RESUMO
Monodelphis glirina is endemic to the Amazon and its life habits and natural history are poorly known. Data on the species were collected in northern Mato Grosso, Brazil, including observations on its behavior and simpatry with congeners. During 10 expeditions and with an effort of 3,680 buckets-day, 29 M. glirina, three M. saci and one M. emiliae individuals were captured. Adults accounted for 82.8% of M. glirina captures, with a sex ratio of three males for each female. Capture of young and lactating females was seasonal, as both were captured only in the rainy season. We observed three events of M. glirina preying on rodents in pitfall traps, all with the same feeding behavior. We also report an individual climbing a tree at night, including a video recording. Our report contributes to a better understanding of the ecology of this highly diversified and still poorly known genus.(AU)
Monodelphis glirina é endêmica da Amazônia e aspectos dos seus hábitos de vida e história natural são pouco conhecidos. Dados sobre a espécie foram coletados no norte de Mato Grosso, Brasil, incluindo observações sobre seu comportamento e simpatria com congêneres. Durante 10 expedições e com um esforço de 3.680 baldes-dia, foram capturados 29 M. glirina, três M. saci e um M. emiliae. Adultos representaram 82,8% das capturas de M. glirina e a razão sexual foi três machos para cada fêmea. A captura de jovens e fêmeas lactantes foi sazonal, uma vez que ambos foram capturados apenas na estação chuvosa. Observamos três eventos de M. glirina predando roedores em pitfall traps, todos com o mesmo comportamento de alimentação. Também registramos um individuo escalando uma árvore durante a noite, incluindo um video. Nosso trabalho contribui para uma melhor compreensão da ecologia desse gênero altamente diversificado e ainda pouco conhecido.(AU)
Assuntos
Animais , Comportamento Animal , Monodelphis/crescimento & desenvolvimentoRESUMO
The purpose of this study was to characterize cytogenesis and apoptosis in the developing retina of the Brazilian opossum, Monodelphis domestica. Monodelphis is a small pouchless marsupial whose young undergo a protracted period of postnatal development. Moreover, the Monodelphis retina represents a unique in vivo compartment for investigating cellular interactions that occur during early neural development and is an important system to study plasticity of neural stem cells following transplantation. Using bromodeoxyuridine (BrdU) labeling of newly generated cells, double-labeling immunohistochemistry and TUNEL labeling of apoptotic cells we have performed a detailed analysis of cell birth and death in the Monodelphis retina from fetal development through early postnatal life. Pregnant opossums or pups received a single injection of BrdU between gestational day 12 and postnatal day 35 (35PN), eyes were collected two hours after injection or on day 15, 30, or 60 of postnatal life. BrdU-labeled cells were visualized immunohistochemically. Cells were classified according to their morphology, location and immunoreactivity for cell-type specific antibodies. Cell genesis in the opossum retina begins at E13 and was near completion by 25PN. Apoptotic retinal cells were identified using the TUNEL technique for labeling of fragmented DNA. Apoptosis covered a relatively broad period of postnatal development, beginning around 10PN, peaking at 30PN, and concluding before 60PN. These results demonstrate that the retina of Monodelphis, a polyprotodont marsupial, is generated in a similar pattern to the wallaby, a diprotodont marsupial, and to eutherian species.