Zhanjiang Ascendas Industrial Co., Ltd. is a comprehensive enterprise specializing in aquatic seedling cultivation, marine aquaculture and feed research and development. The company invested 15 million yuan in zhanjiang Donghai Island southeast wharf to build the Ascendas Dongfeng snail farm (main field), the production of Dongfeng snail seedlings in 2014 was identified as high-tech products in Guangdong Province. The farm is fully equipped, with standardized bronch breeding, snail seedling cultivation workshop and other advanced facilities, was awarded the title of "Ministry of Agriculture Aquatic Healthy Breeding Demonstration Farm" by the Ministry of Agriculture, and passed the quality management system and food safety management system certification, is the equipment, technical strength and scale of the west Guangdong region are among the best seawater seedling breeding farms.
Breed excellent varieties of mud dongfeng snail
Mud East Wind Snail, commonly known as Yellow Snail, distributed in the East China Sea and the South China Sea, lives in the sedimentary seabed of several meters to tens of meters deep, is a wide salinity, wide temperature carnivorous shellfish, the suitable temperature range is 13 °C -33 °C, the most suitable growth water temperature is 25 °C -30 °C, the salinity adaptation range is 20 ‰-34 ‰, the most suitable salinity is 25 ‰-32 ‰, and the pH adaptation range is PH7.5-8.4. The breeding period of mud-east wind snails is from March to October, and the breeding peak period is from June to September. Mud Dongfeng snail meat is delicious, rich in nutrition, contains a variety of amino acids and rare elements and rare cholesterol, has high economic value, is a very best-selling high-quality seafood shellfish in the domestic and foreign markets, since 2005, mud Dongfeng snail breeding in Zhanjiang rapid development, has now become one of the main marine shellfish breeding industry in Zhanjiang City.
Most of the research on the domestic mud east wind snail focuses on its biological characteristics (including embryonic development), breeding technology, bait analysis and preparation, disease prevention, seedling technology, ecological control, etc. Breeding related research is relatively small, and the breeding of mud east wind snail is a topic that needs to be deeply excavated. With the advancement of time, the germplasm degradation of artificially bred Dongfeng snails is obvious, the growth is slowed down, the disease resistance is weakened, and some degraded groups have been breeding for more than one year.
In order to protect and develop the germplasm resources of Mud Dongfeng snail, and select breeding varieties with excellent growth, disease resistance and reproductive traits, from 2016 to 2020, Ascendas Dongfeng Snail Farm invested 4 million yuan in the breeding of mud Dongfeng snail seeds, and after the completion of the project, it achieved an annual output of 10,000 mud Dongfeng snail parents, 30 million mud Dongfeng snail seedlings, an output value of 4.7 million yuan, and the growth rate of the breeding mud Dongfeng snail family line was 15%-25% higher than that of the parents, and the survival rate was increased by 20%-30%. Products are mainly sold in Guangdong, Guangxi, Hainan, Fujian, Zhejiang, Qingdao and other places, by providing a large number of high-quality mud Dongfeng snail seedlings to the market, driving the breeding of mud Dongfeng snails, to increase the employment of fishermen and improve the economic income of fishermen has made a contribution. In the process of breeding, the operation specifications of mud dongfeng snail seedlings, bait and grow-out were formulated, which promoted the industrial breeding of dongfeng snail in the coastal area of Guangdong; the circulating water system was built, and the discharge of aquaculture water reached the national standard, which realized zero pollution of the aquaculture water body and promoted the sustainable and healthy development of the mud dongfeng snail breeding industry.
Undertake a number of Dongfeng snail science and technology research and development projects
Ascendas Dongfeng snail farm is fully equipped with facilities such as pro-snail breeding workshop, seedling workshop, algae pond, experimental office building, feed warehouse, pharmaceutical warehouse, water quality analysis and seedling quality testing laboratory, production management room, power supply, gas supply, heat supply, water supply and drainage treatment system. Invested 4.7 million yuan to rebuild 460 acres of first-class shrimp ponds in the nunnery as a shrimp pond breeding dongfeng snail site. Among them, 2.9 million yuan was invested in the transformation of the water surface area, water supply and drainage system of 150 mu of shrimp mud pond in the annuli of Donghai Island, the mulch film was laid on the pond wall and the bottom of the pool, and the 300m seawater treatment system of the southeast pier of Donghai Island was built to enter the sea pipeline, and the oxygenation facilities were added to make it a Dongfeng snail breeding pond. In the shallow subtidal line of the Tokai Island Anri, the Dongfeng Snail Sea Area was cultivated for 15 hectares and used for bronch breeding. Construction of a 1.6-hectare pilot base for Dongfeng snail on Tongzhou Island. It has become one of the largest demonstration and promotion bases for large-scale standardized breeding of Dongfeng snail breeding in China.
In 2010, 2011 and 2012, Ascendas Dongfeng Snail Farm undertook the scientific and technological research and development project of Dongfeng Snail, "Dongfeng Snail Factory Seedlings and Large-scale Breeding and Bait Production"; from 2012 to 2013, Dongfeng Snail Farm undertook the guangdong Provincial Marine Fisheries Bureau's science and technology promotion special scientific and technological research and development project "Factory Farms, Ponds, From 2011 to 2013, he undertook the Guangdong Provincial Aquatic Breeding System Construction Project "Selection and Breeding of Fangban Dongfeng Snail", and in 2016, he undertook the Guangdong Provincial Aquatic Seed System Construction Project "Mud Dongfeng Snail Breeding". Among them, "Dongfeng Snail Factory Seedling and Large-scale Breeding and Bait Production" won the second prize of Zhanjiang Municipal People's Government Science and Technology Progress Award. A kind of soft body bait for the grow-out period of the square spotted Dongfeng snail and a technology for using mulch shrimp pond to cultivate the square spotted Dongfeng snail have been patented.
Zhanjiang Ascendas Industrial Co., Ltd. has a strong technical force, the existing various types of professional and technical personnel 12 people, including 2 senior technical personnel, intermediate technical personnel 10 people, and long-term cooperation with sun Yat-sen University School of Life Sciences, South China Sea Fisheries Research Institute, Guangdong Ocean University and other scientific research institutions.
Technical route of breeding of nihon dongfeng snail
Collect, select and nurture high-quality parents. From the origin of the South China Sea to introduce sexually mature individuals or immature individuals cultivated into bronch, bronch should collect wild snails with good physique, average shell length of 6 cm, smooth body surface, good vitality, complete spiral shape, healthy and disease-free near the spawning period, the ratio of male to female is about 1:1, released in the filtered and disinfected spawning pond, the proportion of pool water is 1.018 ~ 1.022, the water temperature is 28 ~ 31 °C, and the micro-flowing water is properly inflated.
The bronch is transported to the breeding farm and subjected to strict disinfection. Remove the mud moss and other attachments on the surface of the snail shell, rinse it with filtered seawater, and disinfect it with a concentration of 10 to 15 mg/l of povidone iodine for 5 minutes, at which time it is necessary to pay attention to aeration and oxygenation. Cultivated in parental ponds, fortified with nutrients and moderately induced labor. The conchs are temporarily reared and quarantined to eliminate the sick group.
Establish a family lineage. Determine standardized breeding conditions and measurement procedures to ensure consistency in water quality, bait density, and seedling release specifications, clarify the interval between batches, and ensure the reliability and validity of data. Individuals from the South China Sea mud dongfeng snail and the native mud dongfeng snail group who enter the breeding system in China are inbred or hybridized to obtain a family lineage. Its F1 generation disease resistance and growth rate are more than 10% higher than the same snail seedling growth rate.
Genetic marker analysis is performed intensively on the family line to obtain genetic markers. Each lineage is bred under the same factory conditions and selected according to the needs of growth rate. The seedlings, young snails, adult snails, and near-mature parent snails were selected at a standardized growth rate, calculated and analyzed, and the families that did not meet the requirements were eliminated.
The seedlings, young snails, adult snails and near-mature parent snails of the anti-pathogenic lineage are attacked by pathogenic bacteria once respectively, and after standardized selection, calculation and analysis, the families that do not meet the requirements are eliminated.
According to the data obtained by standardized breeding conditions and standardized determination procedures (4-5 effective assays/year), the comprehensive breeding value was calculated, the mating weight was established, the growth rate of the selected breeding line was increased by 15%-25%, the survival rate was increased by 20%-30%, and the mating scheme was established.
Repeated selection. The growth rate of the selected mud dongfeng snail families increased by 15%-25% compared with that of the general parents, and the survival rate was increased by 20%-30%. In the 3-5 generations of breeding, the genetically stable breeding lines of good breeds with excellent traits such as fast growth or strong disease resistance and adaptability to the local geographical environment were obtained, and genetic stability evaluation was carried out.
Field cultivation. While retaining the selective breeding family line, according to the breeding value, mating between the families, breeding 1-3 core groups or families, homogeneous group mating, while breeding, tracking, according to the factory, field, beach breeding effects are statistically analyzed, according to the standard retention of seeds, after 3-5 generations to obtain the core group or family line.
Mud Dongfeng snail seed. According to the obtained genetic traits stable, good breeding effect of the family data, through statistical analysis to produce varieties. Continue the breeding process, cultivate excellent varieties, and prevent the degradation of the germplasm of mud-easterly snails. Formulate norms for the selection and breeding and cultivation of snails in the mud and east wind. Establish a breeding system for mud-east wind snails and cultivate more fine seeds.
Source: Marine & Fisheries
Reporter: Zhou Lixiong