Ovoviviparous
From Free net encyclopedia
Ovoviviparous animals develop within eggs that remain within the mother up until they hatch or are about to. This strategy of birth is known as ovoviviparity. It is similar to vivipary in that the young are provided with a sheltered environment. However, the growing and developing embryo are nourished by the egg yolk rather than the mother's body, who only works as some sort of protecting incubator. But even if the embryo doesn't receive any nutrition from its mother, there is a connection between them which is necessary for gas exchanging. And it is this connection that is the one of the first steps in evolving true vivipary.
Ovoviviparity is employed by many fish (including sharks), reptiles, and invertebrates. The young of ovoviviparous amphibians are sometimes born as larvae, and undergo metamorphosis outside the body of the mother.
See also
cs:Vejcoživorodost de:Ovoviviparie es:Ovovivíparo fr:Ovoviviparité it:Ovovivipari nl:Ovovivipariteit pt:Ovovivíparo tr:Oovivipar