Why are offspring of oviparous animals at a greater risk as compared to offspring of viviparous animals?
Oviparous animals lay eggs outside their body. As a result, the eggs of these animals are under continuous threat from various environmental factors. On the other hand, in viviparous animals, the development of the egg takes place inside the body of the female. Hence, the offspring of an egg-laying or oviparous animal is at greater risk as compared to the offspring of a viviparous animal, which gives birth to its young ones.
In oviparous animals, the development of the zygote takes place outside the body of the female parent whereas in viviparous animals, it takes place inside the body of the female. Because in oviparous animals, the fertilized eggs are laid in the open environment where they are not protected from the predators. Thus their survial rate is very less as compared to offspring of viviparous animals