized calcium (iCa). The diet was analyzed for proximate nutrients, minerals and vitamins D2 and D3, and feed intake was estimated. Average values reported for D3 metabolites, including 25(OH)D3, 1,25(OH)2D3, and 24,25(OH)2D3, were 25.1 ng/ml, 52.23 pg/ml, and 7.65 ng/ml, respectively. Average PTH was 0.22 pmol/L while average iCa was 1.46 mmol/L. Values reported for Ca, P, Mg were within expected ranges. Dietary concentration of D3 was 6.7 ng/g and the average daily intake per sloth was 113.7 IU/kg body weight. No detectable levels of vitamin D2 metabolites 25(OH)D2, 1,25(OH)2D2, or 24,25(OH)2D2 were found in the diet or serum. These data will serve as a starting point for future investigations into the vitamin D metabolism and calcium homeostasis of two-toed sloths to improve the health in managed settings.


Assuntos
Bichos-Preguiça , Animais , Cálcio , Hormônio Paratireóideo , Projetos Piloto , Vitamina D , Vitaminas
18.
Sci Rep ; 11(1): 18944, 2021 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-34615902

RESUMO

Fossil sloths are regarded as obligate herbivores for reasons including peculiarities of their craniodental morphology and that all living sloths feed exclusively on plants. We challenge this view based on isotopic analyses of nitrogen of specific amino acids, which show that Darwin's ground sloth Mylodon darwinii was an opportunistic omnivore. This direct evidence of omnivory in an ancient sloth requires reevaluation of the ecological structure of South American Cenozoic mammalian communities, as sloths represented a major component of these ecosystems across the past 34 Myr. Furthermore, by analyzing modern mammals with known diets, we provide a basis for reliable interpretation of nitrogen isotopes of amino acids of fossils. We argue that a widely used equation to determine trophic position is unnecessary, and that the relative isotopic values of the amino acids glutamate and phenylalanine alone permit reliable reconstructions of trophic positions of extant and extinct mammals.


Assuntos
Comportamento Alimentar/fisiologia , Isótopos de Nitrogênio/análise , Bichos-Preguiça/genética , Aminoácidos/análise , Aminoácidos/química , Animais , DNA Mitocondrial , Ecossistema , Fósseis , Herbivoria/fisiologia , Isótopos/análise , Mamíferos/genética , Filogenia , Bichos-Preguiça/metabolismo , /metabolismo
19.
Arq. bras. med. vet. zootec. (Online) ; 73(4): 877-884, Jul.-Aug. 2021. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285269

RESUMO

The aim of this study was to establish reference parameters for the hematological and biochemical levels of five healthy captive sloths of the speciesBradypus variegatus(brown-throated sloth) feeding onCecropia pachystachya(Ambay pumpwood), alternating with a period of free diet in the Dois Irmãos State Park (DISP) Recife, Pernambuco - Brazil.(AU)


O objetivo da presente pesquisa foi estabelecer parâmetros de referência para níveis hematológicos e bioquímicos, de cinco preguiças sadias, da espécie Bradypus variegatus (preguiça-de-garganta-marrom), em cativeiro, alimentando-se de Cecropia pachystachya (embaúba) em períodos alternados com dieta livre, no Parque Estadual de Dois Irmãos (PEDI) Recife, Pernambuco-Brasil.(AU)


Assuntos
Animais , Bichos-Preguiça/sangue , Cecropia (Planta) , Brasil , Padrões de Referência/métodos , Testes Hematológicos/veterinária
20.
Biol Rev Camb Philos Soc ; 96(6): 2638-2660, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34309191

RESUMO

Sloths are unusual mobile ecosystems, containing a high diversity of epibionts living and growing in their fur as they climb slowly through the canopies of tropical forests. These epibionts include poorly studied algae, arthropods, fungi, and bacteria, making sloths likely reservoirs of unexplored biodiversity. This review aims to identify gaps and eliminate misconceptions in our knowledge of sloths and their epibionts, and to identify key questions to stimulate future research into the functions and roles of sloths within a broader ecological and evolutionary context. This review also seeks to position the sloth fur ecosystem as a model for addressing fundamental questions in metacommunity and movement ecology. The conceptual and evidence-based foundation of this review aims to serve as a guide for future hypothesis-driven research into sloths, their microbiota, sloth health and conservation, and the coevolution of symbioses in general.


Assuntos
Artrópodes , Bichos-Preguiça , Animais , Evolução Biológica , Ecossistema , Simbiose
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