RESUMO
Fleas (Siphonaptera) of an isolated population of Chaetophractus vellerosus (Mammalia: Xenarthra) from Magdalena (Buenos Aires province) were studied, and their presence was associated with host-related factors (age, sex, weight, size, and physical condition) and temporal dynamics (seasonality and year). Three species of fleas were identified: Polygenis (Polygenis) platensis (Rhopalopsyllidae), Tunga penetrans (Tungidae), and Pulex irritans (Pulicidae). Prevalences were significant for year, season, and physical condition. Intensities were significantly different for year, physical condition, and weight. The intensities of fleas were higher in 2009 than in other years, probably because of lower rainfall than the annual average leading to extremely dry climatic conditions in 2008. Intensities decreased in individuals with major body weight and increased in individuals with poor physical condition. In this study, the dynamics of the flea community associated with an armadillo population is analyzed for the first time taking into account host-related factors and temporal dynamics, and also how these factors influence the community.
Assuntos
Tatus/parasitologia , Infestações por Pulgas/veterinária , Animais , Argentina/epidemiologia , Feminino , Infestações por Pulgas/epidemiologia , Interações Hospedeiro-Parasita , Masculino , Prevalência , Estações do Ano , Sifonápteros/classificação , TungaRESUMO
A new species of Tunga (Siphonaptera: Tungidae) collected from armadillos in Argentina is described. The new species is characterized by large and pigmented eyes, the presence of two bristles on antennal segment II, two bristles at the base of the maxilla, and a discoid neosome compressed anteroposteriorly. The gravid female is located in the carapace of the host, perforating the osteoderms. The new species resembles Tunga penetrans and Tunga terasma in general appearance. However, it differs by the greater anteroposterior compression of the neosome, a more angular head, and a manubrium with a pointed proximal end and convex ventral margin (the proximal end of the manubrium is rounded or slightly pointed in T. terasma, and the ventral margin is straight in both T. penetrans and T. terasma). In addition, specimens of T. penetrans have more bristles in antennal segments II and III, and lack bristles in the posterior tibia. This is the first report of a species of Tunga perforating the osteoderms of its host and thereby showing a high degree of specialization. Tunga terasma is recorded for the first time in Argentina; the male is described again and the characteristics of the species amended. This information may be useful in epidemiological studies of diseases caused by species of Tunga.
Assuntos
Tatus/parasitologia , Tunga/classificação , Tunga/fisiologia , Distribuição Animal , Animais , Argentina , Feminino , Masculino , Especificidade da Espécie , Tunga/anatomia & histologiaRESUMO
Middle ears of adult Chaetophractus villosus, C. vellerosus and Zaedyus pichiy were studied for qualitative and quantitative comparisons. A great similarity in the overall shape of the middle ear structures was observed in the three species. The well-developed auditory bulla was formed by the intimate fusion of the tympanic and entotympanic. Internally, a recessus meatus and a wide epitympanic recess extending dorsally into an epitympanic sinus were recognized. The petrosal promontorium, nearly triangular, was the most salient feature in the tympanic cavity. The auditory ossicles corresponded to the transitional middle ear type. The m. tensor tympani and the m. stapedius were conspicuous. The lack of a stapedial artery was confirmed in all cases. The tympanic area and middle ear ossicles were relatively larger in C. vellerosus than in the other two species. It is hoped that the results of the present paper coupled to the bullar hypertrophy found in a previous work will provide a significant basis for future functional studies on the hearing capabilities in the dasypodids.
Se estudió cualitativa y cuantitativamente la morfología del oído medio en adultos de Chaetophractus villosus, C. vellerosus y Zaedyus pichiy. Se observó una gran similitud en las estructuras del oído medio de las tres especies. La bula auditiva, bien desarrollada, se observó formada por la fusión del timpánico y entotimpánico. Internamente se pudo reconocer un recessus meatus y un amplio receso epitimpánico que se extendía dorsalmente en un seno epitimpánico. El promontorio, casi triangular, fue la estructura más notoria del interior de la cavidad timpánica. Los huesecillos auditivos correspondieron al tipo transicional. Se observó un gran desarrollo en los músculos tensor del tímpano y estapedial. Se confirmó la falta de una arteria estapedial en las tres especies. El área del tímpano y los huesecillos auditivos fueron relativamente más grandes en C. vellerosus que en las otras dos especies. Se espera que los resultados del presente trabajo, sumados a la hipertrofia de la bula timpánica reportada previamente, provean una base significativa para futuros estudios sobre la capacidad auditiva en los dasipódidos.
Assuntos
Animais , Tatus/anatomia & histologia , Orelha Média/anatomia & histologia , Xenarthra/anatomia & histologiaRESUMO
The morphology and relative size of the tympanic bulla of three species of dasypodids from Argentina, Chaetophractus villosus, C. vellerosus and Zaedyus pichiy, were studied. The bulla was observed to be morphologically similar and evidently hypertrophied in the three species. The degree of hypertrophy was higher in C. vellerosus and C. villosus than in Z pichiy. By means of ANCOVA it was clear that, although C. villosus has a bigger skull than C. vellerosus, the relative size of their tympanic cavity was similar in both species. On the other hand, the skull of C. vellerosus and Z pichiy are of similar size but the bulla was relatively shorter in the later.
Fueron estudiados la morfología y el tamaño relativo de la bula timpánica, en tres especies de dasipódidos de la Argentina, Chaetophractus villosus, C. vellerosus and Zaedyus pichiy. Se observaron una morfología similar y una hipertrofia evidente en la bula en las tres especies. El grado de hipertrofia fue mayor en C. vellerosus y C. villosus que en Z pichiy. Mediante ANCOVA se demostró que, aunque el cráneo de C. villosus es mayor que el de C. vellerosus, el tamaño relativo de la bula fue similar en ambas especies. Por otra parte, la bula de Z pichiy es relativamente más pequeña que la de C. vellerosus, a pesar que sus cráneos son de tamaño similar.