منابع مشابه
Reproductive 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 کاملMaternal-Embryonic Relationship of Viviparous Fishes
SYNOPSIS. Viviparous reproduction in fishes provides opportunities for maternal phenotypic modifications to influence offspring phenotype following fertilization. Various physiological adaptations associated with the maintenance and control of prenatal embryonic development may provide the means by which postnatal phenotype is impacted by maternal phenotype. It is widely recognized that postzyg...
متن کاملMultiple mating and its relationship to brood size in pregnant fishes versus pregnant mammals and other viviparous vertebrates.
We summarize the literature on rates of multiple paternity and sire numbers per clutch in viviparous fishes vs. mammals, two vertebrate groups in which pregnancy is common but entails very different numbers of embryos (for species surveyed, piscine broods averaged >10-fold larger than mammalian litters). As deduced from genetic parentage analyses, multiple mating by the pregnant sex proved to b...
متن کاملClimate and sex ratio variation in a viviparous lizard.
The extent to which key biological processes, such as sex determination, respond to environmental fluctuations is fundamental for assessing species' susceptibility to ongoing climate change. Few studies, however, address how climate affects offspring sex in the wild. We monitored two climatically distinct populations of the viviparous skink Niveoscincus ocellatus for 16 years, recording environ...
متن کاملTeleost Fishes
The ulstrastructure of the saccular and lagenar maculae were studied in 15 species of teleost fishes, using the scanning electron microscope. Particular attention was paid to hair cell orientation patterns, composition of the ciliary bundles on the hair cells, hair cell distributions, and supporting cell types. The hair cells on both otolithic organs are divided into several groups with all of ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Neotropical Ichthyology
سال: 2006
ISSN: 1679-6225
DOI: 10.1590/s1679-62252006000400012