CATDOLL : CATDOLL: How to use shallow water ponds to raise fish?

1. How to use shallow water ponds to raise fish?

With the rapid development of aquaculture, ponds are being used more frequently and the siltation at the bottom of ponds is becoming more and more serious, especially in village ponds, which has caused many water bodies to be too shallow and the aquaculture space to be narrow. If these ponds are not renovated and repaired, the aquaculture environment will deteriorate.

1. Determine the appropriate breeding type

. Ponds with a water depth of less than 1.0m can be slightly modified to breed eels and loaches. If there is too much sludge at the bottom of the pond, cash crops such as lotus roots can be planted to absorb fertilizer, and a small amount of fish can be bred in the pond. In addition, according to the habits of the farmed fish, fish that grow fast, have a short growth period, are not demanding on pond conditions, and can adapt to living in shallow water can be selected for breeding, such as tilapia, carp, crucian carp, freshwater silver pomfret, etc., which are available for breeding.

2. Efforts to expand water space

The size of the aquaculture water space directly affects the growth and survival of the aquaculture species. If the water level is too shallow, the aquaculture water space will inevitably be relatively small. When stocking fish, a certain stocking density should be mastered. In principle, sparse stocking is the main method, which can relatively increase the aquaculture water space. In the use of aquaculture water, the water level should be kept stable for a long time according to the needs of the aquaculture species. At ordinary times, attention should be paid to filling the pool with water to maintain the highest water level. When the water level drops, new water should be added in time. The low-lying areas on the bank of the pool can be filled with hard soil to try to raise the bank surface, expand the aquaculture water space, and maximize the use of the aquaculture water.

3. Improve the aquaculture water environment

Shallow ponds are greatly affected by the environment due to their shallow water level, especially the obvious changes in water temperature. To change this situation, breeders should take corresponding technical measures according to the different seasons of the year. For example, in spring and autumn, appropriate shallow water in the pond is conducive to the increase of water temperature, which is convenient for aquatic plants in the water body to carry out photosynthesis, increase the natural basic bait organisms of the cultured species, and also help to start feeding early and stop feeding late, which can promote the rapid growth of the cultured species; in summer, the water temperature is high, the water level should be deepened as much as possible, and the cultured water should be changed frequently to regulate the water quality and control the water temperature; when the hot summer comes, measures should be taken to avoid the heat. Where conditions permit, a shed can be built by the pond to provide shade. The simple method is to cover the water with grass, or plant aquatic plants in the pond and around the pond to purify the water quality and regulate the water temperature; in winter, the water temperature drops, and when the cultured species reaches the specifications of commercial fish, they should be sold as soon as possible and try not to overwinter. If you raise eels and loaches in the pond, you can drain the pond water before the ice period comes, let them dive into the mud bottom, and then lay straw on the mud to protect them from the cold.

4. Strengthen daily management

Shallow ponds should be managed more strictly. In addition to paying attention to changes in water quality, ponds should be patrolled frequently, and problems should be solved promptly. Especially in the rainy season in summer, attention should be paid to preventing rainwater from flooding the pond and destroying the bank. Due to the shallow water, attention should be paid to the lack of oxygen in the pond in summer, which may cause flooding. At night, theft should be prevented to avoid accidental losses. In terms of feeding, it is necessary to ensure that the farmed species are well fed, adhere to the principle of small and frequent meals, and feed more feed that the farmed fish like to eat.

, in order to maintain a reasonable supply of nutrients and ensure the same year of investment and the same year of profit. Fertilizer and water should be applied in time when needed.

, to ensure the abundance of natural basic bait organisms in the aquaculture water. When the aquaculture species reaches commercial specifications, once the price is reasonable, they should be caught and sold to obtain profits as soon as possible and avoid and reduce aquaculture risks.

5. Do a good job in disease prevention

In shallow ponds, the water quality is easy to deteriorate, which accelerates the reproduction and growth of pathogens in the water body. If you don't pay attention, it will cause the death of the farmed species. Therefore, disease prevention work should be done in time. In the early stage of farming, the pond bottom should be thoroughly cleaned with quicklime. Because there is more silt in shallow ponds and the bottom is more acidic, the dosage can be slightly increased. It can be sprinkled all over the pond at a dosage of 300g/square meter to adjust the pH value of the farming water body and improve the water quality. When the seedlings are released, they should be disinfected in vitro, and salt water can be used for immersion and medicinal bath. In daily management, quicklime, bleaching powder and other drugs should be used regularly to disinfect the water body and purify the water quality. Pests such as rats and snakes should be captured by artificial methods, and try not to let them invade, otherwise they will be injured by pests due to the shallow water and the farmed species cannot escape.

2. Can fish that breed in rivers be raised in ponds?

OK

1. First of all, check whether there are industrial manufacturers upstream and downstream of the river. Because if there are industrial manufacturers upstream and downstream of the river, they will discharge industrial waste into the river. Even if it is treated, it will still cause a certain degree of pollution. Therefore, it is not recommended to set up farms near industrial production plants.

2. Secondly, pay attention to the growth conditions of surrounding farmland. If the farmland is in the prevention or treatment stage of certain pests and diseases, pesticides will be used, and pesticide residues will flow into the river with irrigation discharge. Therefore, it is not recommended to set up farms near farmland.

3. Pumping and drainage should be carried out in rivers in two different basins as much as possible.

4. The farm should set up a reservoir, which should occupy about one tenth of the total breeding area. After the river water is input, 2-5ppm bleaching powder should be sprayed on the whole pond to mix evenly, and the aeration pump should be turned on and turned off after about 24 hours. Wait for the reservoir to settle and the volatilization gas to evaporate for 3-5 days before it can be used for breeding.

5. Finally, observe whether there are any farmers nearby, because some farmers’ ponds are diseased and if the water discharged after spraying pesticides is used, it may cause cross-infection of fish in their own ponds and cause disease.

3. How should rotifers be controlled in pond aquaculture?

Regarding the prevention and control of rotifers, I would like to express my own views and hope that my answer can help you.

① First, let me introduce the biological habits of rotifers

Rotifers are small zooplanktons, with a size of 100-300 microns. There are many species, including Brachionus plicatilis and Crystalline cysts. Rotifers are ciliates, with a strong tolerance to low oxygen. They feed by filtering or predation, mainly on microorganisms, small algae, protozoa, and organic particles.

② Next, let’s talk about the harm of rotifers

Due to the extremely high reproduction speed of rotifers, they can devour most of the algae in a very short time, while consuming a large amount of oxygen. Fish and shrimp will die of lack of oxygen in a short period of time. After the death of fish and shrimp, the decomposition will accelerate the deterioration of water quality. If the breeding density is high, the water quality of the breeding waters will seriously deteriorate, which will cause very large direct or indirect losses to the breeders.

③ The main cause of rotifer occurrence

The water quality in the aquaculture area is seriously polluted, which is suitable for the reproduction of rotifers. When the pond is filled with water, rotifers enter the pond along with the water, and then reproduce in large numbers when conditions are right. The main reasons for the large-scale reproduction of rotifers are:

A breeding pond is not cleaned all year round, resulting in excessive organic matter at the bottom of the pond. Due to low dissolved oxygen, harmful bacteria multiply in large numbers. These are all food for rotifers, so rotifer outbreaks are very likely.

B Some small algae in the water are mainly green algae and diatoms. Since green algae and small diatoms are small in size, they are the natural food of rotifers. Excessive organic matter will cause green algae and diatoms to reproduce in large quantities, and rotifers will have sufficient food and can easily reproduce in large quantities.

C. Irrational use of some drugs. Currently, the commonly used drugs for killing rotifers in fish ponds are mainly mancozeb drugs. These drugs have good effects in the initial use, but they are prone to drug resistance when used frequently, and they kill algae seriously. At present, there are few reports on the toxicity tests of these drugs on fish and shrimp, and whether they are toxic has not been determined, so they are not recommended for use.

D. The stocking density is low. Although rotifers are harmful organisms, they are also excellent bait, especially for the fry of fish, shrimp and crab. However, if it is extensive farming with a low stocking density, when the shrimp fry's feeding rate is lower than the rotifer's reproduction rate, the rotifer will explode on a large scale.

E The shell of rotifer eggs is very strong and can withstand harsh natural environments and most drugs. According to records, rotifer eggs can survive for up to 27 years. Therefore, once a pond has an outbreak of rotifers, it is difficult to cure it, and it is likely to break out again when conditions are right.

④ Prevention and control of rotifers

A. Strictly check the water source to prevent rotifers from entering the pond with the water.

B. If conditions permit, thoroughly clean the pond. If conditions do not permit, you can use "atomic oxygen" and "full-effect bottom modification tablets" regularly during the breeding process to decompose excessive organic matter, increase the redox potential, and inhibit the excessive reproduction of pathogenic bacteria at the bottom.

C To balance the algae phase, "live fertilizer" can be used to cultivate larger beneficial algae such as diatoms and reduce the proportion of small algae such as green algae.

D. Once rotifers break out, try to use drugs with low toxicity, low irritation, and mild algae killing, such as "Century No. 1". Its main ingredients are Chinese herbal medicines, which have been found to be very effective against rotifers in recent years. It can also be used for local killing according to actual conditions.

E. According to the conditions of your own pond and the level of breeding, the stocking density should be reasonably adjusted. If the conditions are good, the number of seedlings can be appropriately increased, and the reasonable breeding of silver carp has a good effect on inhibiting rotifers.

4. What is the role of oxygenators in pond aquaculture?

When the machine is running, the impeller sucks up the oxygen-poor water at the bottom and pushes it out to the surroundings, turning stagnant water into running water.

The water under the impeller is strongly stirred by the blades and tubes, causing water jumps and waves on the water surface, forming a water curtain that can wrap up air. This not only expands the surface area of ​​the gas-liquid interface, but also makes the double membrane between the gas and liquid thinner and constantly renews, which promotes the dissolution rate of oxygen in the air.

During stirring, harmful gases in the water, such as hydrogen sulfide, ammonia, methane, sulfur dioxide, etc., are desorbed from the water through aeration and discharged into the air.

As the impeller rotates, negative pressure is formed at the rear of the agitation pipe, allowing air to be sucked into the water through the agitation pipe and immediately stirred into microbubbles that enter the impeller pressure zone. This is also beneficial to increasing the dissolution rate of oxygen in the air and improving the oxygenation efficiency.

5. What should we do if fish get enteritis in aquaculture?

Prevention and treatment of fish enteritis:

(1) Do not feed spoiled feed. Feeding with green feed can help prevent enteritis.

(2) Regulate intestinal health. Adding Yucca schidigera extract to feed can inhibit the accumulation of ammonia nitrogen and nitrite, while improving the balance of beneficial intestinal flora, enhancing resistance and preventing the outbreak of enteritis.

(3) Maintain sufficient dissolved oxygen in the water, adjust the pH value of the water, and control the water temperature.

(4) When fish enteritis breaks out, it is important to adjust the water and improve the bottom first to prevent the disease from further deteriorating. When the condition is relatively mild, use amoxicillin + doxycycline hydrochloride for treatment. When the condition is relatively serious, use florfenicol + doxycycline hydrochloride for treatment.

In short, although fish are easy to raise, if diseases are not properly prevented and controlled, great losses will be caused. We should adhere to the principle of prevention is better than cure. Long-term use of Yucca extract can effectively prevent the incidence of enteritis, improve water quality, regulate the intestines, enhance physical fitness, and ensure high yield and high income of tilapia farming!

6. How to maintain the breeding pond in fish farming common sense?

The maintenance of aquaculture ponds includes two key measures: dredging and slope protection. After winter drying, dredging and slope protection should be carried out as soon as possible to avoid affecting production next year. In addition, it is also critical to design the drainage and irrigation facilities of the fish pond. It is necessary to make the drainage and water inlet convenient so that water can be replenished and replaced in time.

7. What impact does hydrogen sulfide in ponds have on the growth of freshwater fish?

In aquaculture water, the existence form of hydrogen sulfide is mainly affected by the pH and temperature of the water. Under acidic conditions, non-ionic hydrogen sulfide is the main form, while under alkaline conditions, ionic hydrogen sulfide is the main form.

It is non-ionic hydrogen sulfide that is toxic to aquatic animals. After entering the blood of aquatic animals, non-ionic hydrogen sulfide can combine with the iron in the hemoglobin of aquatic animals, reducing the blood's ability to transport oxygen, causing difficulty in breathing for aquatic animals, and even causing poisoning and death.

At the same time, hydrogen sulfide also has adverse effects on the skin of aquatic animals.

If farmed animals live in water bodies with excessive hydrogen sulfide content for a long time, their growth rate will slow down, their immunity will decline, and they will be more susceptible to disease.

It is generally believed that the non-ionized hydrogen sulfide content in aquaculture water should not be higher than 0.1mg/l, and that in nursery water should not be higher than 0.05mg/l. It is best not to detect it. 2. Judgment of hydrogen sulfide poisoning 1. Fish gills are dark brown, gill covers are tightly closed, and blood is chocolate-colored 2. Often swims on the surface of the water 3. The dissolved oxygen in the water, especially in the bottom layer, is very low 4. Use vinegar or hydrochloric acid to acidify brown blood, and a rotten egg smell of hydrogen sulfide is released 5. The smell of rotten eggs can be smelled downwind 6. The probability of hydrogen sulfide poisoning in hydrogen sulfide test low pressure, rainy weather environment, typhoon weather, stirring of bottom mud, etc. will be much greater! 3. Treatment of excessive hydrogen sulfide in aquaculture pond water There are mainly the following measures to treat excessive hydrogen sulfide in aquaculture water:

1. Maintain an aerobic environment at the bottom of the pond to allow the organic matter at the bottom of the pond to fully decompose under aerobic conditions.

Maintaining an aerobic environment at the bottom of the pond is the main means of preventing high levels of hydrogen sulfide in aquaculture water.

During the breeding process, the breeding water of intensive ponds should not be too deep to facilitate convection between the surface and bottom water bodies; during the aquatic animal breeding cycle, oxidizing bottom modification such as potassium persulfate should be used regularly to increase the redox potential of the pond bottom; if conditions permit, bottom aeration devices can be installed at the bottom of the pond to increase the dissolved oxygen in the bottom water body; silt should be removed in time during breeding intervals to remove organic matter that has not been completely decomposed from the bottom of the pond.

2. Use photosynthetic bacteria and other microbial preparations to remove hydrogen sulfide from water bodies by utilizing the absorption and utilization of hydrogen sulfide by photosynthetic bacteria during the photosynthetic reaction.

Species of photosynthetic bacteria of the Rhodospirillaceae family can use hydrogen sulfide as a hydrogen donor and electron acceptor to carry out photosynthetic reactions in anaerobic environments, but the prerequisite is that there must be a certain amount of light. The light intensity at the bottom of most intensive ponds is relatively weak, and the photosynthetic bacteria proliferate slowly, which affects the removal of hydrogen sulfide from the bottom water of the pond.

3. Use ferrous sulfate and other iron-containing soluble compounds to react iron ions with hydrogen sulfide to form water-insoluble precipitates, thereby achieving the purpose of removing hydrogen sulfide from water. Due to cost considerations, it is less used.

4. Avoid acidification of the bottom sediment and bottom water of aquaculture water to prevent the formation of non-ionic hydrogen sulfide.

5. Avoid water containing a large amount of sulfate ions from entering the aquaculture water body to reduce the source of sulfur in the water body.

8. What are the benefits of planting aquatic plants in river crab breeding ponds?

There is a fishing proverb that "the size of the crab depends on the water plants". The success or failure of river crab farming is closely related to the quality of water plants. The grass is not only an indispensable plant bait for river crabs, but also an important place for shrimps and crabs to live, eat, shed their shells, and avoid enemies. In places with abundant water plants, there are a large number of various plankton, aquatic insects, small fish and shrimps, and shellfish, which provide river crabs with palatable animal bait. Water plants can increase dissolved oxygen in the water through photosynthesis, and can also absorb ammonia nitrogen and inorganic nutrients in the water, increase water transparency, and keep the water alkaline, which is conducive to the growth and development of river crabs. 1. Benefits: "Good grass" breeds good crabs: The coverage rate of Elodea, Hydrilla verticillata, and Vallisneria in the pool is controlled at 50%-60%. In this environment, it has multiple effects on the health of river crabs.

1. The grass is crisp, tender and tasty, rich in nutrients, and is a natural bait for river crabs.

2. Has important pharmacological effects

3. It can improve the quality and value of river crabs. River crabs grow in waters with fresh water quality, high dissolved oxygen content, dense aquatic plants, and abundant bait. They are bright in color and large in size. Their taste and price are similar to those of natural river crabs, thus achieving the goal of increasing production and income of aquaculture.

4. Submerged plants can increase the amount of dissolved oxygen in the water by photosynthesis, absorb ammonia nitrogen and inorganic nutrients in the water, and increase the transparency of the water. 5. It can protect the slope and prevent the collapse of the pond bank.

6. It can provide an ideal place for river crabs to hide, live and molt

7. It has strong reproductive and regeneration abilities, which can not only purify water quality, but also improve the bottom quality, creating a good environment for the growth of river crabs.

1. Ingredients for steamed river crabs:

6 river crabs 1 small piece of ginger 3 teaspoons of cooking wine Salt to taste

2. Steps for steaming crabs: First, rinse 6 river crabs with water and then scrub them clean with a toothbrush. In order to make the finished product beautiful, I tie it tightly with a rope so that the steamed crab legs are not easy to fall off. In order to save trouble and convenience, you don’t have to cut some ginger.

Put the crabs into the steamer, put shredded ginger on each crab, pour a little cooking wine, sprinkle a little salt, boil water, and cook on medium heat for about 25 minutes.

Then, make the sauce: chop the ginger into small pieces, add 3 teaspoons of balsamic vinegar to make the sauce. Finally, cut off the string of the steamed crab, place it on a plate and serve it on the dining table.

Everyone is welcome to leave comments!

9. What are the biological bacteria in ponds in aquaculture?

1. Bacteria: In aquaculture, bacteria are defined as important decomposers of water material circulation and energy flow, and are also the main source of nutrition for zooplankton. Therefore, the number of bacteria in the pond is actually very meaningful for the production of fish and shrimp. In general aquaculture, fertilizers and bacterial strains can be applied to cultivate various bacteria.

Of course, some farmers call bacteria that are beneficial to fish and shrimp beneficial bacteria, and some bacteria that are harmful to fish and shrimp harmful bacteria. However, there are always two sides to everything. Some harmful bacteria are not without shortcomings or harm, and some beneficial bacteria do not always produce benefits. Therefore, in farming, we need dialectical thinking.

2. Actinomycetes: Actinomycetes are a type of prokaryotic organism between bacteria and fungi, which are common in soil, air and water. They are named because they appear in actinomycete colonies. Actinomycetes are mainly in the form of hyphae and spores, and are very similar to fungi in culture, so they are very easy to confuse.

In aquaculture, most actinomycetes are aerobic bacteria, while very few are anaerobic bacteria. In addition, in aquaculture, there is rarely a habit of using actinomycetes alone. Generally speaking, actinomycetes are mixed with some probiotics, such as EM bacteria, which is a mixture of dozens of bacteria including actinomycetes.

3. Fungi: The scope of fungi is actually very wide. Currently, humans have discovered millions of species of fungi. It is a spore-forming, chloroplast-free eukaryotic organism. In particular, fungal cells contain substances similar to chitin, and can reproduce through both asexual and sexual reproduction.

There are many types of fungi, mainly yeast, mold and mushroom. In aquaculture, except for yeast, which can play some beneficial roles (decomposing organic matter and enhancing absorption), other molds and mushrooms will only produce harmful effects. For example, chytridiomycosis, chytridiomycosis and sea chytridiomycosis are all diseases that are difficult to cure in aquaculture.

4. Mold: Mold is actually a type of fungus. In aquaculture, it often plays the role of a harmful bacteria. Many of the fungal diseases that farmers often talk about refer to mold infections. For example, the more common diseases: Saprolegniasis and gill mold disease are both types of mold and bring great losses to farmers.

10. What are the hazards of ammonia nitrogen in pond aquaculture? What are the control methods?

Ammonia nitrogen is a harmful gas formed in the fish farming process when fish food residues and feces accumulate in the pond. It affects the growth of fish, causes lack of oxygen in the fish pond, and causes various diseases. Therefore, it is critical to add an aerator to increase oxygen and regulate water quality.

Desilting after pond opening in winter is an important measure to fundamentally solve the problem of excessive ammonia nitrogen.