Can a worm be both viviparous and oviparous?

It cannot be viviparous, it is ovoviviparous and oviparous.

Shark Breeding Strategies There are three types of shark breeding strategies 1Oviparous Fertilized eggs are produced outside the shell and have a very limited number of ovulations per ovulation. The eggs are sack-shaped or spiral-shaped, and are usually laid and fixed in coral reefs, seafloor plants, or rock crevices.

2.Ovoviviparous (non-placental viviparity) The fertilized egg develops in the uterus, and the fetus feeds on the eggs released into the uterus by the yolk sac or ovaries, and finally produces it in the form of a fetus. The placenta does not form in the uterus.

The number of litters per litter is extremely limited, except for whale sharks, which can reach more than 300 litters per litter, the rest of the species have dozens of litters at most, and the least is the fox shark (thresher shark), which only lays 2 litters per litter. 3.Viviparity (placental viviparity) The fertilized egg develops in the uterus, and the nutrients required for the growth of the fetus rely on the placenta and umbilical cord directly out of the mother's body** like mammals, and each litter is up to dozens of tails.

We are the union of the eggs of the sperm in the fetus, so it is oviparous, viviparous. In the mother's belly is wet raw. It takes greens, radish, beef, and onions to grow up, so it is also metabiotic.

People are also colored , and there are substances visible in bodily functions. But when it comes to human life, qi, it is not material, nor can it be seen, so it is colorless...

What's not a snake, isn't it?

There are both oviparous and viviparous snakes.

In general, aphids reproduce in "parthenoviviparity" in spring and summer, and in winter they lay eggs after mating between males and females, and the eggs laid can develop after wintering. But in the warmer climates of the south, they are parthenogenetic all year round.

Generational alternation of insects.

Some insects undergo parthenogenesis for several generations in a row, followed by hermaphroditism, alternating between parthenogenesis and parthenogenesis. For example, most aphids and gall bees produce parthenogenetic offspring in spring and summer, and in late autumn, parthenogenesis produces female and male offspring, which is called parthenogenesis. Adopt hermaphroditic methods of reproduction to adapt to adverse environmental conditions.

Parthenogenesis plays an important role in the widespread distribution of insects. Sometimes, by taking a female to a new place, it is possible for it to breed in that area. Parthenogenesis can be considered a favorable adaptation for insects to cope with harsh environments and expand their distribution.

However, parthenogenesis cannot improve the viability of the organism, only hermaphroditism can improve the viability of offspring, so most parthenogenetic species have intersex reproductive generations.

Many aphids also often produce larvae directly in spring and summer. This kind of "ovoviviparity" of insects is actually only the egg stays in the mother's body until the embryo matures and becomes a larva or nymph before being born, and the egg does not absorb the mother's nutrition during the development of the mother's body, which is essentially different from the mammalian fetus to absorb the mother's nutrition through the placenta in the mother's body. Because the eggs mature in the body of the female, this avoids the dangers that the eggs may encounter when exposed to the external environment, and can better ensure the safety of the growth and development of the offspring.

Parthenogenesis of aphids is also one of the most peculiar ways of reproduction in insects, that is, females can reproduce offspring without mating with males. In general, aphids reproduce in "parthenoviviparity" in spring and summer, and in winter they lay eggs after mating between males and females, and the eggs laid can develop after wintering. But in the warmer climates of the south, they are parthenogenetic all year round.

Aphids are commonly known as greasy insects, dense insects, and oilworms. Aphids can be oviparous or ovoviviparous, can be produced by mating or are directly born from female aphids without mating.

Insects, of course, are oviparous.

Mammals are viviparous.

Insects, of course, are oviparous.

Mammals are viviparous.

Really

First of all, it is clear that viviparity (except for platypus ovoviviparous) is the most advanced form of evolution of mammals.

Aphids are genus arthropods that are obviously not that advanced.

P.S. Aphid details.

The groups of animals that can lay eggs and directly produce young children are:

Some pit vipers (e.g., pit vipers), snakes (e.g., anachidae), medakas (e.g., guppies), and some cartilaginous fishes (including some species of sharks and stingrays).

It should be said that such creatures do not exist, in a sense, there will be such a situation in the process of biological evolution, but such creatures cannot adapt to changes in the environment and perish, and nature is the survival of the fittest.

Only the platypus is more special and is an oviparous mammal.

Aphids, oviparous and parthenoviparous.

Most people are viviparous, and Nezha is oviparous.

According to the seventeenth volume of the "One Ahama Sutra" and the eighth volume of the "Kusha Treatise", the so-called four births, that is, birds, chickens, fish, etc., are born from egg shells, which are called oviparous. For example, humans and animals are born from the womb, which is called viviparity. For example, insects, mosquitoes, moths, etc. are born from moisture, which is called wetness.

For example, the heavens, hungry ghosts, etc., have nothing to support, and they come out of nowhere, and they are incarnated. Among the four lives, if you judge according to the victory or inferiority, the number of victories and the most will be the most victorious in incarnation. This is due to the fact that a small part of the three pleasures of ghosts, beasts, and people, all of the two pleasures of hell, heavens, and all of them are incarnated.

See Appendix) 2) There are four types of attachments for sentient beings, namely, touching, smelling, sand, and sound. For example, the "Theory of Enlightenment" cloud (Taisho 31·882a).

There are four kinds of birth: (1) Touch, such as a man and a woman having a child. (2) Sniffing, such as cattle and sheep, male and female have desire, and male and female have children when they sniff the female and other roots. (3) Sand birth, such as chickens, finches, etc., female finches have lust, and give birth to children with eggs in the dust and sand.

4) Vocal birth, such as cranes, peacocks, etc., have desires, hear the sound of male songs, and also give birth to eggs. ’

Oviparous: It is hatched from the egg that lays it.

Viviparity: It is born directly.

It's not oviparous, it's not viviparous, it's not.

In general, higher animals, such as mammals, are viviparous.

Some lower ones, such as amphibians, are oviparous.

However, there are some things that are oviparous mammals, such as platypus.

There are also ovoviviparous, that is, eggs are laid, but the ones inside the mess are already hatched, such as sharks.

Any living thing is adapted to its living environment. Even if both oviparity and viviparity can exist in nature, there must be them.

Each has the right to adapt to the environment.

You say that viviparity has the advantage of oviparity, but oviparity does not necessarily exist. For example, a fish can lay millions of eggs, but only one or two can eventually grow into individuals. The mortality rate is extremely high. And nutrients are wasted. And the survival rate of viviparity is millions of times that of oviparity.

Because of the constant temperature, viviparous animals have a stronger range of motion and ability to adapt to the environment than oviparous. For example, ants are hard to see in the Arctic and Antarctic regions.

Oviparity also has a relatively big advantage is to provide continuous food energy to organisms in nature, although the survival rate of eggs is low, but it is beneficial to the survival of other animals.

I don't know why you called the source so many exclamations, but I thought about it carefully, and also.

du is a bit more reasonable for zhi viviparity, for the following reasons.

DAO oviparity is short...... timeBut the incubation time is long, ......2.Oviparity has the least impact on the mother, and the mother is more able to protect the safety of the next generation, while the viviparous mother is very fragile, and a slightly larger movement may be illuminated into a corpse ......and two livesHave you ever eaten eggs, chickens are laying eggs ...... without fertilization?To some extent, the hen has been pregnant for a long time, and she doesn't know if she can live when she is born, and when it comes to one corpse and two lives, she can still beat the pregnancy when she is not pregnant, and she can still beat it, and she is fragile when she gives birth, but the eggs are the same. And when pregnancy is in danger, you can run with the ball, you take the eggs to run and see, all of them are broken 3

Oviparous production does not have pregnancy complications or is less ...... complicationsThe complication of oviparity is to always conceive and give birth4Egg production is ...... higherThe yield is not high, no, ......Ten and nine of the eggs were laid, and they were all eaten ......Count as much as viviparity survives (referring to birds......If you say fish and insects ......Tens of thousands of children have been eaten before they are ...... birthDon't feel sorry for ......As for ants and bees, ......I don't know if you think the fertility machine is better, or the guards responsible for protecting the fertility machine are better? ）5.

The developmental stage of oviparity is less affected by the maternal constitution ......It is less affected by the mother and more affected by the outside world, the mother is at a constant temperature, and if the outside world is not good, it will become a steamed egg......In this way, it is better to give birth to a viviparity.

Viviparous and oviparous have their own advantages.

Viviparity has a higher survival rate than oviparity.

Therefore, oviparous animals lay a lot of eggs, but very few survive.

Viviparity is no better than oviparity in every way.