Morphological evaluation of the ileum, proximal colon and distal colon of green turtles (Chelonia mydas) dead on the slopes in the Environmental Protection Areas of Cananéia-Iguape-Peruíbe and Mosaic Jureia-Itatins Conservation Units, Peruibe-SP

Abstract

Among the consequences of disordered human occupation brings to the environment, we can mention the changes in the areas used by green turtles for food, which start to present higher amounts of anthropogenic solid wastes such as plastic debris and other oil derivatives. These materials cause numerous gastrointestinal disorders in these animals, causing, in most cases, their death. The aim of this study was to morphological evaluation of the ileum, proximal colon and distal colon of green turtles (Chelonia mydas) found dead and stranded in Peruibe coastline. Removal of organs from the digestive system was performed after excision of the ventral part, called plastron. To describe the intestinal portions, samples were collected from the opening made by the mesenteric border. The samples were fixed and prepared for microscopic analysis. The results of this study demonstrated the presence of rectilinear and folded pleats, longitudinal smooth muscle fibers, submucosa formed by loose connective tissue and blood vessels in the muscular layer; an inner circular layer and a long longitudinal layer, both with smooth muscle. The presence of folds was found in the proximal colon, but absent in the distal colon. It was observed alternation of bulging regions (with smooth muscle) and histologically, pleated mucosa containing glands and lymphocytes, muscular mucosa formed by smooth muscle and submucosal constituted by loose connective tissue. In scanning electron microscopy, the smooth muscle layers in the ileum were well evidenced, as well as the presence of numerous blood vessels in the proximal and distal colon. Therefore, this study can be of great value, to assist in field work and veterinary medicine in captivity.