Crabs are crustaceans (crustaceans) whose bodies are protected by hard shells. In biological taxonomy, crabs are considered to be in the same category as shrimps, lobsters, and hermit crabs. The vast majority of species of crabs live in or near the sea, but there are some that inhabit fresh water or live on land.

Wherever they live, they breathe. How do crabs breathe? The breathing organs of crabs are called gills.

How do crabs reproduce the next generation? They rely on the mother crab to give birth to baby crabs, and each time the mother crab lays a lot of eggs, which can number millions or more. After these eggs hatch in the abdomen of the mother crab, the larvae can be detached from the mother's body and float around with the coastal currents. After a few retreats, they grow into large-eyed larvae, which then grow into juvenile crabs after a few retreats, which are almost identical in appearance to adult crabs, and after a few more retreats, they become crabs. Most of the marine crabs are eggs that mature and are discharged directly into the ocean without hatching.

The hard shell of the crab protects the crab from predators, but the shell does not expand as the body grows. So the crab growth is intermittent, that is, after a period of time, the old shell molted body will continue to grow. The largest crab on Earth is the spider crab, whose legs spread out to a width of 3.7 meters, and the smallest is the bean crab, which is less than half a centimeter in diameter.

The crabs may be small, but they have all the essentials. After removing their hard shells, we can see that part of the crab's body is protected by a layer of shells that resemble shields, which biologists call the carapace.　The body of the crab is symmetrical and can be divided into the frontal region, eye region, heart region, liver region, stomach region, intestinal region and gill region. The crab has appendages (appendages) attached to each side of the body. The appendages on the head are called antennae, which have tactile and olfactory functions, and some appendages have mouth functions, which are used to tear food and deliver it into the mouth.

The crab has five pairs of appendages in the thorax, called thoracic legs. A pair of appendages located in front of the strong-shaped chelipeds, can be used to forage for food, the remaining four pairs of appendages is the crab's feet, the crab walks to move to rely on these four pairs of appendages, they walk in a unique and interesting appearance, most of them are walking horizontally rather than straight ahead. The exception is the monk crab, which walks straight.

Crabs spend most of their time searching for food, and they are not picky eaters; they will eat anything their chelae can get their hands on. Small fish and shrimp are their favorites, but some crabs eat seaweed and even dead animals or plants.

Crabs eat other animals, and other animals may also eat crabs, for example, humans eat crabs as a delicacy. There are also water birds that eat crabs! Some fish love to eat crab legs as much as humans do. When young, immature crabs swim in schools in the sea, they may be eaten by other sea creatures, which is why crabs lay so many eggs when they spawn.

River crabs eat what food how to raise

The general use of pots to raise it, the water is a little deeper or a little shallower does not matter, will not drown it. But it's best to have the water just soaked through the shell. You can let it bask in the sun, not too long on it. The water can be used tap water, but to sunbathe for a day before using.

Crabs are omnivorous.

You can feed them fish ah, whether raw or dried fish, they can accept. You may also feed them fish feed, red worms, shrimp, snails, mussels. It's best to feed them grasses regularly, bitter grass, ilex algae etc. As long as the feeding is ok,you don't need to worry about the rest. Crabs are very good to keep.

What kind of food do crabs eat how to raise

Give it fish food a grain of the kind

What do domesticated crabs eat

Crabs are omnivorous animals, if there is a condition, you can feed the red nematodes, you can feed the yolk of the egg, of course, crabs can also eat the offal of the chickens and ducks or small fish and shrimp. At the same time to feed some grass type of food. Pay attention to the amount of feeding, and it should be finished within half an hour, otherwise the remaining food will pollute the feeding water. The feeding intensity of crabs increases or decreases with the change of season and water temperature. In summer and fall as the water temperature rises above 15℃, the feeding ability of the crabs is enhanced, and then feeding is done once a day. When the water temperature drops below 15℃, the feeding ability of crabs decreases, and feeding can be done once every other day or several days. It is better to feed the crabs in the evening, because the crabs are diurnal aquatic animals.

How to raise crabs? What do crabs eat? 30 points

Do you mean mass raising, or just a few?

For mass raising, you need ponds, scientific feeding!

For just a few, you can keep it in a pot, but the water shouldn't be too deep, and it's best if the eyes can show through the water if you stick them out. But it's best if the water is just soaked through the shell. You can use tap water, but you need to sunbathe for a day before you use it.

Crabs are omnivorous.

If you have the conditions, feed live red nematodes, you can also feed egg yolk. (Pay attention to the amount of feeding, eat within half an hour shall prevail, can not eat will make the water dirty).

You can also feed them fish, sea crabs can be fed chicken and duck offal or small fish and shrimp, whether raw fish or dried fish, they can accept.

You can also feed them fish feed, red worms, shrimp, snails, mussels.

What do crabs eat? Domesticated ? A

I hope the contents of the feeding manual will be helpful to you.

1. Before feeding

For the first time, please give them a 1-2 minute saltwater bath with salty warm water to remove parasites or lice organisms, and set up a water bowl, shelter and bottom sand with 1-2 teaspoons of calcium salt (they will take up the required salt from the sand directly). New crabs usually burrow into the sand for a few days to weeks to adapt to the new environment, they may not be very active or not eating at this time, wait for them to familiarize with the sand in your house, don't put them on your hand at this time to minimize disturbing them, put them in some darker and quieter place, maintain the food changed every day and the proper temperature and humidity.

2. Sunlight, ventilation, and hidden objects

Try to find a location close to a window or a place where the sunlight can shine diagonally. But not to the point of direct sunlight. Put the tank at a lower level, with the highest edge of the tank right at the bottom edge of the window. The arrangement should be a little more sheltered, especially a hut, to suit their habits. Hermit crabs are very timid, and a hut makes them feel safe, and they themselves are very fond of resting inside during the day.

3. Terrarium

A terrarium provides a comfortable environment for hermit crabs to live in and can be made of plastic or glass. The plastic box has a lid and a certain height to prevent escape, and there are holes in the lid for proper ventilation, plus the lid can be closed tightly to retain heat and moisture.

4. Space

The rearing tank should be lined with bottom sand so that they can have a suitable place to hide and shed their shells. The depth of bottom sand in the tank should be at least 1 to 2 times of the height of the body in the tank (at least 5-7cm), and the thickness of the sand should be about 2-3mm, if the sand is too young it will be ingested into their shells, and if the sand is too thick it will not allow them to return to the surface of the sand after they molt. There should be space for shelter and water bowl, and enough space for them to walk around. If you want to make more space in the tank, you can put some climbers or driftwood in the tank for them to climb.

5. Different sizes of individuals

If you keep both large and small individuals in the same tank, you should be careful to watch out if the large individuals will attack the small ones, if this happens, please keep them separately.

6. Backup tanks

If you have too many land hermit crabs (more than 6 crabs in 1 foot tank), you should prepare 1-2 backup tanks as a shelter for the molting crabs. For example, if an individual is found to be showing signs of molting, they can be placed in another tank. Alternatively, the reserve tank can be used as a treatment room for individuals that are sick or stressed and cut themselves.

7. Cleaning

Be aware that detergents are very toxic to land hermit crabs, so never use detergents such as dishwashing liquid or lye when cleaning the tank. In summer, bacteria can breed easily, so you can clean more frequently, but in winter, you don't need to clean so frequently. On average, clean the tank once every 2-3 months. If you notice any odor or insects, you should clean the tank as soon as possible. Before cleaning, you should pay attention to whether any individual hermit crab is missing from the tank. If there is a missing individual, it means that the individual is hiding in the sand and may be about to molt, then you should stop cleaning the tank. Prepare a plastic tank and let the hermit crabs bathe in warm water with calcium salt, the depth of the water is the same height of the conch shell. When bathing, we put the snail shell mouth side up, put them into the water, let them walk in the water for 1~2 minutes and then pick them up.

8. Temperature and humidity

Since hermit crabs live in subtropical areas, the temperature should be maintained at 20-30 degrees Celsius, and when it is at 15 degrees Celsius, their movements will start to slow down, and they will die if it is below 10 degrees Celsius. You can use heat blankets or ultraviolet lamps to keep the tank at 26-30 degrees Celsius. Since hermit crabs breathe with gills, they can not breathe when the humidity is low. Please maintain the humidity at 60-80%, and use water with calcium salt (not tap water with chlorine) to spray manually 2-3 times a day in the morning and in the evening.

9. Food

Land hermit crabs are nocturnal, so it is best to feed them after 10pm. Change the food every day. Land hermit crabs usually use their front chelicerae to look for organic matter in the sand, so they can be fed with rice, bread crumbs, eggs, fruits and vegetables, fish feed, etc. It is also good for corn and popcorn. It also has a special fondness for corn and popcorn. If after molting you can give them more calcium and protein foods such as meat, fish, eggshells, cooked shrimp (with shells) and other foods.

Do not give them onions, food containing mustard, spicy food, processed food with preservatives or additives, sugar, food containing a lot of oily food, food containing the effect of insect prevention, vegetables and plants containing insecticidal effect.

10. Drinking water

Mineral water, distilled water or cooled water can be used, do not give tap water containing chlorine, land hermit crabs use gills to breathe, and water containing chlorine will harm their health. You need to use 2 water basins to put fresh water separately (......)

What do domesticated crabs eat?

Crabs are omnivores that favor animal bait. In the bait feeding, the strict implementation of the "four fixed four see" scientific baiting method, mastering the "pre-fine, middle green, meat and vegetable collocation" principle. Feeding 1 time in the morning and 1 time in the evening, the daily feeding amount generally accounts for 3-4% of the body weight of river crabs, and it is appropriate to finish eating within 1-2 hours. In the early stage of stocking, animal bait is the main species of fresh live fish, snails and mussels, etc., and then gradually increase the amount of feeding plant-based concentrate feed, such as wheat, maize, soybean meal, etc., the high temperature season, do not cast animal bait, less cast plant-based concentrate bait, and more cast green and coarse fodder, such as watercress, pumpkin, potato, etc., to enter the late stage of culture, for the crab to promote the fattening weight gain stage, should increase the amount of plant-based concentrate feed and animal feed. The bait should be increased to ensure that the crabs are well-fed and eat well.

What do crabs eat? I have a few crabs, but I don't know what to feed them.

Crabs are omnivores, and they will eat anything, such as bread crumbs, rice crumbs, small fish, shrimp and so on. Wild crabs generally eat some planktonic plants and animals, and artificial feeding crabs, mainly fed with specialized feed.

How to raise live crabs

The life of the crab is short, in its life history through the flea-like larvae, big eye larvae, juvenile crabs and adult crabs and other stages. The following is a brief introduction to crab culture technology:

(a) button crab cultivation: choose good water quality, adequate water; injection, drainage is convenient, no leakage, no seepage, less silt pond, the area should not be too large, sunny, greenhouse construction can be referred to the construction of agricultural vegetable greenhouse construction methods. Cultivate basic bait, transplant water plants (which must be strictly sterilized) and set up necessary escape prevention facilities. Crab seedlings can be appropriately shallow when entering the pool. It is conducive to raising the water temperature and the growth of algae and water plants in the water. Feed bait every day and always pay attention to the weather, water sanction, individual growth, the amount of bait-competing organisms depends. With the growth of young crabs should also increase some plant bait, pay attention to water quality regulation in daily management, to master the water quality is fat and fresh, change water should be changed diligently and less change, do not cause drastic changes in water temperature and water level. After about 2 months of cultivation can reach the button crab.

(B) adult crab culture: adult crabs like clean water, greater transparency of the water environment, aquatic plants, bait rich, most of the current ponds, lakes, river swings and rice paddy farming. Now the pond as a simple introduction:

1, pond conditions water, easy access to drainage, good water quality and pollution, choose clay, sandy soil or sandy soil, good ventilation, is conducive to the growth and reproduction of aquatic grasses and benthic insects, snails and mussels, earthworms, etc., the old pond should be thoroughly desilted, the pond area should not be too small. Pond can be built several slightly above the water surface of the mound, that is, the crab island, the island can be transplanted aquatic plants, the pond should not be too steep, otherwise, the river crab is easy to dig holes, and is not conducive to the evening climb out of the water activities. Artificial burrows can also be built.

2, transplantation of water plants: the natural production of river crabs depends mainly on the amount of water plants and benthic organisms (bait organisms) in the waters. It is an indispensable technical measure to plant water plants in the breeding process. Planting water plants in addition to vitamin supplementation for crab feeding ten years, but also can be raised to fight each other, the role of hiding, is to improve the survival rate of river crabs during the period of a powerful measure, in addition to absorbing harmful ammonia nitrogen in the pool, carbon dioxide, organic matter, the release of oxygen, stabilizing the role of the water quality. The masses often say "crab size, look at the water plants". Therefore, for the pond culture of river crabs must make great efforts to plant good water plants, water plants of our categories are mainly duckweed, full of red, water hyacinth, water flora, rotunda black algae, goldfish algae, bitter grass, aquatic peanuts, etc., and pay attention to the transplantation of disinfection and prevention of pests.

3, anti-escape facilities: anti-escape facilities are mostly plastic film, there are also cement boards, depending on their respective situations.

4, pond disinfection: generally half a month before the release of seedlings with quicklime pond disinfection, the amount of 75 kg per mu. On the one hand, it can kill hostile organisms, on the other hand, it can improve the bottom of the pond, increase the content of calcium ions in the water, and promote the growth of moulting of river crabs. Na water should be fertilized in time, cultivate algae and basic bait, transparency is generally maintained at 40-50cm is appropriate, if you find a tadpole or frog eggs should be removed in time, so as not to compete for food, for the harm of young crabs.

5, put seedlings: seedling purchase, to the Yangtze River water system production of crab seedlings is preferred, the requirements of neat specifications, step foot complete, robust, crawling active, no injury and no disease.

To successfully breed crabs, the prerequisite is to familiarize yourself with the habits of crabs, which requires a certain amount of effort.

What kind of food do crabs eat

Crabs are omnivores, feeding on aquatic plants, benthic animals, organic debris and animal carcasses.