MORFOLOGIA DOS ÓRGÃOS GENITAIS FEMININOS DO MUÇUÃ (Kinosternon scorpioides)

Abstract

RESUMO -Estudaram-se os órgãos genitais femininos de dez exemplares de muçuã (Kinosternon scorpioides) adultos, visando conhecer a anatomia, topografia e possíveis variações anatômicas. Os animais foram submetidos à eutanásia sacrificados com dose letal (3ml) de tiopental sódico 2,5%, seguido de abertura da cavidade celomática e dissecação macroscópica, auxiliada por lupa. Os resultados mostraram os órgãos genitais femininos do muçuã formados por um par de ovários e ovidutos. Os ovários apresentavam-se constituídos por folículos em diferentes estágios de desenvolvimento, sustentados pelo mesovário, enquanto que os ovidutos estavam fixados pelo mesoviduto e divididos em cinco segmentos, infundíbulo, magnum, istmo, útero e vagina, esta última inserida na cloaca, compartimento comum aos aparelhos urogenital e digestório. Com base nos achados, conclui-se que os órgãos genitais femininos do muçuã são funcionais bilateralmente, porém, semelhança anatômica ao oviduto esquerdo das aves.Palavras-chave: Anatomia; Genital feminino; Muçuã.ABSTACT -With the aim to study and describe the anatomy, the topography and possible anatomic variations of the female genital organs of the mud turtle Kinosternon scorpiedes, ten adult animals were used for such purpose. The animals were sacrificed by an overdose (3ml) of sodium pentobarbital 2,5%. After the sacrifice, the coelom cavity has been opened and with the aid of a magnifying glass the parts were dissected and photographed. The results did shown that the genital organs of Kinosternon scorpiedes female are formed by a pair of ovaries and one pair of oviducts. The ovaries showed up as being constitued by follicles in different stages of development sustained by a mesovary ligament. The oviducts were divided into five segments, infundibulum, magnum, isthmus, uterus and vagina, fixed by a mesoviduct that begins next to the ovaries and goes to insent itself into the cloaca, this last one being common to the urogenital and digestive systems. These findings allowed the conclusion that this species of mud turtle female genital organs display a bilateral way of function, similar to that of the birds left oviduct. Key-words:Anatomy; Female genital; Muçua. IntroduçãoO muçuã (Kinosternon scorpioides) é uma das tartarugas menos estudadas pela ciência e uma das mais ameaçadas de extinção (FIGURA 1A). É um pequeno réptil nativo da Região Amazônica, pertencente à Ordem Testudines, Família Kinosternidae, distribuído desde a Costa Rica até o norte da Argentina e Brasil. No Maranhão, é encontrado principalmente na região da Baixada Maranhense, onde é chamado de Jurará (PEREIRA, 2000).Vários fatores põem em risco a sobrevivência dessa espécie, sendo um dos principais o fato de animais serem consumidos como iguaria na culinária maranhense e paraense. Associado a isso, queimadas, desmatamentos e caça indiscriminada contribuem para a diminuição da população de muçuãs na natureza, sendo estes os principais motivos pelos quais sua captura é proibida pelo Instituto Brasileiro do Meio Ambiente e dos Recurs...

Reproductive biology, morphology, and morphometry of ovaries and oviducts of Trachemys scripta elegans in Brazilian Cerrado

“…T. scripta elegans, like most reptiles, exhibits both functional and separate oviducts, having the only junction in their final portion to form a cloaca (Fox 1977), diverging from birds that only have the left oviduct developed (Dyce et al 2004). The topography of the oviducts, beginning near the cranial end of the ovaries and extending laterally to the insertion in the cloaca, agreed with previous reports (Wyneken 2001, Machado Júnior et al 2006, Silva et al 2017) and the anatomical division in five regions: infundibulum, uterine tube, isthmus, uterus, and vagina, agreed with other reptiles (Girling 2002), turtles (Alkindi et al2006, Machado Júnior et al 2006, Firmiano et al 2012, Silva et al2017) and birds (Girling 2002, Parizzi 2006), but diverged from lizards (Guillette Junior et al 1989, Girling et al 1997), snakes (Perkins & Palmer 1996), and geckos (Sever et al 2000). In these species the oviducts are subdivided into three or four regions.…”

“…The ovaries presented a topographic layout, appearance, and presence of yellow-colored follicles at different stages of development similar to those of sea turtles (Wyneken 2001); K. scorpioides (Machado Júnior et al 2006, Chaves et al 2012, Chelonia mydas (Kondak 2012) and Eretmochelys imbricata (Pérez-Bermúdez et al 2012). The asymmetric position of the ovaries, caused by differences in volume and quantity of follicles, corroborated with Chaves et al (2012) disagreeing with the symmetry observed by Storer et al (2000) and Machado Júnior et al (2006).…”

“…Duarte et al (2011) point out that the stages of maturation of females are associated with the yelk deposition in ovarian follicles. In reptiles, turtles (Machado Júnior et al 2006) and birds (Dyce et al 2004) the yelk serves as a nutritive matter to the embryo throughout its development within the egg and its production and secretion are stimulated by estrogen (Rosanova et al 2002), which is released after puberty and acts locally in the ovarian cortex and medulla promoting the differentiation of gonads (Pieau & Dorizzi 2004) and oviducts (Owens & Morris 1985). This study associates the analysis of the length of the carapace with the presence of vitellogenic follicles, athreptic follicles, corpora lutea and corpus albicans in the ovaries and distended and sinuous oviducts with or without the presence of eggs as indicative of sexual maturity (Ernst 1971, Wyneken 2001, Castro 2006, Rossi et al 2006, Delgado 2006, Chaves et al 2012.…”

“…A pair of ovaries and oviducts represented the female genital organs of T. scripta elegans, attached to the ceiling of the celoma cavity, respectively, by the mesovarium and mesoviduct, as described in other species of turtles (Wyneken 2001, Machado Júnior et al 2006, Chaves et al 2012, Pérez-Bermúdez et al 2012, Silva et al 2017) and reptiles (Storer et al 2000), which differ from birds that have only developed left oviduct (Dyce et al 2004). The ovaries presented a topographic layout, appearance, and presence of yellow-colored follicles at different stages of development similar to those of sea turtles (Wyneken 2001); K. scorpioides (Machado Júnior et al 2006, Chaves et al 2012, Chelonia mydas (Kondak 2012) and Eretmochelys imbricata (Pérez-Bermúdez et al 2012). The asymmetric position of the ovaries, caused by differences in volume and quantity of follicles, corroborated with Chaves et al (2012) disagreeing with the symmetry observed by Storer et al (2000) and Machado Júnior et al (2006).…”

Kinosternon scorpioides (Linnaeus 1766) – Scorpion Mud Turtle

“…In comparison, female maturity in K. s. abaxillare occurs between 120 and 130 mm CL, and that for K. s. albogulare apparently at 122 to 132 mm CL (Goode 1994). The reproductive anatomy of adult females was reviewed by Machado Júnior et al (2006), and male reproductive anatomy was described in detail by Carvalho et al (2010).…”