Ovoviviparity

Ovoviviparity

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Ovoviviparity is a mode of reproduction in animals in which embryos develop inside eggs that are retained within the mother's body until they are ready to hatch. This reproductive strategy is an intermediate form between oviparity, where eggs are laid outside the mother's body, and viviparity, where the embryo develops inside the mother and is born live.

Characteristics

In ovoviviparous animals, fertilization is internal, and the eggs are retained within the female's body. The developing embryos receive their nourishment from the egg yolk, not directly from the mother, as is the case in viviparous animals. Once the embryos are fully developed, they hatch inside the mother and are then born live. This strategy provides the developing young with protection from environmental hazards and predators during the early stages of development.

Examples in Nature

Ovoviviparity is observed in various animal groups, including some species of fish, reptiles, and invertebrates. For example, many species of sharks, such as the great white shark, exhibit ovoviviparity. In reptiles, certain species of snakes, like the boa constrictor, also reproduce in this manner.

Image of a flea with detail showing the resilin pad

Advantages and Disadvantages

The primary advantage of ovoviviparity is the increased protection it offers to developing embryos. By retaining the eggs within the body, the mother can shield them from predators and environmental fluctuations. However, this strategy also has disadvantages, such as the increased energy demand on the mother to carry the developing young and the potential for reduced mobility.

Related Reproductive Strategies

Ovoviviparity is one of several reproductive strategies found in the animal kingdom. It is important to distinguish it from similar strategies such as:

• Oviparity: Eggs are laid outside the mother's body, and the embryos develop externally.
• Viviparity: Embryos develop inside the mother and receive direct nourishment from her, leading to live birth.

Related Pages

• Reproduction
• Embryo
• Fertilization
• Animal physiology