A cultivation method for polyps of a multi-tentacle hydrozoan

Abstract

The present invention discloses a cultivation method for poly-tentacle hydroid of jellyfish, belonging to the technical field of cultivating specific traits of jellyfish. After overwintering, the hydroid of jellyfish is cultured at a constant temperature and then cultured with temperature increase. Through artificial regulation of factors such as the living environment and feeding amount of the hydroid, the operation method is simple and highly feasible in production applications; there is no need to introduce additional chemical or physical means such as drugs, reagents, and rays for artificial intervention, and the cultivated products all conform to the growth laws under specific environmental conditions in the natural environment, without causing environmental pollution and biological pollution; on the premise of not needing to purchase high-value special production equipment additionally and not needing to transform the production environment on a large scale, the proportion of the number of individuals with multiple oral arms in the offspring individuals can be achieved, thereby increasing the yield and output value, with a high input-output ratio and higher economic benefits can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of cultivating specific traits of jellyfish, in particular to a method for cultivating polyp of jellyfish with multiple tentacles. Background Art

[0002] Jellyfish (Rhopilema esculentum Kishinouye) has become an important edible jellyfish in China due to its rich collagen, unsaturated amino acids and bioactive components, and is also one of the important marine aquaculture economic animals in coastal areas of north and south China. Jellyfish belongs to Cnidaria, Scyphozoa, Rhizostomeae, Rhizostomatidae, Rhopilema. Due to years of large-scale marine fishing activities, the wild jellyfish resources in natural waters are gradually exhausted, and currently the supply mode of jellyfish is mainly artificial seawater aquaculture. In the long-term artificial breeding work of jellyfish, due to the small number of wild individuals, the parental population for offspring breeding cannot be effectively expanded, and continuous inbreeding has caused the current jellyfish germplasm resources to show inbreeding depression phenomena such as smaller individuals, more diseases, and higher mortality rates. Therefore, carrying out the construction and cultivation of new jellyfish strains with excellent growth traits has a very important promoting effect on the maintenance of jellyfish germplasm resources and the green and long-term development of the artificial aquaculture industry.

[0003] Jellyfish has a unique life history of alternating periodic sexual reproduction and asexual reproduction. When the water temperature reaches above 20°C, sexually mature jellyfish individuals release female and male gametes into the living water body respectively, and the female and male gametes combine to form fertilized eggs. After 7-8 hours, the fertilized eggs complete cleavage to form planula larvae. The planula larvae attach to the substrate to form a pedal disc, and the pedal disc continues to develop and gradually produces a mouth, a manubrium, an oral disc and tentacles to form a complete polyp, completing the sexual reproduction period. After the polyp is formed, it carries out physiological activities such as feeding and metabolism in a sessile state. During the growth and life process in the sessile stage, the polyp can move on the surface of the attachment substrate, produce podocysts, and the podocysts can germinate to form new polyps under suitable environmental conditions. The germinated polyps are the same as their parental polyps and can move to produce new podocysts to achieve individual proliferation.

[0004] Jellyfish mostly live in the form of eight oral arms. During the long-term process of jellyfish aquaculture, a very small number of adult jellyfish individuals have been observed to have more than eight oral arms (subsequently referred to as multi-oral-arm individuals). Through statistical analysis, there is a high correspondence between the number of oral arms and the number of scapular tissues on the head of jellyfish. The additional oral arms, scapular tissues, etc. can increase the proportion of the jellyfish head in the total weight of the jellyfish individual. In previous basic research, we found that the number of tentacles produced by the polyps in the sessile life stage is related to the number of oral arms of the jellyfish formed later, and the number of tentacles can be increased to a certain extent by regulating environmental conditions, and further increase the proportion of multi-oral-arm jellyfish individuals in the produced jellyfish population. During the production and sales process of jellyfish, the umbrella part and the head of the jellyfish are sold separately, and the selling price of the head is much higher than that of the umbrella part. Therefore, multi-oral-arm jellyfish individuals can generate a higher total value than eight-oral-arm jellyfish individuals under the same total weight. Increasing the proportion of multi-oral-arm jellyfish individuals in the population can increase the total output value of jellyfish production. Summary of the Invention

[0005] The object of the present invention is to provide a cultivation method for polyps of jellyfish with multiple tentacles to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above object, the present invention provides the following solution:

[0007] The present invention provides a cultivation method for polyps of jellyfish with multiple tentacles, which comprises culturing the polyps of jellyfish at a constant temperature after overwintering and then culturing them with a temperature increase.

[0008] Preferably, the temperature of the constant-temperature cultivation is 13°C, and the time is 35 - 45 days.

[0009] Preferably, the constant-temperature cultivation is specifically as follows:

[0010] After the polyps overwinter, when the water temperature is between 10°C and 13°C, natural water temperature cultivation is carried out. When the water temperature rises to 13°C, 13°C constant-temperature cultivation is started. During this period, feeding is carried out twice a day, and the feeding amount is 20 - 30 times the estimated amount of attached larvae. After feeding, aeration is carried out, and the water is changed 3 - 4 hours after feeding, and the water body with a total volume of 1 / 3 - 1 / 2 is replaced.

[0011] Preferably, the temperature increase cultivation is carried out at a gradient of 0.4 - 0.6°C per day for 18 - 22 days until the temperature rises to 20°C.

[0012] Preferably, the temperature increase cultivation is specifically as follows:

[0013] After the constant-temperature cultivation is completed, the temperature is increased at a gradient of 0.4-0.6 °C per day for 18-22 days until it reaches 20 °C. During this period, feeding is carried out twice a day. After feeding, aeration is carried out. The feeding amount is 30 times the estimated attached larva amount. Water is changed 3-4 hours after feeding, and 1 / 3-1 / 2 of the total water volume is replaced.

[0014] Preferably, the steps before the constant-temperature cultivation also include the following:

[0015] (1) Fertilized egg hatching: The environmental conditions for fertilized egg hatching are as follows: the depth of the nursery pond is 1.2-1.8 m, the hatching water temperature is 19-26 °C, the salinity is 24-35‰, the pH is 7.6-8.6, and the dissolved oxygen is 5-7 mg / L;

[0016] (2) Scyphistoma larva cultivation: Before the ephyra larvae develop into complete scyphistomas after attachment, feeding is carried out once a day. The feeding amount at the 4-tentacle stage is 5 times the attached larva amount, 10 times at the 8-tentacle stage, and 20 times at the 16-tentacle stage. 1 / 8-1 / 4 of the total water volume is replaced, the water temperature is 20-25 °C, and the dissolved oxygen is 4-7 mg / L;

[0017] (3) Scyphistoma pre-winter cultivation: Feed twice a day with a time interval of 7-10 h. The feeding amount is 25 times the estimated attached larva amount. After feeding, aeration is carried out. Water is changed 3-4 hours after feeding, and 1 / 3-1 / 2 of the total water volume is replaced;

[0018] (4) Scyphistoma winter cultivation: When the water temperature is lower than 10 °C, feed twice a week. When the water temperature reaches lower than 5 °C, feed once a week. The feeding amount is 100 times the estimated attached larva amount. Change the water once a week and replace all the water.

[0019] Preferably, individuals with strong vitality, no physical damage, a weight of more than 8 kg, multiple oral arms, and good gonad development status are selected as the breeding parents of the fertilized eggs.

[0020] Preferably, the feeding is carried out on the scyphistoma larvae using jellyfish ephyra larvae, rotifers or Artemia nauplii.

[0021] Preferably, shading treatment is carried out throughout the cultivation process.

[0022] The present invention also provides.

[0023] Based on the above technical solutions, the present invention has the following technical effects:

[0024] 1. Through artificial regulation of factors such as the living environment and feeding amount of the scyphistoma, the operation method is simple, and the feasibility in production applications is high;

[0025] 2. There is no need to artificially intervene by introducing additional chemicals or physical means such as drugs, reagents, and rays. The cultivated products all conform to the growth laws under specific environmental conditions in the natural environment and will not cause environmental pollution or biological pollution.

[0026] 3. On the premise of not needing to purchase high-value special production equipment additionally and not needing to transform the production environment on a large scale, it is possible to achieve the proportion of the number of individuals with multiple oral arms in the offspring individuals, thereby increasing the yield and output value. The input-output ratio is high, and higher economic benefits can be obtained. Detailed implementation manners

[0027] The various exemplary implementation manners of the present invention will be described in detail below. Unless otherwise specified, the methods in the examples are all conventional methods, and the reagents used are all conventional commercially available reagents or reagents prepared by conventional methods if not otherwise specified. This detailed description should not be regarded as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and implementation manners of the present invention.

[0028] It should be understood that the terms described in the present invention are only for describing particular implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0029] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0030] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the present invention specification, which are obvious to those skilled in the art. Other implementation manners obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are only exemplary.

[0031] Regarding the use of "comprising", "including", "having", "containing", etc. in this article, they are all open-ended terms, that is, they are meant to include but not be limited to.

[0032] The technical solutions described in the present invention are conventional solutions in the art unless otherwise specified. The reagents or raw materials used are purchased from commercial channels or are publicly available unless otherwise specified.

[0033] Example 1

[0034] 1. Aurelia aurita collection: Capture Aurelia aurita individuals with strong vitality, no individual damage, a weight of more than 8 kg, and sexual maturity as candidate breeding parents. Microscopically observe the gonad tissue to identify the gonad development level and gender, and select individuals with good gonad development status as breeding parents, including 10 male parents and 10 female parents. The environmental conditions for fertilized egg hatching are as follows: the depth of the nursery pond is 1.2 - 1.8 m, circular or square. The hatching water temperature is 19 - 26 °C, the salinity is 24 - 35‰, the pH is 7.6 - 8.6, and the dissolved oxygen is 5 - 7 mg / L.

[0035] 2. Scyphistoma larva cultivation: After the planula larvae attach and during the process of developing into complete scyphistomas, the scyphistoma larvae can be fed with Aurelia aurita planula larvae, rotifers, and Artemia nauplii, etc., once a day. The feeding amount at the 4-tentacle stage is 5 times the estimated amount of attached larvae, 10 times at the 8-tentacle stage, and 20 times at the 16-tentacle stage. Replace 1 / 8 - 1 / 4 of the total water volume, with the water temperature at 20 - 25 °C, the dissolved oxygen at 4 - 7 mg / L, and cover with a black cloth.

[0036] 3. Pre-winter cultivation of scyphistoma: Feed twice a day with an interval of more than 8 hours. The feeding amount of Artemia is 25 times the estimated amount of attached larvae. After feeding, inflate the water, and change the water 3 - 4 hours after feeding, replacing 1 / 3 - 1 / 2 of the total water volume, and cover with a black cloth.

[0037] 4. Winter cultivation of scyphistoma: When the water temperature is below 10 °C, feed twice a week. When the water temperature reaches below 5 °C, feed once a week. The feeding amount of Artemia is 100 times the estimated amount of attached larvae. Change the water once a week, replacing all the water, and cover with a black cloth.

[0038] 5. Post-winter cultivation of scyphistoma: Conduct natural water temperature cultivation when the water temperature is between 10 °C and 13 °C. When the water temperature rises to 13 °C, start 13 °C constant temperature cultivation, and the constant temperature period lasts for 40 days. During this period, feed twice a day. The feeding amount of Artemia is 20 - 30 times the estimated amount of attached larvae. After feeding, inflate the water, and change the water 3 - 4 hours after feeding, replacing 1 / 3 - 1 / 2 of the total water volume, and cover with a black cloth.

[0039] 6. Strobila cultivation: After the constant temperature cultivation ends, carry out temperature increase cultivation at a gradient of 0.5 °C per day for 20 days until the temperature rises to 20 °C. During this period, feed twice a day. After feeding, inflate the water. The feeding amount of Artemia is 30 times the estimated amount of attached larvae. Change the water 3 - 4 hours after feeding, replacing 1 / 3 - 1 / 2 of the total water volume, and cover with a black cloth.

[0040] 7. Statistical analysis: The total number of polyps after constant-temperature cultivation is about 521,000. Among them, the number of individuals with more tentacles than the conventional 16 tentacles is about 57,300, and the proportion of individuals with more tentacles is about 11%.

[0041] Comparative Example 1

[0042] The differences from Example 1 are as follows:

[0043] 1. Parent selection: Select jellyfish individuals with good vitality and sexual maturity of eight oral arms as candidate parents. After microscopic observation, select male and female individuals with well-developed gonads for offspring breeding.

[0044] 2 - 4. During the polyp larval stage, before overwintering, and during overwintering: The feeding method is the same as the traditional aquaculture production cultivation conditions. The feeding amount at the 16-tentacle stage is 15 times the estimated settlement amount, 20 times before overwintering, and 150 times during overwintering.

[0045] 5. After the polyps overwinter: There is no artificial constant-temperature cultivation period, and the feeding amount is 20 times the estimated settlement amount.

[0046] The remaining steps are the same as those in Example 1.

[0047] Statistical analysis: A total of about 507,000 polyps are obtained through statistical analysis. Among them, the number of polyps with more tentacles is about 6,600, and the proportion of individuals with more tentacles is about 1.3%.

[0048] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A cultivation method for poly-tentacle hydroids of jellyfish, where the poly-tentacle means the number of tentacles is more than 16, and it is characterized in that, The scyphistoma of jellyfish is subjected to constant-temperature cultivation after overwintering, and then to temperature-raising cultivation; The temperature of the constant-temperature cultivation is 13 °C, and the time is 35 - 45 days; the temperature-raising cultivation is carried out at a gradient of 0.4 - 0.6 °C per day until the temperature reaches 20 °C.

2. The cultivation method according to claim 1, characterized in that, The specific process of the constant-temperature cultivation is as follows: After the scyphistoma overwinters, when the water temperature is between 10 °C and 13 °C, natural water temperature cultivation is carried out. When the water temperature rises to 13 °C, 13 °C constant-temperature cultivation begins. During this period, feeding is carried out twice a day, and the feeding amount is 20 - 30 times the estimated larval attachment amount. After feeding, aeration is carried out, and water is changed 3 - 4 hours after feeding, replacing 1 / 3 - 1 / 2 of the total water volume.

3. The cultivation method according to claim 1, characterized in that, The specific process of the temperature-raising cultivation is as follows: After the constant-temperature cultivation ends, temperature-raising cultivation is carried out at a gradient of 0.4 - 0.6 °C per day until the temperature reaches 20 °C. During this period, feeding is carried out twice a day, and after feeding, aeration is carried out. The feeding amount is 30 times the estimated larval attachment amount. Water is changed 3 - 4 hours after feeding, replacing 1 / 3 - 1 / 2 of the total water volume.

4. The cultivation method according to claim 1, characterized in that, Before the constant-temperature cultivation, the following steps are also included: (1) Fertilized egg hatching: The environmental conditions for fertilized egg hatching are as follows: the depth of the breeding pond is 1.2 - 1.8 m, the hatching water temperature is 19 - 26 °C, the salinity is 24 - 35‰, the pH is 7.6 - 8.6, and the dissolved oxygen is 5 - 7 mg / L; (2) Scyphistoma larva cultivation: Before the ephyra larvae attach and develop into complete scyphistoma, feeding is carried out once a day. The feeding amount at the 4-tentacle stage is 5 times the larval attachment amount, at the 8-tentacle stage is 10 times, and at the 16-tentacle stage is 20 times. 1 / 8 - 1 / 4 of the total water volume is replaced, the water temperature is 20 - 25 °C, and the dissolved oxygen is 4 - 7 mg / L; (3) Cultivation before the scyphistoma overwinters: Feeding is carried out twice a day, with a time interval of 7 - 10 h. The feeding amount is 25 times the estimated larval attachment amount. After feeding, aeration is carried out, and water is changed 3 - 4 hours after feeding, replacing 1 / 3 - 1 / 2 of the total water volume; (4) Cultivation during the scyphistoma overwintering period: When the water temperature is lower than 10 °C, feeding is carried out 2 times a week. When the water temperature reaches lower than 5 °C, feeding is carried out once a week. The feeding amount is 100 times the estimated larval attachment amount. Water is changed once a week, replacing all the water.

5. The cultivation method according to claim 4, characterized in that, Individuals with strong vitality, no damage, a weight of more than 8 kg, multiple oral arms, and a good gonadal development state are selected as the breeding parents of the fertilized eggs.

6. The cultivation method according to any one of claims 2-5, characterized in that, The feeding is carried out by using jellyfish ephyra larvae, rotifers or Artemia nauplii to feed the scyphistoma larvae.

7. The cultivation method according to claim 1, characterized in that, Shading treatment is carried out throughout the cultivation process.