A method for low-temperature breeding of artificially bred moon jellyfish

Abstract

This invention relates to the field of marine organism rearing technology, specifically providing a method for the low-temperature breeding of moon jellyfish in artificial rearing. The method includes seawater preparation, collection of planktonic larvae, cultivation of polyps, and cultivation of adult jellyfish. The polyps are cultivated at a low temperature of 12-15℃ and fed with rotifers and nutrients. During the cultivation of adult jellyfish, *Lactobacillus plantarum* is used to assist in the cultivation. This method, through low-temperature cultivation and the addition of nutrients, improves the attachment rate of planktonic larvae, the survival rate of polyps and discoid bodies, and increases the size of adult jellyfish, significantly improving the breeding efficiency and quality of moon jellyfish.

Description

Technical Field

[0001] This invention relates to the field of marine organism breeding technology, specifically to a method for low-temperature breeding of artificially bred moon jellyfish. Background Technology

[0002] Moon jellyfish are a type of jellyfish widely distributed in coastal waters worldwide. They have a transparent, bell-shaped body with short tentacles along the edges. The life cycle of moon jellyfish is complex, including both sexual and asexual reproduction stages. During sexual reproduction, male and female jellyfish mate to produce planktonic larvae, which attach to a suitable substrate and develop into polyps. The polyps then reproduce asexually to form disc-shaped larvae, which eventually develop into adult jellyfish. Their reproduction is influenced by various environmental factors such as temperature, salinity, and light.

[0003] Low temperatures are beneficial to the growth and development of moon jellyfish larvae at all stages. In particular, the polyps not only have a higher survival rate in low-temperature environments but also significantly increase in size, laying a solid foundation for subsequent development into disc-shaped larvae and adult jellyfish. Therefore, exploring and optimizing breeding methods for moon jellyfish under low-temperature conditions is of great significance for improving the efficiency of artificial breeding and the quality of the jellyfish. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a method for low-temperature breeding of artificially raised moon jellyfish.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention proposes a method for low-temperature breeding of artificially raised moon jellyfish, specifically including the following steps:

[0006] S1. Preparation of artificial seawater: Prepare artificial seawater with a salinity of 28-32‰;

[0007] S2. Collection of planktonic larvae: During the sexual reproduction season of moon jellyfish, sexually mature male and female moon jellyfish are placed in artificial seawater with an aerator and left to stand still. After 24 hours, the male and female jellyfish release sperm and eggs from their mouths to produce planktonic larvae. The artificial seawater is filtered through a 500μm sieve to remove jellyfish tissue fragments, and then filtered a second time through a 38μm sieve to collect the planktonic larvae.

[0008] S3. Polyp Culture: Rinse the planktonic larvae obtained in step S2 with artificial seawater to ensure cleanliness, then place the planktonic larvae in artificial seawater at a density of 1 larva / cm³. 3 Polyethylene corrugated plates are used as the attachment substrate for planktonic larvae. After attachment, they develop into polyps. The polyps are cultured at a water temperature of 12℃~15℃. Live food and nutrients are fed regularly every day. 50% or more of the artificial seawater is replaced 2 hours after feeding every day.

[0009] S4. Adult Jellyfish Cultivation: After the polyps in step S3 mature, they release discoid bodies through asexual reproduction. The discoid bodies are collected and placed in a culture container. The salinity of artificial seawater is adjusted to 22-25‰ as the jellyfish culture medium, which is added to the culture container. The density of discoid bodies is 20-30 per L. The jellyfish are cultured at a water temperature of 22-25℃. Live food, nutrients, and auxiliary microorganisms are fed regularly every day. Gentle bubbles are used for cultivation. 50% or more of the culture medium is replaced every day. After 50-60 days of cultivation, the discoid bodies develop into adult jellyfish.

[0010] Preferably, in step S2, the density of sexually mature male and female jellyfish is 1-1.5 per 10L of water.

[0011] Preferably, in step S3, the polyethylene corrugated plate is 20-30cm from the bottom of the tank, and the live bait 1 is rotifers, with 100 rotifers added to each liter of artificial seawater.

[0012] Preferably, the nutrients in step S3 include the following components in parts by weight: 2 parts lysine, 2 parts arginine, 2 parts glutamic acid, 3 parts vitamin B12, 3 parts vitamin E, 0.5 parts calcium chloride, 0.5 parts magnesium chloride, and 0.5 parts potassium chloride, with 0.4 to 0.6 g of nutrients added per liter of artificial seawater.

[0013] Preferably, in step S4, the live bait 2 consists of rotifers and cladocerans, with 100 rotifers and 50 cladocerans added per liter of jellyfish culture medium, and 0.5–0.7 g of nutrients added per liter of jellyfish culture medium.

[0014] Preferably, the auxiliary microorganism in step S4 is *Lactobacillus plantarum*, with 10^6 CFU of *Lactobacillus plantarum* added per liter of jellyfish culture medium. *Lactobacillus plantarum* was purchased from the China General Microbiological Culture Collection Center, with the number CGMCC1.12935.

[0015] The beneficial effects achieved by this invention are as follows:

[0016] This invention provides a low-temperature breeding method for artificially raised moon jellyfish, which has significant beneficial effects and is innovative. By culturing polyps in a low-temperature environment of 12-15℃, the survival rate of polyps is effectively improved, and their volume is significantly increased, laying a solid foundation for subsequent development into jellyfish larvae and adult jellyfish. Regarding nutritional supply, this invention adds lysine, arginine, glutamic acid, vitamin B12, vitamin E, and nutrients such as calcium, magnesium, and potassium to each liter of artificial seawater, providing comprehensive and balanced nutrition and significantly improving the size and health of the larvae. This invention also introduces beneficial microorganisms such as *Lactobacillus plantarum*, adding 10^6 CFU of *Lactobacillus plantarum* per liter of jellyfish culture medium, effectively improving water quality, reducing the growth of harmful bacteria, enhancing the immunity of larvae, and improving overall health. This microbial-assisted culture method is also an innovation of this invention, further improving the success rate of breeding by improving water quality and enhancing immunity. Through these innovative measures, not only is the quality of moon jellyfish improved, but breeding costs are also reduced. The method is simple to operate, highly applicable, and has significant practical application value. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 These are the attachment rates of planktonic larvae in Examples 1-3 and Comparative Examples 1-2;

[0019] Figure 2 The survival rates of the polyps in Examples 1-3 and Comparative Examples 1-2 are shown.

[0020] Figure 3 The umbrella diameters of adult moon jellyfish are those of Examples 1-3 and Comparative Examples 1-2. Detailed Implementation

[0021] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0022] It should be noted that, unless otherwise specified, all chemical reagents involved in this invention were purchased through commercial channels.

[0023] Example 1: This example proposes a method for the low-temperature breeding of artificially raised moon jellyfish, specifically including the following steps:

[0024] S1. Preparation of artificial seawater: Prepare artificial seawater with a salinity of 28‰;

[0025] S2. Collection of planktonic larvae: During the sexual reproduction season of moon jellyfish, sexually mature male and female moon jellyfish are placed in artificial seawater with an aeration head and kept still at a density of 1.5 jellyfish / 10L of water. After 24 hours, the male and female jellyfish release sperm and eggs from their mouths to produce planktonic larvae. The artificial seawater is filtered through a 500μm sieve to remove jellyfish tissue fragments, and then filtered a second time through a 38μm sieve to collect the planktonic larvae.

[0026] S3. Polyp Culture: Rinse the planktonic larvae obtained in step S2 with artificial seawater to ensure cleanliness, then place the planktonic larvae in artificial seawater at a density of 1 larva / cm³. 3 Polyethylene corrugated boards were used as the attachment substrate for planktonic larvae. The polyethylene corrugated boards were placed 20cm from the bottom of the tank. After attachment, the larvae developed into polyps. The polyps were cultured at a water temperature of 12℃. Rotifers and nutrients were fed regularly every day. 100 rotifers and 0.5g of nutrients were added to each liter of artificial seawater. 50% of the artificial seawater was replaced 2 hours after feeding every day.

[0027] S4. Adult Jellyfish Cultivation: After the polyps in step S3 mature, they release discoid bodies through asexual reproduction. The discoid bodies are collected and placed in a culture container. The salinity of artificial seawater is adjusted to 22‰ as the jellyfish culture medium, which is added to the culture container. The density of discoid bodies is 30 per liter of water. The culture is carried out at a water temperature of 25℃. Rotifers, cladocerans, nutrients, and Lactobacillus plantarum are fed regularly every day. Approximately 100 rotifers, 50 cladocerans, 0.6g of nutrients, and 10^6 CFU of Lactobacillus plantarum are added to each liter of jellyfish culture medium. Gentle bubbles are used for cultivation. 50% of the jellyfish culture medium is replaced daily. After 50 days of cultivation, the discoid bodies develop into adult jellyfish.

[0028] The nutrients in step S3 include the following components by weight: 2 parts lysine, 2 parts arginine, 2 parts glutamic acid, 3 parts vitamin B12, 3 parts vitamin E, 0.5 parts calcium chloride, 0.5 parts magnesium chloride, and 0.5 parts potassium chloride.

[0029] Example 2: This example proposes a method for low-temperature breeding of artificially raised moon jellyfish, specifically including the following steps:

[0030] S1. Preparation of artificial seawater: Prepare artificial seawater with a salinity of 32‰;

[0031] S2. Collection of planktonic larvae: During the sexual reproduction season of moon jellyfish, sexually mature male and female moon jellyfish are placed in artificial seawater with an aeration head and kept still at a density of 1 jellyfish / 10L of water. After 24 hours, the male and female jellyfish release sperm and eggs from their mouths to produce planktonic larvae. The artificial seawater is filtered through a 500μm sieve to remove jellyfish tissue fragments, and then filtered a second time through a 38μm sieve to collect the planktonic larvae.

[0032] S3. Polyp Culture: Rinse the planktonic larvae obtained in step S2 with artificial seawater to ensure cleanliness, then place the planktonic larvae in artificial seawater at a density of 1 larva / cm³. 3 Polyethylene corrugated boards were used as the attachment substrate for planktonic larvae. The polyethylene corrugated boards were placed 30cm from the bottom of the tank. After attachment, the larvae developed into polyps. The polyps were cultured at a water temperature of 15℃. Rotifers and nutrients were fed regularly every day. 100 rotifers and 0.5g of nutrients were added to each liter of artificial seawater. 60% of the artificial seawater was replaced 2 hours after feeding every day.

[0033] S4. Adult Jellyfish Cultivation: After the polyps in step S3 mature, they release discoid bodies through asexual reproduction. The discoid bodies are collected and placed in a culture container. The salinity of artificial seawater is adjusted to 25‰ as the jellyfish culture medium, which is added to the culture container. The density of discoid bodies is 30 per liter of water. The culture is carried out at a water temperature of 22℃. Rotifers, cladocerans, nutrients, and Lactobacillus plantarum are fed daily at regular intervals. Approximately 100 rotifers, 50 cladocerans, 0.6g of nutrients, and 10^6 CFU of Lactobacillus plantarum are added to each liter of jellyfish culture medium. Gentle bubbles are used for cultivation. 60% of the jellyfish culture medium is replaced daily. After 56 days of cultivation, the discoid bodies develop into adult jellyfish.

[0034] The nutrients in step S3 include the following components by weight: 2 parts lysine, 2 parts arginine, 2 parts glutamic acid, 3 parts vitamin B12, 3 parts vitamin E, 0.5 parts calcium chloride, 0.5 parts magnesium chloride, and 0.5 parts potassium chloride.

[0035] Example 3: This example proposes a method for the low-temperature breeding of artificially raised moon jellyfish, specifically including the following steps:

[0036] S1. Preparation of artificial seawater: Prepare artificial seawater with a salinity of 30‰;

[0037] S2. Collection of planktonic larvae: During the sexual reproduction season of moon jellyfish, sexually mature male and female moon jellyfish are placed in artificial seawater with an aeration head and kept still at a density of 1.2 jellyfish / 10L of water. After 24 hours, the male and female jellyfish release sperm and eggs from their mouths to produce planktonic larvae. The artificial seawater is filtered through a 500μm sieve to remove jellyfish tissue fragments, and then filtered a second time through a 38μm sieve to collect the planktonic larvae.

[0038] S3. Polyp Culture: Rinse the planktonic larvae obtained in step S2 with artificial seawater to ensure cleanliness, then place the planktonic larvae in artificial seawater at a density of 1 larva / cm³. 3 Polyethylene corrugated boards were used as the attachment substrate for planktonic larvae. The polyethylene corrugated boards were placed 25cm from the bottom of the tank. After attachment, the larvae developed into polyps. The polyps were cultured at a water temperature of 13℃. Rotifers and nutrients were fed regularly every day. 100 rotifers and 0.5g of nutrients were added to each liter of artificial seawater. 70% of the artificial seawater was replaced 2 hours after feeding every day.

[0039] S4. Adult Jellyfish Cultivation: After the polyps in step S3 mature, they release discoid bodies through asexual reproduction. The discoid bodies are collected and placed in a culture container. The salinity of artificial seawater is adjusted to 24‰ as the jellyfish culture medium, which is added to the culture container. The density of discoid bodies is 30 per liter of water. The culture is carried out at a water temperature of 24℃. Rotifers, cladocerans, nutrients, and Lactobacillus plantarum are fed regularly every day. Approximately 100 rotifers, 50 cladocerans, 0.6g of nutrients, and 10^6 CFU of Lactobacillus plantarum are added to each liter of jellyfish culture medium. Gentle bubbles are used for cultivation. 70% of the jellyfish culture medium is replaced daily. After 60 days of cultivation, the discoid bodies develop into adult jellyfish.

[0040] The nutrients in step S3 include the following components by weight: 2 parts lysine, 2 parts arginine, 2 parts glutamic acid, 3 parts vitamin B12, 3 parts vitamin E, 0.5 parts calcium chloride, 0.5 parts magnesium chloride, and 0.5 parts potassium chloride.

[0041] Comparative Example 1: This comparative example proposes a low-temperature breeding method for artificially bred moon jellyfish. The only difference between this method and Example 1 is that the culture temperature of the polyps in step S3 is 22°C. All other components, component contents, and experimental steps are the same as in Example 1.

[0042] Comparative Example 2: This comparative example proposes a method for low-temperature breeding of artificially bred moon jellyfish. The only difference between this method and Example 1 is that nutrients and Lactobacillus plantarum are not added. All other components, component contents, and experimental steps are the same as in Example 1.

[0043] Experimental example: The survival status of moon jellyfish at each stage of the breeding process in Examples 1-3 and Comparative Examples 1-2 was monitored, and the attachment rate of planktonic larvae, the survival rate of polyps, and the umbrella diameter of adult moon jellyfish were recorded.

[0044] Figure 1 The figure shows the attachment rate of planktonic larvae in Examples 1-3 and Comparative Examples 1-2. As shown in the figure, the attachment rate of planktonic larvae in Examples 1-3 and Comparative Example 2 is greater than that in Comparative Example 1, indicating that low temperature can improve the attachment rate of planktonic larvae, which is beneficial for further incubation. Figure 2The figures show the polyp survival rates of Examples 1-3 and Comparative Examples 1-2. The polyp survival rates of Examples 1-3 are greater than those of Comparative Examples 1-2, with Comparative Example 1 having the lowest survival rate. This indicates that low-temperature incubation, the addition of nutrients, and Lactobacillus plantarum can improve the polyp survival rate and increase the success rate of cultivation. Figure 3 The figures show the bell diameters of adult moon jellyfish from Examples 1-3 and Comparative Examples 1-2. As shown in the figures, the bell diameters of adult moon jellyfish from Examples 1-3 are larger than those from Comparative Examples 1-2, with Comparative Example 2 being larger than Comparative Example 1. This indicates that low-temperature culture of polyps and feeding with nutrients and Lactobacillus plantarum can help moon jellyfish grow to a larger size, thus improving their quality.

[0045] The present invention and its embodiments have been described above. This description is not restrictive, and practical applications are not limited thereto. In conclusion, if those skilled in the art are inspired by this description and, without departing from the spirit of the invention, design similar methods and embodiments to this technical solution, all such designs should fall within the protection scope of the present invention.

Claims

1. A method for cryopreservation of artificially reared Aurelia sp. polyps, characterized by, Specifically comprising the following steps: S1, configuration of artificial seawater: configure artificial seawater with salinity of 28-32 ‰; S2, collecting planulae: in the sexual reproduction season of A. digitale, put sexually mature male and female A. digitale into artificial seawater in an aeration head, and the male and female A. digitale release sperm and eggs from their mouths to produce planulae, which are collected by filtering through a silk screen; S3, polyp culture: wash the planulae obtained in step S2 with artificial seawater, place the planulae in artificial seawater, use a polyethylene corrugated plate as the attachment substrate for the planulae, and develop into polyps after attachment, and culture the polyps at a water temperature of 12-15℃, feed with live prey 1 and nutrients at regular times every day, and replace 50% or more of the artificial seawater after 2 hours of feeding; S4, adult medusa cultivation: after the polyps in step S3 mature, release disc-shaped bodies through asexual reproduction, collect the disc-shaped bodies and place them in a culture container, adjust the salinity of the artificial seawater as the medusa culture solution, and add it to the culture container, and culture at a water temperature of 22-25℃, feed with live prey 2, nutrients, and auxiliary microorganisms at regular times every day, and cultivate with soft bubbles, replace 50% or more of the medusa culture solution every day, and cultivate for 50-60 days to develop into adult medusae; The polyethylene corrugated plate in step S3 is 20-30 cm from the bottom of the tank, and the live prey 1 is rotifer, 100 rotifers per liter of artificial seawater; The nutrients in step S3 include the following components by weight: lysine 2 parts, arginine 2 parts, glutamic acid 2 parts, vitamin B12 3 parts, vitamin E 3 parts, calcium chloride 0.5 parts, magnesium chloride 0.5 parts, and potassium chloride 0.5 parts, and 0.4-0.6 g of nutrients per liter of artificial seawater; The live prey 2 in step S4 is rotifer and cladocera, 100 rotifers and 50 cladocera are added per liter of medusa culture solution, and 0.5-0.7 g of nutrients are added per liter of medusa culture solution; The auxiliary microorganism in step S4 is Lactobacillus plantarum, and 10^6 CFU of Lactobacillus plantarum is added per liter of medusa culture solution.

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