Why do river crabs live longer than sea crabs, and how long do river crabs live?

How long do river crabs really live?

Generally speaking, the lifespan of river crabs is 3 years old and 24 months old. Some of the river crabs that grow along the coast can reach sexual maturity in the same year, although they weigh only more than 10 grams, and their lifespan is only 1 year. Because some breeding units do not know how to distinguish between sexual maturity, they often mistake small crabs for crab seed procurement and stocking, and as a result, 99% of them cannot escape the June pass, which affects stocking and economic benefits.

In some places, far from the sea, for example, Xinjiang and other places, it is not uncommon for river crabs to live for 3-4 years, which is mainly related to the environmental factors of river crabs.

2. The relationship between reproduction and lifespan of river crabs.

As soon as the reproduction of river crabs ends, their lives are almost over, and some river crabs do not have the conditions to enter the ocean, and the clock of life will also stop, and it will die in freshwater waters. The size of the crab cannot determine the age, and the green crab is a sign of sexual maturity. After becoming a green crab, it cannot molt, of course, some people also molt again.

Those environmental factors that affect longevity need to be further studied.

3. The life law of river crabs.

The reproductive migration of river crabs in the Yangtze River basin is roughly from August to December, and the peak period is around the "frost fall". The fishing proverb says: "The cold dew sends the feet, and the frost falls."

At this time, fishermen go down to catch crabs, which is the coming of the annual crab flood. In the season of "beginning of winter", the river crabs in the inland rivers and lakes begin to dormant and overwinter, and the crab flood is basically over.

Because river crabs have always lived in freshwater areas, they can survive as long as there is water, and sea crabs are accustomed to seawater, and leaving seawater is like a baby leaving its mother, and it needs to adapt, so it may die.

The lifespan of river crabs is 2-3 years, which varies depending on the species of crab. River crab, commonly known as crab, hairy crab, hairy crab, clear water crab, etc., is one of the precious aquatic products, its meat is delicate and delicious and nutritious, rich in essential protein, calcium, iron and other nutrients. The river crab is a large crustacean with a body divided into 21 segments, and the whole body is divided into two parts: cephalothorax and abdomen because the head and thoracic segments heal each other.

The back of the adult crab is inky, and the cephalothorax is on average 7 cm long and wide.

River crabs, also called "crabs" and "hairy crabs", have a square shape and a hard texture of the cephalothorax formed by the combination of head and thorax. There is a pair of eyes on the front of the body and two pairs of sharp crab teeth on the sides. The pair of appendages at the very front of the crab are called chelicerae, and the surface is covered with villi; After chelicerae there are 4 pairs of footsteps, flattened and long; The abdominal limb has degenerated.

The male and female of the river crab can be distinguished by its abdomen: the female has a round abdomen, and the male has a triangular abdomen.

River crabs often burrow in the mud banks of rivers, rivers and lakes and marshes, are nocturnal, feed on fish, shrimp, animal carcasses and grains, often migrate to the estuary of the sea to spawn in autumn every year, hatch in March and May of the following year, develop into juvenile crabs, and then swim back to the river. The meat is tender and is a favorite food.

River crabs are crabs that grow in freshwater and breed in river water. Before reproductive migration, they are all juvenile crabs, because of their yellowish shell color, commonly known as "yellow crabs", their gonads are very small, basically undeveloped, and the weight of the liver is much greater than the weight of the gonads. When it completes the last molt, it develops into a "green crab", the shell color is dark green, the gonads are fully developed, the male crab has a dense chelicerae hair, the foot bristles are thick and long, the female crab's abdomen completely covers the ventral surface of the cephalothorax, and the bristles on the edge of the abdomen are long and dense.

River crabs have a lifespan of five years, depending on the species of river crab. River crab, commonly known as hairy crab, hairy crab, hairy crab, clear water crab, etc., is one of the precious waters. Its meat is delicate, delicious and nutritious, rich in essential protein, calcium, iron and other nutrients. A large carapace of river crabs.

Summary. First, the water quality is poor and there are many germs. 1. Poor water quality and many germs.

The crab pond is not disinfected in time, resulting in poor water quality in the pond, and the reproduction of harmful germs is accelerated, so that the crabs are infected by bacteria, suffer from gill rot, etc., and the crabs will die in serious cases. 2. Long-term acidity and alkali are too high. As the temperature gradually rises and the sunlight exposure time is getting longer and longer, the algae in the crab pond photosynthesis is vigorous, which will make the acid and alkali in the water body in the pond too high, resulting in chronic poisoning and death of crabs.

3. The water temperature is too high. When the crab is shed for the first time, if the water temperature in the pond is too high, it will be easy to die due to the weak constitution of the crab at this time. 4. The amount of dissolved oxygen in the water body in the pond is insufficient.

When cyanobacteria and moss break out in the crab pond, the amount of dissolved oxygen in the water will drop significantly, and a large amount of toxins will be released, and the amount of dissolved oxygen in the water in the pond will be insufficient. A large amount of toxins will be released, making the crab hypoxic and poisoned. 5. Stress response.

In high temperature weather, the water environment in the crab pond is destroyed after the rainstorm, which is easy for the crabs to have a stress reaction and suddenly die.

Is there a result. First, the water quality is poor and there are many germs. 1. Poor water quality and many germs.

The crab pond is not disinfected in time, resulting in poor water quality in the pond, and the reproduction of harmful germs is accelerated, so that the crabs are infected by bacteria, suffer from gill rot, etc., and the crabs will die in serious cases. 2. Long-term acidity and alkali are too high. As the temperature gradually rises and the sunlight exposure time is getting longer and longer, the algae in the crab pond photosynthesis is vigorous, which will make the acid and alkali in the water body in the pond too high, resulting in chronic poisoning and death of crabs.

3. The water temperature is too high. When the crab is shed for the first time, if the water temperature in the pond is too high, it will be easy to die due to the weak constitution of the crab at this time. 4. The amount of dissolved oxygen in the water body in the pond is insufficient.

When cyanobacteria and moss break out in the crab pond, the amount of dissolved oxygen in the water will drop significantly, and a large amount of toxins will be released, and the amount of dissolved oxygen in the water in the pond will be insufficient. A large amount of toxins will be released, making the crab hypoxic and poisoned. 5. Stress response.

In high temperature weather, the water environment in the crab pond is destroyed after the rainstorm, which is easy for the crabs to have a stress reaction and suddenly die.

It may be due to the fact that the weather has been too hot lately, resulting in high water temperatures.

How long a river crab can survive without water mainly depends on the season at that time, if the season is summer, the river crab can generally only survive for about 1 day in an environment without water;

If the season is winter, river crabs can generally survive for 2-3 days in an environment without water. Precautions for eating river crabs: Do not drink cold drinks when eating river crabs, otherwise it may cause diarrhea; River crabs should not be eaten with tomatoes, melons, peanuts, sweet potatoes, pumpkins, honey, persimmons, rabbit meat, pears, pomegranates, celery, etc.

The normal lifespan of river crabs is 1 1/2 to 2 years, and they die after laying eggs. How long can you live without water depends on the temperature, you can live for 1 week below 20 degrees, and about 3 days above 20 degrees This refers to adult river crabs, and there is no problem in the case of water only or 3 months.

There are several kinds of crabs, saltwater and freshwater, and the crabs of general seawater have to be packed with oxygen to survive for an hour or two after leaving the water, and the freshwater ones can be kept fresh for 5 or 6 days as long as they are not allowed to run away.

After living for a month, I will sneak away, hide and seek every once in a while, so that I can find it.

River crabs are amphibians that can survive without water.

If you don't have water or food, you won't live long...

If you refrigerate, you won't die for a week. However, the mortality rate is higher after one week.

Put it in the basket and sprinkle it with water from time to time, this kind of weather can be left for 3-5 days.

How long can river crabs live depends on how to store them, generally speaking, this kind of thing can survive for about a week after buying home, of course, if it is not stored properly, it may die after a day of storage.

After buying it, you can't clean the river crab with tap water, otherwise it may cause the river crab to die, because the tap water contains some special substances, and the river crab will die after inhalation.

When storing river crabs, you need to pay attention not to let the river crabs layer on top of each other, add water to about half the height of the river crabs, and do not completely submerge the river crabs, so that the river crabs will not lack oxygen.

To store the crab, you can tie it up, put it on a plate, cover it with a moist towel, and then bring the plate to the freezer of the refrigerator to refrigerate.

If the river crab is still lively, you can try to raise it for a few days, so that you can eat relatively fresh river crabs, generally speaking, river crabs can be put into a plastic bucket, and then put some feed every day.

River crabs can also be put in a fish tank, then sprinkled with an appropriate amount of water to keep the river crabs moist, and then put the crabs in the refrigerator and sprinkle some water every day.

In addition, if there are too many river crabs at home, you can choose to give them away at this time.

The life span of river crabs is mostly only 2-3 years, the life span is related to the variety, ecological environment and the maturity of the gonads, the river crab usually burrows in the mud bank or gravel and aquatic weeds, day and night, artificially breeding river crabs choose clear water quality, rich bait ponds or lakes, keep the water quality clean, change the water once a week in spring and autumn, and change the water once a week in summer.

The life span of river crabs is mostly only 2-3 years, the life span of river crabs is related to the variety, ecological environment and the maturity of the gonads, long-term life in the environment with high temperature, rich bait protein, high salt content in the water, there will be precocious gonads, and the river crabs at this time can not live for more than one year.

River crab is a crab that grows in fresh water, breeds in the river water, usually burrows in the mud bank or gravel and aquatic weeds, hides in the cave during the day, and forages at night, mainly feeds on aquatic weeds, snails, mussels, and aquatic insects in the water, and generally does not feed on land, and during the growth process, it will become an adult crab after 13-15 times of molting.

River crabs in the artificial breeding of the choice of water quality, rich bait pond or lake breeding, the water depth is kept between meters, the shallowest place is 10 centimeters, transplant aquatic plants in the pond, not only food, also have a hidden effect, around the feeding anti-escape device, every day in the morning and evening respectively fed.

River crab breeding during the easy to be infected with rotting shell disease, black gill disease, ciliarisis and other diseases, mainly because of too many bacteria in the water, deterioration of environmental conditions, pond water is too fertilized, in order to avoid the occurrence of diseases, spring and autumn water change once a week, summer 3 days to change the water once, when the temperature is too high, you need to change the water every day, the amount of water exchange is 1 3 of the whole pond, keep the water quality clear and clean.