CATDOLL : CATDOLL: Characteristics of clams

1. Characteristics of clams

Clams are the same size as the shell, triangular or oval, with unequal sides in most species. The shell is usually thin, some species have closed shells, most species have one or both ends open, and often have a shell skin; the shell surface is smooth or has concentric growth lines, and the inner edge of the shell is flat and sharp. The top of the shell is mostly protruding and tilted forward. There is usually a clear boundary between the meniscus and the J surface. There is an external ligament on the edge of the shell top, and another ligament groove, with the internal ligament in the middle.

1. Morphological characteristics

Clams are as big as shells, triangular or oval, with most species having unequal sides. Shells are usually thin, some species have closed shells, most species have one or both ends open, often with a shell skin; shell surface is smooth or has concentric growth lines, the inner edge of the shell is flat and sharp. The top of the shell is mostly protruding and tilted forward. There is usually a clear boundary between the meniscus and the J surface. There is an external ligament on the edge of the shell top, and another ligament groove, with the internal ligament in the middle. The left shell has a split main tooth at the hinge, inverted "V" shape, the top is usually healed, and the posterior branch of the main tooth is next to a secondary piece; the main tooth of the right shell is usually separated. Both the left and right shells have lateral teeth, a single one on the left shell and double ones on the right shell. The mantle sinus is usually deep, round or angular, the water tube is long, and the end is healed.

2. Characteristics of living habits

The feeding method of the clams is passive filtering. As long as the particle size is suitable, they will eat. The main food types are: planktonic and benthic unicellular algae such as Chlorella, Cylindrica, Navicula and Nitzschia, as well as invertebrate eggs, bivalve D-shaped larvae, copepods, nauplii and a large amount of organic debris. Because algae have large seasonal changes and regional differences, the food composition of shellfish collected and analyzed in different seasons or different regions is also different. The feeding time of clams and the individual size and concentration of bait will affect the feeding rate. It has been reported that compared with the horn algae of Mou's horn algae and the Yunxiao microalgae isolated from the sea area, the juvenile spat of the western tongue has a higher selectivity for the four-segment algae, and Chlorella has a very poor effect as both the starter bait and the subsequent bait.

3. Reproduction characteristics

The breeding season varies with different species. There are 1-2 breeding seasons for clams. For example, the firm macaques distributed on the Algarve coast of Portugal have two breeding seasons, July-August and October. The Chinese clams in Dandong, Liaoning have only one breeding season, between July and August. The same species has different breeding seasons in different distribution areas. There are reports that the Atlantic clams have different breeding seasons in different regions. The Atlantic clams in natural habitats such as New Jersey and New York in the United States have two breeding seasons a year, spring and autumn, and can lay eggs many times in each breeding season. However, the Atlantic clams introduced and cultured in Georgia, the United States, have only one breeding season in spring each year. Embryonic and larval development The eggs of clams are sinking eggs, and the number of eggs they carry is closely related to the size and age of the individual.

2. A good breeding model brings good returns. What is the clam breeding model?

Clam farming starts with seedlings. After sowing, the distribution of seedlings should be checked in time. Seedlings that are too dense, too sparse, or partially dead should be replaced in time. Clam farming starts with planting. After 6 to 7 months of cultivation, the seedlings will grow larger, eat more, and have stronger resistance to enemies. The seedlings should be moved to the low tide area to accelerate their growth.

Clam farming should do a good job in disaster prevention. In areas susceptible to typhoons, floods, hot summers, oil spills and other pollutants, preventive measures and rescue measures should be taken. Harvest in advance or move to safe sea areas before the typhoon arrives. After the flood, the covered mud and sand should be cleaned up in time, and the scattered clams should be collected to reduce losses. (IV) Clam farming should prevent enemies and pests. During the cultivation period, regular inspections should be carried out to remove serious enemies and pests in time. Monitor water temperature and water quality, measure water temperature every morning (6:00) and noon (14:00), and observe water color. Daily water storage is mainly based on water quality. The pH value in the pond should be controlled between 7-8, the dissolved oxygen should reach more than 4mg/L, the water color should maintain a relatively ideal yellow-green color, and the transparency should be controlled at 20-40cm. Clam farming should be sampled and measured regularly.

Take samples every half month, measure and observe their growth. If the density is too high or the clams are locally accumulated, they should be evacuated and fed in time. As long as the conditions are good, clams rarely migrate. Feed management for clam farming. The main thing is to cultivate the biomass of feed in the pond. In early spring, spray the entire pond with fresh fish and shrimp paste to increase the organic debris in the pond. Use compound fertilizer and organic fertilizer water on sunny days in summer and autumn; in late autumn and winter, use soybean milk to feed the entire pond.

Prevention and control of clam farming diseases. Use quicklime (10kg/mu) or chlorine dioxide (0.125kg/mu) and other drugs to disinfect water and prevent diseases every month. The princes that block enemies and prevent escape are generally 1.2 meters high and buried 0.2 meters below the surface of the beach, but they must be checked frequently and repaired in time if they are dumped or damaged. After each drainage, the beach should be carefully checked for invasion of enemies such as blue crabs. Once found, the enemies should be removed in time. Cultivating clams can prevent intestinal protozoa from growing on the beach.

When breeding clams, you must pay attention to catching seedlings and check the distribution of seedlings in time. When the seedlings grow larger, their food intake increases, and their ability to resist damage increases, you can move the seedlings to low tide areas to accelerate their growth. You must also pay attention to the impact of natural disasters such as typhoons and floods on clam seedling breeding. You must take preventive and rescue measures, and pay attention to avoiding excessive density of clams and local accumulation. You must evacuate them in time and start breeding and aging clams.

The main beam probably adopts the method of centralized breeding. It is necessary to select a suitable breeding farm, and then it is also necessary to change the water source regularly. It is necessary to feed some feed in time. It is necessary to choose some feed with more comprehensive nutrition. It is necessary to constantly learn the planting methods, so as to improve the efficiency.

The main breeding mode is based on artificial breeding mode. This breeding method is relatively reliable and can make the breeding effect better.

The breeding model needs to be managed more strictly, and it is necessary to learn breeding techniques, ensure breeding skills, and conduct regular inspections.

3. Only by mastering the breeding technology can breeding be done easily. What are the clam breeding technologies?

Only by mastering the breeding technology can breeding be done easily. What are the clam breeding technologies?

Clams are one of the four major aquaculture shellfish in my country. They are delicious and nutritious, rich in protein, polysaccharides, carbohydrates and a variety of nutrients, and are loved by many consumers. With the expansion of market demand, its aquaculture area is also gradually expanding. The following Qinong.com introduces clam aquaculture technology.

Only by mastering the breeding technology can breeding be done easily. What are the clam breeding technologies?

Clam farming technology

1. Breeding sites

The breeding site of clams should be selected in the low-lying tidal flats with smooth flow, flat terrain, high sand content, or in ponds with good water and bottom mud conditions. The transportation conditions of the breeding site must be good to avoid industrial pollution. For breeding on the tidal flats, the tidal flats should be turned over and the fine sand should be washed by the tide and exposed to the sun before being leveled. In areas that are easily washed by the tide and covered by fine sand, embankments should be built to prevent flooding and prevent the outflow of seedlings. For breeding in ponds, the riverbanks and sluice gates should be repaired. The water surface should be drained one month before stocking, the bottom mud should be exposed to the sun, and disinfection should be done. Then, the filtered sea surface should be used for breeding.

2. Planting seedlings

The time of sowing depends on the size of the seedlings. Generally, white seedlings are sown in April-May, medium seedlings are sown in December to the next spring, and large seedlings are sown before laying eggs. There are two ways to sow seedlings, dry sowing and wet sowing. Dry sowing is to sow the clam seedlings evenly after the tide recedes and the ground is exposed to avoid piles; while wet sowing is to sow evenly in areas with slow tides before the tide recedes. Wet sowing has a long planting time and a higher survival rate, but it is only suitable for large and medium-sized seedlings. The relative density of sowing seedlings must be paid attention to. If the relative density of sowing round seedlings is too high, the clams will grow slowly, but if the relative density is too sparse, the production will be low, so the relative density of sowing seedlings must be controlled.

3. Strengthen management

After sowing the seedlings, it is necessary to frequently inspect and manage the area to check whether the seedlings have flowed out, the growth rate and survival rate of the clams, and to promptly replenish the seedlings and take relevant countermeasures. In addition, it is also necessary to pay attention to the repair of the dam and riverbank to prevent the clams from escaping. In addition, the clams that have just been bred are extremely weak and often float on the dam. At this time, it is necessary to pay attention to the death caused by human trampling. After breeding, it is necessary to strengthen management or transplant them to other places in time.

4. Strengthen disease prevention and control

Disease prevention and control should be strengthened during breeding, especially in the high temperature environment in summer, which is the period when clams are prone to diseases. Clams often infect each other after they die and rot. In addition, high temperature weather can easily pollute the water and bottom mud, which is the breeding period of sparganosis and microbial species. The breeding area should be disinfected and sterilized regularly. Lime powder or chlorine dioxide can be used to spray and disinfect the water. In addition, when raising seedlings in summer, oxytetracycline can be added to the water to prevent diseases and pests, inhibit the breeding of seedlings, and benefit the growth of clams.

The above is the clam farming technology produced by Qinong.com. The clam farming technology is introduced in detail here, and I hope it can help everyone.

When breeding, you must first find a beach away from industrial pollution, and the sand content must be particularly high, and the water quality must be relatively clear. Then you must strengthen management, and then you must fence off this piece of beach, and there must be someone guarding it, and don't trample on it while looking for seedlings.

It is necessary to learn technical management skills, pay attention to water temperature, pay attention to the method of breeding, choose a suitable breeding site, pay attention to the time of sowing seedlings, and understand the specific breeding cycle.

Choose a good geographical environment for breeding, pay attention to the principles of breeding, pay attention to the management during the breeding period, pay attention to the construction of the pond, and understand the water source situation.

There is a difference between them. The harm caused by staying up late and not being able to sleep is different. Not being able to sleep may be due to insomnia. Staying up late is because you are too excited to sleep.