What Is Piebaldism?

The variegated grouper is also called grouper, belonging to the order Periformes. The body is long, oval, slightly flat, and has a large mouth. It is supplemented with maxillary bones. The teeth are pointed and sometimes enlarged into canine teeth. Body covered with small scales, sometimes buried under the skin; dorsal and anal spines are well developed. Caudal fins are round or concave. There are many body color variations, often brown or red, with stripes and spots, and large and medium-sized marine fish with warm water.

Piebald

Grouper is rich in nutrients, tender and white, similar to chicken, and is known as "sea chicken". Grouper is a low-fat, high-protein first-class food fish. It has been promoted by Hong Kong and Macao as one of the four famous fishes in China. It is a must-have for high-end feasts.

Groupers like to inhabit the sea areas of rocky reefs, gravels, and coral reefs near coastal islands, and are generally not grouped. The habitat water layer rises and falls as the water temperature changes. Spring and summer are distributed at water depths of 10 to 30 meters, and summer and summer seasons also occur at water depths of 2 to 3 meters. When the water temperature drops in autumn and winter, they swim to deeper waters of 40 to 80 meters. The suitable temperature range is 15 to 34 ° C, and the optimal water temperature is 22 to 28 ° C. It has a wide range of salinity and can survive in Shanghai with salinity of 10 . It is a carnivorous and fierce fish. It uses predatory methods to capture benthic crustaceans, various small fishes, and cephalopods.

The grouper fishing in Fujian has a long history. According to records, the fishery industry in Pingtan County began in the Qing Dynasty and has a history of 300 years. Every year from April to November is the flood season for catfish fishing, and from May to October it is the flood season. Longline and hand fishing are the main fishing tools for groupers. In 1993, the output reached more than 1,900 tons. The output of Pingtan County and Lianjiang County in the main producing areas exceeded half of the province. Grouper culture has three forms of cage, dike and pond culture, which has become a foreign exchange earning fishery along the coast of Fujian Province. Most of the cultured seed comes from small-sized fish species caught in natural sea areas. Blue grouper has begun artificial breeding in batches, opening up broad prospects for large-scale development of grouper culture.

Grouper is a coastal warm-water middle and lower layer fish, which mainly inhabits rocky reefs, seabed caves and gapped coral reefs. Generally do not form a large group, ferocious, is a carnivorous fish, can eat each other. Especially in the juvenile stage, small individuals are often swallowed by large individuals. Food is mainly crustaceans such as shrimp and crab, followed by fish and molluscs. Groupers are hermaphrodites. As the individual grows, sexual changes can occur. Generally, the females are male and female, and it is not easy to distinguish males and females before the gonads are immature. Spawning is started every year from March and has the characteristics of multiple spawning. According to research observations, the blue grouper feeding cycle has two peaks in a year. The first peak appears in May in spring and the second peak occurs after August in autumn.

According to tests, when the blue grouper is at a water temperature of 22-30 ° C, the fish is active, the food intake is large, and the growth is fast; when the water temperature drops below 22 ° C and above 19 ° C, the second is; when the water temperature drops below 19 ° C, the food intake is The amount is significantly reduced, the growth rate is slowed, and the activity is weakened with the decrease of water temperature. It is also observed in indoor pools that overwinter, and the water temperature drops below 10 and no dead prey is eaten, but live crustaceans can still choose food; When the water temperature drops below 7.5 , the feeding is stopped and the fish is at a standstill; when the water temperature is lower than 5.5 , death occurs. It has a wide range of adaptation to salinity, and can survive between 11 to 41 , and the most suitable is about 30 .

Labor in recent years

Grouper

A research report by the University of Hong Kong shows that various grouper fish species have been continuously overfished and many grouper fish species are facing extinction crisis. On the IUCN's Red List of Endangered Species, 20 of 163 species of grouper are facing extinction, and 5 are endangered.

In 2009 alone, more than 275,000 tons of groupers were eaten worldwide. Based on an average of 3 kg each, the number is equivalent to 90 million. The University of Hong Kong also pointed out that the actual number may be greater. Because data from Hong Kong and Indonesia show that most of the groupers being sold weigh only 1 kg.

According to the report, overfishing, lack of regulation and poor conservation efforts are the main reasons for the endangerment of groupers. It is reported that the total sales of groupers worldwide each year are as high as 1 billion US dollars. Fishermen's fishing, regardless of size, on the one hand eliminates adult males, on the other hand prevents small fish from surviving to adulthood, stifling the grouper's breeding opportunities.

All groupers, including the common red spot, star spot, rat spot, and dragonfly, are female at birth and only turn into males in adulthood. However, groupers take 10 years to reach adulthood, and many young fish are caught before they grow up, reducing the chances of successful breeding and the number of fishes falling sharply.

Due to the decline in demand, the demand has continued to rise. Fishermen use dilute Shane to make up fish. Although they can catch a certain number of large and small groupers, they fry fish (commonly known as fish hair). Some species were rushed out and no fry were gathered. In addition, fry are replenished even in the artificial breeding industry.

In Asia, including but not limited to China, because of its large population and customers willing to pay, they will still order grouper dishes even if the price rises. In addition, Asian restaurants have attracted a large number of guests by recruiting live fish in fish tanks. Due to freight and customs issues, the grouper's selling price in China has been further pushed up, and many Chinese tourists have devoted themselves to dining in restaurants in Hong Kong. Eighty percent of grouper catches worldwide are caught in Asian waters.

Yvonne Sadovy, a scholar of marine and freshwater organisms, points out that Hong Kong is adjacent to mainland China and is a major center of the global grouper trade. The regulations governing the import and sale of seafood have become outdated and therefore fail to comply with international conventions and regulations. agreement. People in Hong Kong who are engaged in fisheries pointed out that Hong Kong Grouper was originally found on the coast of Fujian, but because of the huge demand from China, it has been overfished in the past 20 years.

Some Hong Kong foodies have learned that Shiba fish is facing extinction, and they will consider not to eat it anymore. It is also said that there are many seafood that can replace grouper and are equally delicious.

There are legislative guarantees for the protection of groupers in foreign countries. For example, the United States and Canada have stipulated the size specifications of groupers that can be caught. At the same time, the capture of female groupers is prohibited for most of the time. These measures are worthy of reference for China's fishery resources department. The minimum catch size for groupers in Xiangshan and other places in China is 250 grams, so the country is also working hard to protect fishery resources through legislation.

Chinese experts mapped out the world's first grouper genome map:

Sun Yat-sen University and BGI Gene held a press conference in the afternoon of March 18, 2011 in Guangzhou Sun Yat-sen University to announce that "the mapping of the grouper genome sequence was completed". It is reported that this is the third fish genome sequencing project and whole genome sequence map completed by China, and it is also the world's first genome sequence map of Perchidae grouper grouper. This means that the taste of farmed grouper is similar to that of wild grouper in the future.