The difference between wild fish and farmed fish

Answer:

Some people say that you can tell whether farmed fish or wild fish can be judged by the color of their bodies. There are many such experiences on the Internet. In fact, based on my personal contact with traders and actual fish farming experience, this experience is not reliable for many types of fish. The skin color of most fish can often change with changes in the environment. In order to sell their appearance and pass themselves off as wild fish, many traders have ways to change the skin color of artificially farmed fish. A common method is to put farmed fish in rivers and breed them with wild fish for ten and a half months. When the difference in skin color between the two cannot be seen, fish them out and sell them as wild fish. This trick can deceive most consumers. who. Another trick is the most direct and quickest, and it can also deceive many consumers, which is to use pigments to dye farmed fish. The pigments come from a wide range of sources, such as yellow mud water, red mud water, kaolin mud water, etc. You can also use chemicals directly. dye. Many people think that artificial dyeing will cause discoloration, and you will find pigments in fish ponds. In fact, they are wrong. This kind of fish skin dyeing does not simply apply, so it will not decolorize into the water. To sum up, it is unreliable to distinguish between wild fish and farmed fish by skin color alone. Many aquatic experts can be fooled by traders' "technical" methods. Most ordinary people can only distinguish wild fish from farmed fish by skin color. share.

1. Body shape is an important reference for judging wild fish and farmed fish. Farmed fish are generally fat and strong due to sufficient feed and rich nutrition, while wild fish are generally fatter and stronger in the natural environment. Full of competition, there is always a meal but no meal, and the body is often thin and slender.

Of course, it also depends on the situation. During the spawning period, some wild female fish appear to have a larger belly because they are full of fish eggs. Consumers who do not understand may mistakenly think that they are fat and strong. In fact, the big belly of wild fish caused by the production of offspring can be seen if you are careful. The big belly only reflects the abdominal cavity, while the fat body of farmed fish is even fatness throughout the body.

2. The body fat content of farmed fish and wild fish is an important basis for distinguishing the two. Today's fish feed is composed of high fat and high protein, and the feeding is sufficient. Therefore, the body fat content of artificially raised fish is very high. Not only the abdominal cavity and fish intestines are full of fat, but there may even be a thick layer of fat under the skin of the fish, and even Fish belly is mainly fat. Due to the lack of food, wild fish often have very low body fat content, with less fat in the fish intestines and abdominal cavity, and even less fat on the fish meat.

In addition, the high-fat feed of farmed fish can lead to high cholesterol, large gall bladders, abundant bile and strong color. The gallbladder of wild fish is smaller, there is not so much bile, and the color is relatively lighter.

Because farmed fish eat artificially mixed high-fat and high-protein feeds and eat large amounts, they are fed regularly and have low digestion and absorption rates. Therefore, the excrement is often black and has a strong smell. Heavy. Wild fish, on the other hand, eat purely natural food and have a small amount of food, so they are fully digested, and their defecation is light in color and has a much lighter fishy smell. You can notice it by carefully observing the water quality in the fish pond.

For farmed fish, if the stall owner starves the fish, that is, raising them in clear water for several days without feeding, then this method will basically fail. Some eager traders immediately purchase the goods and sell them immediately. Such farmed fish are passed off as wild fish. As long as they are slaughtered, careful consumers can see the clues and pierce the intestines of the fish to observe the undigested food and digestive residues. Traces of fish feed.

The peritoneum is also the basis for distinguishing wild fish from farmed fish. Due to feed and living environment reasons, farmed fish often have a dark black film in their belly, while wild fish have no black film or have a very light black film.

3. The number of wild fish is limited, while the number of farmed fish is huge. If a fishmonger sells large quantities of wild fish all day long, there is a possibility of fraud both emotionally and rationally. In order to deceive consumers, some fishmongers often hide large amounts of farmed fish and only put a small amount of fish on the stalls, claiming to be wild fish to deceive consumers. After the deception is finished, they take out some more.

4. Wild fish tend to have strong survivability. As long as the density is not very high, they often do not need artificial oxygen supply. However, because of their poor survivability, farmed fish must require artificial oxygen supply once they leave the fish pond. . Therefore, in those stalls pretending to be wild fish, we often see oxygen pumps supplying oxygen.

In order to prove that the fish they catch are fresh river fish, fishermen in many places often sell them on the riverside or on the dock after catching them, and many citizens also go to buy them.

However, some unscrupulous traders take a fancy to the business opportunities and often go to the riverside to pretend to be wild fish, or commit crimes in gangs. Each person brings a small part of the fish to the riverside dock and streets to sell, and then hides it after the sales are finished. They get the goods wherever they are, so they continue to sell "wild fish" all day long without seeing their fishermen.

5. Wild fish are caught, and there are often many varieties and different sizes, while farmed fish are often cultured and caught in batches, with little difference in size. Some dealers who are not good at cheating can do this See how they cheat. Some fishmongers are clever and use farmed fish of different varieties and specifications to pass them off as wild fish, which makes it difficult for many people to know what they are doing.

6. As people’s concept of pursuing pure natural food increases, wild fish are sold well everywhere. Therefore, they are rarely sold to other places. A large number of fish that are not produced locally are called wild fish and are likely to be on the market. It's fake farmed fish. Some fishmongers are convinced that local fish are not produced locally, and people do not know enough about it, so they often use farmed fish that are regional specialties from other places to pass them off as wild fish. This situation is more common with low-yielding, regional, and elevated fish.