Artificial acclimatization phagostimulant for anguilla marmorata as well as preparation method and acclimatization device thereof

Abstract

The invention relates to a phagostimulant for artificial domestication of astrocandra glabra, a preparation method of the phagostimulant and a domestication device. The phagostimulant is a composite micro-capsule with a slow release function. A capsule core of the composite microcapsule comprises a short peptide mixture, enzymolysis fish soluble pulp, free amino acid and a nucleotide compound, the capsule wall of the composite micro-capsule is provided with a slow-release structure. The phagostimulant is high in phagostimulant signal continuity, environment simulation is closer to nature, and the domestication success rate is remarkably increased.

Description

Technical fields:

[0001] This invention belongs to the field of aquaculture technology, specifically relating to an artificial domestication attractant for the star kangaroo eel, its preparation method, and domestication device. Background technology:

[0002] Conger eels are a type of marine benthic fish with significant economic value. However, their nocturnal, hiding, and stress-sensitive lifestyle leads to severe refusal to feed in captivity under aquaculture conditions. Difficulty initiating feeding, a lengthy acclimatization period, and the resulting high mortality rate (over 60%) have become key bottlenecks restricting the industrialization of their aquaculture.

[0003] Currently, the commonly used feeding methods in the industry mainly rely on fish paste, fishmeal, or simple amino acid mixtures. While these substances have some feeding effect, they have significant drawbacks: First, they are mostly water-soluble small molecules that rapidly diffuse and dilute after being introduced into the water, making the feeding signal fleeting and unable to form a sustained and effective stimulus, thus failing to guide the fish to establish a stable conditioned reflex. Second, conventional domestication environments (such as cement ponds) are often excessively bright, with turbulent or poor water flow, and lack necessary shelter, which is far removed from the low-light, slow-flowing, and well-hidden benthic environment of the star conger eel in its natural habitat. This further exacerbates its stress response and suppresses its feeding desire.

[0004] It is evident that existing technologies suffer from the following technical problems: the attractant dissolves rapidly, resulting in a short-lived feeding signal; the cement ponds are brightly lit and have turbulent currents, which does not conform to the benthic, low-light living habits of the star kangaroo eel; the environment and feeding stimuli have not formed a synergistic control mechanism; and the acceptance rate of artificial feed is low, the acclimatization period is long, and the mortality rate is high. Therefore, there is an urgent need for a systematic solution that can provide a persistent feeding signal and can be combined with specific environmental regulation. Summary of the Invention:

[0005] The technical problem to be solved by the present invention is to provide an artificial feeding attractant for the star kongji eel, its preparation method and feeding device. The feeding attractant of the present invention has strong feeding signal persistence, the environmental simulation is closer to nature, and the feeding success rate is significantly improved.

[0006] The technical solution of the present invention is to provide an artificial domestication attractant for starfish, wherein the attractant is a composite microcapsule with a slow-release function; the core of the composite microcapsule contains a mixture of short peptides, enzymatically hydrolyzed fish lysate, free amino acids and nucleotide complex; the capsule wall of the composite microcapsule has a slow-release structure, wherein the slow-release structure is composed of sodium alginate, chitosan and gelatin sequentially from the inside to the outside.

[0007] Preferably, the core comprises, by weight percentage, the following components.

[0008] Short peptide mixture 5-10%;

[0009] Enzymatic hydrolysis of fish sol yields 5-15%;

[0010] Free amino acids and nucleotide complexes: 2-5%;

[0011] The remainder consists of glycerin and water.

[0012] Preferably, the short peptide mixture contains Gly-Pro, Ala-Glu, and Leu-Arg-Gly.

[0013] Preferably, the mass ratio of sodium alginate, chitosan, and gelatin in the sustained-release structure is 2:1:1.

[0014] Preferably, the composite microcapsules have a particle size of 50-200 μm and can continuously release the feeding-inducing components for 24-48 hours in a still water environment.

[0015] This invention also provides a method for preparing the above-mentioned artificial domestication attractant for star kangaroo eels, comprising the following steps:

[0016] Step 1: Mix the short peptide mixture, enzymatically hydrolyzed fish lysate, free amino acids and nucleotide complex with glycerol, and homogenize to obtain a homogeneous attractant solution;

[0017] Step 2: Add the feeding attractant liquid dropwise into a 2% sodium alginate solution to react and form microcapsules with sodium alginate as the primary wall material;

[0018] Step 3: Transfer the microcapsules obtained in Step 2 into a 1% (w / w) chitosan solution for the first coating treatment;

[0019] Step 4: Transfer the chitosan-coated microcapsules to a 1% gelatin solution for a second coating treatment to form sodium alginate-chitosan-gelatin three-layer composite microcapsules;

[0020] Step 5: Freeze-dry the three-layer composite microcapsules to obtain the dried finished product.

[0021] The present invention also provides an artificial domestication device for star kangaroo eels, the device including a feeding agent dispensing unit for containing and slowly releasing the feeding agent.

[0022] Preferably, the palatability enhancer dispensing unit is a cylindrical container with a 10-30 μm microporous membrane on its wall to achieve slow release of the palatability enhancer.

[0023] Preferably, the device further includes,

[0024] A micro-flow circulation unit is used to generate a directional water flow of 0.1-0.3 m / s in the acclimatization tank;

[0025] The light-induced control unit is used to provide a low-light environment with a wavelength of 500-520nm;

[0026] Hidden habitat units, located at the bottom of the acclimatization pool, provide hiding spaces for the starconger eels;

[0027] The attractant delivery unit is located upstream of the directional water flow.

[0028] Furthermore, the microfluidic circulation unit includes a water pump and a flexible guide tube; the light-induced control unit is an LED soft light; and the concealed habitat unit is an arc-shaped shelter module with a length of 40-60cm and a height of 15-20cm.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The feeding signal is long-lasting and stable: This invention creatively uses a three-layer composite microcapsule structure to encapsulate the feeding ingredients, which can be slowly released within 24-48 hours. This overcomes the shortcomings of traditional feeding attractants that dissolve instantly, and provides the star kangaroo eel with a continuous and stable chemical signal stimulation, which greatly promotes the establishment of its feeding conditions.

[0031] High feeding efficiency: The short peptide mixture, enzymatically hydrolyzed fish lysate and nucleotide complex in the capsule core constitute a highly efficient and synergistic feeding system. Its ratio is optimized for the olfactory and gustatory receptors of the star conger eel, resulting in high feeding activity.

[0032] High environmental adaptability: This invention combines a special attractant with a modular domestication device. The directional microfluidic energy created by the device can stably deliver the attractant signal to the fish's hiding area. The low light environment and shelter module effectively reduce the stress level of the fish, realizing the synergistic effect of chemical signals and physical environment, and solving the domestication problem from the system level.

[0033] Safe and environmentally friendly: The capsule walls of the attractants (sodium alginate, chitosan, and gelatin) are all natural and biodegradable polymer materials, which do not pollute the environment and meet the requirements of green aquaculture. Attached image description:

[0034] Figure 1 This is a schematic diagram of the domestication device of the present invention.

[0035] In the diagram, 1 is the acclimatization pool; 2 is the water pump; 3 is the diversion pipe; 4 is the light-induced control unit; 5 is the hiding place unit; and 6 is the attractant delivery unit. Detailed implementation method:

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0037] A feeding attractant for artificial domestication of the star angel eel is a composite microcapsule with a slow-release function. The core of the composite microcapsule contains a mixture of short peptides, enzymatically hydrolyzed fish lysate, free amino acids, and nucleotide complexes. The capsule wall of the composite microcapsule has a slow-release structure, which consists of sodium alginate, chitosan, and gelatin from the inside out.

[0038] The core capsule, by weight percentage, consists of the following components:

[0039] Short peptide mixture 5-10%;

[0040] Enzymatic hydrolysis of fish sol yields 5-15%;

[0041] Free amino acids and nucleotide complexes: 2-5%;

[0042] The remainder consists of glycerin and water.

[0043] In this embodiment, the short peptide mixture comprises Gly-Pro, Ala-Glu, and Leu-Arg-Gly. The mass ratio of sodium alginate, chitosan, and gelatin in the sustained-release structure is 2:1:1.

[0044] The method for preparing the above-mentioned artificial domestication attractant for star kangaroo eels includes the following steps:

[0045] Step 1: Mix the short peptide mixture, enzymatically hydrolyzed fish lysate, free amino acids and nucleotide complex with glycerol, and homogenize to obtain a homogeneous attractant solution;

[0046] Step 2: Add the feeding attractant liquid dropwise into a 2% sodium alginate solution to react and form microcapsules with sodium alginate as the primary wall material;

[0047] Step 3: Transfer the microcapsules obtained in Step 2 into a 1% (w / w) chitosan solution for the first coating treatment;

[0048] Step 4: Transfer the chitosan-coated microcapsules to a 1% gelatin solution for a second coating treatment to form sodium alginate-chitosan-gelatin three-layer composite microcapsules;

[0049] Step 5: Freeze-dry the three-layer composite microcapsules to obtain the dried finished product.

[0050] Specifically, in this embodiment, during preparation, 6g of short peptide mixture (Gly-Pro, Ala-Glu, and Leu-Arg-Gly mixed in equal mass), 10g of enzymatically hydrolyzed fish lysate, and 3g of free amino acids and nucleotide complex were weighed, mixed with 8g of glycerol and an appropriate amount of water, and homogenized in a homogenizer at 10,000 rpm for 5 minutes to obtain a uniform attractant solution.

[0051] The above-mentioned feeding attractant liquid was dripped into a container containing a 2% sodium alginate solution using a peristaltic pump, and allowed to stand and solidify for 30 minutes to form sodium alginate microcapsules.

[0052] After filtering out the microcapsules, rinse them lightly with deionized water, immerse them in a 1% chitosan acetic acid solution (pH 6.0), and gently stir for 15 minutes to complete the second coating.

[0053] The microcapsules were filtered out again and immersed in a 1% gelatin solution (temperature maintained at 40°C). After gently stirring for 10 minutes, a third layer was formed.

[0054] The resulting composite microcapsules were filtered out, rinsed with deionized water, and then freeze-dried to obtain a dry, free-flowing powdered attractant. The particle size of the composite microcapsules was determined to be 50-200 μm, and they could continuously release the attractant components in a still water environment for 24-48 hours.

[0055] The artificial domestication device for star kangaroo eels of the present invention, such as Figure 1 As shown, including

[0056] The palatability agent dispensing unit 6 is used to contain and release the aforementioned palatability agent.

[0057] A micro-flow circulation unit is used to generate a directional water flow of 0.1-0.3 m / s in acclimatization tank 1;

[0058] The light-induced control unit 4 is used to provide a weak light environment with a wavelength of 500-520nm;

[0059] Hidden habitat unit 5, located at the bottom of acclimatization pool 1, provides hiding space for starconger eels;

[0060] The attractant delivery unit is located upstream of the directional water flow.

[0061] In this embodiment, the attractant delivery unit 6 is a cylindrical container to form a slow-release cylinder, and its wall surface is provided with a microporous membrane of 10-30μm to achieve slow release of the attractant. The microfluidic circulation unit includes a water pump 2 and a flexible guide tube 3; the light-attracting control unit 4 is an LED soft light; and the concealed habitat unit 5 is an arc-shaped shelter module with a length of 40-60cm and a height of 15-20cm.

[0062] In use, the device is arranged in an acclimatization pool 1, with a flexible guide pipe 3 laid along the pool wall and connected to a water pump 2. Once activated, it creates a stable directional water flow with a velocity of approximately 0.2 m / s within the pool. A dimmable LED soft light is installed above the pool, with the light color adjusted to greenish-blue (wavelength 510 nm). Multiple curved PVC shelter modules are evenly placed on the pool bottom as hiding places for the starconger eels. At the upstream inlet of the directional water flow, a cylindrical slow-release cylinder is installed. The cylinder wall is made of a PE membrane with 20 μm micropores, and approximately 200 g of the aforementioned attractant is filled inside.

[0063] In the initial stage of domestication, the present invention maintains a low light and low flow rate environment and releases a low concentration of attractant; in the middle stage, the flow rate and light gradient are increased to induce feeding response; in the later stage, attractant is released intermittently to consolidate feeding behavior.

[0064] taming effect verification

[0065] One hundred healthy star conger eels, captured artificially, were randomly divided into an experimental group and a control group, with 50 eels in each group. The experimental group was acclimatized using the apparatus and method described in this embodiment of the invention. The control group was kept in a still water tank with natural light illumination and fed an equal amount of unencapsulated attractant mixture daily.

[0066] The acclimatization period was 21 days. The results showed:

[0067] Feeding initiation time: The average time for the experimental group of star kongji eels to first exhibit active feeding behavior was day 4, while it was day 9 in the control group.

[0068] 21-day domestication success rate: 46 individuals in the experimental group successfully established stable feeding behavior on artificial feed, with a success rate of 92%; 28 individuals in the control group had a success rate of 56%.

[0069] Survival rate: 48 fish survived at the end of the experimental group, with a survival rate of 96%; 39 fish survived at the end of the control group, with a survival rate of 78%.

[0070] The above data fully demonstrates that the attractant and domestication device provided by this invention can significantly shorten the feeding initiation time, improve the domestication success rate and survival rate, and effectively solve the core problem of artificial domestication of the star kongji eel.

[0071] The above description only illustrates preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. Any equivalent procedural modifications made using this specification are included within the patent protection scope of this invention.

Claims

1. A feeding attractant for artificial domestication of star scallops, characterized in that: The attractant is a composite microcapsule; the core of the composite microcapsule contains a mixture of short peptides, enzymatically hydrolyzed fish lysate, free amino acids, and nucleotide complexes; the capsule wall of the composite microcapsule has a sustained-release structure, which is composed of sodium alginate, chitosan, and gelatin sequentially from the inside out.

2. The artificial feeding attractant for star kangaroo eels according to claim 1, characterized in that: The core comprises, by weight percentage, the following components: Short peptide mixture 5-10%; Enzymatic hydrolysis of fish sol yields 5-15%; Free amino acids and nucleotide complexes: 2-5%; The remainder consists of glycerin and water.

3. The artificial feeding attractant for star kangaroo eels according to claim 2, characterized in that: The short peptide mixture contains Gly-Pro, Ala-Glu, and Leu-Arg-Gly.

4. The artificial feeding attractant for star kangaroo eels according to claim 1, characterized in that: The mass ratio of sodium alginate, chitosan, and gelatin in the sustained-release structure is 2:1:

1.

5. The artificial feeding attractant for star kangaroo eels according to claim 2, characterized in that: The composite microcapsules have a particle size of 50-200 μm and can continuously release feeding-inducing components in a still water environment for 24-48 hours.

6. A method for preparing the artificial domestication attractant for the star kangaroo eel as described in any one of claims 1-5, characterized in that: Includes the following steps, Step 1: Mix the short peptide mixture, enzymatically hydrolyzed fish lysate, free amino acids and nucleotide complex with glycerol, and homogenize to obtain a homogeneous attractant solution; Step 2: Add the feeding attractant liquid dropwise into a 2% sodium alginate solution to react and form microcapsules with sodium alginate as the primary wall material; Step 3: Transfer the microcapsules obtained in Step 2 into a 1% (w / w) chitosan solution for the first coating treatment; Step 4: Transfer the chitosan-coated microcapsules to a 1% gelatin solution for a second coating treatment to form sodium alginate-chitosan-gelatin three-layer composite microcapsules; Step 5: Freeze-dry the three-layer composite microcapsules to obtain the dried finished product.

7. A device for the artificial domestication of star angel eels, characterized in that: The device includes an attractant delivery unit for containing and releasing the attractant as described in any one of claims 1-5.

8. The artificial domestication device for star kangaroo eels according to claim 7, characterized in that: The attractant delivery unit is a cylindrical container with a 10-30 μm microporous membrane on its wall.

9. The artificial domestication device for star kangaroo eels according to claim 7, characterized in that: The device also includes, A micro-flow circulation unit is used to generate a directional water flow of 0.1-0.3 m / s in the acclimatization tank; The light-induced control unit is used to provide a low-light environment with a wavelength of 500-520nm; Hidden habitat units, located at the bottom of the acclimatization pool, provide hiding spaces for the starconger eels; The attractant delivery unit is located upstream of the directional water flow.

10. The artificial domestication device for star kangaroo eels according to claim 7, characterized in that: The micro-flow circulation unit includes a water pump and a flexible guide tube; the light-induced control unit is an LED soft light; the concealed habitat unit is an arc-shaped shelter module with a length of 40-60cm and a height of 15-20cm.

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