My Deep-sea Fishery

In addition, large yellow croaker is a warm and humid nearshore migratory fish that often lives in the middle and lower layers within 60 meters of water depth and is extremely difficult to catch.

But compared with bluefin tuna, large yellow croaker is still far behind.

The most important thing is that the large yellow croaker has been cultivated artificially.

Although the breeding conditions are very harsh.

The breeding pond should be a rectangular pond with an east-west direction, with an area of ​​more than 6 acres, which can maintain a water depth of more than 2.5 meters, and the bottom of the pond should have a certain **** toward the drainage outlet. The bottom quality should be sandy and muddy.

The breeding site should have convenient transportation, and the surrounding environment should be relatively quiet, rich in fresh water resources, and convenient for water supply and drainage.

Generally, a large yellow croaker culture pond needs to be equipped with at least two 1.5-kilowatt waterwheel type aerators and one 1.5-kilowatt jet-type aerator.

In addition, the environment of the production area surrounding the aquaculture pond needs to comply with the relevant regulations of the Environmental Standards for the Production Area of ​​Non-polluted Aquatic Products, and the water quality for aquaculture should comply with the relevant regulations such as the "Water Quality Standard for Fisheries" and the "Water Quality for Freshwater Aquaculture of Non-polluted Food".

But no matter how harsh the conditions are, mankind has a way to achieve it.

However, with the success of large yellow croaker farming technology over the years, the price of large yellow croaker has not fallen much.

Whether it is the large yellow croaker whose seed has been desalinated or the real seawater large yellow croaker, the price is extremely high.

In fact, it is more difficult to breed large yellow croaker than most people think.

It is said that the steps before raising large yellow croaker are extremely complicated, and the pond must first be cleaned and disinfected.

Before the fingerlings are stocked, the entire pond should be drained, and the bottom of the pond should be exposed to the sun for a period of time to remove excess silt.

Fifteen days before stocking large yellow croaker fry, it should be thoroughly disinfected with quicklime, and the pond should be cleaned with water, and 150 kilograms of quicklime per acre should be sprinkled in the whole pond.

Drugs such as tea cakes and bleaching powder can also be used to disinfect the pond.

The drugs used for disinfection in Qingtang should comply with the relevant provisions of the "Guidelines for the Use of Non-Pollution Food and Fishery Drugs".

The food domestication of large yellow croaker fry is even more important in farming large yellow croaker.

First, the bait must be domesticated. The first choice is fresh low-value fish and surimi processed by coastal small fish and shrimp, mixed with eel feed to make compound feed for feeding, and then gradually increase the artificial compound bait and reduce the amount of surimi. Until the artificial compound feed is completely fed.

In the bait domestication stage, workers are required to place feed at fixed points and at regular intervals, and bait signal training is also required, that is, a fixed signal is sent before bait is cast to allow the fish to form a conditioned reflex and make them accustomed to feeding in groups.

If the domestication is not successful for half a month, these large yellow croaker will basically starve to death.

The desalination of large yellow croaker is not simple, and many fry will die in the process.

Desalination treatment is to gradually add fresh water to the nursery pond to reduce the specific gravity of the pond water and adapt the seedlings to grow in fresh water.

The gradient change of salinity during desalination has a significant impact on the survival rate of large yellow croaker. The larger the gradient and the longer the desalination time, the lower the survival rate of large yellow croaker fry.

Generally, it takes 7 to 10 days of desalination. When the salinity of the pool water reaches below 2‰, the seedlings can be put into the pond to grow. This process is not a painstaking effort.

And so far, it's not over yet.

When the stocked seedlings are free of disease, injury, deformity and strong mobility, the stocking density should be determined according to the pond conditions and technical level.

The bait selected during the entire breeding process must be a marine fish compound feed, and the farmers need to feed it twice a day.

Before feeding bait, it is necessary to send a fixed signal to let the fish form a conditioned reflex to make them accustomed to feeding in groups. Feed the bait from less to more. You can hear the "cooing" sound of large yellow croaker in the water. When the sound grows from small to loud, it proves that the fish has entered the food court and eaten. When the fish is full, the sound gradually disappears.

The daily feeding rate is 7-8% of the fish's body weight in the early stage, and 3-5% of the fish's body weight in the middle and late stages.

Bait feeding should be carried out in strict accordance with the "four fixed" principle, and the amount of bait must be adjusted appropriately according to the situation of the remaining bait, in combination with the weather, water temperature, water quality, and fish activity.

In order to increase the survival rate of large yellow croaker, farmers also need to regularly add aquatic multi-dimensional, astragalus polysaccharide, three yellow powder and other drugs to the bait to prevent the occurrence of diseases.

In addition, the bait eaten by cultured large yellow croaker is not cheap, and all the bait it eats should comply with the relevant regulations of the "Safety Limits of Non-polluted Food and Fishing Compound Feed". The drugs used should comply with the relevant provisions of the Guidelines for the Use of Non-Pollution Food and Fishery Drugs.

Water quality also directly affects the normal growth of large yellow croaker. Only by adjusting the water quality can it promote the normal growth of large yellow croaker, effectively prevent the occurrence of diseases, increase the production of aquaculture, and achieve the purpose of increasing production and income in aquaculture.

The water quality for feeding large yellow croaker requires freshness and does not need to be too fat.

In the initial stage of stocking fingerlings, the water level is about 70-80 cm. After that, fresh fresh water 5-10 cm is added to the pond every 2 days, and the water is not changed until the highest water level is reached.

The water level is relatively low in early spring and late autumn ~www.readwn.com~, which helps to increase the water temperature.

Increase the water level as much as possible in summer and winter.

The most important thing is that the water needs to be changed every 2 days. The amount of water change is 14 to 13 of the whole pond. It is very troublesome for most people to even change the water.

When the water temperature is lower than 13°C, basically do not change the water.

When the water temperature is higher than 28℃, the water needs to be changed every day. The amount of water is about 13. In the summer high temperature season, the water is drained in the afternoon and the water is in at night. This can stimulate the water, increase the appetite of the large yellow croaker, and shape the body color of the large yellow croaker.

All these difficulties have always caused the price of large yellow croaker to remain high.

As for the wild large yellow croaker?

It has long been included in the "World Conservation Union Red List of Endangered Species".

Large yellow croaker was once an important economic fish species in my country's oceans. In history, it was once listed as one of the four major marine fisheries along with small yellow croaker and cuttlefish.

In 1974, the output of large yellow croaker was as high as more than 200,000 tons. However, due to the development of boat knocking fishery in the 1950s, the fishing of unspawned broodstock in the 1960s and 1970s, the excessive use of wintering grounds and the fishing of juveniles, the resources of large yellow croaker were rapid. In decline, the output of the East China Sea in 2000 was only 9,035 tons, and Guanjingyang, Maotouyang, and Dayuyang were unable to form fishing floods.

This is impossible, because the economic value of large yellow croaker is too high.

The meat of large yellow croaker is fresh and tender and rich in protein. It is a good product for fresh food. It is not only freshly sold, canned and processed into "melon-raised croaker" and "croaker", but also can be used comprehensively.

The maw of large yellow croaker can be dried into various valuable foods, such as "fish maw", and it can be made into yellow fish glue, which is the raw material of high-grade adhesive for industrial use.

In addition, large yellow croaker has certain medicinal value and is the raw material of some Chinese and Western patent medicines.

The swim bladder of large yellow croaker can be made into Chinese medicine, which has an immediate effect on the treatment of sinusitis.