CATDOLL : CATDOLL: How to prevent and treat black gill disease in freshwater shrimp?

How to prevent and treat black gill disease in freshwater shrimp?

【Symptoms】The activity of diseased larvae is significantly weakened, and they mostly swim slowly at the bottom. Their phototropism becomes weaker. The metamorphosis period of larvae is prolonged or they cannot metamorphose. Their abdomen curls up, their body color turns white, and they do not eat. Adult shrimp float on the water surface, move slowly and sluggishly. The gills of diseased shrimp are black, with a lot of black and brown dirt attached. In addition to the black gills, some shrimp diseases have black spots on the sides of their cephalothorax and plastron (Figure 18). The gill filaments are necrotic, the tissues fall off, and finally they have difficulty breathing, leading to death. Except for a small part of the liver above the cephalothorax, which is still yellow-brown, almost the entire liver of the diseased shrimp turns white. The black gill disease of green shrimp is caused by Vibrio. When the gill filaments are examined under a microscope, it can be found that some of the gill filament tissues have fallen off or are in a state of vacuolar degeneration, and the tissues are full of active Vibrio. Both larvae and adult shrimps are infected with this disease, and the mortality rate is high.

Figure 18 Black gill disease of freshwater shrimp

【Prevention and control methods】① Before breeding, the water body or container must be disinfected and sterilized. The shrimp pond must be cleaned and prepared; the nursery container must be disinfected with drugs; the net cage should be cleaned before use and exposed to the sun for sterilization. ② Reduce the breeding density and feed appropriately to prevent excess bait from rotting and deteriorating and polluting the water body. ③ Remove the dirt at the bottom of the pond or the bottom of the box, drain the lower layer of water frequently, and add fresh water to reduce the chance of pathogen reproduction. ④ For diseased shrimp, 2 mg/L of bleaching powder can be sprayed throughout the pond. ⑤ Garlic is used to treat shrimp fry Vibrio disease, which is more effective. The specific method is to peel and mash the garlic, filter and extract the juice to make 5-10 mg/L (increase or decrease according to the severity of the disease) and treat for 24 hours. Garlic is low-cost and can be used as a broad-spectrum fishery medicine to treat shrimp diseases. ⑥ The diseased pond water can only be discharged after strict disinfection. It is strictly forbidden to use the diseased pond water for shrimp breeding.

【symptom】

The activity of diseased larvae is significantly weakened, and they mostly swim slowly at the bottom. Their phototropism becomes weaker. The metamorphosis period of larvae is prolonged or they cannot metamorphose. Their abdomen curls up, their body color turns white, and they do not eat. Adult shrimp float on the water surface, move slowly and sluggishly. The gills of diseased shrimp are black and attached with a lot of black and brown dirt. In addition to black gills, some diseased shrimps have black spots on the sides of their cephalothorax and plastron.

The gill filaments become necrotic, the tissues fall off, and finally the patient has difficulty breathing, leading to death. The liver of the diseased shrimp turns almost entirely white, except for a small part above the cephalothorax, which is yellowish-brown. Black gill disease of freshwater shrimp is caused by Vibrio. Examination of the gill filaments under a microscope reveals that some of the gill filament tissues have fallen off or are in a state of vacuolar degeneration, and the tissues are filled with active Vibrio. Both larvae and adult shrimp are infected with this disease, and the mortality rate is high.

【Prevention and treatment methods】

① Before breeding, the water body or container must be disinfected and sterilized.

Shrimp ponds must be cleaned and tidied; seedling containers must be disinfected with drugs; net cages should be cleaned before use and exposed to sunlight for sterilization.

② Reduce the stocking density and feed appropriately to prevent excess bait from rotting and polluting the water.

③ Clear the dirt at the bottom of the pool or box, drain the lower layer of water regularly, and add fresh water to reduce the chance of pathogen reproduction.

④ For diseased fresh shrimp, 2 mg/L of bleaching powder can be sprayed throughout the pond. ⑤ Garlic is used to treat shrimp fry Vibrio disease, which is effective. The specific method is to peel and mash the garlic, filter and extract the juice to make 5-10 mg/L (increase or decrease according to the severity of the disease) and treat for 24 hours. Garlic is low-cost and can be used as a broad-spectrum fishery medicine to treat shrimp diseases. ⑥ The diseased pond water can only be discharged after strict disinfection. It is strictly forbidden to use the diseased pond water for shrimp farming.

This article is from: China Agricultural Press "Diagnosis and Control of Pests and Diseases"

Prawn cooking methods and knowledge

Prawn cooking methods and knowledge

What is Shrimp?

Green shrimp is one of the freshwater shrimps with high economic value. It grows fast, is large, reproduces quickly, has strong vitality, and is widely distributed in freshwater lakes in my country. Green shrimp has tender and delicious meat and rich nutrition. Every 100 grams of edible part contains 16.40 grams of protein. Nutritionists believe that it has a certain brain-boosting function.

The body of the shrimp is short and thick, and the whole body consists of two parts: the cephalothorax and the abdomen. The sections of the cephalothorax are connected, and a large bone plate covers the back and both sides, called the cephalothorax or carapace. The cephalothorax is thick, the front part of the abdomen is thicker, and the back part gradually becomes thinner and narrower. The frontal horn is located in the center of the front of the cephalothorax, with a straight upper edge and a sharp end. There is a sword-like protrusion at the front of the carapace, with 11 to 15 teeth on the upper edge and 2 to 4 teeth on the lower edge.

Green shrimps have poor swimming ability and can only swim short distances. They often crawl in the grass at the bottom of the water. However, when frightened or attacked by enemies, they can use their abdomen to contract sharply, their tail fan to paddle the water backwards, and then suddenly straighten their bodies and escape from the water. They grow fast. The young plants hatched in May and June can usually grow to about 3 cm in about 40 days, and each can weigh 3-5 grams in November. Green shrimps shed their skin 13-15 times in their lifetime. Their growth and development are completed by molting. Their life span is generally 14-18 months.

Nutritional analysis

1. Shrimp is rich in nutrition, and its meat is soft and easy to digest. It is an excellent food for people who are weak or need to recuperate after illness;

2. Shrimp is rich in magnesium, which plays an important role in regulating heart activity and can protect the cardiovascular system. It can reduce the cholesterol content in the blood, prevent arteriosclerosis, and dilate the coronary artery, which is beneficial for preventing hypertension and myocardial infarction.

How to cook green shrimp

There are many ways to cook prawns. Here are some common ones.

Prawns in tomato sauce

I like the taste of ketchup. This method of eating shrimps does not require you to spit out the shells. The shrimp shells are rich in calcium.

Main ingredients: prawns (300g) Seasoning: shredded ginger (appropriate amount) tomato sauce (appropriate amount) pepper (appropriate amount) sugar (appropriate amount)

practice:

1. Wash the shrimps, cut off the whiskers and remove the mud lines.

2. Marinate with ginger, pepper and cooking wine for 10 minutes

3. Put oil in the wok. When the oil temperature is 70% hot, put in the prawns and fry them. Remove them and fry them again when the oil temperature rises. Remove them and drain the oil.

4. Stir-fry ginger and garlic until fragrant, then add tomato sauce

5. Cook until the soup is thick

6. Add the prawns that have been drained of oil. When the prawns are evenly covered with the soup, serve.

7. Add a little water starch to the remaining soup, pour it on the prawns, and sprinkle some white sesame seeds.

Braised Prawns

Shrimp meat contains protein, fat, carbohydrates, calcium, phosphorus, iron, vitamin A, vitamin B, and vitamin B. Braised shrimp meat can retain calcium and taste delicious.

Main ingredients: prawns (250g) Seasoning: corn oil (appropriate amount) green onions (appropriate amount) fresh ginger (appropriate amount) soy sauce (appropriate amount) rice wine (appropriate amount) salt (appropriate amount) chicken essence (appropriate amount)

practice:

1. Wash the prawns, cut off the claws and legs, open the back, and remove the shrimp thread.

2. Heat the oil in the pan, add the scallion slices and ginger slices and stir-fry.

3. Add the prawns into the pan and stir-fry

4. Add appropriate amount of rice wine, soy sauce, sugar and salt and stir-fry

5. Add two spoons of water and cook for two minutes. Add chicken stock and stir-fry for a while. Serve on a plate.

Tips:

You must add light soy sauce, but you don’t have to. Soy sauce that is too dark will affect the color and taste of the shrimp.

Thai Shrimp Curry

Make a Thai curry shrimp dish, pair it with a bowl of Thai fragrant rice, and look forward to the beautiful country of Thailand.

How to make marinated green shrimp

Raw marinated green shrimp can enhance human immunity, promote lactation, relieve neurasthenia, facilitate recovery after illness, prevent arteriosclerosis, eliminate "jet lag", enhance resistance, reduce blood sugar and lipids, improve eyesight, widen the intestines, promote digestion, treat colds, eliminate cold, soothe the liver, lower blood pressure, calm the nerves, prevent cancer, nourish blood and replenish deficiency, relieve skin diseases and protect cardiovascular system, promote lactation, increase bone density, eliminate "jet lag", calm down; fresh green shrimp and white shrimp not only contain calcium, but also rich in trace element magnesium, which plays an important role in regulating heart activity. Here we explain the time, seasoning, steps, and cooking tips required for making marinated green shrimp at home, and teach you how to make marinated green shrimp nutritious and delicious.

Main ingredients: 1000g shrimp, auxiliary ingredients: 50g carrot, 50g coriander, 50g celery, a little dried shrimp, a little squid (dried) Seasoning: a little salt, some soy sauce, 25g green onion, 25g ginger, some light soy sauce, some dark soy sauce, some rose wine

Steps: 1. Wash the live prawns, peel off the shells, rinse with running water, drain, add appropriate amount of clean water and a little salt, mix well, soak for about 40 minutes, rinse with clean water and set aside

2. Peel the carrots, remove the stems and seeds of the green peppers, wash them separately, and cut them into small pieces; remove the roots and leaves of the coriander and celery, wash them, and cut them into small pieces for later use.

3. Soak dried shrimps and dried squid in clean water until soft, then steam them in a steamer over high heat. Take them out and drain the water. After they cool down, chop the squid into small pieces and cut each dried shrimp into two halves.

4. Add appropriate amount of water to the soup pot and bring to a boil. Add onion and ginger and cook for 5 minutes. Then add green pepper, carrot, coriander and celery and cook for 10 minutes. Turn off the heat, remove from the pot and filter out the vegetables in the soup. Pour the clear soup into a large soup bowl.

5. Add dried shrimp and minced squid, mix well, then add appropriate amount of Maggi soy sauce, seafood soy sauce, dark soy sauce, light soy sauce and rose wine, mix well, finally add green shrimp, mix well, place in the refrigerator and soak for 24 hours to let the shrimp fully absorb the flavor, remove the green shrimp and take it out when eating...

Fried shrimp recipe

The deep-fried shrimps can be eaten with the skin, which is sweet and delicious, very convenient, and can also supplement calcium. Children should eat more shrimps, which are good for their growth and development. The deep-fried shrimps are red and green, crispy on the outside and tender on the inside, fragrant and delicious, and children also like to eat them.

Method 1 Ingredients: 250g green shrimp

Accessories: oil, salt, flour, white pepper

step:

1. Clean the shrimp first and drain the water

2. Sprinkle salt and a little white pepper on the surface of the shrimp, add appropriate amount of flour and mix well. It is best to cover the shrimp with flour.

3. When the oil is hot, pour in the shrimps and use chopsticks to separate the shrimps one by one.

4. After frying, take it out and continue to turn up the heat to increase the oil temperature.

5. When the oil temperature rises, pour in the fried shrimp and fry for 12 seconds.

6. Remove from the water and drain the oil.

Method 2

Main ingredients: 250 grams of shrimp

Accessories: 200g leek, 50g wheat flour

Seasoning: 60g peanut oil, 15g cooking wine, 3g salt, 1g MSG, 25g pepper and salt

step:

1. Cut off the whiskers and legs of the prawns and wash them;

2. Put the prawns in a bowl, add cooking wine, salt, flour and a small amount of water, and mix into a thick paste;

3. Wash and clean the chives, cut them into pieces of the same length as the shrimps, and put them into the shrimp paste and mix well;

4. Put the pan on the fire, add oil and heat it until it is 60% to 70% hot, scoop up the shrimp and chive paste with a spoon or a large spoon, and put it into the pan one spoonful at a time;

5. Then use chopsticks to cut it open, fry until the shrimp shell turns red, then remove and serve;

6. Dip in pepper oil or spicy soy sauce when eating.

Tips for making fried shrimp:

This product requires a frying process, so about 500 grams of peanut oil is needed.

How to cook boiled shrimp

Boiled green shrimps are a famous dish for family gatherings, not only because boiled green shrimps can show the original flavor of shrimps, delicious and strong. And the method of boiling green shrimps is very simple. As long as you have enough ingredients, anyone can make a first-class spicy dish!

Method 1:

Main ingredients: 500g shrimp,

Accessories: vermicelli, lettuce, 5g onion, 5g ginger, 5g garlic, pepper, dried chili, Pixian bean paste, water

step:

1. Wash the prawns, cut off the whiskers, cut the back with scissors, and pick out the shrimp thread (cutting the back will make the shrimp more flavorful, but it is time-consuming and laborious, so I didn't cut it to save trouble)

2. Put a proper amount of oil in the pot, over low heat, do not heat the oil, add Pixian bean paste and stir-fry until fragrant, stir-fry until red oil comes out

3. Add onion, ginger and garlic slices, stir-fry until fragrant, add appropriate amount of water, after the water boils, turn down the heat, cover the pot and simmer for a while to cook the flavor of the seasoning into the water

4. Turn up the heat and add the prawns. At this point you can taste the soup and add salt and other seasonings as needed.

5. When the prawns change color and bend, you can fish them out. Take a large bowl (the vermicelli and greens should be boiled in water beforehand and placed at the bottom of the bowl) and arrange the prawns into the shape you like. Pour the broth into the bowl as well.

6. Heat another pot, add more oil, and simmer until the oil is not heated. Add the dried chili peppers and Sichuan peppercorns before the oil is heated. Adding the chili peppers and Sichuan peppercorns when the oil is not hot will make them more fragrant and will not burn the chili peppers.

7. When the color of the dried chili peppers starts to darken, you can turn off the heat and pour the oil directly on the prawns.