CATDOLL : CATDOLL: Why is there a centimeter-long red color on the tail of the bighead carp in the fish pond?

Why is there a centimeter-long red color at the tail of the bighead carp in the fish pond?

Hello, this is normal. Yu Changli has some red things on his tail, which is very normal. I hope it can help you. The sheets are dead and he is going to reproduce. He is preparing a house, so there will be red things on his tail. Please give a good review. Bye

If the fish tail has color variation, it may be caused by parasites or bacterial infection. At this time, the fish pond needs to be disinfected.

Do fish have parasites?

Fish have parasites.

Especially for fish that live in places with poor water quality, the number of parasites in their bodies will also increase. However, most fish have parasites that are not transmitted to humans, and they will be killed directly after being cooked at high temperatures. Therefore, unless in some special circumstances, eating fish that have been heated and heated will not cause parasites.

Parasites are lower eukaryotic organisms with pathogenicity, acting as both pathogens and vectors of disease transmission. Parasites are characterized by the presence or attachment of all animals outside their bodies in order to maintain the nutrients or shelter they need for survival, development and reproduction.

Do fish have parasites?

Does raw fish contain parasites? Raw fish is nutritious, tender, crispy and delicious. It is a common food in our lives and many people like to eat it. It can supplement the body with many vitamins and proteins. Let's learn about whether raw fish contains parasites below.

Do fish have parasites when they are raw? 1 Parasites are not only found in freshwater fish, but also in marine fish. Whether it is caught marine fish or farmed marine fish, they are not immune. Therefore, marine fish can be eaten raw not because there are no parasites in their bodies, but because of another reason, which is osmotic pressure.

To put it simply, the principle of osmotic pressure is that water molecules always penetrate from high concentration to low concentration, and the concentration of seawater is completely different from that of freshwater. Therefore, in order to adapt to different living environments, the body functions of marine organisms and freshwater organisms are also completely different. Therefore, marine organisms cannot survive in freshwater, and similarly, freshwater organisms cannot survive in seawater.

That is to say, the parasites in marine fish cannot survive in the human body for a long time. However, some marine parasites can barely survive in the human body, but they cannot develop to maturity, such as the third-stage larvae of Anisakis.

Although Anisakis larvae cannot mature in the human body, it is still disgusting to think about them in the body! Don't worry, it is not difficult to kill them, just freeze them. Different countries and regions in the world have corresponding standards for freezing salmon before they are put on the market. According to these standards,

Salmon needs to be frozen at -18 to 25 degrees Celsius for 48 hours to a week before it can be put on the market. Marine parasites such as Anisakis are not resistant to low temperatures, so freezing can kill them completely. Therefore, it is unsafe to slice and eat fish directly after they are caught and brought ashore without being frozen.

The reason why freshwater fish cannot be eaten raw is that the osmotic pressure in the human body is very different from that in freshwater, so freshwater parasites can survive for a long time once they enter the human body.

Take the most common freshwater parasite Clonorchis sinensis, also known as liver fluke, for example. Once it enters the human body, it can live in the body for up to 20 years. Freshwater parasites can survive in the human body for a long time, so can we freeze freshwater fish like marine fish? No.

The most common parasites in freshwater fish are liver flukes and lung flukes. Trematodes have a strong tolerance to low-temperature freezing and can revive once thawed. Therefore, even freshwater fish that have been frozen cannot be safely eaten.

Does this mean that freshwater fish cannot be eaten? Yes, they can be eaten. Whether it is marine parasites or freshwater parasites, heating is the best way to kill them, so as long as they are cooked, there is no risk of infection with parasites.

Are there parasites in raw fish? 2. Parasites in sashimi

Fish is rich in nutrition. Every 100g of fish contains nearly 19g of protein. It also contains omega-3 fatty acids that the human body needs but cannot synthesize on its own. This fatty acid has long been considered to have the effect of preventing cardiovascular diseases. And eating it raw can help preserve a large amount of vitamins A, D and B. But I still worry about eating it raw. After all, will it be unclean? Will it contain bacteria?

The answer is definitely yes.

Although most of the fish used in sashimi are marine fish, which do not have as many parasites as freshwater fish, there is still a risk of infection with parasites. The most notorious and worthy of everyone's vigilance is Anisakis. Commonly eaten salmon carries a lot of this parasite, and tuna and sea bream also have certain risks. How much harm can this kind of parasite bring to us?

Within a few hours of ingestion, the Anisakid nematode will try to drill holes in our intestinal wall. However, the intestinal wall tissue is relatively strong and hard for it to penetrate completely, so the Anisakid nematode will get stuck in our intestinal wall, causing local tissue swelling and bleeding. At the same time, it will trigger an immune response, be wrapped by immune cells, cause digestive tract obstruction, and cause acute and severe abdominal pain, nausea and vomiting.

The past and present of parasites

When certain infected marine mammals (such as whales or sea lions) excrete, the eggs are passed into the seawater, where they become infective larvae. These larvae are ingested by crustaceans, which are then eaten by fish or squid. When humans eat raw or undercooked infected fish or squid, the nematode larvae enter the human body. Once inside, the larvae can invade the gastrointestinal tract. Eventually, the parasite dies, but it can cause inflammation and mass in the esophagus, stomach, or intestines.

Some people experience a stinging sensation in their mouths when (or after) eating raw or undercooked fish. This is actually a physiological reaction to worms swimming in the mouth or throat. You can reach into your mouth and pull out the worms, or cough them out to prevent infection. In addition, some people may vomit after a stomach infection, and there is a chance that worms can be expelled from the body through vomiting.

Of course, our bodies have basic defenses, and when we eat a small amount of larvae, our gastric juices may have digested them, but the body will remember the invasion of this foreign substance and regard it as an allergen.

The second most common parasite: Fish tapeworms (such as Diphyllobothrium latum)

Fish tapeworm infection is an infection of the human intestine by parasites found in fish. Fish tapeworm (Diphyllobothrium latum) is the largest parasite that infects humans. People can become infected when they eat raw or undercooked freshwater fish that contain fish tapeworm cysts.

Main occurrence areas:

The infection is seen in many freshwater fish regions, such as Africa, Eastern Europe, North America, South America, and some Asian countries including China.

What are the signs and symptoms of fish tapeworm infection?

When people eat infected fish, the larvae begin to grow in the intestines. The larvae can grow into adult worms in 3 to 6 weeks. The worms attach to the intestinal wall and can be up to 9 meters long. The tapeworms take nutrients from the infected body, causing vitamin B12 deficiency and anemia. Most infected people have no obvious symptoms, but in severe cases, they may experience abdominal discomfort or pain, diarrhea, weakness, weight loss, etc.

How to reduce the risk of parasites

Many people think that if sashimi has parasites, they can just eat more wasabi. Don't underestimate parasites. Whether it's wasabi or other seasonings, it's hard to kill them. Soaking in a certain concentration of wasabi for 45-55 minutes can effectively kill parasites, but we only dip it once at most, how can we soak it for that long! And the so-called certain concentration is 1-3g/ml (very concentrated!) in the experiment.

Scientists have studied the effectiveness of various condiments against parasites. Forget vinegar and soy sauce, as parasites can survive in them for days. High-concentration liquor can kill parasites in half an hour, but who would soak fresh sashimi in liquor for half an hour before eating it? So those of us who eat sashimi with mustard and soy sauce should not imagine that condiments can help us kill parasites. To prevent parasites, we still have to start with the choice of ingredients.

1. Choose farmed deep-sea fish. Don’t think the word “wild” is particularly high-end. Deep-sea farming is the way to curb parasites from the source. 75% of the fish we import in large quantities from Norway, Scotland, Chile and other places are farmed in the deep sea.

The entire process, from artificial insemination of broodstock, to freshwater aquaculture of fry, followed by seawater aquaculture, and then to the capture and packaging of adult fish, is strictly and accurately scientifically controlled. The control of feed and environment, vaccination of fry, strict disinfection of aquaculture and fishing personnel, and quarantine of import and export customs make these farmed fish very safe.

There is no need to worry about good wild deep-sea fish. The deep-sea fish that the Deep Sea Fishing Club fishes on boats are all high-quality deep-sea fish.

2. Rapid freezing is one of the most effective ways to eliminate parasites. The fish processing method is the second line of defense against parasites after choosing farmed fish. Of course, heating is the best way to kill parasites, but who can blame us for talking about sashimi today? In the United States and European and American countries, in order to not damage the taste of the meat too much and improve effective defense, the commonly used method is rapid freezing (IQF).

The FDA recommends freezing meat at -20°C for seven days and at -35°C for 15 hours, while the EU stipulates that it must be kept at 20°C for 24 hours to kill parasites. In short, freezing is a very effective way to kill parasite larvae and eggs. However, we often like big keywords such as "chilled" and "air transport". When we hear about freezing, we think that the meat will no longer be fresh.

In fact, those freshly-frozen fishes need 5-7 days to go through a series of processes such as processing, transportation, and customs. It is purely imaginary that they were swimming in the Atlantic yesterday and are in our mouths today. The so-called freshly-frozen fishes do not have much better meat quality. On the contrary, the ultra-low temperature freezing technology (below -55℃) can better ensure the taste and color of the fishes.

3. It is best to understand the source of the fish you eat, especially for those children who like to buy fish online. Be sure to ask the store carefully whether it has the "Import Goods Inspection and Quarantine Certificate" and read the information on it carefully. If you go to a store to eat sashimi, it is best to find a store with a large customer flow and a good reputation. When you go to the supermarket, you should also specifically ask which ones can be eaten raw.

In short, sashimi is still somewhat risky, so you should always be cautious when buying and eating it. Generally speaking, choosing a regular, reputable store is less risky, but don't eat too much at once, don't eat it every day, and try not to eat it when your immune system is not in good condition. It's better to eat more wasabi, red ginger, etc. when eating, which is a bit of psychological comfort.

In addition, beef and pork may also have tapeworms. The most common type of beef is the "unhooked tapeworm", which does not attach to the intestines, so beef can be eaten half-cooked. The "hooked tapeworm" in pork easily attaches to the intestinal wall, so people are advised to eat it well-done. Raw and cooked food should also be handled and stored separately to avoid cross infection; knives and cutting boards used for cooking should also be separated to prevent food from being contaminated by unclean knives and cutting boards.

Does raw fish have parasites? 3 1. How to eat raw fish

1. Sashimi Rice Bowl

Ingredients needed: salmon sashimi, mustard, sashimi soy sauce, rice, sushi vinegar, caviar, seaweed, cooked rice, avocado

Preparation method

(1) Soak the seaweed and wash it. Marinate it with mustard and sashimi soy sauce.

(2) Let the cooked rice cool down, add a small amount of sushi vinegar and mix.

(3) Add a small amount of caviar to the rice and stir.

(4) Place the marinated rice on top of the cooked rice.

(5) Wash and cut the sashimi into small pieces, add a small amount of mustard and sashimi soy sauce and mix.

(6) Peel the avocado, cut it into small pieces and put it into the bowl with rice. Then put the marinated sashimi into the bowl and serve.

2. Salmon sushi

Ingredients needed: sushi rice, sushi vinegar, sashimi soy sauce, salmon sashimi

Preparation method

(1) Wash the sushi rice and cook it in a rice cooker without adding too much water.

(2) Let the cooked rice cool down and break it up. Add an appropriate amount of sushi vinegar and mix well.

(3) Wash the raw fish and use kitchen paper to absorb excess water. Place it on a cutting board.

(4) Use a knife to cut the sashimi into rectangles of even thickness and set aside.

(5) Put on a disposable glove and shape the rice into several long strips.

(6) Wrap the sushi rice with the sliced ​​sashimi.

2. Precautions for eating raw fish

1. People with weak gastrointestinal function, such as the elderly and the weak, should eat less or no raw fish. It is likely to cause other symptoms such as indigestion.

2. The water quality is very poor now, so sashimi may contain substances such as parasites. Although sashimi is delicious, it is better to eat less of it.

3. Food safety is very important. When eating sashimi, you must buy sashimi produced by regular manufacturers, so that it is safe to eat. Do not eat sashimi of unknown origin.