RESUMEN
Knowledge of reproductive health in wild southern tamanduas (Tamandua tetradactyla; Mammalia: Myrmecophagidae) is fragmentary. During necropsies of roadkill xenarthran species in Brazil, a case of ovarian filariasis in an adult female southern tamandua was observed. Macroscopically, both ovaries were irregularly enlarged and had numerous smooth protuberances. Histologically, the affected ovarian parenchyma presented adult nematodes (including females with microfilaria) surrounded by pleocellular inflammatory infiltrates. The morphological characteristics of the nematodes were consistent with the superfamily Filarioidea (order Spirurida). The adjacent ovarian parenchyma had developing and atretic follicles at different stages of maturation. Filarial nematodes were not observed in other tissues. The cause of death of this tamandua was fatal acute polytrauma as a consequence of the motor vehicle collision. This case adds to a prior report of ovarian filariasis in two southern tamanduas in Nicaragua and Guatemala, dating back almost 100 years, and suggests filarial infections could potentially have an impact on reproductive success in southern tamanduas and possibly other xenarthrans. Several xenarthran species are under different levels of threat and knowledge of their basic reproductive health is crucial for conservation programs.
RESUMEN
BACKGROUND: The giant anteater belongs to the supraorder Xenarthra which occupies a systematically isolated position among placental mammals. The species is categorized as Vulnerable by the International Union for Conservation of Nature, and understanding its reproductive characteristics is critical for future conservation efforts. METHODS: Gross and microscopic anatomy of the genital organs of 23 male and 21 female adult and young roadkill giant anteaters in Brazil were studied. RESULTS: Male giant anteaters presented a short conical penis, intraabdominal testes, and prostate, vesicular and bulbourethral glands. A tubular remnant of the partially fused Müllerian ducts extended from the seminal colliculus through the prostate gland, continued cranially in the genital fold, bifurcated, and attached with one elongation each to the left and right epididymal corpus. The structure presented a total length of up to 10 cm and contained a yellowish liquid in its lumen. Histologically, the caudal section of this structure resembled the female vagina, the middle portion corresponded to the uterus, and the extensions showed characteristics of uterine tubes. In adult female giant anteaters, ovoid ovaries with occasional seminiferous cord-like structures were observed. The animals possessed a simple uterus, which was directly continuous with the vaginal canal. The caudal portion of the vagina had two lumina, separated by a longitudinal septum and opening into two apertures into the vaginal vestibule, cranial to the urethral opening. In the urethral and the lateral vestibular wall, glandular structures with characteristics of male prostate and bulbourethral glands, respectively, were found. The vestibule opened through a vertical vulvar cleft to the exterior. A pair of well-differentiated Wolffian ducts with a central lumen originated ventrally at the vaginal opening into the vestibule and passed in a cranial direction through the ventral vaginal and uterine wall. Each duct extended highly coiled along the ipsilateral uterine tube until the lateral pole of the ovaries where it merged with the rete ovarii. DISCUSSION: The reproductive morphology of giant anteaters reveals characteristics shared with other Xenarthrans: intraabdominal testes, a simple uterus, and a double caudal vagina. The persistence of well-differentiated genital ducts of the opposite sex in both males and females, however, singles them out among other species. These structures are the results of an aberration during fetal sexual differentiation and possess secretory functions. The possibility of a pathological degeneration of these organs should be considered in reproductive medicine of the species. CONCLUSION: Knowledge of the unique reproductive characteristics of the giant anteater is essential for future reproductive management of the species. Additionally, further research on the peculiarities of the persisting genital duct structures might help to understand sexual differentiation in placental mammals in general.
RESUMEN
The objective of this study was to obtain data on craniometric parameters in the crab-eating fox (Cerdocyon thous) and to define the general skull type of this species, analysing whether the craniometric classification of domestic dogs can be applied. Eleven skulls of C. thous were included in the analysis, irrespective of age and sex. The location of nine craniometric points established for craniometry in domestic dogs was determined and based on the distances between these points, 17 craniometric parameters were measured. Those parameters were used to calculate the following six craniometric indices: 53.17 ± 2.54 mm skull index, 2.33 ± 0.08 mm craniofacial index, 59.17 ± 3.57 mm neurocranial index, 125.58 ± 6.63 mm facial index, 37.52 ± 2.65 mm basal index and the index of the foramen magnum 54.47 ± 3.48 mm. According to the analysed indices, the skull shape in C. thous can be classified as mesaticephalic.
El objetivo de este estudio fue obtener datos sobre los parámetros craneométricos del zorro cangrejero (Cerdocyon thous) y definir el tipo general de cráneo de esta especie, analizando si se puede aplicar la clasificación craneométrica de los perros domésticos. Once cráneos de C. thous fueron incluidos en el análisis, independientemente de la edad y el sexo. Se determinó la ubicación de nueve puntos craneométricos establecidos para la craneometría en perros domésticos y, en función de las distancias entre estos puntos, se midieron 17 parámetros craneométricos. Esos parámetros se usaron para calcular los siguientes índices craneométricos: índice craneal de 53,17 ± 2,54 mm, índice craneofacial de 2,33 ± 0,08 mm, índice neurocraneal de 59,17 ± 3,57 mm, índice facial de 125,58 ± 6,63 mm, índice basal de 37,52 ± 2,65 mm y el índice del foramen magnum 54,47 ± 3,48 mm. Según los índices analizados, la forma del cráneo en C. thous se puede clasificar como mesaticefálica.
