A method for artificial domestication, ripening, inducing spawning and egg case collection of Strombus luhuanus

Abstract

The present invention belongs to the technical field of large-scale seedling cultivation of shellfish, and discloses a method for artificial domestication, ripening and induced spawning of hedge snails and collection of their egg sacs. The most suitable food and bait combination for the snail is successfully explored through experiments, and a sufficient amount of algae bait is cultivated by artificial cultivation, simulating the natural living environment of the snail, and successfully completing the artificial domestication of the snail. Similar to the ripening promotion of other shellfish, the purpose of ripening can be achieved by increasing the amount of bait and strengthening the nutrition of the parent snail. The present invention efficiently solves the problem of induced spawning of the snail by reducing salinity and providing attachments such as fine sand and other ecological cultivation combination methods. Through the above method, the artificial domestication of hedge snails is solved for the first time in the world, so that the snail is fully adapted to the artificial breeding environment, and the artificial ripening and induced spawning work is completed for the first time. The egg-laying amount is very large and the quality is high, providing a solid basic support for the subsequent artificial breeding of the snail.

Description

Technical Field

[0001] The present invention belongs to the technical field of large-scale seedling cultivation of shellfish, and more specifically, relates to a method for artificial domestication, ripening and spawning induction of Background Art

[0002] Strombus luhuanus ), commonly known as red-mouthed snail and strawberry snail, named after the inner side of the shell opening being orange-red, belongs to the class Gastropoda, order Mesogastropoda, family Strombidea, genus Strombus ).

[0003] In China, Summary of the Invention

[0004] In order to make up for the deficiencies in the prior art, the present invention proposes a method for artificial domestication, ripening and spawning induction of

[0005] The second object of the present invention is to provide a method for collecting the egg capsules of

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] A method for artificial domestication, ripening and spawning induction of

[0008] S1. Cleaning and disinfection: Select a culture pond with moderate light, clean and disinfect it, and at the same time disinfect the algae attachment devices for standby;

[0009] S2. Bait cultivation: After expanding the cultivation of the mixed algae, add it to the pre-prepared culture pond to complete the bait cultivation. Among them, the culture pond is pre-filled with sand-filtered seawater with a water depth of 0.5-1 m, microtube aeration is carried out, and the algae attachment devices are pre-placed in the culture pond; after the mixed algae enter the culture pond, static cultivation is carried out for 3-5 days first, and then countercurrent cultivation is started. When the algae attachment devices are visibly covered with algae, it is considered that the bait cultivation is completed;

[0010] ​S3, adaptive domestication: During the breeding period, adult snails of the scallops are captured in the natural distribution area and transported out of water at low temperature; then, the adult snails are placed in the breeding pond where the feed has been cultured in S2 and domesticated for 10 to 20 days. When most of the adult snails actively eat, have normal stress reactions, and have normal defecation, they are considered to have adapted to the breeding pond environment and domestication is complete;

[0011] S4. Promote maturation and induce spawning: When 2 or 3 to 5 adult snails are found to be grouped independently, connected head to tail or with shell openings facing each other, increase the amount of feed in the breeding pond and carry out nutritional enhancement. At the same time, spread a layer of fine sand with a thickness of 0.5 to 2 cm on the bottom of the pond to spread and place an attachment base for the adult snails to lay eggs. After 2 to 5 days of nutritional enhancement, reduce the salinity of the seawater in the breeding pond by 1 to 4‰, stop the convection of water, and maintain the reduced salinity overnight, and turn on the convection of water the next day to allow the adult snails to continue laying eggs during the spawning period.

[0012] Preferably, in the above-mentioned method for artificial domestication, ripening and induced spawning of Epipremnum acutum, the mixed algae described in S2 include Chaetoceros, Platyhelminthes, Chrysophyte, diatoms and Cyclotella.

[0013] Preferably, in the above-mentioned method for artificial domestication, ripening and induced spawning of Epipremnum aquatica, during the convective water culture of S2, the water inlet flow rate is 3 to 10 L / min.

[0014] Preferably, in the above-mentioned method for artificially domesticating, ripening and induced spawning of P. fasciatus, the nutritional fortification in step S4 is to add large algae such as Undaria pinnatifida and Enteromorpha into the breeding pond, and the attachment base for the adult snails to lay eggs is Gnaphalium sphaerocephalum and Abalone plate.

[0015] As a specific implementation method, in the above-mentioned method for artificial domestication and maturation and induced spawning of the snail, the size of the culture pond selected by S1 is [5-8m long × 2-4m wide]), the bottom and walls of the pond are cleaned in advance, and strong chlorine (concentration 20-40 g / m 3 ) or potassium permanganate (concentration 5-15 g / m 3 ) for disinfection. The algae attachment tools used are abalone baskets and abalone plates, which also need to be soaked overnight for disinfection for one day.

[0016] As a specific implementation method, in the above-mentioned method for artificial domestication, ripening and induced production of water snails, in a breeding pond with a size of [length 5-8m × width 2-4m], each specific algae in the mixed algae is subjected to secondary expansion culture to a volume of about 10-15 L, and when the algae species are darker in color, they are poured into the breeding pond; the time for the attached device to be visibly covered with algae varies depending on the convection water culture time and the weather and light conditions, and takes about 4-8 days.

[0017] As a specific implementation method, in the above method for artificial domestication, ripening promotion and spawning induction of Thais luteostoma, the specific operation of the mature snails' low-temperature and water-free transportation in S3 is as follows: During the breeding period (from the end of April to the end of September), catch 30 - 40 catties of mature Thais luteostoma, about 300 individuals, from the natural distribution sea area. Place multiple pre-frozen mineral water bottles in the transportation box and separate them from the Thais luteostoma with a cloth for transportation.

[0018] As a specific implementation method, in the above method for artificial domestication, ripening promotion and spawning induction of Thais luteostoma, the fact that the mature snails actively feed, have normal stress responses, and normal defecation means that most mature snails actively extend their oral tongues to scrape the algae on the attachment appliances, the bottom of the pool, and the walls, quickly turn over when frightened, and excrete a large amount of spherical or cylindrical feces (with a diameter of about 5 mm).

[0019] As a specific implementation method, in the above method for artificial domestication, ripening promotion and spawning induction of Thais luteostoma, the amount of large algae such as Undaria pinnatifida and Enteromorpha prolifera in S4 is 100 - 300 g, the number of Ulva lactuca is 50 - 100 pieces, and the number of abalone plates is 5 - 15. The mature snails lay eggs continuously from May to July and from September to October, with peak periods in May, June, and September. Each female snail lays 10 - 20 strings of eggs each time.

[0020] The present invention also provides a method for collecting the egg sacs of Thais luteostoma, which is to collect the fine sand, the attachment base for the mature snails to lay eggs, and the cylindrical and hemp rope-shaped adhesives on the bottom of the pool in step S4 of the above method, and pre-place them on a basket with an 80-mesh sieve, thus obtaining the egg sacs of Thais luteostoma.

[0021] The present invention also provides the application of the above method for artificial domestication, ripening promotion and spawning induction of Thais luteostoma, or the method for collecting the egg sacs of Thais luteostoma in the artificial cultivation of Thais luteostoma.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention culturing a sufficient amount of algal bait by an artificial cultivation method, simulating the natural living environment of this snail, and successfully completing the artificial domestication of this snail. Similar to the ripening promotion of other shellfish, the purpose of ripening promotion can be achieved by increasing the amount of bait and strengthening the nutrition of the broodstock. The present invention efficiently solves the problem of spawning induction of this snail through an ecological cultivation combination method such as reducing salinity and providing attachments such as fine sand. Through the above method, for the first time in the world, the artificial domestication of Thais luteostoma is solved, enabling this snail to fully adapt to the artificial breeding environment, and for the first time completing the work of artificial ripening promotion and spawning induction. The spawning amount is very large and the quality is relatively high, providing a solid basic support for the subsequent artificial breeding of this snail. Description of the Drawings

[0024] Figure 1Showing the cultivation of algae in the breeding pond of Strombus luhuanus, top view of the pond; (A) The bottom and walls of the breeding pond are covered with large green algae; (B) The bottom of the pond is covered with microalgae about 2 mm thick, brown and filamentous.

[0025] Figure 2 Showing the attachment devices such as abalone plates and abalone frames placed in the breeding pond. (A) The attachment plate (at the red frame) is covered with microalgae (at the blue arrow); (B) A large amount of spongy and soft microalgae grow on the abalone frame.

[0026] Figure 3 Showing the morphology of the algae cultured in the breeding pond. (A) Microalgae scraped from the abalone basket in the breeding pond; (B) The morphology of various algae under the microscope; (C) The morphology of the optimal microalgae bait for the parent snails, Thalassiosira (Bacillariophyta).

[0027] Figure 4 Showing the Enteromorpha prolifera growing at the bottom of the breeding pond.

[0028] Figure 5 Showing the artificially domesticated parent snails in the breeding pond. (A) Parent snails living in groups; (B) The parent snail extends its oral tongue (at the arrow) at the front end of the shell opening to scrape the algae on the wall; (C) Parent snails feeding on the abalone basket, with a large amount of cylindrical feces discharged nearby (at the arrow); (D) Feces discharged by the parent snails on the abalone plate (at the arrow).

[0029] Figure 6 Showing the parent snails dispersing into 2 or 3 - 5 for male - female mating.

[0030] Figure 7 Showing the parent snails laying eggs on fine sand (A), abalone frame (B), wall (C), and abalone plate (D).

[0031] Figure 8 Showing the eggs of the parent snails, (A) The egg - laying amount of one parent snail; (B) The egg sac under the microscope, and the larvae in the membrane can develop to the blastula stage.

[0032] Figure 9 Showing the egg sacs collected in the basket, (A) The egg sacs in a cluster; (B) The basket containing the egg sacs floating on the breeding pond. Detailed implementation method

[0033] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific drawings and embodiments. In the embodiments, the experimental methods used are all conventional methods unless otherwise specified, and the materials, reagents, etc. used can be obtained from commercial channels unless otherwise specified.

[0034] Embodiment 1

[0035] I. Disinfection of the breeding pond

[0036] Select a cement pond with moderate light (size: [length 5 - 8m × width 2 - 4m]), clean the bottom and walls of the pond, and apply strong chlorine essence (concentration 20 - 40 g / m 3 ), or potassium permanganate (concentration 5 - 15 g / m 3 ) for disinfection. Together with abalone baskets, abalone plates and other algae attachment utensils, soak and disinfect overnight for one day.

[0037] II. Bait Cultivation

[0038] Drain the disinfected water completely, then inject sand-filtered seawater with a water depth of 0.5 - 1m into the culture pond and aerate with microtubes. Cultivate common algae including Chaetoceros, Platymonas, Isochrysis, Navicula, Cyclotella, etc. After secondary expansion culture of each algal species, the volume is about 10 - 15 L. When the color of the algal species is darker, pour it into the culture pond.

[0039] Add the cultivated mixed algal species into the culture pond. After 3 - 5 days of static culture in the culture pond, start flowing water culture with an inflow rate of 3 - 10 L / min. When the attachment utensils are visibly covered with algae, it is considered that the bait cultivation is completed. The time of flowing water culture varies depending on weather and light conditions, about 4 - 8 days.

[0040] As Figure 1 , Figure 2 shown, sufficient algal bait is cultivated, and the whole culture pond is light green ( Figure 1 A), and greenish - blue and brown algae grow on the bottom and surrounding walls of the culture pond ( Figure 1 B). The corrugated plates ( Figure 1 A), abalone plates ( Figure 2 A), and abalone baskets ( Figure 2 B) put into the culture pond are all covered with spongy and soft algae. These algae include microalgae such as diatoms, green algae, Chlorella ( Figure 3 ), and macroalgae such as Enteromorpha ( Figure 4 ), with rich algal species and high density.

[0041] When the parent snails start to mate, algae such as Thalassiosira and Enteromorpha can also be collected from the surrounding of the farm for nutritional enhancement to accelerate the spawning progress of the parent snails.

[0042] III. Adaptive Domestication

[0043] During the breeding period (from the end of April to the end of September), 30 - 40 catties of adult Thais clavigera, about 300 individuals, were captured from the natural distribution area. Multiple pre-frozen mineral water bottles were placed in the transport box, separated from the Thais clavigera by a cloth, and the adult Thais clavigera were transported at low temperature and out of water. After being transferred to the farm, the adult Thais clavigera were evenly put into the breeding ponds where the bait cultivation was completed in step two. They were domesticated in the breeding ponds for 10 - 20 days, observing the feeding, movement, and mating of the adult Thais clavigera, and checking the mortality rate of the adult Thais clavigera. If most of the adult Thais clavigera actively extend their oral discs to scrape the algae on the attachment devices, the bottom of the pond, and the walls, quickly turn over when frightened, and excrete a large number of spherical or cylindrical feces (about 5 mm in diameter), etc., it is considered that they have adapted to the environment of the breeding pond.

[0044] The results are as Figure 5 shown. The parent snails lived in good condition in the breeding pond. Except for about 5% mortality caused by transportation stress in the first 3 days in the breeding pond, there was basically no death in the following six-month breeding. The parent snails liked to live in groups ( Figure 5 A), often gathered in places such as sand and gravel, shelters, etc., stretched out their eyes and tentacles, and could move quickly. The parent snails scraped the algae attached to the bottom of the pond, the walls, etc. by extending their oral discs ( Figure 5 B). The parent snails liked to stay hidden during the day and come out at night. When fed sufficiently, they could excrete cylindrical or round feces about 5 mm in diameter ( Figure 5 C, D).

[0045] IV. Promoting Maturity and Inducing Spawning

[0046] Observe the mating situation of the adult Thais clavigera. If it is found that 2 or 3 - 5 adult Thais clavigera form independent groups, head-to-tail connected or shell openings facing each other, it indicates that the adult Thais clavigera are mating or preparing to mate and fertilize ( Figure 6 ). Increase the amount of bait in the breeding pond. Generally, 100 - 300 g of large algae such as Undaria pinnatifida and Enteromorpha prolifera are collected from the surrounding breeding ponds and put into the breeding pond for nutritional enhancement. At the same time, spread a layer of fine sand with a thickness of 0.5 - 2 cm on the bottom of the pond, scatter 50 - 100 pieces of Ulva lactuca, and place 5 - 15 abalone plates as the attachment base for the adult Thais clavigera to lay eggs. After feeding for 2 - 5 days, add fresh water to reduce the seawater salinity in the breeding pond by 1 - 4‰, stop the flowing water, and keep the reduced salinity overnight, and then turn on the flowing water the next day. The adult Thais clavigera lay eggs continuously from May to July and from September to October. The peak periods are in May, June, and September. Each time the female snail lays eggs, it lays 10 - 20 strings.

[0047] V. Collection of Egg Sacs

[0048] The female snails attach to all kinds of substrates, but most of the egg bags are produced on fine sand, followed by caltrops, and a small amount is produced on the bottom of the pond and abalone plates. The egg bags are sticky eggs, which are adhered to the attachments of fine sand to form cylindrical and hemp rope shapes. They are fluffy in appearance and light in weight. There are brown and yellow filamentous egg bags repeatedly wrapped around the dorsal and ventral sides of caltrops, and sometimes the egg bags can adhere multiple pieces of caltrops into a ball. Collect the adhesions together and put them on a basket with an 80-mesh screen placed in advance. The basket floats in the breeding pond. The collected egg bags can be used for the hatching of the hedge snail seedlings.

[0049] The parent snail likes to lay its eggs on fine sand, sticking the sand together. The single egg bag is thread-like, and after sticking together, it becomes a ball, fluffy and soft ( Figure 7 A). Sometimes the eggs are laid on the abalone basket frame, wall, abalone board ( Figure 7 B, C, D), the eggs at this time are white in color because there is no sand or other substances sticking to them. Generally, a female snail can produce 10 to 20 strings of egg bags each time ( Figure 8 A), the larvae in the egg sac develop to the blastocyst stage ( Figure 8 B), after hatching, they become planktonic larvae. Prioritize the collection of egg bags laid in the sand and gravel, and scoop up the fluffy parts of the sand and put them into a basket with a pre-set 80-mesh screen ( Figure 9 A), then tie some foam around the basket and float it on the surface of the pond ( Figure 9 B) to prepare for further hatching of snail seedlings.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for artificially domesticating, accelerating maturation and inducing spawning of Epipremnum aquatica, characterized in that: The following steps are involved: S1. Cleaning and disinfection: Select a culture pond with moderate light, clean and disinfect it, and also disinfect the algae attachment equipment for later use; S2. Bait culture: After the mixed algae are expanded and cultured, they are added to a culture pond prepared in advance to complete the bait culture, wherein the culture pond is injected with sand-filtered seawater with a water depth of 0.5 to 1 m in advance, and microtubes are used for oxygenation, and algae attachment apparatuses are placed in the culture pond in advance; after the mixed algae enter the culture pond, they are first cultured in static water for 3 to 5 days, and then cultured in flowing water. When the algae attachment apparatus is visibly covered with algae, the bait culture is considered to be completed; S3, adaptive domestication: During the breeding period, adult snails of the scallops are captured in the natural distribution area and transported out of water at low temperature; then, the adult snails are placed in the breeding pond where the feed has been cultured in S2 and domesticated for 10 to 20 days. When most of the adult snails actively eat, have normal stress reactions, and have normal defecation, they are considered to have adapted to the breeding pond environment and domestication is complete; S4. Promote maturation and induce spawning: When 2 or 3 to 5 adult snails are found to be in independent groups, connected head to tail or with shells facing each other, increase the amount of feed in the breeding pond and carry out nutritional fortification. At the same time, spread a layer of fine sand with a thickness of 0.5 to 2 cm on the bottom of the pond to spread and place the attachment base for the adult snails to lay eggs. After 2 to 5 days of nutritional fortification, reduce the salinity of the seawater in the breeding pond by 1 to 4‰, stop the convection water, and keep the reduced salinity overnight, and turn on the convection water the next day to allow the adult snails to continue to lay eggs during the spawning period. S2 The mixed algae include Chaetoceros, Platyhelminthes, Chrysophytes, Diatoms, and Cyclotella; S4 nutritional enhancement is to put large algae such as kelp and enteromorpha into the culture pond, and the attachment base for the adult snails to lay eggs is kelp and abalone plate.

2. The method for artificial domestication, ripening and induced spawning of Epipremnum aquatica according to claim 1, characterized in that: When S2 is cultured in flowing water, the water inlet flow rate is 3-10L / min.

3. A method for collecting egg sacs of Phylum fasciatum, characterized in that: The fine sand, the attachment base for laying eggs by adult snails, and the cylindrical and hemp rope-shaped adhesions on the bottom of the pond in step S4 of the method described in any one of claims 1 to 2 are collected together and placed on a basket with an 80-mesh screen in advance to obtain the egg bag of the snail.

4. Use of the method according to any one of claims 1 to 2, or the method for collecting egg sacs of P. fasciatus according to claim 3, in the artificial cultivation of P. fasciatus.

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