CATDOLL : CATDOLL: How to keep crabs alive?

How to keep crabs alive?

1. Feeding management of crabs. River crabs like to eat fresh food. Therefore, in daily feeding management, it is forbidden to use feed that has been stored for a long time and deteriorated. At this stage, meat feed should still be the main feed, and some nutritious vegetarian feed should be used in moderation, especially more plant feed, so as to ensure good water quality in the pond.

The frequency of feeding should be determined according to the changes in climate temperature. In hot summer, feeding once or twice is sufficient. The specific amount depends on the weight of the crab. If there are any uneaten residues, they should be salvaged immediately to avoid deterioration and affect the water quality.

2. For crab breeding management, strengthen daily feeding management and implement daily inspections. Inspect at least 1-2 times a day, once in the morning and once in the evening, and pay attention to the foraging of river crabs. When abnormal conditions occur, check immediately for diseases and take symptomatic medication to avoid the spread of infectious diseases that affect breeding benefits.

As the number of aquaculture increases, water hypoxia often occurs. Water changes and oxygenation should be done in a timely manner to reduce the high mortality rate caused by hypoxia. In addition, the pond should be checked for leaks and blocked to prevent the invasion of natural enemies and avoid escape.

3. Disinfection management of crabs, remove germs and bacteria in the pond, and create a good breeding environment for healthy river crab breeding. Pond disinfection management should be done before and after breeding. Before the young crabs enter the pond, they should be disinfected in advance, and the silt in the pond should be cleaned in time in winter. During the breeding management process, the disinfectant selected should be low in toxicity and fast in volatility to avoid environmental damage caused by disinfection.

Extended information;

Crab's living habits

1. Foraging

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

2. Competition

Crabs eat other animals, and other animals may also eat crabs. For example, humans regard crabs as delicacies. Water birds also eat crabs. Some fish also like to eat crab legs, just like humans. When young crabs float in the sea in groups, they may be gobbled up by other marine creatures. Therefore, crabs lay a lot of eggs when they spawn.

3. Reproduction

They rely on the mother crab to give birth to the crabs, and each time the female crab will lay a lot of eggs, the number can reach millions or more. After these eggs hatch in the abdomen of the female crab, the larvae can separate from the mother and float everywhere with the coastal tide.

After several molts, they grow into big-eyed larvae, which molt several more times to become juvenile crabs. The juvenile crabs look almost the same as adult crabs, and after several more molts, they become crabs. Most marine crabs are released directly into the ocean after their eggs mature without hatching.

Reference source: Baidu Encyclopedia - Crab

How to raise crabs and hairy crabs?

Don't let the water cover the crab's shell, and it's best not to let the water cover the crab's mouth, otherwise it will easily drown.

Pay attention to water changes.

Crabs like to eat small fish and shrimp.

After cutting, you can feed the crabs raw. Or you can cook wheat or corn kernels and feed them

No need to eat professional feed, which is full of hormones and additives

Raw corn kernels can be purchased in large supermarkets, and just a little bit is enough.

However, in winter, crabs generally like to eat fish and shrimp.

If there are no small fish, it will be difficult to keep them alive.

Crab farming technology?

Conditions for crab breeding ponds:

Convenient transportation and quiet environment; abundant water resources, good water quality and no pollution, convenient drainage and irrigation; flat pond bottom and the slope ratio of the pond bank is 1:2.5-3.

Escape prevention facilities:

There are mainly three types of fences: cement brick wall, calcium plastic board fence, and polyethylene mesh fence. At present, calcium plastic fence is widely used. The calcium plastic board is buried 20 cm in the soil along the ridge and compacted, and fixed with wooden stakes at intervals of 1 meter.

Sterilization and pond cleaning:

Remove excess silt, leaving only about 10 centimeters of silt, and sprinkle the entire pond with quicklime, using 200-250 kilograms per mu, to achieve thorough pond cleaning and disinfection, remove weeds and weeds, kill pathogens, and improve bottom quality. Rinse the pond once 7 days after applying the medicine to remove dirt, then add water after drying the pond for 3-5 days.

Suitable aquatic plants for crab ponds:

To raise crabs in a pond, you must first plant a good pond grass. Water grass is one of the natural baits that river crabs like to eat. It can also play a good role in purifying water quality. It is also a place for river crabs to live and avoid enemies. The area of ​​water grass should account for more than 70% of the pond area. The main varieties are Hydrilla verticillata, Vallisneria, Elodea, etc. Hydrilla verticillata and Elodea are mainly transplanted and cuttage, while Vallisneria is planted by sowing.

It is advisable to put snails in the crab pond:

Snails are one of the natural baits that river crabs like to eat, and they can also purify water quality. Before stocking crabs, we will contact the market and put 300-500 kg of fresh snails per mu to cultivate the basic bait for river crabs.

Crab species selection:

It is advisable to choose Chinese mitten crabs from the Yangtze River system that are of uniform size, have complete appendages, are free of disease and injury, and are agile in movement.

Reasonable stocking of crab ponds:

Generally, crab seed stocking should achieve "three suitability" and "one temporary stocking", namely, appropriate density, timely stocking, moderate specifications and temporary stocking before stocking. The stocking density of crab seed is generally about 500-600 per mu, so that river crabs have sufficient living and growth space. The stocking time of crab seed is generally from the end of February to March each year. If the stocking is too early, the winter casualties will be heavy. If it is too late, the water temperature will rise and some river crabs will molt, which will affect the survival rate of the pond. The stocking specification of crab seed is preferably 100-200 per kilogram. If the specification is too large, each first molting will be difficult and the damage will be heavy; if the specification is too small, the growth base will not be large, which will affect the listing specification. "Temporary stocking" of crab seed is a necessary transition stage before the stocking of crab seed. A "temporary stocking area" must be set up in the pond first. The length of the temporary stocking time should be determined by the water temperature and the growth of aquatic plants in the pond. The temporary stocking area is about 1/5 of the stocking area.

Scientific and reasonable feeding:

River crabs are omnivorous animals that prefer animal bait. In terms of feeding, the scientific feeding method of "four determinations and four observations" is strictly implemented, and the principle of "fine in the early stage, green in the middle, and a combination of meat and vegetables" is mastered. Feed once in the morning and evening, and the daily feeding amount generally accounts for 3-4% of the river crab's body weight, and it is best to eat it within 1-2 hours. In the early stage of stocking, animal bait is the main feed, and the main varieties are fresh live small fish, snail and clam meat, etc. Later, the amount of plant concentrate feed, such as wheat, corn, soybean meal, etc., is gradually increased. In the hot season, no animal bait is fed, less plant concentrate feed is fed, and more green roughage is fed, such as water plants, pumpkins, potatoes, etc. In the late stage of breeding, it is the stage of promoting fat and weight gain for river crabs, so plant concentrate feed and animal bait should be increased to ensure that the river crabs are full and well fed.

Crab pond water quality control:

Generally, the water depth is maintained at 0.6-0.8 meters, and is adjusted to 1-1.2 meters in high temperature seasons. Water quality regulation focuses on three aspects: First, frequently change the water, generally change the water every 7-10 days, inject 10-20 cm of water every day when the temperature is high, and change the water every 3 days. Second, adjust the pH value of the water body, generally control the pH value between 7.5-8.5. Quicklime is mainly used for regulation, and the whole pond is poured once every 7-10 days, and the amount per mu per meter of water depth is about 10-15 kilograms. Third, photosynthetic bacteria are used to regulate water quality, with a dosage of 3-5 kilograms per mu, and poured throughout the pond to transform harmful substances such as ammonia, nitrogen, and hydrogen sulfide in the water body and control the growth and reproduction of harmful bacteria.

Crab fishing:

Generally, in October, the fish are caught and put on the market in due time according to the temperature and market conditions, and the main tool is ground traps.

Freshwater crab breeding technology

Crab farming technology

Ecological breeding technology of crabs

Crab reservoir enclosure culture technology

Gucheng Lake Crab Ecological Farming

Healthy breeding technology of river crab

River crab breeding technology

The technology of breeding adult river crab

Prevent escape.