Several measures for shortening the culture cycle of cultured scallop

Scallop I think we are still very familiar with in life, many people like to eat scallops very much, scallop is one of the most common seafood people eat, and the nutritional value of scallops is also very high, its protein content is very high, so the market demand for scallops is still quite large.

Several measures for shortening culture cycle of scallop

1. There are two suitable temperature growth periods in a year for timely seedling division and inverted cage scallop. It takes three suitable temperature growth periods for chlamys farreri seedlings to grow into adult shellfish. Therefore, it is necessary to seize the time to divide seedlings before the end of August of that year in production, so that the shell height of shellfish seedlings will reach 2 cm ~3 cm by the end of the year. The big seedlings can be harvested from October to November at the end of the year; the small seedlings can be harvested from April to May in the spring of the third year.

In addition, the time of cage inversion also has a great impact on the growth of scallops. Generally, when the water temperature rises to about 5℃ in the spring of the next year, the cage should be inverted in time. If the work of cage inversion can be completed around the middle of April, the scallop can make full use of the two suitable temperature growth periods of the year and grow into a shell height of 6 cm ~7 cm.

2. Regulate the culture water layer in time. In winter (water temperature is lower than 5℃) and summer (water temperature is higher than 25℃), sink the scallop into the middle and lower seawater for culture, so that it can safely overwinter and spend summer; in spring and autumn (water temperature is 10℃~23℃), raise the scallop to 2 m ~3 m water layer for culture. In these two seasons, due to the suitable upper water temperature, the bait is rich, which is conducive to the growth of scallops.

3. Timely removal of attached organisms A large number of attached organisms attach to scallop culture, resulting in poor water flow and reduced bait, which seriously affects the growth and survival of scallops. The methods of removing attached organisms are as follows: ① sinking raft in July and August in summer to avoid attached water layer;② timely brushing cage, pouring cage, washing net cage once every 1 month ~2 months, pouring cage once every April and August every year, pouring cage can completely remove attached organisms.

4, adjust buoyancy with scallop growth, coupled with the attachment of attached organisms, raft load gradually increased, in order to maintain a reasonable water layer and prevent sinking raft, should adjust buoyancy in time, can increase the number of floats or double row suspension float. Daily management should also check whether there is floating off, rope loose, broken net cage opening, net cage intertwined with each other and other phenomena, found problems solved in time.

5. In order to improve the utilization rate of sea area and increase economic benefit, the interculture and rotation culture of shellfish and algae are generally implemented in scallop culture. The metabolites of scallop provide organic fertilizer for kelp and increase the nitrogen content of sea area; carbon dioxide exhaled by scallop increases the raw material for photosynthesis of kelp. The oxygen discharged by kelp photosynthesis is beneficial to the respiration of scallops; the kelp algae floating in water plays a role in shading scallops, which is beneficial to the feeding and growth of scallops, so the two are beneficial to each other. The main methods in production are raft culture and rope culture. The former raises kelp on one raft every 1 ~2 rafts, while the latter raises scallop in one cage every 4 ~5 ropes. Bay scallop can be cultured in rotation with kelp. After kelp is harvested in June, bay scallop seedlings can be temporarily cultured. In July, bay scallop seedlings can be cultured in cages. In October, kelp seedlings can be cultured in the sea (only occupying 10% of the culture sea area). Bay scallop can be harvested in November. After harvest, kelp seedlings can be cultured, which can double the utilization rate of the sea area.

What is scallop?

Scallop is a bivalve animal, its shell was fan-shaped, like a fan, so the name scallop. It is one of the precious marine treasures, distributed along the coast of our country. In the past, most of them relied on fishing natural resources. In recent years, artificial breeding has been developed along the coast. The main cultivated species include the original scallop Chlamys farreri, the shrimp scallop Yessoensis introduced from Japan and the bay scallop from the United States. Scallops are generally harvested all year round, but the quality is better in spring.

Scallop shells are purple-brown, light brown, apricot yellow, reddish brown or gray, etc. In the sea, scallops usually attach to rocks, gravel, shells, coral reefs or other objects by foot silk, and some of them live on the sandy bottom of the sea, from the shallow sea below the tide line to the deep sea of 5000 meters. It likes to live in groups, often individuals are involved with each other, one even one, can form a natural scallop field. It is observed that it takes about 3 years for scallops to grow from spawning to adulthood, among which it takes about 19 months for scallop yessoensis to grow faster, but bay scallop with the fastest growth rate can be harvested and marketed in the same year.

Key points of scallop culture technology

1. Seed selection: Select healthy and disease-free shellfish seedlings with shell height of 0.5cm, try to use local seedlings, both in quantity and quality, and use foreign seedlings to consume a large amount of seedling energy after long-distance transportation, resulting in a large number of deaths.

2. Timely seedling division: oyster attachment period is at the end of July. Therefore, try to postpone the last seedling stage,

3. Living habits: bay scallops are mostly distributed at 3-10 meters below the sea surface, and their character is more spicy. The temperature tolerance range is-1-31℃, the growth stops below 5℃, the growth is slow below 10℃, and the growth is faster at 18-28℃. When the environment is not suitable, can cut the foot silk by itself to use two shells to open and close the water to carry on the rapid movement. Under the condition of artificial culture, low density stocking and higher density stocking grew faster, and the seedling grew faster earlier than the seedling later.

4. Reproductive habits: bay scallop is hermaphrodite. Its growth and development is fast, spring breeding seedlings, breeding to autumn shell up to 5 cm when the gonads mature, and can be used for parent shellfish eggs to cultivate seedlings. In the northern waters of China, bay scallop has two breeding peaks in spring and autumn, from late May to June in spring and from September to October in autumn. After autumn reproductive period, abdomen is transparent and azoospermic eggs exist.

In the process of scallop cultivation, only by shortening the cultivation cycle of scallops can more profits be obtained. Therefore, the cultivation cycle of scallops is very important. Farmers should not only communicate with each other and learn from each other, but also constantly develop new technologies and methods.