Morphology of female genital tracts in Dasypodidae (Xenarthra, Mammalia): a comparative survey

Abstract

Previous works about comparative spermatology in Dasypodidae determined that sperm morphology is a striking variable among genera. It was suggested that this sperm feature may be related to specific morphologies of the female reproductive tract. The present comparative study of the morphology of the female genital tract from seven species corresponding to six genera of Dasypodidae is aimed to determine the main similarities and differences between the species and to establish a possible correlation with the sperm shapes and sizes. Genital tracts were studied macroscopically and histologically. Dasypus hybridus has disk-shaped ovaries and the cortex occupies almost all the organ with a single oocyte in each follicle. Tolypeutes matacus, Chaetophractus villosus, Chaetophractus vellerosus, Zaedyus pichiy, Cabassous chacoensis and Clamyphorus truncatus possess ovoid and elongated ovaries, with both longitudinally polarized cortex and medulla, and the peculiar presence of several oocytes in the same follicle. D. hybridus and T. matacus have a simple pear-shaped uterus, but in the other species the uterus is pyramid shaped and bicornuate. The uterine cervix is very long in all studied species. Only T. matacus presents a true vagina as in most eutherian mammals; on the other hand, in the other species a urogenital sinus is observed. The structure of female reproductive tracts in Dasypodidae contains a mixture of assumedly primary and other derived features. According to the different morphologies of the regions analyzed, a classification of the female genital tracts in three groups can be performed (group 1: Dasypus; group 2: Tolypeutes; group 3: Chaetophractus, Zaedyus, Cabassous, Clamyphorus) and a correlation between each group and a specific sperm morphology can be established.

Monitoring the reproductive physiology of six‐banded armadillos (Euphractus sexcinctus, Linnaeus, 1758) through different techniques

“…Regarding vaginal cytology, it was not conducted everyday because the six‐banded armadillos' females present a small vulvar commissure that makes the introduction of the swab difficult, demanding the use of an anaesthetic protocol for this procedure. This characteristic is similar to that verified for other armadillo species, as C. villosus, C. vellerosus, Zaedyus pichiy, Chlamyphorus chacoensis, Chlamyphorus truncatus and Dasypus hybridus , in which the authors report difficulty in monitoring the oestrous cycle through vaginal cytology (Cetica et al., ; Luaces et al., ). Because of this, accurate identification of the different oestrous cycle phases (proestrus, oestrus, metestrus, dioestrus) was not possible in six‐banded armadillos, but we only distinguished the oestrogen phase from the progesterone phase at using the association of parameters studied.…”

“…Regarding the ovary dimensions identified by ultrasonography in six‐banded armadillos, they are similar to that previously measured during necropsies in the same species (0.8 × 0.44 mm; Rezende et al., ), and also similar to that reported for other armadillos as the T. matacus (0.8–1.0 cm) and C. villosus (0.6–1.0 cm). However, the armadillos C. vellerosus (0.5 cm), Z. pichiy (0.4 cm) and C. truncates (0.2–0.3 cm; Cetica et al., ) present lower ovary dimensions than that verified in this study. Such information evidenced the variation on reproductive aspects among different armadillo species and emphasized the efficiency of ultrasonography for ovary investigation.…”

“…There was also recording of the dimensions of the ovarian structures, such as follicles and corpora lutea. Images were stored for further analysis and establishment of relationship to other physiologic parameters (Cetica, Aldana, & Merani, ).…”

Inmovilización química de armadillos de tres bandas (Tolypeutes matacus) mediante el uso de dos protocolos anestésicos en el Norte Argentino

“…Animals immobilised in this way must be closely monitored for signs of hypothermia. Cetica et al (2005) described the morphology of the female reproductive tract and found it to have ovoid, elongate ovaries with longitudinally polarised cortex and medulla, and several oocytes in each follicle. The uterus was simple and pear-shaped, and the uterine cervix is long as in all armadillos.…”

Distribución y comentarios sobre el cabasú chaqueño Cabassous chacoensis (Wetzel, 1980) en el noroeste argentino

“…La mayoría de los datos existentes hacen referencia a su distribución geográfica y tipo de hábitat; sin embargo, también se han realizado estudios citogenéti-cos (Luaces et al, 2010), placentarios (Adamoli et al, 2001) y sobre la morfología del aparato reproductor de las hembras (Cetica et al, 2005). Además, existen datos etológicos y alimenticios de un individuo mantenido en cautiverio hasta su muerte súbita (Nellar et al, 2008).…”