How to distinguish between dormant and dead crabs, difference between sleeping and dead crabs

Crabs are rich in protein, minerals, and vitamins, and are popular for their high edible value. Crabs belong to the class Mollusk, Decapod, and are crustaceans whose bodies are protected by a hard shell and breathe by gills. There is a certain amount of attention to eating crabs, and you can't eat dead crabs.

Distinguishing whether a crab is dormant or dead is generally divided into 4 steps: looking, touching, smelling, and pinching.

1.Depending on whether the bubbles are spit out, the live crab is more energetic and will spit out a circle of small white bubbles from time to time, while the dormant crab will also spit out bubbles when put into the water, but the dead crab will not spit out bubbles.

2.Whether the body is touched or not, the crab is dormant and contracts and moves when its eyes are touched with the hand, while the dead crab eyes usually stick out and do not move; Stretch the calf of the hairy crab with your hands, and when you pull it away, it will retract and the dead crab will not move.

3.Whether it is normal to smell fishy, the taste of crabs in the dormant period is relatively light, and the overall appearance of a salty smell, while dead crabs will emit an unpleasant fishy amine smell, and the longer the time, the greater the smell.

4.Pinch the hardness and softness of the body, the dormant crab is more energetic, the shell and abdomen are harder, and the navel will be retracted, and the dead crab will be significantly softer.

Dead crabs produce large amounts of histamine, and human consumption of dead crabs can lead to histamine poisoning. Histamine is an allergic poison, so eating dead crabs can cause allergic food poisoning. People who are allergic to histamine can cause a reaction even with a single bite.

Symptoms are mostly flushing of the cheeks, flushing of the chest and flushing of the body** and conjunctival hyperemia, as well as headache, dizziness, chest tightness, general weakness and irritability. Another important cause of poisoning by eating dead crabs is bacterial infection. In general, wild river crabs live in a less environmentally friendly environment than artificial crabs and marine crabs.

Once they die, bacteria inside and outside the body multiply, breaking down the crab meat and producing toxins. Comparatively, the risk of bacterial infections is higher.

The dead crab does not move at all, does not spit bubbles in the water, and the limbs are naturally loose and dull in color. The opposite is live crabs.

The crab breathes when it sleeps, spits bubbles in the water, and touches its pincers and body, it reacts, and when it wakes up, it starts moving, its eyes shrink inward, and its eyes turn. But when the crab died, it didn't breathe, and its body didn't react, and its eyes didn't shine, as if they were covered with a layer of ash.

Crabs also breathe when they sleep, put the crab in the water, if you find that the crab is spitting bubbles, it means that the crab is alive and sleeping. However, if the crab does not react in the water and does not breathe bubbles, it means that the crab is dead.

When the crab sleeps, if it touches the crab's pincers or body, the crab will shrink its pincers and wake up and start moving. And after the crab dies, the body will not have any reaction.

The crab's eyes are retracted when sleeping, and when you touch it with your hand, its eyes will turn slightly. But when the crab dies, its eyes become completely unresponsive, and its eyes seem to be covered with a layer of gray and dull.

minus 5 will cause the crab to freeze to death. This animal lives in water, and usually when the surface of the water freezes, the temperature under the water is not very low, so it is not very cold-tolerant, and can only survive when it is above 0. When the temperature is 3-5, it will stop eating and enter a dormant state, and its feeding ability will be weak below 10, and it will be able to carry out various activities normally above 15.

No, people will use ice to maintain the temperature during the transportation of seafood. Because the temperature is low, the crab will enter a state of hibernation, and when the temperature is normal, the crab will wake up naturally.

About minus five degrees.

If it is refrigerated at low temperature (below minus 18 degrees) it is edible, but you will find that the crab is very fat, because the Mid-Autumn Festival is the time when the crab is in season, and the water in the frozen crab meat will crystallize and expand and puncture the cell wall, and after thawing, the water will be lost with heating, and it will feel that the meat quality of the crab is obviously firewood, so it is best not to freeze the crab, try to eat it at one time, refrigerate it at 0-4 degrees after steaming, and eat it as soon as possible, but it must be heated thoroughly when you eat it again, This is because seafood is more susceptible to microbial contamination.

Dormant crabs can be distinguished by appearance, taste and hardness, dormant crabs will continue to spit out white bubbles in their mouths because of breathing, and their abdomen is hard, and their eyes will naturally bounce when pressed down, while dead crabs will not spit foam, their abdomen is softer, and they will also emit a fishy smell, and even flow black liquid.

1. Appearance distinction

Crabs can distinguish between dormant and dead by their appearance. Crabs in the dormant stage, which can still breathe, can be put into a basin with water, and the bubbles that are clearly spit can be seen, while the dead crabs cannot spit out bubbles and do not move when placed in the water.

2. Taste differentiation

Crabs can distinguish dormancy and death by taste, the dormant crab has a lighter taste, and the overall appearance is a salty and fishy taste, while the dead crab will emit an unpleasant fishy smell, and after a long time, the smell will become more and more obvious, and the crab will even shed black liquid in the body.

3. Hardness differentiation

Crabs can distinguish between dormancy and death by their hardness. The dormant crab is more energetic, the shell and abdomen are harder, and the navel will retract when the navel is opened, and the eyes will naturally bounce when pressed down, while the dead crab begins to rot inside, and the abdomen is softer, and there is no reaction to touching its eyes or abdomen.

Cause Analysis:

1. Mosquitoes will bite the eyes of crabs, the eyes of crabs are extremely difficult to repair by bacterial infections and lose their antibacterial ability, all the nervous system of crabs are in the eyes, mosquitoes use toxic straws to insert directly into the eyes of crabs, not only destroying its nervous tissue, but also toxins will enter its body.

2. The joints and eyes of the crab are not protected by the carapace, and the shed is easy to be bitten by mosquitoes, so when the crab is on the shore, it will become the target of the mosquito, and the mosquito will suck blood on the joints or eyes of the crab, and the crab will be bitten by the mosquito many times, which will lead to the death of the crab.

Crabs (páng xiè) belong to the class Mollusca, decapod, and are crustaceans whose bodies are protected by a hard shell and breathe by gills. Taxonomicly, it is the same animal as shrimp, lobster, and hermit crab.

Habits. A small group of crabs breed entirely in freshwater, and they mostly inhabit the rocks of mountain streams. There are also a few crabs, such as ground crabs, that can adapt to life on land, burrowing in damp mud holes, and migrating to the sea during the breeding season. The vast majority of crabs are omnivorous.

Some crabs are carnivorous, such as pike crabs, which can prey on fish, shrimp and molluscs. Crabs, such as the crab, scrape or filter feed on algae and organic detritus.

The above content refers to Encyclopedia - Crabs.