CATDOLL : CATDOLL: What are the reproductive characteristics of fish? Fish that reproduce asexually?

1. What are the reproductive characteristics of fish?

Most fish are dioecious, and chase, lay eggs, ejaculate, and hatch when they reach sexual maturity. The feeding habits of fry are different from those of adult fish, and gradually become the same as they grow up. Some fish are fertilized and develop in vivo, and female fish give birth to small fish directly, which is ovoviviparous or pseudoviviparous.

The eggs of some cartilaginous fish and a few bony fish are not only fertilized in vivo, but also develop in the oviduct or ovarian cavity. The embryos are well protected by the mother, and the reproduction of these fish is generally not restricted to a specific breeding site. The oviparous female must expel the eggs from the mother's body, and they can only meet the sperm expelled by the male in the water to complete fertilization and embryonic development.

2. Fish that reproduce asexually?

Asexual species such as the Amazon sailfin perch generally use gynogenesis to reproduce, and all offspring are "clones" of their mother. In order to develop embryos, female Amazon sailfin perch will mate with males of similar species, but they do not use the male's sperm, so in theory the offspring will not inherit any genes from the father.

Scientists believe that if sexual species reproduce asexually, they will develop genetic defects and eventually become extinct after a few generations, so the Amazon sailfin perch should have become extinct long ago.

According to mathematical models established by scientists, this asexual female fish should have become extinct 70,000 years ago, but today they still reproduce in southeastern Texas and northeastern Mexico.

What allows the Amazon sailfin perch to survive? Researchers at the School of Biological Sciences at the University of Edinburgh in the UK believe that it is a genetic "trick" that helps the Amazon sailfin perch survive. They may have obtained some DNA from male fish of other species to trigger reproduction and update their own gene pool.

Dr. Lawrence Levy said the study of the Amazonian sailfin perch may also help better understand the survival secrets of other species that reproduce in a similar way. One of them is the salamander, which has been thriving on Earth for more than a million years.

3. How do fish reproduce?

Evolution means having many children, each with slight differences (mutations), and then those that adapt to the environment survive, reproduce, and pass on their genomes.

In the example of the fish biting the hook, the fish that are curious and less vigilant are selected and killed. In this way, the less curious and more vigilant fish are more likely to survive and give birth to offspring. The proportion of fish that are not easily caught will increase in the next generation.

If fishermen kill enough individuals, selection may be complete within a single generation!

In fact, because there are no restrictions on personal recreational fishing, many non-migratory fish in China's coastal waters have evolved and become more cautious in the past 10 to 20 years. Everyone feels that it is becoming increasingly difficult to catch fish.

Similarly, in North America, fishing has never been very difficult because of the restrictions on the amount of fish caught by sports fishing licenses. Fish that are wary or curious about the food that is brought to their mouths have the opportunity to reproduce, and both genes will be passed on to the next generation. Intuitively speaking, fish are more "stupid".

But of course these fish that don't bite the hook don't "know", they are just more picky and more easily frightened. As for understanding the meaning of "fishing line" and "trap", they need to evolve consciousness first, and that may never happen.

peace out.

4. How do fish reproduce?

There are two main ways:

1. Ovoviviparous fish

Their way of conception is direct internal fertilization, and the female fish can also become pregnant and give birth to small fish directly, such as the ornamental fish such as guppies, red arrowfish, mollies, breams, etc. If we don’t observe carefully, we really can’t find that they will also have such behavior.

2. Oviparous fish

The reproductive method of oviparous fish accounts for a large proportion of the fish's conception methods.

Most of them need an attachment for the eggs, and then the female fish lays eggs on the attachment and the male fish fertilizes the eggs. After a certain incubation period, the eggs can hatch into small fish fry.

5.What are the reasons for fish growth and reproduction?

1. Oviparous. This is the reproduction method of most fish. The fish expel the eggs from the body, and the embryos develop completely outside the body. The nutrients are provided by the eggs and have nothing to do with the mother's nutrition.

2. Ovoviviparity: The fertilized egg develops in the mother's reproductive tract, and its nutrition is provided by the yolk, which has nothing to do with the mother's nutrition.

3. Viviparity. The fertilized eggs of some fish develop in the mother's reproductive tract, and the embryos are connected to the mother's blood circulation. The development of these embryos is not only nourished by the yolk, but also related to the mother's nutrition.

Extended information: In order to breed excellent fry, you must choose healthy broodstock with excellent color, fins and size for breeding. Special care, close attention to water quality changes, live bait, or occasional feeding of fish grass can breed the best fry. Some fish have special requirements for water quality conditions when breeding. Be careful to prevent broodstock from swallowing their own eggs or fry. Fish lovers can estimate the number of fry based on the smooth spawning situation and provide enough food for the fry.

6. What is the concept of fish breeding cycle?

Ordinary fish can ovulate in spring when the water temperature reaches above 20 degrees. However, different fish have different breeding times. For example, carp spawns from March to August, with the peak period from April to June. Grass carp spawns from early May to early June, with the peak period in mid-to-late May.

7. How do fish reproduce by sowing?

After the fish chases its tail, it will generally lay eggs in three or four days. Usually during the breeding season, male and female fish will mate, and after successful pairing, they will chase each other. This is the fish trying to mate, so after a few days, the female fish will lay eggs, and the male fish will fertilize them. After obtaining the fertilized eggs, the parent fish are usually removed from the tank to prevent them from accidentally eating the eggs and affecting the hatching of the fry.

8. How do fish reproduce?

There are many types of fish, and the main mode of reproduction is oviparity. Among them, most of the fish in the class Chondrichthyes are fertilized internally, and in addition to oviparity, there are also ovoviviparity. Fish in the class Osteichthyes are fertilized externally, and most of them are oviparous, and a small number undergo metamorphosis. Usually during the breeding season, fish will mate and release eggs, which will hatch after a period of time. There are also some that hatch eggs in the body and release fry.

9. How many types of reproduction methods do fish have?

There are two ways of reproduction in fish: oviparous and viviparous.

10. How do fish mate and reproduce?

In teleost fish, most species are fertilized externally, so males don't have copulatory organs. However, a few species are fertilized internally, so males must have copulatory organs to complete their mission of reproducing offspring.