It has a yolk sac viviparity
mode of reproduction and has been reported to carry as many as 300 pups (Joung et al., 1996).
, at 5 weeks, the midgut and allantoic membrane, as primordia of the small intestine and bladder, form a continued alveus with the hindgut and cloaca.
: Diversity, biogeography, and conservation.
Some immunological and endocrineological problems raised by the evolution of viviparity
(25) A series of knockout mouse studies on these genes has gathered persuasive evidence that at least some of these genes are essential in the current form of the developmental and reproductive systems, which suggests that they made critical contributions to mammalian evolution in a variety of ways, such as the establishment of viviparity
(22-26) and presumably certain sophisticated brain functions.
This genus inhabits mainly lowland forests and evolved with a group of specializations related to viviparity
, which are unique among reptiles and convergent only with placental mammals: a long period of gestation (9 to 12 months) and microlecithal eggs (0.92.2 mm) with a highly placentotrophic nutritional pattern (Blackburn & Vitt 1992; Blackburn 1993; Jerez & Ramirez 2001, 2003).
Mangroves get around this problem by developing a system of reproduction called viviparity
, where seeds stay on the tree longer and store nutrients needed for rapid establishment and growth once they leave the 'parent' tree.
The literature in the area of evolutionary psychology suggests that, compared to males, viviparity
and the development of the placenta placed an important burden of time and energy in females .
Convergent evolution of viviparity
, matrotrophy, and specializations for fetal nutrition in reptiles and other vertebrates.
Heisermann, "Regulation of vitellogenesis in reptiles: correlations with oviparity and viviparity
," in Proceedings of the 9th International Symposium on Comparative Endocrinology, Current Trends in Comparative Endocrinology, pp.
Shine, "Reptilian viviparity
in cold climates: testing the assumptions of an evolutionary hypothesis," Oecologia, vol.