Eutherian-like reproductive specializations in a viviparous reptile
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منابع مشابه
Eutherian-like reproductive specializations in a viviparous reptile.
The viviparous Brazilian scincid lizard Mabuya heathi exhibits a suite of reproductive specializations widely believed to be confined to the eutherian mammals. This skink ovulates the smallest known reptilian egg ( approximately 1.0 mm in diameter). Placental transport accounts for >99% of the dry mass of the periparturient fetus, representing a degree of placentotrophy proportionately greater ...
متن کاملMaternal basking behaviour determines offspring sex in a viviparous reptile.
Two primary dichotomies within vertebrate life histories involve reproductive mode (oviparity versus viviparity) and sex determination (genotypic sex determination versus environmental sex determination). Although reptiles show multiple evolutionary transitions in both parameters, the co-occurrence of viviparity and environmental-dependent sex determination have heretofore been regarded as inco...
متن کاملGeographical differences in maternal basking behaviour and offspring growth rate in a climatically widespread viviparous reptile.
In reptiles, the thermal environment during embryonic development affects offspring phenotypic traits and potentially offspring fitness. In viviparous species, mothers can potentially manipulate the embryonic thermal environment through their basking behaviour and, thus, may be able to manipulate offspring phenotype and increase offspring fitness. One way in which mothers can maximise offspring...
متن کاملReproductive Adaptations among Viviparous Fishes (cyprinodontiformes: Poeciliidae).
Within the family Poeciliidae, a wide range of adaptations accompanying viviparity has evolved. The reproductive mechanisms of five representative species were examined and related to the habitats in which they are employed. Poecilia reticulata, the guppy, represents the majority of poeciliids which have a single stage of embryos in the ovary at a time. Most of the nutrients are prepack-aged in...
متن کاملMating does not influence reproductive investment, in a viviparous lizard.
Mating is crucial for females that reproduce exclusively sexually and should influence their investment into reproduction. Although reproductive adjustments in response to mate quality have been tested in a wide range of species, the effect of exposure to males and mating per se has seldom been studied. Compensatory mechanisms against the absence of mating may evolve more frequently in viviparo...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 1984
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.81.15.4860