Most of the known spawning fish breeding, but not all.Some underwater inhabitants as the aquarium and the wild, their offspring is born.So many fans are interested in the issue of aquatic fauna on what fish are viviparous and how they multiply.
Sharks
Many sharks are known that are viviparous.For example, such species include the tiger, herring, frilled shark, hammerheads, and others.Also in this list, there is a blue shark.The size of the fish is typically less than 3.8 meters.But puberty they begin when they reach two meters.In males, this period comes with a body length of 1.9 meters.
After mating has occurred, the female can become pregnant immediately.The sperm in her body can persist for months, waiting for ovulation.After the females were fertilized egg, it begins during gestation, which can last from 9 months to a year.It is believed that the blue shark is among the most prolific of all the major counterparts.The number of juveniles who were born, is different, and the number varies from 4 to 120 individuals.Babies are born independent, ready to predatory life, but only half of them reaches its maturity, as larger fish are not averse to profit by them.
Fish ramp
But this method of breeding fish is found not only in sharks.Some types of rays are also viviparous, such as stingray.Usually, female brings a kid, length - about 35 centimeters.For live-bearing skates are also manta rays, which are another name - Sea Devils.These large fish, too, bring a baby who at birth already reaches meters and its weight - 50 kg.To offspring to be born, if the mother shoots her baby, that is rolled into a roll.Scarce immediately spreads its "wings" and the female swims.During pregnancy, this fish exhibits unprecedented aggression and ability to flood the boat.
As babies develop in the womb?
known that live-bearing fish brings the baby is already formed, but scientists for years could not understand how to get the fry in the womb oxygen if they do not have the placenta and umbilical cord.But in 2008 the mystery was solved.Okinawan fishermen caught a pregnant sea devil left him, and scientists to study.In order to better understand the gestation period of this fish, the researchers slightly improved ultrasound device, after which he began working in the salt water.Surveillance continued until the birth, which occurred eight months later.On one calf was born female.The newborn weighed 50 kilograms.
Because the live-bearing fish is under the supervision of the entire period of gestation, the researchers were able to unravel the mystery of how the fruit breathes.While in the womb, the baby uses his gills and circulates them through the amniotic water.To do this, he is an adult, opens and closes the mouth.Water that falls to it passes through a special channel and reaches the valve behind the head (it is not only the rays, but also sharks).Adults motion does not close his mouth to immediately filter the water and plankton.Cubs who are in the womb, has to use his mouth as a pump.In this way, the fetus can breathe and eat.
relationship of parents with fry
As Young immediately after the ready to lead an independent life, they mostly do so.Most of them are now independent of the mother.And in some cases they do better to stay away from their parents.Adults usually do not distinguish their offspring to eat, and if they are hungry, they may profit by their own kids.
Other live-bearing fish
described our sharks and rays are cartilaginous fish.Among the bony fish are more common ones that multiply spawning.Yet among them you can meet and live-bearing.These include tsimatogaster.This type of fish on some factors like a perch, and on other grounds reminiscent of carp.Their habitat - the Pacific Ocean, the northern part of it.
But not only are live-bearing fish fry which are fed directly from the mother in utero.The female can hatch eggs in the belly.The fry are fed from the yolk.When the time comes to give birth to fry eggs are formed and the mother begins to throw them.For example, this method of breeding fish inherent eelpout.At birth, the fry are already formed.Over time the female can produce up to three hundred fish, but this is a la carte.The size of each newborn fry is four centimeters.Among
fishing viviparous fish is sea bass.This is a very prolific species that are caught in large quantities in the Barents Sea and the Atlantic Ocean.This live-bearing fish for one season gives the offspring of a few hundred thousand.It lays larvae, each of which is equal to about six millimeters.
only live-bearing fish
Baikal Lake Baikal - a beautiful and deep lake, and it is home to many underwater inhabitants.Among the variety you can meet only viviparous fish called golomyanka.To many, this fact may seem surprising, because usually in the northern latitudes, by means of breeding fish spawning.It is home to two species golomyankas.Most grow up to 25 cm, small does not exceed 15 cm. Golomyanka does spawning migrations, as it does in the rest of the fish that spawn.When the time comes, and in the womb of the female calf turns into fry, the mother rises closer to the surface.Most likely, it is necessary for children to feed on plankton organisms.Viviparous golomyanka gives a large litter, depending on the species.There appears small at a time, not more 1,5 thousand. Fishies.At large, the figure is about 2.5 thousand. Fry.After birth, the mother dies.What is surprising is that this type of fish found only in Lake Baikal.Such a mechanism of birth and death will no longer be repeated in other underwater creatures.
aquarium inhabitants
But viviparous fish are found not only among commercial fish species.Many aquarium owners know that some of my favorites fry hatching.Mainly inherent in a live birth family poeciliidae, Gudieva and some others.Usually this schooling fishes and they have small dimensions.Also among them are males slightly smaller than females, and their colors seem brighter.When they reach sexual maturity, the anal fin of the male becomes gonopodium by which fertilization occurs.Each type has its own distinctive features in the structure of this process.This is necessary in order to eliminate the possibility of hybridization.But breeders annually breed new varieties of ornamental fish, which leads to the appearance of unusual colors and shapes.This mainly concerns the guppy.No selection viviparous ornamental fish rapidly loses its color and gradually degenerates.
Development fry
period of development from eggs to fry in the womb of the female depends on the family and the type of fish.After fertilization, gestation can last a week or two.But some fish during this period can be extended to 2.5 months.Most livebearers family poeciliidae youngsters get close and thus much easier than the caviar, whereas in other species is much greater than the weight of fry fertilized eggs.And due to the fact that the milk from the male to the female may remain in a prolonged period, the eggs can be fertilized immediately, but over time and not once.Therefore, even when a single fertilized fish is able to produce offspring several times.It is easy to bring up, because the fry immediately after birth are active.Number of juveniles depends on the type of fish and may be a few units and hundreds.
Content livebearers
order to live-bearing fish breeding is successful, it is important to take care of their living conditions.For their contents are usually suitable common aquariums, which are overgrown with vegetation.In addition, the neutral water requires regular replacement.Weekly replaced by 15 to 40% liquid.But some species will feel much more comfortable if the water is salted.Such conditions are mainly for mollies and belonezoksov.For this purpose, ten liters is added a tablespoon of sea salt.Also, the ideal water temperature for most species usually varies from 20 to 25 0C.
to fish diet was balanced, they need to be added to the feed plant components.This can be a salad, filamentous algae, oatmeal and other foods.
