The selective forces driving the transition from oviparity to viviparity may best be investigated by looking for consistent differences between closely related oviparous and viviparous
species (Shine 1985).
Reproductive and fat body cycles of the viviparous
lizard, Sceloporus mucronatus (Sauria: Iguanidae).
As is characteristic of viviparous
asterinids, the gonads of Cryptasterina hystera were ovotestes (Komatsu et al., 1990; Byrne, 1996).
Reproductive biology of viviparous
and oviparous species of the leaf beetle genus Oreina.
Reproductive mechanism of unisexual and bisexual strains of the viviparous
Male and female reproductive cycles of the viviparous
lizard, Mabuya capensis (Sauria: Scincidae) from South Africa.
Qinghai Lizard is a viviparous
, agamid sand lizard endemic to the north Tibetan (Qinghai) plateau with a broad altitudinal range from 2000 to 4600 m (Zhao & Adler, 1993).
collected from the Mountain Qixing in Shangrao County, Jiangxi Province, China is described and illustrated from alate viviparous
Effects of hypoxia and hyperoxia on oxygen-transfer properties of the blood of a viviparous
Gyrodactylids have direct lifecycles, lack a free-swimming larval stage or oncomiracidium which is present in egg-laying monogeneans, but instead have developed other highly successful reproductive strategies: are viviparous
(give birth to full-sized living individuals) and can increase rapidly in number (Harris et al., 2004; Bakke et al., 2007).
"Rays are live-bearing (viviparous
) while skates are egg-laying (oviparous), releasing their eggs in hard rectangular cases sometimes called 'mermaid's purses,'" the museum stated, adding rays have spines on their tails while skates do not.
Currently, no viviparous
organism has been experimentally induced to develop phenotypic sex opposite of genotype.
'This snake is viviparous
(giving birth to living young that develop within the mother's body rather than hatching from eggs) and produces up to 50 young ones in a litter.
General appearance of adult viviparous
female of Smynthurodes betae collected from haustoria of Phelipanche ramosa.
In addition, the quantity-quality tradeoff is more obvious in oviparous species, which, unlike viviparous
species, allocate a discrete amount of resources to offspring upon or soon after fertilization (Ford & Seigel 1989; King 1993).