(scallop)
Variety source: Yellow Sea
Features: It belongs to mollusk, bivalve, Claudian, Heteropoda, Scallopidae and Scallop. Living on rocks and sandy seabed from 3m to 30m; Filter feeding, the bait is mainly phytoplankton; Temperature range-1.5℃ ~ 25℃; The suitable salt range is16 ‰ ~ 43 ‰; The spawning period is May to June; It has a wide range of uses, tender meat, delicious taste and high economic value.
It is a natural species in China's sea areas. It is suitable for aquaculture in China's vast sea areas, especially in the northern coastal areas. Chlamys farreri is attached to life and has well-developed feet. The height of adult shells can reach more than 8 cm. Named after the right shell front ear has obvious foot holes and several fine comb teeth. The growth line of the shell surface is thin, with radial ribs of different thickness; The left shell is about 10, and the right shell is about 20 pieces, with irregular microprotrusions on the ribs.
(bay scallop)
Variety source: 1982 introduced from America.
Bay scallop is not suitable for breeding in China, mainly because the individual filtration capacity of bay scallop will reach 1.2 cubic meter to 1.5 cubic meter within 24 hours. With the increase of scallop culture area in China, the water quality in a large area is too high and the dissolved oxygen is too low. The output of scallop is less than one year, other cultured organisms are greatly reduced, and the seabed silt is thickened. As a result, China's marine environment will be seriously damaged, and personal opinions will be quickly generated by fisheries and environmental protection departments.
Features: Mollusca, Claudiobranchia, Heterocladocera, Scallopidae, Scallop. The shell is fan-shaped, the two shells are almost equal, the rear ear is larger than the front ear, and there is a foot hole under the front ear. There are 18 radiation edges on the shell surface, and the shell surface is dark brown or brown. The optimum growth temperature is 5-30℃ and 18-28℃. Chlamys farreri Chlamys farreri is named Jones et Preston. The common names are scallop clam (composed of its obturator internus) and sea fan, which belong to mollusca, Cladosporium, Pinctada, Chlamydae and Scallop.
morphological character
Big shell, measure scallops. Generally, the shell is 74cm long, 77MM high and 27.5 mm wide. The size and sides of the shell are slightly symmetrical, and the right shell is flat, with many different thicknesses of radiation on it. The size of the front and rear ears of shells is different, the front is big and the back is small, and the shell surface is mostly light gray.
Ecological habit
Chlamys farreri lives below the low tide line, with fast current, high salinity and high transparency, and the water depth is 10-30m on the rocky reef or hard seabed with shell gravel. It lies on the attachment base, its feet are connected, and its right shell is below. Animals can open and close their double shells to drain water and swim a short distance in response. Closing the shell can make a crisp sound and you can swim in the water with your feet off. In normal life, two shells are usually opened to filter unicellular algae, organic debris and other small microorganisms in seawater. If the environment doesn't adapt, the crural line can be cut off automatically, and the shell muscles can expand and contract quickly, relying on the power of shell opening and closing drainage and the power of ocean current for short-distance movement. Chlamys farreri has strong low temperature resistance and can survive below 0℃. 15-20℃ is the optimum growth temperature. When the water temperature exceeds 25℃, the growth is inhibited, and the shells can hardly grow below 4℃. For high salinity species, the optimum salinity range is 23-34. Chlamys farreri has high oxygen consumption rate and poor manna resistance.
Origin and season
It is produced in the northern coastal areas of China, mainly in Shandong Long Island, Weihai, Penglai, Shidao, Wendeng, Dalian, Liaoning and Changshan Island.
Reproductive characteristics
Chlamys farreri is hermaphrodite, and there is hermaphroditism. In the breeding season, the female gonad is orange and the male gonad is milky white, which is obviously different. After the breeding season, the gonads degenerate, and the male and female shapes are the same, showing colorless and translucent shape. Chlamys farreri has two breeding periods every year. The first time was from May to July, and the water temperature 14-20℃. The second time was from September to June, and the water temperature was 22-20℃. The breeding season is mainly related to water temperature, which varies greatly in different sea areas. The southern coast of Shandong Province entered the peak breeding season in the first half of May. However, in the waters of the northern island of Long Island, the breeding peak is only in June and July. In addition to water temperature, the change of gonad tree planting is also an important basis for determining the breeding season. When the gonad index reaches 15% on average, it enters the breeding season. During the breeding season, it has the habit of discharging many times. After the first discharge, it can be discharged in about a week, and the shelling is repeated many times. The amount of eggs laid increases with the increase of individuals. The height of the shell is 6-7cm, which is twice that of the second instar. The spawning amount is 8 million-10/00000, and the spawning amount is about 2 million at a time. The number of eggs laid by the third instar with a shell height of 8-9cm is150,000, and the number of eggs laid at one time is about 4 million. The mature egg is about 70 microns in diameter and the sperm is about 50 microns in length.
grow seedlings
The suitable density for larval culture is 8- 12 /mL, and the culture water temperature is 18-20℃. The fertilized eggs can be fed with Phaeodactylum tricornutum, Isochrysis tricornutum, Chrysophyta tricornutum, Chlorella, Sargassum and Platymonas when they hatch to the D-shaped larval stage. Taking Isochrysis globosa as an example, the initial daily food intake of D-shaped larvae is 1 0,000-10.5 million/ml; The daily food intake at the top of the shell is 1.5-50000/ml; Feed in 3-6 times. The mixed feeding effect of multiple baits is better than that of single bait. Change water twice a day. The light is generally controlled at 500lx. Pour the pool every 5-7 days. In seawater with high heavy metal content, 2-3g of disodium ethylenediamine tetraacetate (EDTA) is added per cubic meter of water. The attachment base is generally a small curtain made of brown rope (rope diameter is about 8mm) or polyethylene net. After adhesion, it needs to be treated with 0.5% sodium hydroxide to clean oil stains. After repeated hammering and soaking, debris, impurities and soluble harmful substances are removed. Putting the attachment base too early will not only affect the normal management of the nursery pond, but also be easily polluted by residual bait and impurities, which will make the water quality worse and make it difficult for larvae to attach. If the attachment base is put in too late, a large number of larvae will miss the best attachment opportunity and sink and die. The best release time should be when more than 50% larvae in the pond have eye spots, and generally cooperate with the inverted pond.
Key points of breeding
Raft culture: Build a raft frame in the sea area, and then hang a breeding cage on the raft frame. Among them, about 200 are controlled in the first floor of Yabei 1cm, and the stocking amount is115 hectares with 400 cages; Ear piercing and hanging culture: drill a small hole in the front ear of the young shellfish with a shell height of more than 3CM, and then hang it on the culture rope for culture; Bottom-sowing culture: shellfish fry are directly sown to the seabed or intertidal zone for culture, and can be mixed with prawns.
incubation time
Chlamys farreri is perennial, and 1-2-year-old shellfish grow faster. Under the condition of artificial raft culture, the shell height of the larvae cultured at room temperature in that year can reach more than 2cm before winter, and the shell bottom height can reach about 7cm in the following year.
economic value
High economic value. In addition to eating fresh shellfish in coastal areas all the year round, in order to keep fresh and facilitate transportation, most of them take out their adductor muscles and transport them around after freezing. This kind of shellfish is called frozen scallop column or frozen fresh shellfish. It is an important cooking material for high-class hotels and restaurants, and it is entering ordinary families. Scallop made from scallop adductor muscle is one of the eight treasures of seafood. Argopecten irradians, also known as Argopecten irradians, belongs to Mollusca, Lamarck, Heteropoda and Scallopidae.
morphological character
The shell is fan-shaped, the two shells are almost equal, the rear ear is larger than the front ear, and there is a foot hole under the front ear. There are 18 radiation edges on the shell surface, and the shell surface is dark brown or brown. Native to the Atlantic coast of the United States, it is a local mollusk. Zhang Fusui was introduced to China from the United States in 1982. Bay scallop has the characteristics of strong adaptability, fast growth, short culture cycle and high yield. Its meat is delicious, rich in protein and vitamins, and has high nutritional value. As a high-quality mariculture variety, it can be harvested all year round and has good quality in spring.
Living habits
Bay scallops are mostly distributed at a depth of 3- 10 meters below the sea surface, and their personalities are pungent. The temperature range is-1-3 1℃, the growth stops below 5℃, the growth is slow below 10℃, and the growth is faster at 18-28℃. Its salt tolerance range is 16 ‰-43 ‰, and its suitable salt range is 2 1 ‰-35 ‰. When the environment is not suitable, the crural line can be cut by itself, and the two shells open and close to hit the water quickly. Bay scallop can jump about 1-2 meters once entering the water.
The average shell energy of bay scallop is above 5-6 cm, and the largest individual is about 7 cm after 8 months in high water and fertilizer sea area. The average shell height is only about 5 cm in the inner gulf current slow sea area. Under the condition of full artificial culture, low-density stocking grows faster than high-density stocking, and seedling separation is earlier than seedling separation.
Reproductive habit
Bay scallop is hermaphrodite. Its growth and development are rapid, and the seeds cultivated in spring will mature in autumn (the shell height is about 5 cm), which can be used to collect eggs for parent shellfish to cultivate seeds. The smallest size in biology is 2.2 cm. The gonad is confined to the abdomen, and the testis is located on the periphery of the abdomen, which is milky white when mature; The ovary is located inside the testis and is brownish red when it matures. There is usually a black membrane on the surface of gonad. During gonadal maturation, the black membrane gradually disappears, and the testis and ovary are distinct.
When the gonad begins to develop, a certain amount of bait is given under the condition of temperature control, which can promote the gonad to mature ahead of time and expel sperm eggs, which is the biological basis of early seedling and multi-crop seedling. In the northern waters of China, there are two reproductive peaks in spring and autumn, from late May to June in spring and from September to 10 in autumn. After the autumn reproductive period, the abdomen is transparent and there are no sperm eggs. Native to Japan and Korea. It has been introduced into China for artificial propagation and proliferation in northern coastal areas such as Shandong and Liaoning.
characteristic
It belongs to filter-feeding bivalve shellfish. Its shell is fan-shaped, its right shell is prominent, yellow-white, its left shell is slightly flat, and its right shell is slightly smaller, which is purple-brown. There are 15-20 radial ribs on the shell surface, and shallow footline holes on both sides of the shell ear. The right shell rib is wide and low, and the rib is narrow; The ribs of the left shell are thinner and wider. There is a triangular internal ligament under the top of the shell. The natural distribution water depth is 6-60m, and the bottom material is gravel. Patinopecten yessoensis is a cold-water shellfish, and its growth temperature ranges from 5℃ to 23℃. Mainly produced in the southern waters of the Kuril Islands in Japan and Russia, Hokkaido in Japan and the northern part of this continent. The suitable salinity range is 24-40, which is distributed in the coastal waters with high salinity, hard bottom without fresh water injection, less sediment and water depth less than 40m. It is mainly cultivated in Liaodong Peninsula in northern China and Long Island in Shandong. The growth rate is slow, from juvenile to shell height 1L- 12cm, and the shortest time is 1 year for 7 months. According to records, the maximum shell height can reach 27.94 cm and its life span is about 25 years. The breeding season of scallop Patinopecten yessoensis in northern China is from March to April, and the spawning temperature is 3-65438 00℃. The ratio of women to men in the natural population is about 6:4. The fertilized eggs of Patinopecten yessoensis continued to develop after fertilization in seawater, and the shell length of type D larvae in the early stage was110—120μ m; After the stage of planktonic larvae, when the average shell length of larvae reaches 220-240 microns, eye spots appear and then metamorphosis occurs. The young shellfish are 3-4 cm long, and the foot silk glands are degenerated.
Key points of cultivation
1, seedling raising
Selection and preservation of parent mussels: 3-4 mussels with shell length of 8- 13 cm can be used as parent mussels. Generally, it is enough to buy about 5 parent mussels per cubic meter of water (males account for 3-5%). Parent shellfish transportation should be carried out in low temperature season, and the temperature should be lower than 5℃. The parent shellfish are packed in gunny bags, soaked in seawater and tied tightly, and shipped by sea for 15 hours, and the survival rate can reach 100%. The temporary culture density is 30-40 animals /m3, and the temporary culture water temperature is 5-7℃. Small diatoms are the main bait, and a small amount of Chlorella and Platymonas are afraid to feed. The daily feed is 300,000-400,000 tablets /ml, once every 6 hours, and the water is changed 4 times a day, each time 1/3. During the temporary rearing of parent shellfish, the pond is generally not inverted and inflated.
Oviposition and incubation: The gonads of mature scallops are very full. The gonads of female scallops are orange-red or peach-red, and those of male scallops are milky white. When the gonad index is above 13%, and a small amount of parent shellfish is found to be discharged during normal water exchange, the eggs are laid by inverted pond at the same temperature without any other stimulation. The average number of eggs laid by parents for the first time is less than 300,000/piece. If the parents can be preserved for another 3-5 days, they can be released in large quantities. The incubation temperature is 8- 1 1℃, and it is stirred manually every 1 hour during incubation. After 90-70 hours, when 60-70% larvae reach the D-shaped larvae, 200-mesh trawl is used to select the best larvae in time.
Larval culture: density: the density of D-shaped larvae is controlled at 8- 10 /ml in the early stage and 6-7 /ml in the later stage.
Bait: Chrysophyta 30 1 1, 870 1 are high-quality open bait for scallop, which is fed by mixing Chrysophyta and diatom, and the daily feeding amount is 10000-60000 pieces/ml. After being put into the substrate, the bait can be changed into flat algae, and the feeding amount can be increased appropriately.
Water temperature: The optimum water temperature in larval cultivation stage is about 65,438 05℃. After the D-shaped larvae are selected, the water temperature can be raised to 65438 05℃ at the rate of 0.5℃ every day, so that the larvae can be cooled and cultured to facilitate the transition to the sea.
Water change: change the water 2-3 times/day during the culture, 1/3 in the early stage, 2-3 times/day during the culture, 1/3 in the early stage and 1/2 in the late stage, with proper aeration and bottom suction once a day.
Step 2 feed
Bottom sowing proliferation (releasing proliferation): choose sand and mud sediment fishing ground to destroy enemy creatures; The planting density is 8 plants/m2, with 5500 plants per mu; The sowing period is 165438+ late October of the current year/kloc-0+early February of the current year or March-April of the following year; The proliferation time is 17 months and the shell height can reach more than 8cm.
Raft culture: Although releasing and proliferation is a production mode with simple process, no need of any materials and equipment and low cost, there are many harmful organisms on the seabed, which are seriously damaged, with low survival rate and difficult collection, especially in some sea areas where the release and proliferation bottom materials are not available, floating raft culture is another way to produce scallops.
The so-called floating raft culture means that shellfish fry are put into a suitable container according to a certain density and hung on a floating raft (raft) at sea according to a certain distance and a suitable water layer for culture.
Step 3 harvest
Harvesting time: If the individual shellfish is large (more than 3 cm high) at the time of seedling separation, after 1.5 years of cultivation, the body can reach the commodity standard of about 10 cm, and the harvesting time is mainly based on the season with the highest yield of diced meat. The high-yield time of diced meat is May-July, and the highest yield and meat production are in July, that is, the most fattening is in March-May. If diced meat is processed, it is more suitable to harvest in May-July, and March-May is the most suitable harvesting time.
Harvesting method: The method of collecting the acid of scallops cultured on floating rafts is relatively simple, that is, when the scallops reach the standard of commodity specifications, the cage is removed from the raft in its suitable season and shipped back for sale or processing. If some of them have not reached the standard of commodities, they will be locked up again to continue breeding. Great economic value.
Muscle adductor can be used to make a precious seafood-scallop.
These 10 items must be checked in