Hainan people try to raise crayfish warming, success or failure to wait and see!

“I would like to raise the lobster in Hainan. I don’t know whether it is feasible or not.” A few days ago, some farmers had called this publication, stating that due to the shrinking profit and high risk of tilapia breeding, they would like to adopt other varieties. A chance to listen to friends mentioned crayfish, said that in the mainland is very popular, they sprouted the idea of ​​breeding crawfish. Because I haven't had any contact with crayfish, my eager breeders have no idea. I hope I can understand them through the media.

Hainan crayfish breeding? The author is also somewhat surprised. Crayfish in our impression, the main producing areas should be in the middle and lower reaches of the Yangtze River in Hubei, Jiangsu, Zhejiang, Anhui and other places. Although Hainan has unique natural conditions, whether or not crayfish that live inland can adapt to the maritime climate and whether they have a competitive advantage is also a question. Through the visit, the author found that the crayfish culture in Hainan began to become a stark phenomenon.

Advantages of Hainan Cultured Crayfish It is understood that the main producing areas of crayfish in the Yangtze River Valley in Jiangsu, Zhejiang and Hubei, the consumer market throughout the country in major cities. From May to November every year, the crayfish is listed on the market, and in November, the crayfish is dormant due to the low water temperature. Therefore, it is difficult to catch crayfish in the Yangtze River valley in the winter. Even if caught, the crayfish is extremely thin, and there is not much commodity value. Therefore, in the winter and early spring season, there is basically no supply of fresh crayfish in the market.

Wuhan Yangtze River Valley Academy of Agriculture and Forestry (hereinafter referred to as “Yangtze River Academy of Agricultural Sciences”) has attempted to raise crayfish in a greenhouse, increase the temperature in the shed, raise the water temperature, and solve the problem of winter crayfish market supply. Due to the high cost, it is not worthwhile to give up. After some investigations, the Changjiang Academy of Agricultural Sciences put the target in Hainan.

Located in the subtropical Hainan, the temperature and water temperature are relatively high in the mainland. In the Yangtze River valley, it is a season of ice and snow. Hainan can maintain at 18°C-20°C, and the water temperature can also be kept above 10°C. If the water temperature is higher than 10°C, crayfish can grow normally. Therefore, crayfish do not need to sleep in Hainan, there is no consumption of nutrients, can achieve full-year growth, the annual market sales.

“The anti-season sales price is high. For example, the crayfish with the specifications of 20g or more last year will have a price of 20 yuan/500g from June to July. After November, the price will reach 40 yuan/500g.” Hou Shaoshan of Quanjiao Brother Shrimp Breeding Co., Ltd. Tell the author. In addition, because it can grow throughout the year, theoretically the yield of cultivated crayfish in Hainan should be much higher than that of the mainland. "The mainland cultivation of crawfish per mu is generally 250kg, and it can reach 350-400g/mu in Hainan," said Jiangcheng of the Haikou Office of the Yangtze River Research Institute of Agriculture.

It is because of the potential benefits of crayfish breeding in Hainan that more and more people are attracting attention to the feasibility of breeding crayfish in Hainan.

Hainan raising lobster? No!

“Crayon lobsters in Hainan? Nothing!” Wang, boss of Wenchangtan, Hainan Province, shakes his head like a rattle. Speaking of crayfish farming, it is a hurdle in the heart of the boss. With the gradual increase in the number of migrants, crayfish business has begun to rise quietly in Haikou in 2006 and has become more and more popular with the public. Since Hainan is not the origin of crayfish, the cost of transporting crayfish to Hainan from other provinces is relatively high, and the popularity of crayfish in Haikou is very difficult.

Perceived this business opportunity, in 2008 the king boss who had not contacted the crayfish, he readily contracted 200 acres of land, and invested more than 1 million yuan before and after the opening of the pond, investment seedlings, and so on. “At that time it was thought that even if the Hainan market could not consume so much, it was possible to use anti-season aquaculture. After November, there was no fresh crayfish available on the mainland, and it was shipped to the mainland. This time is also the highest price in the year. Even 3-4 times higher than usual." Wang boss laughed.

Looking at the crayfish that grew up and gave birth to the pond, Wang Bo’s heart was happy. Two months have passed, and without waiting for King's boss to be happy, the crayfish in the pond has become less and less. The boss is anxious. After searching for the root, Wang boss attributed the mysterious disappearance of crawfish to too many enemy predators. “One day a light mouse can catch fifty or sixty, and a lot of snakes.” To make Wang boss smile, the dog that had been raised in the tang of the burglary was also throwing away his responsibility to go and catch the crayfish. During the same period, a friend of the crayfish culture began to reflect the occurrence of crayfish deaths in a series of shrimp ponds, and could not be stopped after seeking medical advice.

After one year, boss Wang and his friends basically lost everything. Wang Boss began to conclude that “keeping lobster in Hainan is theoretically possible, but the actual operation is still very difficult.”

Hainan raising lobster? Row!

In Hainan, surrounded by sea and rich in aquatic products, local people are more interested in sea fish and shrimp. Can crayfish be accepted as an exotic species? After successful pilot breeding in 2006-2007, Changjiang Academy of Agricultural Sciences began promoting crayfish farming in Hainan Island in 2009. The speed and effectiveness of the promotion made Jiangcheng quite surprised and "faster than expected." According to him, at present, crayfish farming in Hainan has spread all over the island, and the main breeding areas have been concentrated in Wenchang and Qionghai and the area has been promoted to over 2,000 mu.

Listening to the writer talking about the bizarre disappearance of death in the crayfish breeding process, Jiang Cheng said that the problem should be out of water quality. Crayfish have strong adaptability to water, water pH 5-9 can grow, the most suitable pH value for crayfish growth is 7-8. "The water quality in Hainan is slightly acidic, most of the water pH value is around 6 and crawfish. The clam shell needs a weakly alkaline environment. The body has been growing, but it is not under the shell, and it is slowly being 'deadly'." Jiangcheng analysis said.

Crayfish should be shelled for 20-24 times in their lifetime. In Hainan, due to the suitable weather, the growth rate is fast. It can be used once a week or even 3-5 days. Therefore, it is often necessary to use quicklime to increase the pH of the water and help the crawfish to clamshell. "At the same time, it also produces calcium ions and increases the calcium needed for oyster shells," Jiangcheng added.

Hou Shaoshan believed that it was not ruled out by the crawfish killing each other. He explained that Hainan's climate is suitable for the growth and reproduction of crayfish all year round. The area of ​​shrimp ponds is limited, but shrimp breeding has been ongoing. Once the crayfish density in the shrimp pond is too large, it will cause prawns to eat shrimp. Therefore, we need shrimp at the right time.

In addition, crayfish belongs to freshwater prawn. Excessive salinity can also lead to death. It should be taken into account when choosing a pond site. Jiangcheng suggested that the salinity of water bodies should be controlled within 5 degrees.

After four years of field farming, Jiangcheng is full of confidence in the development of crayfish farming in Hainan. “It is expected that 10,000 mu of crayfish will be cultivated in Hainan in 3-5 years.” Due to the promising prospects, many farmers plan to enter the market as soon as possible. Recently, Quanjiao Brothers Shrimp Breeding Co., Ltd. contracted the technical guidance of Haikou, a boss, at 25 mu of Wenchang Xinqiao. "If the trial is successful, the boss also intends to pack 100 acres of crayfish." Hou Shaoshan told the author.

According to Hu Lei, another person in charge of the brother shrimp industry, the crawfish are currently transported by dehydration and freezing, and the temperature is controlled within 5°C. The survival rate is above 95%. If air transportation is used, it will increase the cost by 2-3 yuan/500g, and the freight will be less than 1 yuan/500g. Compared with the high price in the off-season sales, the transportation cost can be basically ignored.

"The current consumption on the island is also very large. The current production of crawfish of 2000 mu can be consumed only on the island," Jiangcheng said. It seems that breeding crayfish in Hainan is still feasible.