Scophthatmus maximus belongs to the family Halibut, and its English name is Turbot, which is also called butterfly fish or treasure fish in Shandong and Guangdong. The body is flat, almost round, the eyes are on the left, the eyes are bluish brown, and there are a few thorns; The eyeless side is smooth and white, and the dorsal fin and buttocks are long and hard; The head and tail fins are small, the middle part of the body is thick, the visceral mass is small and the meat yield is high. There are more edible parts of the whole body than similar fish.

Scophthalmus maximus belongs to Nordic cold-water fish and is a rare flounder. The fish has strict requirements on seawater indexes such as temperature, and only a few areas in Shandong Peninsula are suitable for breeding.

The maximum lethal temperature of turbot is 28-30℃; The lowest lethal temperature is1-2℃; The highest growth temperature is 21-27℃; The lowest growth temperature is 7-8℃; The optimum growth temperature is 14- 17℃, and the maximum tolerance temperature is 40 ‰. The lowest is 12‰. In the natural environment, turbot's feeding habit is carnivorous, and crustaceans are eaten in the juvenile stage. Adult fish prey on small fish, shrimp, etc. Under the condition of artificial feeding, high-energy granular compound feed is mainly fed after domestication.

The male turbot reaches sexual maturity in one year, and the female fish reaches sexual maturity in two years, and the natural maturity time is May-August every year. Under the condition of controlling temperature and light, mature eggs can be obtained from artificially cultured parent fish all year round. At present, artificial insemination is used for artificial reproduction.

Scophthalmus maximus grows rapidly, and it takes only 10- 12 months from spawning and hatching to selling commercial fish (0.8- 1 kg). Because of its high economic value, high feed conversion rate, strong disease resistance and low oxygen consumption, it is an excellent breeding variety with great development prospects.

Explore the breeding base of Duobao fish

How did illegal drugs enter the process of Duobao fish culture, and is there any loophole in supervision? 165438+1On the morning of October 22, the reporter rushed to the Duobao fish breeding base in Zhuwang Village, Laizhou City, Shandong Province, to investigate this. Shandong Province is the main producing area of Duobao fish in China. According to the statistics of Shandong Provincial Department of Ocean and Fisheries, the annual output value is about 3 billion yuan. Zhuwangcun Duobao fish breeding base is the largest in the province, with an annual output of over 654.38+10,000 tons.

It is no secret to "drug" fish.

Speaking of dolphins, a local industry insider said that dolphin "taking drugs" has long been an open secret in the industry. A few years ago, we invested about 400,000 yuan in breeding greenhouses, and the cost could be recovered in that year. In the first few years, no one used illegal drugs. In recent years, there are more and more fish farmers in Duobao. In the fierce competition, it is inevitable that some people will try to use illegal drugs.

Teng Jialin, head of Zhuwangcun Duobao fish breeding technology research center, said that in recent years, because of the rich profits, many surrounding areas have also started to breed Duobao fish, and some farmers with poor breeding conditions and high breeding density may have used prohibited drugs in the breeding process. Another farmer said that some people use coagulant to make a profit. The fish that were originally farmed 1 year can be listed in eight months with coagulant. In addition, if the culture density is too high, the fish will be easily scratched by collision in the water. In order to prevent fish from rotting, some farmers also use formaldehyde as a medicinal bath and various illegal drugs such as antibiotics. Because of the recycling of drugs, fish species are degraded. In order to ensure the survival of fish, farmers often increase the dosage of drugs. Now farmers use more illegal drugs, such as potassium permanganate, chloramphenicol, ciprofloxacin and formaldehyde.

Many farmers also told reporters that some fishmongers bought dead fish at low prices and sold them as fresh fish after freezing. Some fishmongers add the illegal drug malachite green to the frozen material in order to add color to the treasure fish.

There are loopholes in the supervision of illegal drugs.

The reporter followed the farmers into the Duobao fish breeding shed. In the greenhouse, the reporter found several bottles of formaldehyde in a box. Farmers say that formaldehyde is not a banned drug, and they use formaldehyde to brush the pool for disinfection. In this Duobao fish incident, formaldehyde in Duobao fish was found to exceed the standard in many places in China. In this regard, an official of Laizhou Ocean and Fisheries Bureau said that formaldehyde is not a banned drug, but the residue in fish can not exceed the standard. Therefore, according to the relevant regulations, formaldehyde cannot be used in aquaculture ponds one month before the listing of Duobao fish. As for how this regulation is stipulated, the official did not answer.

The reporter learned that the supervision of illegal drugs belongs to different departments-the Food and Drug Administration is responsible for supervising the sales of drugs and the management of drug sales departments, while the Fisheries Bureau is responsible for managing the use of drugs by farmers and telling farmers which drugs cannot be used.

Officials of the investigation team said that there are still loopholes in the existing farm inspection system. If farmers buy drugs privately and use them secretly in the process of breeding, it is difficult to carry out systematic inspection. For example, ciprofloxacin, which is listed as a non-additive in farmed fish, can be used in farmed livestock, but it is not completely banned, so these drugs can be sold publicly, which also makes supervision difficult.

Many farmers in Zhuwang Village said that their fish do not need any quarantine measures when they leave the factory, but the drug supervision department in Yantai randomly samples them once or twice a year and takes them out for testing. After passing the test, they can get a certificate and sell farmed fish all year round. The local aquaculture industry is deeply affected.

At the breeding base, the reporter met a fishmonger who came from other places to buy Duobao fish. He said that because the government has suspended the shipment of Duobao fish, he has been here for several days, waiting for the news of lifting the ban.

Teng Jiajun, a farmer in Zhuwang Village, said that the heavy rain had made it impossible for Duobao fish to be shipped, which made him very anxious. He raised 65,438+10,000 fish, with a total investment of more than 3 million, including a loan of more than 2 million. It's just the fishing season, but now some farmers have stopped all the shipments of Duobao fish because some drugs have been added to it. Regardless of the test results, this storm will definitely have a greater impact on the Duobao fish market, and he is considering breeding other fish species.

But now some turbot have registered permanent residence? But there are some. Some of them are illegal residents. And these fishmongers sell them to hotels and restaurants at low prices and high prices. People who eat these are rich, and ordinary people like us can't afford them, so don't worry.