Some questions about crab shelling, where does the shell go after the crab is shelled

The shell of the crab does not grow as the body grows, and in order to protect the body that grows larger, the crab must drill out of the original shell and slowly form a new hard shell.

Crabs generally do not eat until they are shed, but after a few days of baiting, if they find that the amount of bait left has increased greatly (in the absence of disease), it indicates that the crab is about to start shedding its shells. Before shedding, the body color of the river crab is dark, and the body color is yellow-brown, black-brown, and the abdominal carapace is rusty. After shelling, the body color of the river crab becomes lighter, the abdominal carapace is white, there is no rust, and the steps are soft.

After shelling, the individual gains about 20% and doubles the body weight compared with the pre-shelling individual. The discovery of river crabs with larger individuals and lighter body color indicates that the crabs have shed their shells.

It is a very difficult choice for the crab, if the inside of the crab expands sharply, and it still relies on the old shell to not leave, then it will die in its old shell sooner or later, so only wait for the old shell to age enough, crack out of the mouth large enough to start a new metamorphosis, at this time the crab body is very soft, the crab must carefully drill out of the old crab shell little by little, otherwise it is very likely to be scratched by the sharp old shell.

Not only are the shells replaced with new ones, but the stomach gills and intestines of the crabs will also shed their old skin, and the crabs that have successfully shed their shells can be said to have completely lost their defenses, and usually they will hide in the cracks of the stones until the new shells become hard before they can come out.

Extended Materials. The process of shelling crabs.

1. Hulling interval.

In the shelling interval, the crab shell calcified, absorbing calcium and trace elements, the river crab will eat a large amount of energy, the accumulation of energy substances and trace elements, and the material preparation for shelling. (At this time, nutrients should be added to the bait, in addition, insufficient calcium and trace elements will also affect the shelling efficiency of river crabs).

2. Early stage of shelling.

In the early stage of shelling, the dermis layer will be separated from the epidermal layer, the epidermis above the old shell will begin to be absorbed, calcium and trace elements will be absorbed into the blood, and the new epidermis will begin to form, and the food intake will be reduced, which is the formation of the second shell. When the old shell is absorbed, the new epidermis separates from the old shell significantly, and feeding stops. The new epidermis is secreted and the crab begins to absorb water and is ready to shed its shell.

At this time, the freshness of the water will affect the shelling of river crabs).

3. Hulling period.

When the body absorbs a large amount of water, cracks appear in the breastplate and abdomen of the crab's head, and the crab bounces its body out of its old shell, a process that takes only a few seconds or minutes. (Accumulation of nutrients in the early stage is the key).

4. The late stage of shelling.

When it first comes out, the new shell of the river crab is soft and elastic, and the river crab begins to absorb a large amount of water to fully extend the new shell to the maximum scale, and the vitality is weak at this time, and it does not feed. This process is also shorter. (This is the time when river crabs are most vulnerable, and a quiet environment is necessary).

5. Follow-up period.

The carapace of river crabs begins to calcify and begins to absorb a large amount of calcium and trace elements, which is determined by the calcium content and trace element content in the water body. When the shell hardens and can support the body, the crab will expel the excess water absorbed by the body and start feeding, completing a shelling cycle.

Crabs shed their shells. Because their shells don't grow, they shed their shells and grow new ones whenever they reach a certain stage of growth and become larger. Each crab goes through a process of shedding its shell more than a dozen times during its lifetime.

When the crab sheds its shell, it will first absorb the calcium carbonate in the shell into the body fluid, and then wrinkles will grow in the shell. When the old shell is removed, these folds slowly open up and become a new shell. Finally, the crab injects calcium carbonate into the new shell.

Do crabs shed their shells and how often do they shed their shells.

1. Do crabs shed their shells?

Crabs are a type of crustacean and are relatively common in our daily lives. The characteristics on the body of crabs are very obvious, and the hard shell is one of their distinguishing features. Crabs shed their shells, which is an essential step in their growth process, and normal crabs shed their shells.

Their shelling represents that they have grown up. Crabs shed their shells because their shells do not grow slowly like the bodies of other animals, but only by shedding their shells.

When crabs shed their shells, they first absorb the calcium carbonate from their shells into their body fluids. Then, a layer of wrinkles will grow in their shells, which will appear softer. At this point, the old shell will slowly come off, and the new shell will be bent open by this fold.

Eventually, the crab will inject the calcium carbonate it has absorbed into the new shell, which will become harder.

2. How often do crabs shed their shells?

As mentioned above, crabs are shelled, and shelling represents the growth of their bodies. In fact, crabs can shed their shells more than once in their lifetime, generally at least a dozen times. At all stages of their life, crabs shed their shells, and more than once.

From big-eyed larvae, to young crabs, juvenile crabs, and adult crabs, they will go through several shells. Specifically, it is not certain how often crabs shed their shells, and it depends on the speed of their own growth and development. Generally speaking, the fastest time can be taken off once every 2 weeks, while the slower time can take about 2 months to take off once.

Crabs shed their shells because their shells cannot expand as their bodies grow, so the way to overcome the problem is to shed their shells. Before shedding the shell, the crab first absorbs the calcium carbonate in the hard shell into the body fluid, and when a layer of soft wrinkles grows in the shell, the old shell cracks and falls off, and the body then stretches the folds into a new shell, and injects calcium carbonate to harden it.

Crabs eat their shells when they shed their shells, which gives them calcium. After the crab is shelled, the body will grow a little larger than before, so before it is shelled, it is necessary to supplement it with nutrients, or when it is shelled, it is necessary to supplement liquid calcium. After the crab has shed its shell, if it finds that it has not eaten the shell, you can take the shell out.

After the crab completes the shelling, it will eat its own shell, and the shell of the crab can add a certain amount of calcium to it, so after the crab is shelled, it is eaten without seeing its shell.

Crab shelling represents growth, every time the crab sheds its shell, its body will grow a little, and the crab will not eat much before and after shedding its shell, so before it enters the shelling, be sure to give it nutrients, or add liquid calcium when shedding.

After the crab sheds its shell, its body is very soft, and it eats its own shell, which helps to harden the shell on its body, but if you find that the crab has not eaten the shell, it is best to give it the shell out, otherwise it will also pollute the water quality.

1. The hard carapace on the crab can protect the crab from natural enemies, but the carapace will not expand as the body grows. Therefore, the growth of crabs is interstitial, that is, after a period of time, the body will continue to grow after the old shell is shed.

2. The life of the crab is short, in its life history it has gone through several stages such as flea-like larvae, big-eyed larvae, juvenile crab and adult crab, and the larvae need to molt 5 times in their life to become the big-eyed larvae of Xifan, and then molt into an adult crab after 13-15 days.

3. It has only one reproductive cycle in its life, and the end of its life is terminated, generally speaking, the life span of river crabs is 1-3 weeks old.

1. Precursors of crab molting.

1. If the shell of the crab is not only yellow, but also shiny, then it means that the crab will begin to molt in about 2-3 days, or the inner shell of the crab will form and appear black, which means that the crab will molt soon. When the temperature is normal, if the food intake suddenly decreases, or when the crab is active at the water's edge or on the grass at night, it is also a sign that the crab is about to molt.

What are the precursors of crab shelling.

1. Precursor to the molting of the crab 1. If the shell of the crab is not only yellow, but also shiny, it means that the crab will begin to molt in about 2-3 days, or the inner shell of the crab will be formed and appear black, which means that the crab will soon molt. When the temperature is normal, if the food intake suddenly decreases, or when the crab is active at the water's edge or on the grass at night, it is also a sign that the crab is about to molt.

I wish you all the best of luck and all your wishes.

It takes off a dozen times to dozens of times in a lifetime, mainly depending on the speed of the crab's growth, because the size of the shell does not grow with the body, so it needs to be constantly shed to adapt to growth.

Crabs undergo about 18 shells in their lifetime, and each shelling is the result of growth and development, and it will be shelled when the body's tissues have grown and nutrients have accumulated to a certain level.

The crab will shed its shell in its lifetime, and if it lives a long life, it can shed its shell more than a dozen times, and its shelling is mainly for growth and development.

Crabs are grown by shedding their shells, and when crabs are shedding their shells, they will first absorb the calcium carbonate from their old shells and store them in body fluids. Then, very soft wrinkles will grow in the crab's shell. After that, their old shells will slowly crack open and slowly fall off.

This fold will open and slowly turn into a new shell, after which the crab will inject the calcium carbonate stored in the body fluids into the new shell, so that their new shell can harden. Crabs can shed their shells more than a dozen times in their lifetime, from larvae, to juvenile crabs, and then to adult crabs.

Crabs shed their shells, and only after they have been shelled will they grow.

The crab will stop in one place before shedding its shell, and its limbs will be slightly tucked inward (note that although it is tucked, it is not stiff), and it will take a long time for the shell to be completed.

After the crab sheds its shell, the shell of the body will become very soft, and you can't catch it with your hands, otherwise it will easily break its legs.

The chance of freshly caught crabs shedding their shells is very small, and it usually takes a period of care to shed their shells.

You said your crab didn't move, I think it's probably dead.

It takes about a week for the crab to molt. If the crab does not move, it is very likely to be dead, because the crab will also move when it molts, and it will not be motionless.

Crabs: Animalia, phylum Arthropods, Crustacean subphylum, Molluscs, True Molluscs, Decapodium, Ventral Embryo, Short-tailed Inferior. It is a crustacean whose body is protected by a hard shell and breathes by its gills.

Taxonomicly, it is the same animal as shrimp, lobster, and hermit crab. The vast majority of species of crabs live in the sea or near the sea, but some inhabit freshwater or land. They rely on the mother crab to give birth to baby crabs, and each time the mother crab lays a large number of eggs, the number of which can reach more than millions.

Crabs rely on the geomagnetic field to determine direction. The history of crab eating in China is long, and it is recorded in "Yi Zhou Shu, Wang Hui Jie" and "Zhou Li, Tianguan, and Blister".

The genetic material of such organisms is complex and highly varied, often as many as more than 100 pairs. Common crabs include hairy crabs (river crabs, hairy crabs, blue crabs), pike crabs, etc. The resources of crabs in China are very abundant, among which the hairy crabs produced by Gucheng Lake, Taihu Lake, Gaoyou Lake, Yangcheng Lake, and Xilou hairy crabs in the lower reaches of the Yangtze River are the top grades.

Crabs will shed their shells many times in each season, and it takes about a week for each shell to be shed I have raised crabs for seven years, and as far as I know, crabs can move freely during the period when they are shedding, and after the shelling is completed, the action will be much worse than before, and the body will become softer There is also a reminder that no matter whether there is a shelling crab will spit foam, if your crab does not even have this basic phenomenon, it will die.

(1) Feed high-quality bait Before each molting comes, it is not only necessary to put compound feed containing ecidin, and strive to molt synchronously, but also to increase the number of animal bait, so that the proportion of animal bait accounts for more than 1 2 of the total amount of bait, and maintain the food and sufficiency of bait to avoid residual eating of soft shell crabs.

2) Increase the calcium ion content in the water It is found that individual river crabs have molted their shells, and quicklime water can be sprinkled, with kilograms of quicklime per mu, and after adding water and slurry, the whole pool is splashed.

3) Keep the water level stable During the molting period, the water level needs to be kept stable, and there is generally no need to change the water.

4) The feeding area and the molting area must be strictly separated It is strictly forbidden to put bait in the molting area, and if there are few aquatic plants in the molting area, aquatic plants should be added and kept quiet.

5) Strengthen the patrol of the pond In the early morning, when the pond is patrolled, the soft shell crab is found, which can be picked up and put into the bucket for 1 2 hours, and then put back into the original pond after the river crab absorbs water and swells and can crawl freely.

As a crustacean, the molting of river crabs is a very important part of their growth process, and each molting of river crabs is accompanied by growth.

Every molting of river crabs is a severe test of life, the shelling period is the most vulnerable time for river crabs, easy to be attacked by natural enemies and very susceptible to diseases, which is also the most headache for breeding users, and it is also a critical period for breeding river crabs. If the crab does not molt or fails to molt, it will lead to the death of the crab and cause breeding losses. Statistics show that the incidence of unsuccessful molting of river crabs is increasing year by year, and the mortality rate during molting accounts for 80% of the breeding rate.

The degradation of crab germplasm, the deterioration of pond water quality, the spread of diseases, and the incomplete nutrition of feed are the main reasons for the failure of river crab molting. The lack of certain nutrients in the breeding process, such as the long-term lack of calcium, phosphorus, iron and other elements in the aquaculture water, and the long-term lack of essential amino acids, bile acids, ecidin, etc., will lead to the occurrence of molting.

The selection of healthy and vigorous high-quality crab seedlings and the strengthening of water quality management are still the most basic tasks to prevent and control the failure of river crab molting. However, the internal health care prevention and treatment methods in nutrition have also attracted more and more attention. Many farmers do not pay attention to internal health care, in addition to being troublesome, mainly doubting the existence of the effect.

In fact, the effect of taking fortified health supplements containing bile acids is obvious.

Bile acids, like cholesterol, are essential nutrients for the growth of shrimp and crabs, and are the precursors of the synthesis of ecdysone by the crustacean body. The addition of bile acids to the feed can increase the synthesis of ecdysone in the body, ensure that the content of ecdysone is sufficient, and ensure the normal and smooth molting of river crabs.

In the early days, the intake of river crabs was small, and the addition of bile acids ensured that the limited bait ingested by river crabs was fully absorbed and utilized, which accelerated the accumulation of nutrients, improved the growth performance of river crabs, and made river crabs gain more weight after molting.

River crabs have poor resistance during the molting period and are susceptible to disease. The hepatopancreas is an important metabolic organ of river crabs, which plays the functions of detoxification, secretion of digestive enzymes, and immune defense. The heavy burden of hepatopancreas and the problem of lesions lead to poor body resistance of river crabs, which indirectly affects the smooth molting of river crabs.

Bile acids can enhance the metabolism of nutrients and eliminate toxic and harmful substances into the body, so as to achieve the purpose of maintaining the health of the hepatopancreas, enhancing the function of the hepatopancreas, and enhancing the physique of river crabs.

In short, bile acids are an indispensable nutritional factor to ensure the successful molting of river crabs, which can prevent and control the molting failure of river crabs by promoting the synthesis of ecdysone, promoting nutrient metabolism, reducing the burden of hepatopancreas, and enhancing the function of hepatopancreas, so as to improve the survival rate and weight gain rate of river crabs, and increase the economic benefits of river crab breeding.