Definition of Viviparous

Humpback Whale, an Example of a Viviparous Marine Animal
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Viviparous organisms are those that give birth to live young, rather than laying eggs. The young develop within the mother's body.

Viviparous Etymology

The word viviparous stems from the Latin word vivus, meaning alive and parere, meaning to bring forth. The Latin word for viviparous is viviparus, meaning "to bring forth alive."

Examples of Viviparous Marine Life

Examples of marine life that are viviparous include:

Of course, humans are viviparous animals as well.

Characteristics of Viviparity

Viviparous animals invest lots of time in the development and care of the young. The young often take several months to develop in the mother's uterus, and they may stay with their mothers for months or even years (e.g., in the case of dolphins, who may remain within their mother's pod for their entire lives). 

Thus, the mother does not have many young at a time. In the case of whales, although dead whales have been found with multiple fetuses, mothers usually give birth to just one calf. Seals usually have one pup at a time.  This is in contrast to some other marine animals like crabs or fish, which may produce thousands or even millions of young, but the young are usually broadcast out into the ocean where there is relatively little chance of survival. So, while the time and energy investment in viviparous animals is great, their young have a strong chance of survival.

Sharks often have more than one pup (hammerheads may have dozens at once), but these sharks grow relatively large in the womb. Although there is no parental care after birth, the young are relatively self-sufficient when they are born. 

Viviparous Antonym and Other Reproductive Strategies

The opposite (antonym) of viviparous is oviparous, in which the organism lays eggs. A very recognizable example of an oviparous animal is the chicken.  Marine animals that lay eggs include sea turtles, skates, some sharks, many fish, and nudibranchs. This is probably the most common reproductive strategy used by animals in the ocean. 

Some animals utilize a reproductive strategy called ovoviviparity - these animals are said to be ovoviviparous>. As you could probably guess from the name, this type of reproduction is in between viviparity and oviparity. In ovoviviparous animals, the mother produces eggs, but they develop within her body instead of hatching outside the body. Some sharks and other types of fish use this strategy. Examples include whale sharksbasking sharksthresher sharkssawfishshortfin mako sharks, tiger sharks, lantern sharks, frilled sharks, and angel sharks.



Also Known As

Live-bearing, bear live young

Viviparous, as Used in a Sentence

Viviparous shark species include bull sharks, blue sharks, lemon sharks, and hammerhead sharks.

References and Further Information