Artificial breeding method for spotted stingrays

Abstract

This invention belongs to the field of breeding medium to large cartilaginous fish, specifically relating to a method for the artificial breeding of spotted stingrays. The method includes estrus control, gestation control of female spotted stingrays, and management of spotted stingray fry. Isolating male and female spotted stingrays during the estrus period and providing females with a special diet increases mating success rates and reduces the probability of injury to females. Training newborn spotted stingray fry to begin feeding effectively helps them adapt to their environment and eventually forage independently. The mixed feed and nutritional fortification agents involved enhance the immunity of the spotted stingray fry, ensure their nutritional needs for growth, and thus improve their survival rate. This method for the artificial breeding of spotted stingrays has significant application value.

Description

Technical Field

[0001] This invention belongs to the field of breeding medium and large cartilaginous fish, specifically relating to an artificial breeding method for spotted stingrays. Background Technology

[0002] The spotted ray (scientific name: Aetobatus narinari), also known as Narva's ray or snowflake ray. The spotted eagle ray, also known as the spotted eagle ray or spotted calf ray, is a species belonging to the genus *Eupterus* in the family Eupteridae, order Stingrays, class Chondrichthyes, phylum Chordata. The largest specimens can reach a length of 330 cm. The spotted eagle ray has a duck-like bill, a long, slender tail with serrated spines at the base, and triangular pectoral fins resembling wings. It is a fast swimmer, inhabiting open ocean and coastal waters, typically dwelling on or near sandy seabeds, and active from the surface to depths of 60 meters. The spotted eagle ray reproduces ovoviviparously, giving birth to 1-5 fry per year after a 12-month gestation period, averaging 3 fry. At birth, the ray's disc width is 18-36 cm. Spotted rays are carnivorous, feeding on hard-shelled mollusks and crustaceans, as well as soft-bodied worms and small bony fish. They are primarily a byproduct of various tropical fisheries, and their catch can be eaten or processed into fishmeal. They are also ideal exhibits in large aquariums and marine parks. Due to overfishing, the number of spotted rays has gradually declined, and the International Union for Conservation of Nature (IUCN) classified them as an endangered species (A2bd) in its 2020 assessment.

[0003] Due to overfishing leading to population decline, and issues such as slow growth, low fertility, and long embryonic development cycles, artificial intervention is urgently needed for spotted stingrays. Newly hatched spotted stingray fry are highly susceptible to not feeding or showing much initiative in their feeding, while their constant swimming requires a significant amount of energy; insufficient nutrition can easily lead to their death. Therefore, improving the survival rate of spotted stingray fry is a key challenge in artificial breeding. Summary of the Invention

[0004] To address the above problems, this invention provides an artificial breeding method for spotted stingrays, specifically focusing on estrus control, gestation control of female spotted stingrays, and management of spotted stingray fry. During estrus, female spotted stingrays are given special food to promote mating behavior and reduce the probability of injury. The method also trains spotted stingray fry to begin feeding. The mixed feed and nutritional fortification agents involved enhance the fry's immunity and supplement elements such as magnesium, which are often deficient during growth, thereby ensuring the fry's survival and preventing them from dying from parasite infections.

[0005] A method for the artificial breeding of spotted stingrays, comprising the following:

[0006] (1) Estrus control: When the spotted ray is in estrus, the male spotted ray is isolated, and then 1 / 6 to 1 / 5 of the female spotted ray's daily food is replaced with special food for 10 to 14 days. After that, the male and female spotted rays are kept together and observed daily for any mating behavior.

[0007] (2) Pregnancy management of female spotted rays: Pregnant female spotted rays are managed separately, fed in the same water, and given an extra 5-8% of their food;

[0008] (3) Management of spotted ray calves: After the spotted ray calves are born, they should be isolated in time and trained to start feeding until they can forage for food on their own.

[0009] The special food mentioned is clams injected with hormones, specifically gonadotropin-releasing hormone or human chorionic gonadotropin produced by the hypothalamus.

[0010] The preparation method of the special food is as follows:

[0011] V1. Fresh clams are manually shelled to obtain clam meat. Hormones are injected into the clam meat at a dose of 8000-10000 IU / kg to obtain processed food.

[0012] V2. Clean the processed food obtained in step V1 to obtain the special food.

[0013] Preferably, the weight of the clam meat in step V1 is consistent with 1 / 6 to 1 / 5 of the daily diet of female spotted stingrays.

[0014] The open feeding training includes hand feeding, gavage feeding, gavage, and fixed-point feeding;

[0015] Ideally, hand-feeding involves removing the shells from food such as clams, razor clams, mackerel, and krill, cutting them into pieces, and having the keeper hold them in their hand while waiting along the route of the spotted ray fry. Once the spotted ray fry swim nearby, they are given a trial feeding.

[0016] Preferably, feeding involves controlling the spotted ray fry with a net, removing the shells of food such as clams, razor clams, mackerel, and krill, cutting them into pieces, and placing them near the spotted ray fry's mouth to encourage them to open their mouths, or directly stuffing the food into the spotted ray fry's mouth for them to chew.

[0017] Preferably, gavage should be performed after attempts to feed by hand or by force-feeding have failed. The specific procedure is as follows: Control the spotted ray fry with a net, turn its body over so that its abdomen is facing up, and ensure that the fry's gills are in the water and that it can breathe independently. Slowly insert the tube into the fry's mouth 14-16 cm downwards, and use a syringe to deliver the mixed feed and nutritional fortification agent through the hollow channel of the tube into the fry's stomach.

[0018] The preparation method of the mixed bait is as follows:

[0019] L1. Clam meat, razor clam meat, krill, and mackerel are ground into meat pastes separately to obtain clam meat paste, razor clam meat paste, krill meat paste, and mackerel meat paste. After mixing, meat paste components are obtained. Turmeric, honeysuckle, burdock, and bamboo are taken in equal parts by weight, mixed and weighed, ground into powder, and passed through a 10-20 mesh sieve to obtain traditional Chinese medicine components.

[0020] L2. Add the Chinese herbal medicine components obtained in step L1 to the meat paste components, add glucose aqueous solution in small amounts several times, and mix and stir evenly to obtain mixed feed.

[0021] Ideally, the base feed should consist of 60-70% clam meat paste, 5-10% razor clam meat paste, 10-15% krill meat paste, and the remainder should be supplemented with mackerel meat paste.

[0022] Preferably, in step L2, the mass ratio of the herbal medicine component: meat paste component: glucose aqueous solution is 0.5-1:10:2-3, and the concentration of the glucose aqueous solution is 2-5%.

[0023] The nutritional fortification preparation is obtained by uniformly mixing the following substances in parts by weight: 1-3 parts microbial culture, 6-10 parts lactoferrin, 1-1.5 parts calcium caseinate, and 0.8-1 parts magnesium citrate.

[0024] Preferably, the microbial suspension is composed of a Bacillus suspension and a Lactobacillus acidophilus suspension at a ratio of 1:0.5-1, with each suspension having a concentration of 1×10⁻⁶. 7 -10 8 The cfu / mL of Bacillus and Lactobacillus acidophilus were obtained from the China General Microbiological Culture Collection Center, with accession numbers CGMCC 1.857 and CGMCC 1.12735, respectively.

[0025] The beneficial effects of this invention are as follows:

[0026] Currently, the breeding of spotted stingrays relies heavily on natural contact between males and females. However, the success rate of mating during the estrus period is low. Artificial intervention can promote mating behavior, but there is a lack of specific practical methods and data on the effectiveness of these methods. This invention refers to methods for promoting mating in bony fish, combined with behavioral feedback from spotted stingrays. Ultimately, it uses special food to stimulate the mating and reproductive desire of female spotted stingrays, combined with the control of male spotted stingrays, to both promote mating behavior and reduce the occurrence of injuries to female spotted stingrays during mating. Spotted rays carry numerous parasites that can damage their mouths and skin. Excessive parasite infestation can even lead to death. Newborn spotted ray fry have low immunity and are highly susceptible to parasite infestation, often resulting in death. Therefore, this invention incorporates traditional Chinese medicine components into the mixed feed, leveraging their anti-parasitic properties to protect the fry. Furthermore, a nutritional fortification preparation is provided for the spotted ray fry. This preparation includes microbial culture, lactoferrin, calcium caseinate, and magnesium citrate. The microbial culture, used in bony fish, acts as an immune enhancer; this invention is the first to apply it to spotted rays. Besides enhancing immunity, Bacillus and Lactobacillus acidophilus help establish the fry's gut microbiota, aiding in independent foraging. Calcium caseinate and magnesium citrate supplement calcium and magnesium, supporting the fry's growth. Based on routine care and management of spotted stingrays, this invention reveals that spotted stingray fry are prone to magnesium deficiency, and conventional spotted stingray management methods often fail to adequately supplement magnesium. Therefore, this invention is the first to incorporate magnesium into the nutritional management of spotted stingray fry. Furthermore, this invention provides a more systematic and comprehensive training method for spotted stingray fry to begin feeding, effectively offering multiple ways to help them start feeding and eventually forage independently. The specific length of the tubing used for gavage is not previously addressed in other studies.

[0027] Spotted stingrays have graceful swimming postures and often attract a lot of attention from visitors in aquariums. The artificial breeding method for spotted stingrays provided by this invention can effectively promote successful mating of spotted stingrays during the estrus period and ensure a high survival rate of fry, which has significant application value. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. In the accompanying drawings:

[0029] Figure 1 A graph showing the pH changes over time in the water used for spotted stingray aquaculture.

[0030] Figure 2 A graph showing the temporal variation of water temperature in the culture water for spotted stingrays;

[0031] Figure 3 A graph showing the temporal variation of ammonia nitrogen in the water used for spotted stingray aquaculture;

[0032] Figure 4 A graph showing the temporal variation of heterotrophic bacteria counts in the water used for spotted stingray aquaculture;

[0033] Figure 5 A graph showing the temporal variation of Vibrio count in the water used for spotted stingray aquaculture;

[0034] Figure 6 A diagram illustrating the feeding of spotted stingray fry.

[0035] Figure 7 A diagram illustrating the practice of gavage administration to spotted ray fry. Detailed Implementation

[0036] Example 1: This example provides a method for the artificial breeding of spotted stingrays, the details of which are as follows:

[0037] (1) Estrus control: When the spotted ray is in estrus, the male spotted ray is isolated, and then 1 / 6 of the female spotted ray's daily food is replaced with special food for 14 days. After that, the male and female spotted rays are kept together and observed daily for any mating behavior.

[0038] (2) Pregnancy management of female spotted rays: pregnant female spotted rays are managed separately, fed in the same water, and given an extra 5% of food;

[0039] (3) Management of spotted ray calves: After the spotted ray calves are born, they should be isolated in time and trained to start feeding until they can forage for food on their own.

[0040] The preparation method of the special food in this embodiment is as follows:

[0041] V1. Fresh clams are manually shelled to obtain clam meat. Hormones are injected into the clam meat at a dose of 8000 IU / kg to obtain processed food.

[0042] V2. Clean the processed food obtained in step V1 to obtain the special food.

[0043] The opening feeding training in this embodiment includes hand feeding, gavage feeding, gavage, and fixed-point feeding. During gavage, the tubing is slowly inserted 14cm downwards from the mouth of the spotted ray fry, and a syringe is used to deliver the mixed feed and nutritional fortification agent from the hollow channel of the tubing to the stomach of the spotted ray fry.

[0044] The preparation method of the mixed bait used in this embodiment is as follows:

[0045] L1. Clam meat, razor clam meat, krill, and mackerel are ground into meat pastes separately to obtain clam meat paste, razor clam meat paste, krill meat paste, and mackerel meat paste. The meat paste components are then mixed according to the following ratio: 60% clam meat paste, 5% razor clam meat paste, 10% krill meat paste, and 25% mackerel meat paste. Turmeric, honeysuckle, burdock, and bamboo shoots are taken in equal parts by weight, mixed, weighed, ground into powder, and passed through a 10-mesh sieve to obtain the traditional Chinese medicine components.

[0046] L2. Weigh the Chinese herbal medicine components, meat paste components, and 2% glucose aqueous solution obtained in step L1 according to a mass ratio of 0.5:10:2. Add the Chinese herbal medicine components to the meat paste components, and add the glucose aqueous solution in small amounts several times. After mixing and stirring evenly, the mixed feed is obtained.

[0047] The nutrient fortification preparation used in this embodiment is obtained by uniformly mixing the following components in parts by weight: 1 part microbial culture, 6 parts lactoferrin, 1 part calcium caseinate, and 0.8 parts magnesium citrate. The microbial culture consists of components with a concentration of 1×10⁻⁶. 7 The mixture consisted of a CFU / mL Bacillus suspension and a Lactobacillus acidophilus suspension at a ratio of 1:0.5.

[0048] Example 2: This example provides a method for the artificial breeding of spotted stingrays, the details of which are as follows:

[0049] (1) Estrus control: When the spotted ray is in estrus, the male spotted ray is isolated, and then 1 / 6 of the female spotted ray's daily food is replaced with special food for 12 days. After that, the male and female spotted rays are kept together and observed daily for any mating behavior.

[0050] (2) Pregnancy management of female spotted rays: pregnant female spotted rays are managed separately, fed in the same water, and given an extra 7% of food;

[0051] (3) Management of spotted ray calves: After the spotted ray calves are born, they should be isolated in time and trained to start feeding until they can forage for food on their own.

[0052] The preparation method of the special food in this embodiment is as follows:

[0053] V1. Fresh clams are manually shelled to obtain clam meat. Hormones are injected into the clam meat at a dose of 9000 IU / kg to obtain processed food.

[0054] V2. Clean the processed food obtained in step V1 to obtain the special food.

[0055] The opening feeding training in this embodiment includes hand feeding, gavage feeding, gavage, and fixed-point feeding. During gavage, the tubing is slowly inserted 15cm down from the mouth of the spotted ray fry, and a syringe is used to deliver the mixed feed and nutritional fortification agent from the hollow channel of the tubing to the stomach of the spotted ray fry.

[0056] The preparation method of the mixed bait used in this embodiment is as follows:

[0057] L1. Clam meat, razor clam meat, krill, and mackerel are ground into meat pastes separately to obtain clam meat paste, razor clam meat paste, krill meat paste, and mackerel meat paste. The meat paste components are then mixed according to the following ratio: clam meat paste 65%, razor clam meat paste 8%, krill meat paste 12%, and mackerel meat paste 15%. Turmeric, honeysuckle, burdock, and bamboo shoots are taken in equal parts by weight, mixed, weighed, ground into powder, and passed through a 14-mesh sieve to obtain the traditional Chinese medicine components.

[0058] L2. Weigh the Chinese herbal medicine components, meat paste components, and 3% glucose aqueous solution obtained in step L1 according to a mass ratio of 0.8:10:2.5. Add the Chinese herbal medicine components to the meat paste components, and add the glucose aqueous solution in small amounts several times. After mixing and stirring evenly, the mixed feed is obtained.

[0059] The nutrient fortification preparation used in this embodiment is obtained by uniformly mixing the following components in parts by weight: 2 parts microbial culture, 8 parts lactoferrin, 1.2 parts calcium caseinate, and 0.9 parts magnesium citrate. The microbial culture consists of components with a concentration of 0.5 × 10⁻⁶. 8 The mixture consisted of a CFU / mL Bacillus suspension and a Lactobacillus acidophilus suspension at a ratio of 1:0.8.

[0060] Example 3: This example provides a method for the artificial breeding of spotted stingrays, the details of which are as follows:

[0061] (1) Estrus control: When the spotted ray is in estrus, the male spotted ray is isolated, and then 1 / 5 of the female spotted ray's daily food is replaced with special food for 10 days. After that, the male and female spotted rays are kept together and observed daily for any mating behavior.

[0062] (2) Pregnancy management of female spotted rays: pregnant female spotted rays are managed separately, fed in the same water, and given an extra 8% of their food;

[0063] (3) Management of spotted ray calves: After the spotted ray calves are born, they should be isolated in time and trained to start feeding until they can forage for food on their own.

[0064] The preparation method of the special food in this embodiment is as follows:

[0065] V1. Fresh clams are manually shelled to obtain clam meat. Hormones are injected into the clam meat at a dose of 10,000 IU / kg to obtain processed food.

[0066] V2. Clean the processed food obtained in step V1 to obtain the special food.

[0067] The opening feeding training in this embodiment includes hand feeding, gavage feeding, gavage, and fixed-point feeding. During gavage, the tubing is slowly inserted 16cm down from the mouth of the spotted ray fry, and a syringe is used to deliver the mixed feed and nutritional fortification agent from the hollow channel of the tubing to the stomach of the spotted ray fry.

[0068] The preparation method of the mixed bait used in this embodiment is as follows:

[0069] L1. Clam meat, razor clam meat, krill, and mackerel are ground into meat pastes separately to obtain clam meat paste, razor clam meat paste, krill meat paste, and mackerel meat paste. The meat paste components are then mixed according to the following ratio: 70% clam meat paste, 10% razor clam meat paste, 15% krill meat paste, and 5% mackerel meat paste. Turmeric, honeysuckle, burdock, and bamboo shoots are taken in equal parts by weight, mixed, weighed, ground into powder, and passed through a 20-mesh sieve to obtain the traditional Chinese medicine components.

[0070] L2. Weigh the Chinese herbal medicine components, meat paste components, and 5% glucose aqueous solution obtained in step L1 according to a mass ratio of 1:10:3. Add the Chinese herbal medicine components to the meat paste components, and add the glucose aqueous solution in small amounts several times. After mixing and stirring evenly, the mixed feed is obtained.

[0071] The nutrient fortification preparation used in this embodiment is obtained by uniformly mixing the following components in parts by weight: 3 parts microbial culture, 10 parts lactoferrin, 1.5 parts calcium caseinate, and 1 part magnesium citrate. The microbial culture consists of components with a concentration of 1×10⁻⁶. 8 The suspension of Bacillus spp. with cfu / mL and the suspension of Lactobacillus acidophilus were prepared in a 1:1 ratio.

[0072] The Bacillus and Lactobacillus acidophilus used in Examples 1-3 were all from the China General Microbiological Culture Collection Center, with accession numbers CGMCC 1.857 and CGMCC 1.12735, respectively.

[0073] Testing process:

[0074] The aquarium continuously monitors the pH, water temperature, ammonia nitrogen, heterotrophic bacteria count, and Vibrio count in the pool where the spotted rays reside to ensure a healthy living environment. In spring, the spotted rays are managed by replacing part of their regular diet with a special food. Keepers hand-feed the female spotted rays, and then provide the remaining regular food. The condition of both male and female spotted rays is continuously observed. The results are as follows:

[0075] (1) Aquatic environment for aquaculture:

[0076] The following are the records of pH, water temperature, ammonia nitrogen, heterotrophic bacteria count, and Vibrio count in the aquaculture water body where the spotted stingrays are cultured from November 2019 to December 2023: Figures 1 to 5 As shown, the pH of the water used for spotted stingray aquaculture was maintained within the range of 7.8-8.2 year-round, the water temperature within the range of 25.5-28℃, the ammonia nitrogen level below 0.1 mg / L, the heterotrophic bacteria count within the range of 400-850 cfu / mL, and the Vibrio count within the range of 200-450 cfu / mL. The water quality was good, the spotted stingrays were quite active, and there were no deaths.

[0077] (2) Management of spotted stingrays during their estrus period:

[0078] In late spring and early summer, female spotted stingrays in their estrus period were isolated in the aquarium and subjected to different hormone tests. Hormone injection was not a good method as it easily caused the female spotted stingrays to become agitated. To avoid potential water pollution problems caused by hormones, the hormones were instead injected into the spotted stingrays' common food, namely clams. Clams are high in protein and are recognized as a favorite food of spotted stingrays. After several trials, it was decided to replace part of their daily food with clams injected with hormones, which could minimize the risk of rejection by the spotted stingrays. Keepers observed the spotted stingrays' swimming posture and dwell time to ensure that the appropriate dosage of hormones was obtained. During food replacement, isolating male spotted rays can reduce the likelihood of females being injured while being chased by males during estrus. Once the hormones have taken effect in the females' bodies, the males can be reintroduced. At this point, the females' cooperation is improved, and observations have shown that mating behavior is more successful.

[0079] (3) Pregnancy management of female spotted rays:

[0080] After a female spotted ray successfully becomes pregnant, a bulge can be observed in her abdomen about three months later. Her swimming posture, time spent at the same spot, and food intake are not much different from before she became pregnant. Managing the pregnant spotted ray separately can prevent abdominal injury that could lead to the death of the spotted ray fry, and it also makes it easier for keepers to observe her food intake.

[0081] (4) Spotted ray fry:

[0082] Spotted manta ray fry are born around 10-12 months old. They are relatively large at birth and have a strong presence, making them easily observable. Newborn spotted manta ray fry are prone to stress, exhibiting symptoms such as being easily startled, swimming erratically, having a slightly poor sense of direction, and being easily injured. Artificial intervention can help them adapt to the aquatic environment more quickly. While common spotted manta ray food is often blended into a paste and fed to fry, this is insufficient to provide adequate nutrition, resulting in a high mortality rate. Enhancing the nutritional intake of spotted manta ray fry can significantly improve their survival rate.

[0083] After a long period of experimentation and adjustment, the artificial breeding method for spotted stingrays provided by this invention was finally obtained. The various control measures and the combination of nutrients were tested many times to ensure that the spotted stingrays do not reject the method and can perform the intended functions.

[0084] Experimental procedure:

[0085] The artificial breeding methods for spotted stingrays described in Examples 1-3 were applied in 2023. Other details not covered herein are as follows:

[0086] Two female spotted stingrays and one male spotted stingray were kept together in three separate ponds: No. 1, No. 2, and No. 3. In ponds No. 1 and No. 2, there was a pair of spotted stingrays that had successfully mated in 2022.

[0087] Table 1 Results of artificial breeding

[0088] Pool 1 Pool 2 Pool 3 Pregnant Spotted Wobbegong (only) 1 2 1 Number of pups born (number) 1 3 2 Number of pups surviving (number) 1 2 2 Pup survival rate (%) 100 67 100

[0089] Note: Cubs are considered relatively healthy and capable of feeding themselves after two months of age.

[0090] The following is a record of the initial feeding training of the spotted stingray calf, number 201, in pool 2:

[0091] Table 2. Initial feeding training of spotted stingray calves (201).

[0092]

[0093]

[0094] The practical diagram of feeding is as follows Figure 6 As shown in the diagram, the practical application of gavage is illustrated below. Figure 7 As shown.

[0095] Because of the long gestation period of spotted stingrays, their numbers are not easily increased in a short period of time. Compared with the unscientific breeding situation in previous years, the birth rate and survival rate of spotted stingray calves in 2023 have significantly improved.

[0096] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention, and those skilled in the art can easily implement other modifications. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details. If those skilled in the art, inspired by this, design similar methods and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for artificial propagation of a spotted eagle ray, characterized by, The artificial breeding method of the spotted eagle ray comprises the following steps: (1) Estrus period control: when the spotted eagle ray is in estrus period, the male spotted eagle rays are isolated, and then 1 / 6-1 / 5 of the daily food of the female spotted eagle rays is replaced with special food, which is continued for 10-14 days. After the end, the male spotted eagle rays are mixed with the female spotted eagle rays, and whether there is mating behavior is observed every day; (2) Female spotted eagle ray pregnancy period control: the pregnant female spotted eagle rays are managed alone, and the original water is fed, and 5-8% of the food is added; (3) Spotted eagle ray baby control: after the spotted eagle ray babies are born, they are isolated in time, and the opening feeding training is implemented until the spotted eagle ray babies can find food by themselves; The opening feeding training comprises hand feeding, stuffing feeding, gavage, and fixed-point feeding; The special food is a clam to which a hormone is injected, and the hormone is gonadotropin-releasing hormone produced by the hypothalamus or human chorionic gonadotropin; The preparation method of the special food is as follows: V1. Fresh clams are artificially shelled to obtain clam meat, and a hormone is injected into the clam meat at a dose of 8000-10000IU / kg to obtain treated food; V2. The treated food obtained in step V1 is washed to obtain the special food; The gavage is performed after the hand feeding or the stuffing feeding fails, and the specific operation is as follows: the spotted eagle ray baby is controlled by a net bag, the spotted eagle ray baby is turned over with the abdomen upward, it is ensured that the gill of the spotted eagle ray baby can breathe in water, a soft tube is slowly inserted into the mouth of the spotted eagle ray baby and placed downward by 14-16cm, and a syringe is used to transport the mixed bait and the nutritional fortification preparation from the soft tube channel to the stomach of the spotted eagle ray baby; The preparation method of the mixed bait is as follows: L1. The clam meat, the surf clam, the euphausiids, and the mackerel are respectively beaten into meat paste to obtain clam meat paste, surf clam meat paste, euphausiids meat paste, and mackerel meat paste, which are mixed to obtain meat paste components. A portion of each of turmeric, honeysuckle, burdock, and bamboo is weighed and ground into powder, and then the powder is sieved through a 10-20 mesh sieve to obtain traditional Chinese medicine components; L2. The traditional Chinese medicine components obtained in step L1 are added to the meat paste components, and a small amount of glucose aqueous solution is added for multiple times. After being uniformly mixed and stirred, the mixed bait is obtained; The clam meat paste accounts for 60-70% of the base bait, the surf clam meat paste accounts for 5-10%, the euphausiids meat paste accounts for 10-15%, and the remaining mackerel meat paste is supplemented; In step L2, the mass ratio of the traditional Chinese medicine components, the meat paste components, and the glucose aqueous solution is 0.5-1:10:2-3, and the concentration of the glucose aqueous solution is 2-5%; The nutritional fortification preparation is obtained by uniformly mixing the following substances in the mass fractions: 1-3 parts of microbial bacteria liquid, 6-10 parts of lactoferrin, 1-1.5 parts of calcium caseinate, and 0.8-1 part of magnesium citrate. The microbial liquid is composed of Bacillus sp. and Lactobacillus acidophilus in a ratio of 1:0.5-1, and the concentration of the two bacterial suspensions is 1x10 7 -10 8 cfu / mL.

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