Morphology of the small and large intestines of the six-banded armadillo (Euphractus sexcinctus) Linnaeus, 1758.

Euphractus sexcinctus has a diverse diet, so it needs anatomical and habitual features to help it get its meals. Therefore, the objective is to study the morphology of the small and large intestines of the six-banded armadillo (E. sexcinctus). The research was authorized and approved under number 136/16. Six animals, obtained from victims of predatory hunting, were dissected for the research. For the anatomical analysis, the specimens were dissected and photographed. The fragments of each organ were submitted to histological routine to obtain slides stained with hematoxylin-eosin, toluidine blue and Masson's trichrome for further analysis. The small intestine has three parts: duodenum, jejunum, and ileum. Histologically, it has the typical four layers of tubular organs. The mucosa is covered by simple cylindrical epithelium with the presence of specializations in the form of microvilli and variation in the number of goblet cells, depending on the portion observed. In the duodenal portion, the presence of the serous layer was not observed. In the jejunal portion, it is possible to observe lymphoid tissue aggregates in the submucosa, which become more evident in the ileum. The large intestine is divided into cecum, colon, and rectum and has the same histological subdivisions as the small intestine, but with some specializations. The presence of simple cylindrical intestinal crypts is clearly observed and the presence of a large number of goblet cells, which increase as it approaches the rectum. In the submucosa of the large intestine, the presence of organized lymphoid plaques is detected. RESEARCH HIGHLIGHTS: The presence of large numbers of goblet cells, which increase as one approaches the rectum. The presence of organized lymphoid plaques is detected. The duodenal portion was not observed presence of the serous layer.

Morphology of urinary system in six-banded armadillo (Euphractus sexcinctus, Linnaeus, 1758).

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.

Morphology of the stifle in agouti (Dasyprocta prymnolopha, Wagler 1831).

The agouti (Dasyprocta prymnolopha, Wagler 1831) is a wild rodent of great zootechnical potential, a fact that enables anatomical and morphological studies to support management actions with this animal. In this perspective, this study aimed to describe the anatomy and histology of the agouti stifle joint. Four adult agoutis were used, two females and two males. The animals were submitted to dissection and identification of the structures of the stifle joint. For light microscopy study, samples of the patellar ligament, cranial and caudal cruciate ligaments, medial and lateral collateral ligaments were used. Agouti has a highly congruent patellofemoral joint; elongated patella; medial and lateral fabellae at the proximal insertion of the gastrocnemius muscle; medial and lateral meniscus with lunula; in addition to the presence of the following ligament structures: patellar ligament, cranial and caudal cruciate ligaments, medial and lateral collateral ligaments, meniscofemoral ligament, caudal meniscal ligament of the medial meniscus, and medial and lateral cranial ligaments. The patellar ligament presents bundles of parallel collagen fibers with a straight path and coated fibroblasts; collateral and cruciate ligaments had loose and dense connective tissue, coated fibroblasts and collagen bundle undulations, the latter most expressive in the caudal cruciate ligament. Thus, except for the shape and angulation of the stifle, which allows specific movements, the agouti stifle has structures analogous to that of other rodents and domestic animals.

Morphological features of lower respiratory tract of nine-banded armadillo (Dasypus novemcinctus, Linnaeus, 1758).

The nine-banded armadillo (Dasypus novemcinctus) is a mammal of the Xenarthra Superorder, which inhabits Central, South and North America. Few morphological descriptions are observed in this species, including the respiratory tract; therefore, the objective of this study was to describe morphologically the lower respiratory tract of the nine-banded armadillo. Five animals were dissected, and the macroscopic and microscopic aspects were analysed. In the anatomical analysis, the perfusion technique was performed with vinyl acetate and the fragments of tissue from respiratory organs (trachea, bronchi, bronchioles and pulmonary lobes) were stained with haematoxylin-eosin for visualization under optical microscopy. Containing about 30 cartilage rings, the trachea is lined internally with ciliated pseudostratified epithelial tissue. The lungs are subdivided into lobes by deep interlobar fissures, with two lobes in the right lung and three lobes in the left lung. Microscopically, the primary, secondary and tertiary bronchi have non-ciliated pseudostratified epithelium with goblet cells. It was found that macro- and microscopically the respiratory tract of this species is similar to existing xenarthras and other excavator animals. These data provide subsidies for the clinic and preservation of this species.