Breeding method of hybrid seedling of taiwan volute and mud volute
By co-culturing Taiwan wind snails and mud wind snail parent snails in the dark, feeding them a specific ratio of vegetables and mixed biological feed, and hatching egg sac clusters under specific conditions, the planktonic larvae were cultivated into juvenile snails. This solved the problems of insufficient metamorphosis rate, fertilization rate and hatching rate in existing technologies, and achieved excellent growth and shell length improvement of wind snail seedlings.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGDONG OCEAN UNIVERSITY
- Filing Date
- 2024-10-30
- Publication Date
- 2026-06-23
AI Technical Summary
The existing hybrid combinations of Taiwan wind snail and mud wind snail have a high metamorphosis rate, fertilization rate and hatching rate, which are insufficient to meet the actual needs of seedling breeding and aquaculture.
By co-culturing parent snails of *Bellamya stenoptera* and *Bellamya stenoptera* in the dark, feeding them a specific ratio of vegetables and mixed biological feed to promote gonadal maturation, hatching egg clusters under specific conditions, cultivating planktonic larvae to juvenile snails, and using mixed algae and shrimp chips as feed to optimize aquaculture environmental parameters.
It significantly improved the metamorphosis rate, fertilization rate and hatching rate of hybrid seedlings, and enhanced the growth and shell length of the East Wind Snail seedlings, thus meeting the needs of seedling cultivation and breeding.
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Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of shellfish breeding, and more specifically, relates to a method for propagating hybrid seedlings of Taiwan wind snail and mud wind snail. Background Technology
[0002] The Oriental Wind Snail, also known as the Sea Pig Snail or Flower Snail, is a mollusc belonging to the family Bryllidae in the order Acanthoglossi. The main species of Oriental Wind Snails farmed in my country are the Spotted Oriental Wind Snail, the Mud Oriental Wind Snail, and the Taiwan Oriental Wind Snail. The Spotted Oriental Wind Snail is also called the Ivory Phoenix Snail. The Mud Oriental Wind Snail, also called the Fog Flower Phoenix Snail, is mainly distributed along the coasts of Zhejiang, Fujian, and Guangdong, and is relatively common in the Fuzhou and Chaoshan regions. The Taiwan Oriental Wind Snail is also called the Taiwan Phoenix Snail.
[0003] Hybrid breeding is essentially the recombination of genetic resources among different parents. It can quickly break the conservation of original heredity, allowing hybrids to obtain greater gene flow and is an important way to increase variation. It can rapidly and significantly improve the vigor, growth, and other desirable traits of hybrid offspring, and is of great significance in the genetic improvement of shellfish. Therefore, hybrid breeding has become an important direction in the genetic improvement research of the Oriental whelk.
[0004] Patent publication number CN104798709A discloses a method for breeding hybrid seedlings of the spotted roe snail. This method involves hybridizing the Thai spotted roe snail with the Hainan spotted roe snail to cultivate hybrid seedlings that exhibit rapid growth and strong disease resistance. Due to their strong disease resistance, breeding hybrid seedlings reduces aquaculture diseases and avoids diseases such as "snout snail disease" and "shell molting disease."
[0005] The paper "Research Progress in Biology and Genetic Breeding of *Bellamya spp.*, authored by Fu Jingqiang, discloses that the genetic distance between *Bellamya spp.*, *Bellamya spp.*, and *Bellamya spp.* reaches the interspecies level. Furthermore, it mentions using a complete diallelic hybridization method, conducting long-distance interpopulation hybridization between *Bellamya spp.* populations from Wengtian, Hainan, and Rayong, Thailand. The experimental results show that during the larval development stage, the hybrid combinations exhibited superiority in both metamorphosis rate and metamorphosis time, with superiority rates of 8.7% and 20.53%, respectively. However, the improved metamorphosis rate of the aforementioned hybrid combinations is still insufficient to meet the actual needs during seedling and aquaculture. Summary of the Invention
[0006] To address the aforementioned technical problems, the primary objective of this invention is to provide a method for breeding hybrid seedlings of Taiwan wind snails and mud wind snails. Compared to existing Taiwan wind snails and mud wind snails, the hybrid seedlings bred by this method not only have a superior metamorphosis rate, but also significantly improved fertilization and hatching rates.
[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:
[0008] This invention seeks protection for a method of propagating hybrid seedlings of *Bellamya stenoptera* and *Bellamya stenoptera*, comprising the following steps:
[0009] S1. Broodstock cultivation and enhancement: Broodstock snails of *Bellamya spp.* and *Bellamya spp.* are mixed and cultured in the dark. They are fed vegetables accounting for 3-5% of their body weight and mixed biological feed accounting for 10-15% of their body weight. They are fed continuously until their gonads mature, and are fed at least once a day. Egg clusters are obtained by hybridization of broodstock snails of *Bellamya spp.* and *Bellamya spp.*
[0010] S2. Seedling cultivation: Egg sacs hatch into planktonic larvae. After 15-20 days of cultivation, the planktonic larvae metamorphose into juvenile snails, thus obtaining hybrid seedlings;
[0011] The mixed biological feed comprises, by weight, 10-30 parts clams, 40-50 parts oysters, 5-15 parts sandworms, and 10-30 parts grain worms.
[0012] This invention first involves co-culturing parent snails of *Bellamya spp.* (Taiwanese whelk) and *Bellamya spp.* (mud whelk) in the dark, making mating easier for the snails under these conditions. During co-culturing, vegetables and a mixed live feed are provided to promote gonadal maturation. Vegetables promote intestinal health and provide balanced nutrition, while the mixed live feed is rich in nutrients and high in protein, accelerating gonadal maturation and enabling rapid egg production. After gonadal maturation, the snails are hybridized to obtain egg clusters. These egg clusters hatch, are cultivated, and metamorphose into juvenile snails, thus yielding hybrid seedlings.
[0013] Through research, the inventors discovered that, compared to the existing Taiwan wind snail and mud wind snail, the hybrid wind snail seedlings have a significantly higher metamorphosis rate, and the fertilization and hatching rates are also significantly improved. The fertilization rate of the wind snail seedlings is increased by 39% and 23% respectively compared to the two existing wind snail species; the hatching rate is increased by 30% and 24% respectively; and the metamorphosis rate is increased by 82% and 66% respectively.
[0014] Furthermore, the inventors discovered through research that when the above-mentioned snail seedlings were cultured, their average weight and average shell length were significantly increased in both the first stage of culture (intermediate cultivation) and the second stage of culture (adult snail culture).
[0015] Specifically, in step S1, male Taiwan whelks and female mud whelks can be mixed for culture, or male mud whelks and female Taiwan whelks can be mixed for culture. More specifically, male whelks can be selected from healthy, vigorous, and undamaged whelks that are 3 years or older, and female whelks can be selected from healthy, vigorous, and undamaged whelks that are 2 years or older.
[0016] Specifically, in this invention, the shell of the Taiwan conch is light brown with a light brown, relatively continuous, and irregular pattern; the shell of the mud conch is muddy-gray with a purplish-red opening, indistinct patterns, and an orange-yellow circle in the center of the operculum. More specifically, the mud conch is the Zhanjiang mud conch.
[0017] Preferably, in step S1, the conditions for mixed culture are: ammonia nitrogen concentration ≤ 0.5 mg / L, nitrite concentration ≤ 0.1 mg / L, salinity 28–31, dissolved oxygen ≥ 5 mg / L, and calcium ion concentration ≥ 100 mg / L. Adding calcium ions during the mixed culture process effectively promotes calcium precipitation within the whelk, meeting its calcium requirements for growth and development.
[0018] Preferably, in step S2, the incubation conditions are: pH 8.3–8.6, dissolved oxygen 5–6 mg / L, water temperature 25–30°C, and seawater specific gravity 1.020–1.014 g / mL.
[0019] Preferably, in step S1, the vegetable is selected from one or more of the following: bok choy, cabbage, pumpkin, mustard greens, tatsoi, flowering cabbage, Chinese kale, shepherd's purse, spinach, amaranth, cabbage, and Chinese cabbage.
[0020] Specifically, bok choy is an annual or biennial herbaceous plant belonging to the genus Brassica in the family Brassicaceae. Its branches are generally hairless; its leaves are obovate with a rounded apex, the outer leaves being green and spreading out on the ground; its petals are bright yellow and obovate; its fruit is a silique; its seeds are brown and spherical; and it has a well-developed root system that grows into large, fleshy roots. Bok choy was originally called "Song," but because of its bluish-white color, it is also known as "white cabbage."
[0021] Preferably, in step S1, the mixed biological feed further contains lecithin powder. More specifically, the amount of lecithin powder added is 100–200 mg / kg.
[0022] Preferably, in step S1, the parent snails of Taiwan East Wind Snail and parent snails of Mud East Wind Snail are mixed and cultured at a female-to-male ratio of 1:1 to 2.
[0023] Preferably, in step S2, the hatching density of the egg clusters is 0.1–0.3 catties / m². 3 .
[0024] Preferably, in step S2, during the cultivation period, mixed algae are fed every 2 to 3 times; allicin is fed every 2 to 3 days, and vitamins are added daily.
[0025] More preferably, the mixed algae include one or more of *Isochrysis zhanjiangensis*, *Platycodon grandiflorus*, and *Streptococcus spp.*. In some specific embodiments, the cell concentration ratio of *Isochrysis zhanjiangensis*, *Platycodon grandiflorus*, and *Streptococcus spp.* is 2–6:3–4:3–4, and the cell concentration of the mixed algae is 40,000–80,000 cells / mL. In some specific embodiments, the mixed algae are fed 2–3 times daily.
[0026] More preferably, the dosage of allicin is 0.1–0.25 g / m³.
[0027] More preferably, the vitamin can be a vitamin commonly used in the field for farming *Bambusa multiplex*, such as vitamin E. More specifically, the dosage of the vitamin is 0.1–0.2 g / m³.
[0028] Preferably, when the planktonic larvae reach a shell length of approximately 1000 micrometers, shrimp chips and yeast are added to the feed. More specifically, the amount of shrimp chips fed is 0.2–0.5 g / m³, and the amount of yeast fed is 0.1–0.3 g / m³.
[0029] Preferably, in step S2, water flows continuously for 24 hours during the incubation period, and the daily water flow is 100-200% of the volume of the incubation container.
[0030] More preferably, after hatching, the water is slowly added and changed every 1 to 3 hours with a slight overflow. When adding or changing the water, ensure that the planktonic larvae are not adsorbed on the water changing net bag. Each water change is 20 to 30% of the hatching tank volume.
[0031] Preferably, in step S2, after the hybrid seedlings are raised into adult snails, they are crossbred and then raised using the methods in steps S1 and S2.
[0032] Compared with the prior art, the present invention has the following beneficial effects:
[0033] This invention provides a method for propagating hybrid seedlings of *Bellamya stenoptera* and *Bellamya stenoptera*. The hybrid seedlings obtained through this method exhibit superior metamorphosis, fertilization, and hatching rates, all significantly higher than those of common *Bellamya stenoptera* and *Bellamya stenoptera*. This invention utilizes hybridization to cultivate *Bellamya stenoptera* seedlings, enriching the germplasm types of *Bellamya stenoptera* and ensuring the healthy, green, and sustainable development of the *Bellamya stenoptera* industry. Detailed Implementation
[0034] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.
[0035] Example 1: Propagation method of hybrid seedlings of Taiwan's Oriental Wind Snail and Zhanjiang's Mud Oriental Wind Snail
[0036] (1) Selection of parent snails: Male Taiwan snails that are 3 years old or older, healthy and vigorous, and undamaged are selected; female Taiwan snails that are 2 years old or older, healthy and vigorous, and undamaged are selected.
[0037] (2) Pairing: The sexes were identified by the genital opening and copulatory organ. The male and female snails were placed in a dark breeding box at a ratio of 1:1. The water parameters were controlled as follows: ammonia nitrogen concentration ≤0.5mg / L, nitrite concentration ≤0.1mg / L, salinity 28~31, dissolved oxygen ≥5mg / L, and calcium ion concentration ≥100mg / L.
[0038] (3) Broodstock snail cultivation and enhancement: Feed once a day, first feed 3% of the snail's body weight of Chinese cabbage, then feed 10% of the snail's body weight of mixed biological feed (by weight, the mixed biological feed includes: 10 parts clam, 40 parts oyster, 10 parts sandworm, and 20 parts grain weevils), the amount of feed should be such that there is a small amount left over. In addition, the mixed biological feed is mixed with 150mg / kg of lecithin powder, and fed continuously until the gonads mature. Drain the entire pond once a day and let it air dry for 20 minutes.
[0039] (4) Determining the sexual maturity of parent snails: Patrol and observe the behavior of parent snails multiple times a day, morning, noon and evening. If tail chasing occurs, the parent snails have reached sexual maturity.
[0040] (5) Seedling cultivation: Egg sacs were obtained by hybridizing the parent snails of *Bellamya taiwanensis* and *Bellamya leuciscus*. The collected egg sacs were placed in hatching tanks for incubation. The hatching density of egg sacs was 0.1 catties / m³. The hatching conditions were: pH 8.3-8.6, dissolved oxygen 5-6 mg / L, water temperature 25-30℃, and seawater specific gravity 1.020-1.014 g / mL. The fertilized eggs gradually developed into vegetative larvae in the egg sacs. Hatching was the process in which the larvae broke through the membrane and became planktonic larvae. During the hatching period, the water flowed 24 hours a day, with a daily flow rate of 150% of the hatching tank volume. After hatching, the water was slowly added and changed every 1-3 hours with a slight overflow. When adding and changing the water, it was ensured that the larvae were not adsorbed onto the water changing net bag. Each water change was 20% of the hatching tank volume. Feed 2-3 times daily with *Isochrysis galbana*, *Platycodon grandiflorus*, and *Hylocereus undatus* as feed, in a cell concentration ratio of 2:3:3, with a total algal cell concentration of 60,000 cells / ml. Feed when the water shows a microalgal color. Add 0.1g / m³ of allicin every 2 days and 0.1g / m³ of vitamin E daily. When the planktonic larvae reach a shell length of approximately 1000 micrometers, add 0.3g / m³ of shrimp chips and 0.2g / m³ of yeast to the feed. After 16 days of cultivation, the larvae metamorphose into crawling snail juveniles, yielding hybrid seedlings.
[0041] Example 2: Propagation method of hybrid seedlings of Taiwan's Oriental Wind Snail and Zhanjiang Mud Oriental Wind Snail
[0042] The difference between this embodiment and Embodiment 1 is that the male *Anoplophora chinensis* is selected from *Anoplophora chinensis* from Zhanjiang, and the female *Anoplophora chinensis* is selected from *Anoplophora chinensis* from Taiwan.
[0043] Example 3: Cultivation of Hybrid Seedlings
[0044] Hollow bricks are evenly laid at the bottom of the aquaculture pond. A sieve frame is placed on top of the bricks, with a sleeve inserted into the fixing holes of the sieve frame, so that one end of the sleeve is on top and the other end is below the bottom of the sieve frame. A layer of 80-mesh silk screen is laid on top of the sieve frame to prevent sand from flowing down to the bottom layer. A 4-cm thick layer of sand (0.8-1.5mm particle size) is evenly laid on top of the silk screen, dividing the aquaculture water into upper and lower layers. PVC water spray pipes are suspended above the aquaculture pond, providing a spray-type water flow of 5m³ / h. 3 The water exchange rate is 3-5 times the original water volume per hour (24 hours). Two PVC air pipes with a hole diameter of 1.5cm are laid flat on the substrate at the bottom of the pool. Holes with a diameter of 0.1mm are drilled in the upper side of the pipe walls for air filling. Continuous aeration for 24 hours maintains the dissolved oxygen content in the pool water at approximately 5mg / L.
[0045] In the first stage of cultivation, hybrid seedlings bred in Example 1 with shell lengths of approximately 1 mm were selected, and 15,000 juvenile snails were introduced per square meter for intermediate rearing. During this period, 100 grams of oyster meat were fed per kilogram of whelks once a day for one month. After the intermediate rearing, uniformly sized juvenile snails with shell lengths of approximately 1 cm were selected from the corresponding rearing ponds using a sieve basket, and 1,250 snails were placed in each 16-square-meter rearing pond to begin the second stage of adult snail cultivation. They were fed once every two days, with 130 grams of mackerel per kilogram of whelks, for eight months.
[0046] At the end of the two stages, 200 snails were randomly collected from each pond for weighing and other physical indicators to compare the growth of snails at different stages.
[0047] Example 4: Cultivation of Hybrid Seedlings
[0048] The difference between this embodiment and embodiment 3 is that the hybrid seedlings from embodiment 2 with a shell length of about 1 mm are selected.
[0049] Comparative Example 1
[0050] The difference between this comparative example and Example 1 is that both the male and female *Bellamya spp.* were selected from *Bellamya spp.* in Taiwan.
[0051] Comparative Example 2
[0052] The difference between this comparative example and Example 1 is that both the male and female *Bellamya spp.* were selected from *Bellamya spp.* from Zhanjiang.
[0053] Comparative Example 3
[0054] The difference between this comparative example and Example 3 is that the Taiwan East Wind Snail seedlings from Comparative Example 1 are used instead of the hybrid seedlings from Example 1.
[0055] Comparative Example 4
[0056] The difference between this comparative example and Example 3 is that the Zhanjiang mud snail seedlings from Comparative Example 2 are used instead of the hybrid seedlings from Example 1.
[0057] Comparative Example 5
[0058] The difference between this comparative example and Example 1 is that bok choy was not used for feeding in step (3).
[0059] Comparative Example 6
[0060] The difference between this comparative example and Example 1 is that in step (3), the conventional bait of the snail, the mackerel, is used for feeding.
[0061] Comparative Example 7
[0062] The difference between this comparative example and Example 3 is that the seedlings bred in Comparative Example 5 are used instead of the hybrid seedlings in Example 1.
[0063] Comparative Example 8
[0064] The difference between this comparative example and Example 3 is that the seedlings bred in Comparative Example 6 are used instead of the hybrid seedlings in Example 1.
[0065] Test Example 1
[0066] Samples were taken from two breeding stages in Examples 3-4, Comparative Examples 3-4, and Comparative Examples 7-8 to measure indicators. The test indicators were average body weight, average shell length, and survival rate. The calculation methods for the test indicators are as follows, and the breeding results are shown in Table 1.
[0067] Average weight = Total weight of 200 snails / 200 * 100%.
[0068] Average shell length = (total length of 200 snail shells) / 200 * 100%.
[0069] Survival rate = (Number of snails harvested / Number of seedlings released) * 100%.
[0070] Table 1
[0071]
[0072] As shown in Table 1, comparing the growth indicators of the three species of whelks in the two breeding stages, it can be found that the average weight, average shell height and survival rate of the hybrid seedlings are significantly higher than those of the common Taiwan whelk and Zhanjiang mud whelk.
[0073] Test Example 2
[0074] Samples were taken and indicators were measured during the seedling stage of Examples 1-2, Comparative Examples 1-2, and Comparative Examples 5-6.
[0075] The fertilization rate, hatching rate, and metamorphosis rate of the planktonic larvae after rearing were statistically analyzed for the above-mentioned mixed crosses. The calculation method is shown below, and the specific test results are shown in Table 2.
[0076] The fertilization rate was the average of 10 randomly selected egg sacs. The hatching rate was the average of the number of larvae counted three times in each pool using a graduated cylinder to measure 500 ml of water. The metamorphosis rate was the ratio of the number of successfully metamorphosed juvenile snails to the number of hatched larvae. The formulas for calculating the fertilization rate, hatching rate, and metamorphosis rate are as follows, and the breeding results are shown in Table 2.
[0077] Fertilization rate = (Number of fertilized eggs / (Number of fertilized eggs + Number of unfertilized eggs)) * 100%.
[0078] Hatching rate = (Number of hatched larvae / Number of fertilized eggs) * 100%.
[0079] Metamorphosis rate = Number of metamorphosed juvenile snails / Number of hatched larvae * 100%.
[0080] Table 2
[0081]
[0082] As shown in Table 2, compared with the existing Taiwan wind snail and mud wind snail, the hybrid wind snail seedlings have a superior metamorphosis rate, and the fertilization rate and hatching rate are also significantly improved. The fertilization rate of the wind snail seedlings is at least 39% and 23% higher than the two existing wind snail species, respectively; the hatching rate is at least 30% and 24% higher, respectively; and the metamorphosis rate is at least 82% and 66% higher, respectively.
[0083] The foregoing examples are merely illustrative, used to explain some features of the method described in this invention. The appended claims are intended to claim the broadest possible scope, and the embodiments presented herein are demonstrated by the applicant's actual experimental results. Therefore, the applicant intends that the appended claims are not limited by the selection of examples illustrating the features of the invention. Some numerical ranges used in the claims also include sub-ranges within them, and variations within these ranges should also be interpreted as being covered by the appended claims where possible.
Claims
1. A method for improving the fertilization and hatching rates of hybrid seedlings of *Bellamya spp.* and *Bellamya spp.*, characterized in that, Includes the following steps: S1. Broodstock cultivation and enhancement: Broodstock snails of *Bellamya spp.* and *Bellamya spp.* are mixed and cultured in the dark. They are fed vegetables accounting for 3-5% of their body weight and mixed biological feed accounting for 10-15% of their body weight. They are fed continuously until their gonads mature, and are fed at least once a day. Egg clusters are obtained by hybridization of broodstock snails of *Bellamya spp.* and *Bellamya spp.* S2. Seedling cultivation: Egg sacs hatch into planktonic larvae. After 15-20 days of cultivation, the planktonic larvae metamorphose into juvenile snails, thus obtaining hybrid seedlings; By weight, the mixed biological feed includes: 10-30 parts clams, 40-50 parts oysters, 5-15 parts sandworms, and 10-30 parts grain worms; In step S1, the vegetable is bok choy; The mud snail mentioned is the mud snail from Zhanjiang. In step S1, the mixed biological feed also contains lecithin powder; the amount of lecithin powder added is 100-200 mg / kg; In the step S2, during the cultivation, the mixed algae is fed 2-3 times per day; the allicin is fed every 2-3 days, and the vitamin is added every day; the feeding amount of the allicin is 0.1-0.25 g / m 3 ; the feeding amount of the vitamin is 0.1-0.2 g / m 3 . In the step S2, when the shell length of the planktonic larvae reaches about 1000 microns, shrimp pieces and yeast are added to the bait for feeding; the feeding amount of the shrimp pieces is 0.2-0.5 g / m 3 ; and the feeding amount of the yeast is 0.1-0.3 g / m 3 . In step S1, the parent snails of Taiwan East Wind Snail and the parent snails of Mud East Wind Snail are mixed and cultured at a female-to-male ratio of 1:1 to 2.
2. The breeding method according to claim 1, characterized in that, In step S1, the conditions for mixed aquaculture are: ammonia nitrogen concentration ≤ 0.5 mg / L, nitrite concentration ≤ 0.1 mg / L, salinity 28-31, dissolved oxygen ≥ 5 mg / L, and calcium ion concentration ≥ 100 mg / L.
3. The breeding method according to claim 1, characterized in that, In step S2, the incubation conditions are: pH 8.3–8.6, dissolved oxygen 5–6 mg / L, water temperature 25–30℃, and seawater specific gravity 1.020–1.014 g / mL.
4. The breeding method according to claim 1, characterized in that, In step S2, the hatching density of the egg clusters is 0.1–0.3 catties / m². 3 .