Wen Hao seed breeding and raising technology [3]
2018-04-22 13:00:38
(Continued from the previous period) 3. Seed selection and seedling density: Choose the clam seedlings with strong digging ability, light surface, no damage, and no disease. The specification is 1.5~3.0cm in body length, and 500~1000 for 500g. Suitably, the environment from which the seedlings are derived should be basically the same or similar to that of the adult cultured clams.
The stocking density of the seed depends on the fertility of the sea area and the individual size of the seed, and it is also related to the tide level of the cultured area. Stocking in submerged areas with shallow water should be larger, and stocking capacity can also be more. The stocking density of large-scale cultured clams is generally 50~80kg/666.6m2 (specification: shell length 1.5~3.0cm).
In order to explore the impact of different culture densities on the growth of clams, we chose four densities of 50 grains/m2, 80 grains/m2, 100 grains/m2, 150 grains/m2, and an average size of 1.2 cm in diameter. Rice, stocked on May 21st, covered with screen mesh to prevent escape, after more than two months of testing, to August 16 inspection, the average specifications were 2.1cm, 2.05cm, 1.95cm, 1.7cm, respectively, survival rate For 83%, 84%, 80%, 70%, the results show that the density of the cultivar with a size of about 2 cm, 100 grains/cm2 or less has little effect on the growth and survival rate, and the growth rate is slow at a density of 150 grains/cm2. The low rate is mainly related to the shortage of food organisms.
Seeding can be carried out when the tide is stable, and seedlings must be sown on the beach. If the temperature is high, you should choose to do it on a cloudy day or at dawn or dusk. Seeds that have been damaged or killed should not be sown in farms and should be handled lightly so as not to injure ligaments and shells.
4. Raise the line at the breeding site to further prevent escape facilities: The role of the site pull line is to “cut off†the mucus belt formed by the clam's own secretions and prevent the clams from clustering to the fence. Pull the line method is: in the field in the direction perpendicular to the direction of the trend of short-pile piles, "well" type pull line, line beach 3 ~ 5cm.
In general, after the string is pulled on the farm, most of the mandarin ducks are concentrated on-line, under the pile, and on the edge of the net. The distribution of the clams in the entire culture site is relatively balanced. Without the site of the pull line, there are a large number of clams clustered on the side of the fence at the low tide level. This situation is not conducive to Wen Hao feeding, breathing, impede the normal growth of Wen Hao.
5. Day-to-day management: (1) Check the stakes and fences, and find that they are lifted in time to pick up and reinforce them, and find that the fence is broken and repaired in time;
(2) The evacuation of purse seine, especially during the tidal period;
(3) Found that there is quicksand or silt rushed into the site, it should be cleaned up in time;
(4) Frequently collecting or expelling predator organisms such as apes, fish, crabs, birds, and echinoderms. Remove barnacles and algae attached to stakes and fences. Clearing method: after sun exposure, the sticks are patted with a stick, and the barnacles and algae dropped out of the court, and the barnacles on the stakes are scraped with a knife; (5) Clearing in time The deceased gentry has prevented the pollution of the beach.
6. Harvesting: The determination of the harvest period of the mandarin duck must take into account the situation of transportation and distribution of mandarin ducks and manure, and it may also be considered to be conducive to the reproduction and protection of resources. It is generally collected during low temperatures in spring and autumn, and is generally not collected during hot summers and winters.
Harvesting methods: (1) After ebbing, step on the beach surface with both feet and step on the side. When the wenyu exposes the beach due to treading, pick it up with a three-toothed hook.
(2) After the iron plane is inserted into the beach surface with a certain depth, the iron shovel retreats at a certain inclination. When the collision occurs, it is turned or vibrated, that is, it is picked up with a three-toothed hook.
(3) The clams in the shallow water zone in the subtidal area are generally collected by hand.
(III) Temporary culture and spitshave technology 1. Temporary rearing pool The temporary stag pool is a brick-through pond, with a single pond area of ​​about 1 mu, a water depth of 1~1.2m, and a bottom layer of 20~30cm sand. Drainage is convenient, water quality is good, there is a storage tank, in order to maintain water quality and cultivate food.
2. Holding density According to the seasonal water temperature, the stocking density is different. When the water temperature is below 20°C, the mu will be raised for 5 to 10 tons. When the water temperature is above 20°C, the mu will be raised for 3 to 5 tons.
3. Restocking method The finished mandarin duck shall be washed with seawater after fishing from the farm, and the grading shall be carried out until the holding tank is filled with water of 5~10cm and evenly sowed and then filled with water.
4. Change the water twice daily in daily management, once in the morning and at night, change the amount of water 100% each time. Change the water and promptly bring out the death rumor so as not to pollute the bottom of the pool. Keep the salinity constant for each change of water so as to avoid sudden changes. After about one week, you can spit away the net sediment and catch and export the package. The survival rate of holdings is generally up to 90%.
3. Summary 1. The first step in the production of artificial breeding of clams is to obtain a large number of mature eggs. There are more induction methods to obtain mature eggs. The most suitable method for artificial induction is dryness (3~4 hours), then water stimulation (2~3 hours), then put in ammonia water (0.15~0.25‰) soak for about 20 minutes, and increase temperature (3~5°C). Through this method of induction, the discharge rate of the parent crab shellfish can reach more than 50%.
(2) Adopting indoor intensive cultivation to promote gonad maturation will enable Wen Qi to reach sexual maturity one month ahead of schedule and develop neatly.
3. Semi-artificial seedlings in the sea area are greatly influenced by natural conditions. Heavy rain began on July 25, 2001, causing changes in sea salinity and water temperature, which led to the spawning concentration of the clams. Therefore, the amount of seedlings was large. During the mature ovulation of clams in 2002, due to the high salinity of seawater, ovulation was not concentrated. And with a very low amount of seedlings. Due to the low cost of semi-artificial seedlings in the sea area and the large amount of seedlings to be harvested, it is still the best way to obtain the grazing maggots before making large-scale seedlings at the factory. However, in August 2001, the seedling density was 21,000 tablets/m2, which was only 103 capsules/m2 in August 2002. Excluding natural deaths, it was thought that with the growth of C. oleifera seedlings, it gradually moved downwards. This increased the number of seedlings in the lower breeding farms. prove.
4. The clams should be kept at a temperature above 10°C. Otherwise, the viability of the seedlings is poor, and the survival rate is low. Therefore, if the clams are harvested, if the clams have a large proportion, they should be carried out at a water temperature of 10°C or more to avoid returning. Low survival rate of seedlings causes losses.
5. Tests found that: After the clams were caught in the spawning period of clams, the clams were of weak constitution and had a high mortality rate during the holding period. Therefore, they should be held for another month after spawning.
6. Temporary grazing of Wenyu will help increase the quality of merchandise, facilitate centralized sales, increase sales prices, and obtain better economic benefits. In particular, storage at New Year's Day will require higher export prices.
7. Piles should be hit by slanting piles. Oblique piles can prevent barnacles and meshes from rubbing under the action of wind and waves after a large number of barnacles are attached. It is not easy to cause the phenomenon of broken ropes and cracked nets, and at the same time can effectively avoid the As a result of strong winds and storms, a large number of clams were lost.
The stocking density of the seed depends on the fertility of the sea area and the individual size of the seed, and it is also related to the tide level of the cultured area. Stocking in submerged areas with shallow water should be larger, and stocking capacity can also be more. The stocking density of large-scale cultured clams is generally 50~80kg/666.6m2 (specification: shell length 1.5~3.0cm).
In order to explore the impact of different culture densities on the growth of clams, we chose four densities of 50 grains/m2, 80 grains/m2, 100 grains/m2, 150 grains/m2, and an average size of 1.2 cm in diameter. Rice, stocked on May 21st, covered with screen mesh to prevent escape, after more than two months of testing, to August 16 inspection, the average specifications were 2.1cm, 2.05cm, 1.95cm, 1.7cm, respectively, survival rate For 83%, 84%, 80%, 70%, the results show that the density of the cultivar with a size of about 2 cm, 100 grains/cm2 or less has little effect on the growth and survival rate, and the growth rate is slow at a density of 150 grains/cm2. The low rate is mainly related to the shortage of food organisms.
Seeding can be carried out when the tide is stable, and seedlings must be sown on the beach. If the temperature is high, you should choose to do it on a cloudy day or at dawn or dusk. Seeds that have been damaged or killed should not be sown in farms and should be handled lightly so as not to injure ligaments and shells.
4. Raise the line at the breeding site to further prevent escape facilities: The role of the site pull line is to “cut off†the mucus belt formed by the clam's own secretions and prevent the clams from clustering to the fence. Pull the line method is: in the field in the direction perpendicular to the direction of the trend of short-pile piles, "well" type pull line, line beach 3 ~ 5cm.
In general, after the string is pulled on the farm, most of the mandarin ducks are concentrated on-line, under the pile, and on the edge of the net. The distribution of the clams in the entire culture site is relatively balanced. Without the site of the pull line, there are a large number of clams clustered on the side of the fence at the low tide level. This situation is not conducive to Wen Hao feeding, breathing, impede the normal growth of Wen Hao.
5. Day-to-day management: (1) Check the stakes and fences, and find that they are lifted in time to pick up and reinforce them, and find that the fence is broken and repaired in time;
(2) The evacuation of purse seine, especially during the tidal period;
(3) Found that there is quicksand or silt rushed into the site, it should be cleaned up in time;
(4) Frequently collecting or expelling predator organisms such as apes, fish, crabs, birds, and echinoderms. Remove barnacles and algae attached to stakes and fences. Clearing method: after sun exposure, the sticks are patted with a stick, and the barnacles and algae dropped out of the court, and the barnacles on the stakes are scraped with a knife; (5) Clearing in time The deceased gentry has prevented the pollution of the beach.
6. Harvesting: The determination of the harvest period of the mandarin duck must take into account the situation of transportation and distribution of mandarin ducks and manure, and it may also be considered to be conducive to the reproduction and protection of resources. It is generally collected during low temperatures in spring and autumn, and is generally not collected during hot summers and winters.
Harvesting methods: (1) After ebbing, step on the beach surface with both feet and step on the side. When the wenyu exposes the beach due to treading, pick it up with a three-toothed hook.
(2) After the iron plane is inserted into the beach surface with a certain depth, the iron shovel retreats at a certain inclination. When the collision occurs, it is turned or vibrated, that is, it is picked up with a three-toothed hook.
(3) The clams in the shallow water zone in the subtidal area are generally collected by hand.
(III) Temporary culture and spitshave technology 1. Temporary rearing pool The temporary stag pool is a brick-through pond, with a single pond area of ​​about 1 mu, a water depth of 1~1.2m, and a bottom layer of 20~30cm sand. Drainage is convenient, water quality is good, there is a storage tank, in order to maintain water quality and cultivate food.
2. Holding density According to the seasonal water temperature, the stocking density is different. When the water temperature is below 20°C, the mu will be raised for 5 to 10 tons. When the water temperature is above 20°C, the mu will be raised for 3 to 5 tons.
3. Restocking method The finished mandarin duck shall be washed with seawater after fishing from the farm, and the grading shall be carried out until the holding tank is filled with water of 5~10cm and evenly sowed and then filled with water.
4. Change the water twice daily in daily management, once in the morning and at night, change the amount of water 100% each time. Change the water and promptly bring out the death rumor so as not to pollute the bottom of the pool. Keep the salinity constant for each change of water so as to avoid sudden changes. After about one week, you can spit away the net sediment and catch and export the package. The survival rate of holdings is generally up to 90%.
3. Summary 1. The first step in the production of artificial breeding of clams is to obtain a large number of mature eggs. There are more induction methods to obtain mature eggs. The most suitable method for artificial induction is dryness (3~4 hours), then water stimulation (2~3 hours), then put in ammonia water (0.15~0.25‰) soak for about 20 minutes, and increase temperature (3~5°C). Through this method of induction, the discharge rate of the parent crab shellfish can reach more than 50%.
(2) Adopting indoor intensive cultivation to promote gonad maturation will enable Wen Qi to reach sexual maturity one month ahead of schedule and develop neatly.
3. Semi-artificial seedlings in the sea area are greatly influenced by natural conditions. Heavy rain began on July 25, 2001, causing changes in sea salinity and water temperature, which led to the spawning concentration of the clams. Therefore, the amount of seedlings was large. During the mature ovulation of clams in 2002, due to the high salinity of seawater, ovulation was not concentrated. And with a very low amount of seedlings. Due to the low cost of semi-artificial seedlings in the sea area and the large amount of seedlings to be harvested, it is still the best way to obtain the grazing maggots before making large-scale seedlings at the factory. However, in August 2001, the seedling density was 21,000 tablets/m2, which was only 103 capsules/m2 in August 2002. Excluding natural deaths, it was thought that with the growth of C. oleifera seedlings, it gradually moved downwards. This increased the number of seedlings in the lower breeding farms. prove.
4. The clams should be kept at a temperature above 10°C. Otherwise, the viability of the seedlings is poor, and the survival rate is low. Therefore, if the clams are harvested, if the clams have a large proportion, they should be carried out at a water temperature of 10°C or more to avoid returning. Low survival rate of seedlings causes losses.
5. Tests found that: After the clams were caught in the spawning period of clams, the clams were of weak constitution and had a high mortality rate during the holding period. Therefore, they should be held for another month after spawning.
6. Temporary grazing of Wenyu will help increase the quality of merchandise, facilitate centralized sales, increase sales prices, and obtain better economic benefits. In particular, storage at New Year's Day will require higher export prices.
7. Piles should be hit by slanting piles. Oblique piles can prevent barnacles and meshes from rubbing under the action of wind and waves after a large number of barnacles are attached. It is not easy to cause the phenomenon of broken ropes and cracked nets, and at the same time can effectively avoid the As a result of strong winds and storms, a large number of clams were lost.