Macroscopic Description of Small and Large Intestine of the Sloth Bradypus variegatus

Abstract

Background: Sloths of the species Bradypus variegatus are mammals with peculiar habits, which feed mostly young leaves of ‘embaúba’ and occur broadly in Central and South America. This specie has the greatest occurrence in Brazilian Northeast, making it a biological model for several researches in the fields as anatomy, physiology, genetics, pathology, histology and ecology, which provide data to literature in order to benefit maintenance and preservation of these animals. This study aimed to describe unpublished data about small and large intestine anatomy of the sloth Bradypus variegatus, in order to collaborate for knowledge of its digestive processes.Materials, Methods & Results: In order to perform this present research, 10 corpses of specie Bradypus variegatus belonged to the acquis of Anatomy Division, Department of Animal Morphology and Physiology (DMFA); Federal Rural University of Pernambuco (UFRPE), with 5 males and 5 females, the study was authorized by Animal Use and Experimentation Ethic Committee license (CEUA-UFRPE), nº 034/2015. All 10 animals used had natural death, were obtained through a donation of CETAS Tangará (Centro de Triagem de Animais Silvestres - Wildlife Screening Center), and located in the city of Recife. Animals were dissected at abdominal and pelvic portion, from a median sagittal incision, followed by lateral folding of skin, muscle and withdrawal of pubis portion for exposition and description of intestines, with analysis of syntopy and measurement of these organs. A relation was observed among external holes of urinary, reproductive and digestive systems. A relation was still observed among intestines and stomach, liver, kidneys, bladder and abdominal cavity wall. Some animals had absence of sigmoid colon, ventral and dorsal descendent colon. Regarding measurement, small intestine ranged from 147.09 to 163.59 cm for males and 117.44 to 151.28 cm for females, while large intestine varied between 39.68 and 43.35 cm for males, and 33.19 and 44.47 cm for females. Urinary and reproductive systems had a same external hole at perineal portion for both gender. Whereas digestive system ended at anus as occur commonly among mammals.Discussion: Among specimens described, most had the same anatomic profile regarding the intestinal portions and syntopy performed over other abdominal cavity organs. A difference was observed on liver size, increment of 20% for females and males sampled, excluding animals that had absence of structure that were minority, once 40% of females had no ventral descending colon, 20% of males and females had no sigmoid colon, and 20% of males had no dorsal descending colon. However, some animals that had absence demonstrated increase of other adjacent structures, for example, male that had no dorsal descending colon developed the largest sigmoid colon observed among animals measured for portions of duodenum, ventral descending colon, ascending colon and dorsal descending colon. Regarding the measurement of small and large intestine, Bradypus variegatus had differences compared to other herbivores, what suggests that this fact is associated to a restricted diet, in which that animal is submitted. Because of literature shortage about digestive system of specie Bradypus variegatus and other species of wild animals in general, it still difficult to infer or plot more accurate affirmations about this subject.