Aspectos anatômicos dos músculos caudais e mediais da coxa do quati (Nasua nasua, Linnaeus, 1766)

Abstract

South american carnivores, members of the Procyonidae family, the coatis (Nasua Nasua) are generalist omnivores that found on fruits the important component for their diet. Thereby, they forage not only on the ground but also in the trees, showing themselves to be skilled climbers. This skill requires more strength and mobility of their hindlimbs when compared to those of their closest relatives, the dogs, with whom they share the same Suborder Caniformia. Thus, it was examined the anatomical aspects of the muscles that integrate the caudal and medial muscular groups of the thigh of coatis, which had its general aspects, location, shape, origin, insertion, syntopy and basic actions evaluated. Both hindlimbs of five adult animals (two females and three males) donated by IBAMA GO (License: 98/2011) were used in this study, which has its protocol approved by the CEUA-UFG (protocol 235/2011). Of these, three animals were euthanized (SISBIO/ ICMBio license: 26278-3). They were fixed with 10% formaldehyde solution and stored in tanks within the same solution, in which they remained for at least 72 hours before the beginning of dissection procedures. Subsequently, they were kept in tanks with ethylic alcohol at 92.8º GL. This doctorate thesis generated two scientific articles. In the first one titled ANATOMICAL ASPECTS OF THE CAUDAL THIGH MUSCLES OF COATI (Nasua nasua, LINNAEUS 1766), it was verified that muscles which comprise the caudal muscular group of the thigh of coatis are the m. semitendinosus, m. semimembranosus, m. biceps femoris and the m. abductor cruris caudalis. The m. semitendinosus has two heads, long and short, besides an intersection tendon. It does not contribute to the formation of the common calcaneal tendon. The m. semimembranosus is incompletely divided into cranial and caudal parts. The m. biceps femoris has only one head and also does not contribute to the formation of the common calcaneal tendon. The ligamentum sacrotuberale is absent and the m. abductor cruris caudalis originates from the deep surface of the m. gluteofemoralis and adjacent part of the m. gluteus superficialis. The second article titled ANATOMICAL ASPECTS OF THE MEDIAL THIGH MUSCLES OF COATI (Nasua nasua, LINNAEUS 1766), it was verified that muscles which comprise the medial muscular group of the thigh of coatis are the m. gracilis, m. pectineus, magnus, brevis and longus adductors muscles and the m. external obturator. All these muscles show particularities regarding to its origin and/or insertion. The m. gracilis is very broad and does not contribute to the formation of the common calcaneal tendon. The m. pectineus extends up to the half of the caudal surface of the femur. The three individual adductors are arranged like three layers that increase craniocaudally, being the adductor brevis positioned between the longus cranially and the magnus caudally. Several anatomical changes were observed in the caudal and medial thigh muscles of coatis in relation to domestic dogs muscles, with some of these, however, resembling more the anatomic patterns of felids. Probably these changes are related to the climbing skills acquired by the coatis during their evolutionary process.