Method for regulating development and reproduction of gonad of patinopecten yessoensis

Abstract

This invention relates to the field of bio-agricultural breeding technology, and particularly to a method for regulating the gonadal development and reproduction of the Yesso scallop. This invention stimulates the neuroendocrine system by simulating a deep-sea spectral environment with blue-green light, and employs a stepped temperature control strategy of "heating-constant temperature-heating" to control metabolic rhythms. During specific temperature-sensitive periods, pulsed feeding of emulsified fish oil, marine red yeast, vitamin E, and Sargassum powder is implemented. Through three-dimensional regulation of "photoinduced initiation-temperature control synchronization-nutritional support," rapid gonadal maturation with high survival rates for the parent scallops is achieved.

Description

Technical Field

[0001] This invention relates to the field of bio-agricultural breeding technology, specifically to a method for regulating the gonadal development and reproduction of the Yesso scallop and its application. Background Technology

[0002] Ezo scallop ( Patinopecten yessoensis It is a typical cold-water large bivalve mollusc with a large adductor muscle and delicious taste, and has extremely high economic value.

[0003] In the seedling production stage, the time window for broodstock gonad maturation directly determines the success or failure of seedling production. Currently, to achieve controllable broodstock maturation and spawning, the industry generally employs traditional measures such as water temperature control and basic feed. However, the limitations of this traditional approach are becoming increasingly apparent. First, the control measures are too simplistic, relying solely on physical heating and basic algae feeding, neglecting the inducing effects of photoperiod, spectral composition, and specific nutrients during the critical period of gamete formation. This amplifies individual differences among broodstock, leading to uneven gonad development; this directly results in asynchronous maturation and inconsistent spawning, increasing production management difficulty and severely impacting fertilized egg quality. Second, the maturation cycle is too long. Under single temperature control and natural light conditions, achieving effective gonadal temperature accumulation typically requires 40 days or even longer, significantly limiting the turnover efficiency of seedling workshops and increasing energy consumption and labor costs. Finally, gamete quality is unstable. Traditional methods lack specific nutritional fortification during the critical period of gonad development (especially the yolk accumulation period), often resulting in insufficient yolk accumulation and a lack of endogenous nutrient reserves.

[0004] Based on this, the present invention is proposed. Summary of the Invention

[0005] To address the aforementioned technical challenges, this invention proposes a multi-factor synergistic regulation technology based on "photoinduced initiation-temperature control synchronization-nutritional support." This technology utilizes blue-green light (480-520nm) LEDs to simulate the deep-water spectral environment and stimulate the neuroendocrine system. A stepped temperature control strategy of "heating-constant temperature-heating" (effective accumulated temperature 60-70℃·d) is employed to control metabolic rhythms. Furthermore, pulsed feeding of emulsified fish oil, marine red yeast, vitamin E, and Sargassum powder is implemented during specific temperature-sensitive periods (6℃ and 7℃). This method, through a three-dimensional mechanism of "photoinduced initiation-temperature control synchronization-nutritional support," achieves rapid and synchronized gonad maturation with high survival rates for parent fish.

[0006] Specifically, the present invention provides the following technical solution: This invention first provides a method for regulating the gonadal development and reproduction of the Yesso scallop, the method comprising the following steps: 1) Broodstock selection: Select healthy Yesso scallops as broodstock; 2) Multi-factor regulation of broodstock maturation: Based on light, temperature and feed, the maturation of broodstock is regulated.

[0007] Furthermore, in step 1), the selection of broodstock includes: selecting healthy scallops with a shell height >10cm from 2-3 year old scallops as broodstock; temporarily culturing the broodstock in seawater with a water temperature of 3-5℃ and a salinity of 30-40‰; the broodstock culturing density is 15-20 scallops / m². 3 ; Preferably, the male-to-female ratio of the parent shellfish is 5-6:1.

[0008] Furthermore, in step 2), the regulation of light includes: irradiating the parent shellfish with blue-green light of wavelength 480-520nm during the ripening period, with a light intensity of 500-800 Lux and a photoperiod of 14-15L:9-10D.

[0009] In some aspects, the temperature control is achieved by using effective accumulated temperature combined with a stepped heating platform. Preferably, the effective accumulated temperature is calculated as follows: K (℃·d) = Σ (Ti− T0); Where T0 = 4.0℃, and Ti represents the average water temperature on day i; More preferably, when the effective accumulated temperature is 60-70℃·d, it is determined that the gonads are mature.

[0010] In other aspects, the stepped heating platform is specifically described in the following table: .

[0011] Furthermore, in step 2), the regulation of the feed includes feeding the parent oysters based on a base feed and a pulse feed; The basic feed includes 35%-40% golden algae ( Isochrysis galbana ), 15-20% of flat algae ( Platymonas sp. ), 20-25% of *Phaeodactylum tricornutum* ( Phaeodactylum tricornutum ) and 20-25% of *Nyctaginosa* ( Nitzschia closterium The pulse bait includes emulsified fish oil, marine red yeast, vitamin E, and Sargassum powder.

[0012] In some aspects, the feeding specifically includes: daily feeding based on a basal diet during the maturation period; adding 1.5-2.0 mg / L emulsified fish oil, 1.0-1.5 mg / L marine red yeast, and 1.0-1.5 mg / L vitamin E to the basal diet after the water temperature rises to 6.0℃; and further adding 2.0-2.5 mg / L Sargassum powder to the basal diet after the water temperature rises to 7.0℃. Sargassum thunbergii ); Preferably, the amount of the basic bait fed at one time is 2-3 × 10⁻⁶. 4 Cells / mL; feed 4-5 times a day before the water temperature reaches 8℃, and feed 8-10 times a day after the water temperature reaches 8℃.

[0013] The present invention also provides a method for inducing spawning and fertilization of scallops, the method comprising any of the aforementioned control methods, and further comprising spawning induction and fertilization steps: Furthermore, when the aforementioned regulation method results in an effective accumulated temperature of 60-70 °C·d, female and male shellfish are randomly sampled, and the gonad color and gonad index (GI) are recorded. When the gonad colors of the sampled individuals are bright and the GI is >18%, synchronous spawning and fertilization are performed.

[0014] In some aspects, the spawning induction steps are as follows: take out the parent shells that are waiting to spawn at a constant temperature, place them in a cool and dry place to air dry for 30-40 minutes, until the edge of the mantle shrinks slightly but is not completely dry; then place the air-dried parent shells in flowing seawater at 10-12℃ and let them stand in the dark for 1-2 hours. In other aspects, the specific steps of fertilization are as follows: when the spawning density of the parent shellfish reaches 40-50 eggs / mL, the parent shellfish are removed, and microscopic examination is performed to control 3-5 sperm cells around each egg. The mixed sperm cells are evenly sprinkled and stirred to complete fertilization.

[0015] The present invention also provides the application of any of the above-described control methods in the reproduction of Yesso scallops.

[0016] The advantages of this invention include at least the following aspects: 1) This invention improves the synchronicity and controllability of maturation through multi-factor synergistic regulation: by inducing metabolic rhythms through spectral / photoperiodic induction and step-temperature platform synchronization, and by implementing pulsed nutritional supplementation during critical temperature-sensitive periods, a synergistic mechanism of "photoinduced initiation - temperature-controlled synchronization - nutritional support" is formed, which enhances the consistency and speed of gonadal development.

[0017] 2) This invention targets nutritional fortification to significantly increase fertility: Targeting the temperature-sensitive period of gonadal development (6℃ and 7℃), this invention innovatively implements "pulse-type" nutritional fortification by adding emulsified fish oil, marine red yeast, vitamin E and Sargassum powder to specifically supplement the lipids and trace elements required for yolk formation.

[0018] 3) The ripening cycle of the present invention is shortened: compared with the traditional method which takes about 40 days, the ripening time of the experimental group of the present invention is only about 30 days, and the ripening efficiency is significantly improved. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 Histological sections of the gonads of female scallops under different maturation-inducing regimens; among them, Figure 1 A is a section of female scallop gonadal tissue obtained from scheme 1. Figure 1 B is a section of female scallop gonadal tissue obtained from scheme 2. Figure 1 C is a section of female scallop gonadal tissue obtained from scheme 3. Figure 1 D is a section of female scallop gonadal tissue obtained from scheme 4. Figure 1 E represents a section of female scallop gonadal tissue obtained from scheme 5. Figure 1 F is a section of female scallop gonadal tissue obtained from scheme 6. Figure 1 G is a section of female scallop gonadal tissue obtained from scheme 7. Figure 1 H is a section of female scallop gonadal tissue obtained in Comparative Example 1. Figure 1 I is a section of female scallop gonadal tissue obtained from Comparative Example 2.

[0021] Figure 2 Histological sections of the gonads of male scallops under different maturation-promoting regimens; among them, Figure 2 A is a section of male scallop gonadal tissue obtained from scheme 1. Figure 2 B is a section of male scallop gonadal tissue obtained from scheme 2. Figure 2 C represents a section of male scallop gonadal tissue obtained from scheme 3. Figure 2 D is a section of male scallop gonadal tissue obtained from scheme 4. Figure 2 E represents a section of male scallop gonadal tissue obtained from scheme 5. Figure 2 F represents a section of male scallop gonadal tissue obtained from scheme 6. Figure 2 G is a section of male scallop gonadal tissue obtained from scheme 7. Figure 2 H is a section of male scallop gonadal tissue obtained in Comparative Example 1. Figure 2 I is a section of male scallop gonadal tissue obtained from Comparative Example 2. Detailed Implementation

[0022] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply.

[0023] The following basic terms or definitions are provided merely to aid in understanding the invention. These definitions should not be construed as having a scope less than that understood by those skilled in the art. Unless otherwise defined below, all technical and scientific terms used in the detailed description of this invention are intended to have the same meaning as commonly understood by those skilled in the art. While it is believed that the following terms will be readily understood by those skilled in the art, the following definitions are set forth to better explain the invention.

[0024] As used in this invention, the terms “comprising,” “including,” “having,” “containing,” or “involving” are inclusive or open-ended and do not exclude other unlisted elements or method steps. The term “consisting of” is considered a preferred embodiment of the term “comprising.” If a group is defined below as comprising at least a certain number of embodiments, this should also be understood to disclose a group that preferably consists only of those embodiments.

[0025] When referring to a singular noun, the indefinite or definite article used, such as "a" or "a kind of," "the," includes the plural form of the noun.

[0026] The terms "approximately" and "generally" in this invention refer to a range of accuracy that, as would be understood by those skilled in the art, still guarantees the technical effects of the discussed features. This term typically indicates a deviation from the indicated value of ±10%, preferably ±5%.

[0027] Furthermore, the terms first, second, third, (a), (b), (c), and similar terms used in the specification and claims are for distinguishing similar elements and are not necessary for the order of description or chronological sequence. It should be understood that such terms are interchangeable in appropriate contexts, and the embodiments described in this invention can be implemented in a different order than that described or illustrated in this invention.

[0028] The embodiments of the present invention will be described in detail below with reference to examples. The present invention includes, but is not limited to, the following embodiments. Any modifications made to the present invention based on existing technology that do not depart from the essential content of the present invention are still within the protection scope of the present invention.

[0029] 1. Selection of parent cygnets The inventors selected scallops with a shell height of >10cm from 2-3 year old scallops that were well-shaped, undamaged and robust as parent shells (the female / male ratio of parent shells was controlled at 5-6:1). After the parent shells were transported to the seedling workshop, the attached organisms (barnacles and tube worms, etc.) and sludge on the shell surface were scrubbed off.

[0030] After washing, the shellfish are temporarily held in water at 3-5℃ to approximate the temperature during natural seawater harvesting, with salinity controlled at 30-40‰. The density of parent shellfish is maintained at 15-20 shells / m³. 3 .

[0031] 2. Multi-factor regulation promotes maturation 1) Phased warming This invention employs effective accumulated temperature (EAT) combined with a stepped plateau method for temperature control, using 4.0℃ as the calculation benchmark (T0) for efficient maturation-promoting accumulated temperature. Previous experiments have shown that calculating the accumulated temperature using this method more accurately predicts gonadal maturity. Under this model, a valid accumulated temperature of 60-70℃·d is considered sufficient for gonadal maturity. The effective accumulated temperature is calculated as follows: K (°C·d) = Σ (T) i - T0); Where T0 = 4.0℃, T i This represents the average water temperature on day i (preferably measured three times daily, in the morning, noon, and evening, with the average value taken as T). i ).

[0032] After preliminary experiments and optimizations, the temperature control process of the stepped platform as shown in Table 1 was finally finalized in this invention.

[0033] Table 1 Implementation Plan for Temperature Control to Promote Ripening .

[0034] 2) Light control During the ripening process, in order to effectively stimulate the neuroendocrine system of the parent oysters, the inventors implemented the following light control strategy: Blue-green LEDs are installed above the surface of the seedling pond for illumination. The blue-green light wavelength is 480-520nm, the light intensity is 500-800 Lux, and the photoperiod is 14-15L:9-10D (14-15 hours of light, 9-10 hours of darkness).

[0035] 3) Feeding To ensure the quality of eggs that develop synchronously with the parent shellfish, the inventors also fed them differentiated feed during the maturation period.

[0036] Basic feed feeding: During the maturation period, basic feed is added to the diet. The basic feed uses a complementary combination of "high DHA flagellates + high EPA diatoms", specifically containing 35%-40% golden algae ( Isochrysis galbana ), 15-20% of flat algae ( Platymonas sp. ), 20-25% of *Phaeodactylum tricornutum* ( Phaeodactylum tricornutum ) and 20-25% of *Nyctaginosa* ( Nitzschia closterium ).

[0037] Pulsed feeding: When the ripening temperature rises to 6.0℃, the inventors found that mixing 1.5-2.0 mg / L emulsified fish oil, 1.0-1.5 mg / L marine red yeast and 1.0-1.5 mg / L vitamin E into the daily basic feed is more conducive to ripening.

[0038] After the water temperature rises to 7.0℃, add 2.0-2.5 mg / L of Sargassum powder. Sargassum thunbergii The microparticles also promote ripening.

[0039] Meanwhile, this invention employs a "small, frequent meals" feeding method, increasing the feeding frequency from 4-5 times per day during the early to mid-stages of the maturation period (before the temperature reaches 8℃) to 8-10 times per day during the later stage of the maturation period (after the temperature reaches 8℃), with a single feeding amount of 2×10 4 - 3×10 4 Cells / mL.

[0040] 3. Induction of labor and fertilization When the effective accumulated temperature K reaches 60-70 ℃·d, the gonadal maturation window is entered. Female and male oysters are randomly sampled, and the gonad color and gonad index (GI) are recorded. The calculation formula is: GI (%) = wet weight of gonad / wet weight of soft body × 100%. When the gonads of the sampled individuals are brightly colored and the GI is >18%, synchronous spawning and fertilization are carried out. The specific operation is as follows.

[0041] 1) Stimulate ovulation: Remove the parent oysters that are waiting to lay eggs at a constant temperature and place them in a cool, dry place to air dry for 30-40 minutes, until the edge of the mantle shrinks slightly but is not completely dry; then place the air-dried parent oysters in flowing seawater at 10-12℃ and let them stand in the dark for 1-2 hours.

[0042] 2) Fertilization control: When the egg density reaches 40-50 eggs / mL, remove the parent shellfish; examine under a microscope to ensure there are 3-5 sperm around each egg; mix the sperm and sprinkle evenly, stirring approximately every half hour to complete fertilization.

[0043] This embodiment uses the system established by the present invention to regulate the synchronous development of gonads in Yesso scallops. The actual operation steps are as follows: 1) Select healthy 2-3 year old scallops (female to male ratio 5:1) from the cultured population with a shell height >10cm, regular shape, no damage, and robust development as broodstock. After the broodstock arrive at the nursery, clean the attached organisms and sludge from the shell surface. Separate the female and male scallops into different tanks according to the color of their gonads (orange-red for females, milky white for males). Temporarily raise them in an environment with a water temperature of 3-5℃ and a salinity of 30‰, with a stocking density controlled at 20 scallops / m². 3 They should be kept in the warm place for 3-5 days.

[0044] 2) During the ripening period, implement the following tiered temperature control plan: .

[0045] 3) During the ripening period, the photoperiod was adjusted to 14L:10D, using blue-green LEDs with a wavelength of 480-520nm. The light intensity was measured at 500-800 Lux at a depth of 10-20 cm below the water surface. A timer was used to fix the switching on and off of the lights, with gradual brightening and dimming for approximately 30 minutes each to reduce abrupt changes in light intensity. Blue-green LED light strips were suspended 0.6-1.2 m above the water surface in the seedling pond to avoid direct sunlight causing localized stress.

[0046] 4) Feeding with supplemental feed and pulse nutrition fortification During the maturation period, feed the following: a) Base diet, containing 40% golden algae, 15% flat algae, 25% triangular brown finger algae, and 20% small crescent-shaped rhomboid algae. b) Pulsed supplementation: When the water temperature reaches 6.0℃, add 2.0 mg / L emulsified fish oil, 1.0 mg / L marine red yeast, and 1.0 mg / L vitamin E to the base diet; when the water temperature reaches 7.0℃, further add 2.0 mg / L Sargassum powder (…). Sargassum thunbergii Microparticles. During the early and middle stages of ripening, before the water temperature reaches 8℃, feed four times a day, with a single feeding amount of 2×10. 4 Cells / mL; During the later stages of maturation, once the water temperature reaches 8℃, feed 8 times a day, with a single feeding amount of 2×10⁻⁶. 4 Cells / mL.

[0047] 5) Water change and emptying the tank Water quality control targets: Dissolved oxygen ≥6 mg / L, pH 7.8-8.2; ammonia nitrogen (as NH3-N) ≤0.10 mg / L, nitrite ≤0.05 mg / L. Tank emptying / sludge discharge frequency: In the early stage of maturation (approximately 4-5 ℃), empty the tank / sludge once daily; in the middle stage of maturation (approximately 5-7 ℃), empty the tank once in the morning and change 50% of the water in the evening; in the late stage of maturation (approximately 8 ℃), when the gonads are fully mature, stop emptying the tank and switch to circulating water to reduce mechanical stimulation.

[0048] 6) Synchronized labor induction and fertilization When the effective accumulated temperature K reaches 60-70 ℃·d, the gonads enter the maturation window. Randomly sample female and male oysters, and record the gonad color and gonad index (GI). GI (%) = gonad wet weight / soft tissue wet weight × 100%. When the gonads of the sampled individuals are brightly colored and the GI > 18%, synchronized spawning and fertilization are initiated: The parent oysters are removed and placed in a cool, dry place to air-dry for 30-40 minutes, until the mantle edge slightly retracts but is not completely dry. The air-dried parent oysters are then placed in flowing seawater at 10-12℃ and kept in the dark for 1-2 hours. When spawning reaches 40-50 eggs / mL, the parent oysters are removed; microscopic examination shows 3-5 sperm cells around each egg; the mixed sperm are evenly sprinkled, and stirred approximately every half hour.

[0049] 7) The following indicators were measured: maturation days (d), parent shellfish survival rate (%), average number of fertilized eggs (10,000 eggs / egg), and fertilization rate (%).

[0050] Rising days (d): The number of days from entering temperature-controlled ripening (D1) to reaching the synchronous ripening window.

[0051] Parent stock survival rate (%): Survival rate = Number of surviving parent stocks at the end of maturation / Initial number of parent stocks at the start of maturation × 100%.

[0052] Average number of eggs laid by female parent shellfish (10,000 eggs / egg): Collect the eggs laid by female parent shellfish in a fixed volume container (10 L bucket), mix thoroughly, take 2 mL of sample, and count repeatedly (counting plate) at least 3 times to obtain the egg concentration C (eggs / mL). Total number of eggs = egg concentration C × total volume V, and then convert to "10,000 eggs / egg" based on the number of laying female shellfish.

[0053] Fertilization rate (%): 1-2 hours after fertilization, aspirate fertilized eggs from the bottom and observe them under a microscope. The appearance of the first polar body is used as the marker of fertilization. Fertilization rate = number of fertilized eggs / total number of eggs × 100% (count ≥200 eggs per sample, 3 replicates).

[0054] The steps in this embodiment are the same as in Embodiment 1, but the stepped temperature control scheme during the ripening period is slightly different. The constant temperature period of 6°C is shortened in the middle of the ripening process. See the temperature control scheme in the table below for details: .

[0055] The steps in this embodiment are the same as in embodiment 1, but the step temperature control scheme during the ripening period is different. Specifically, the initial temperature at the beginning of ripening is reduced and the rate of temperature increase at the beginning of ripening is increased. It is set to 3°C and the temperature increases by about 0.5°C per day. See the temperature control scheme in the table below for details.

[0056] .

[0057] The steps in this embodiment are the same as in embodiment 1, but the step temperature control scheme during the ripening period is different. Specifically, the temperature increase is reduced in the later stage of ripening, with a daily increase of 0.3℃. See the temperature control scheme in the table below for details.

[0058] .

[0059] The experimental steps in this embodiment are the same as in embodiment 1, except for the addition of pulse feed. Specifically, in scheme 5, after the water temperature reaches 6.0℃ during the pulse feed addition process, 1.0 mg / L of emulsified fish oil, 0.5 mg / L of marine red yeast, and 0.5 mg / L of vitamin E are added to the basic feed. When the water temperature reaches 7.0℃, 2.0 mg / L of Sargassum powder is further added. Sargassum thunbergii )particle.

[0060] The experimental steps in this embodiment are the same as in embodiment 1, except for the addition of pulse feed. Specifically, in scheme 6, after the water temperature reaches 6.0℃ during the pulse feed addition process, 2.0 mg / L of emulsified fish oil, 1.0 mg / L of marine red yeast, and 1.0 mg / L of vitamin E are added to the basic feed. After the water temperature reaches 7.0℃, no Sargassum powder is added. Sargassum thunbergii )particle.

[0061] The experimental steps in this embodiment are the same as in embodiment 1, but no pulse bait is added at all.

[0062] This embodiment also establishes a comparative test case of the traditional linear heating method.

[0063] Comparative Experiment Example 1: Temperature control scheme: linear temperature increase, with a daily temperature increase of 0.5℃ until reaching 8℃, without a constant temperature plateau period; light scheme: natural light cycle, without specific spectral control; feed: only basic feed, other operations are the same as in Example 1.

[0064] Comparative Experiment Example 2: Temperature control scheme: linear temperature increase, with a daily increase of 0.5℃ until reaching 8℃, without a constant temperature plateau period; illumination scheme: natural light cycle, without specific spectral control. Other operations are the same as in Example 1.

[0065] The final maturation days, survival rate, average number of eggs conceived, and fertilization rate of broodstock under each of Examples 1-8 are statistically analyzed. Detailed statistical results are shown in the table below: .

[0066] As shown in the table, in the comparison of temperature control conditions for maturation promotion, the step-by-step heating scheme (schemes 1-4) adopted in this invention has a better overall maturation promotion effect than the traditional linear heating scheme (traditional comparative example 1, traditional comparative example 2). This is mainly reflected in the shortened maturation period, increased survival rate of broodstock, increased average number of eggs conceived, and improved fertilization rate. Among them, scheme 1 has the best maturation promotion effect, with the best performance in all indicators. The maturation period is 29±1 days, the survival rate of broodstock is 96.5±1.7%, the average number of eggs conceived is 13.96±24 million / egg, and the fertilization rate is 97.3±1.8%, indicating that this scheme can more effectively promote the synchronous development of gonads in broodstock and improve reproductive quality.

[0067] Further comparison of schemes 1-4 shows that temperature control during the ripening process has a significant impact on the ripening effect. In particular, improper control at the beginning of ripening, insufficient maintenance of the key constant temperature platform, and slow temperature increase in the later stage will reduce ripening efficiency and gamete quality to varying degrees. This indicates that the step-by-step temperature control program of "heating-constant temperature-reheating" is an important condition for achieving efficient ripening.

[0068] On the other hand, regarding feed regulation, a comparison of scheme 1 and schemes 5-7 shows that implementing pulsed nutritional fortification under basic feed conditions can further improve the survival rate, average number of eggs conceived, and fertilization rate of broodstock, and shorten the maturation period. Specifically, supplementing emulsified fish oil, marine red yeast, and vitamin E at the 6.0℃ stage, and further adding Sargassum powder at the 7.0℃ stage, helps to improve the nutritional accumulation and gonad development quality of broodstock.

[0069] In addition, from the appendix Figure 1-2 The gonadal tissue sections of male and female scallops show that different maturation-promoting schemes all promote the development of the gonads of both sexes in Yesso scallops, but the effects vary. Tissue sections from schemes 1-4 generally show fuller follicles and more uniform gamete distribution, with overall developmental status superior to scheme 7 and traditional comparative schemes 1 and 2, indicating that stepwise temperature control is more conducive to synchronous gonad maturation than traditional linear temperature increases. Scheme 1 shows better tissue fullness and maturity in the gonadal sections, but compared to schemes 2-4, the main difference lies in slightly better overall uniformity and maturity; this judgment is consistent with the results in the table showing that scheme 1 has the shortest maturation period, the highest parent scallop survival rate, and the best average egg load and fertilization rate. While schemes 5 and 6 are generally better than scheme 7 and the traditional comparative schemes, they are still inferior to scheme 1, indicating that combining stepwise temperature control with pulsed nutritional enhancement during the critical temperature-sensitive period is more beneficial for improving gamete quality and reproductive performance. Therefore, this invention, under the synergistic regulation of multiple factors, can optimally achieve rapid, stable, and synchronous maturation of the gonads of Yesso scallops.

[0070] Overall, compared with traditional breeding methods, this invention is significantly superior to traditional comparative methods in terms of maturation time, parent shellfish survival rate, average number of eggs conceived, and fertilization rate, making it suitable for industrial application.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for regulating the gonadal development and reproduction of the Yesso scallop, characterized in that, The control method includes the following steps: 1) Broodstock selection: Select healthy Yesso scallops as broodstock; 2) Multi-factor regulation of broodstock maturation: Based on light, temperature and feed, the maturation of broodstock is regulated.

2. The control method according to claim 1, characterized in that, In step 2), the regulation of light includes: irradiating the parent shellfish with blue-green light of wavelength 480-520nm during the ripening period, with a light intensity of 500-800 Lux and a photoperiod of 14-15L : 9-10D.

3. The control method according to any one of claims 1-2, characterized in that, In step 2), the temperature is controlled by using effective accumulated temperature combined with a stepped heating platform. Preferably, the effective accumulated temperature is calculated as follows: K(℃·d)= Σ (T i − T0); Where T0 = 4.0℃, T i This represents the average water temperature on day i. More preferably, when the effective accumulated temperature is 60-70℃·d, it is determined that the gonads are mature.

4. The control method according to claim 3, characterized in that, The stepped heating platform is described in detail below. 。 5. The control method according to any one of claims 1-4, characterized in that, In step 2), the regulation of the feed includes feeding the parent oysters based on a base feed and a pulse feed; Preferably, the base feed includes 35%-40% golden algae ( Isochrysis galbana ), 15-20% of flat algae ( Platymonas sp. ), 20-25% of *Phaeodactylum tricornutum* ( Phaeodactylum tricornutum ) and 20-25% of *Nyctaginosa* ( Nitzschia closterium The pulse bait includes emulsified fish oil, marine red yeast, vitamin E, and Sargassum powder.

6. The control method according to claim 5, characterized in that, The feeding specifically includes: feeding daily based on the basic feed during the maturation period; when the water temperature rises to 6.0℃, adding 1.5-2.0 mg / L emulsified fish oil, 1.0-1.5 mg / L marine red yeast and 1.0-1.5 mg / L vitamin E to the basic feed; when the water temperature rises to 7.0℃, further adding 2.0-2.5 mg / L Sargassum powder to the basic feed; Preferably, the amount of the basic bait fed at one time is 2-3 × 10⁻⁶. 4 Cells / mL; feed 4-5 times a day before the water temperature reaches 8℃, and feed 8-10 times a day after the water temperature reaches 8℃.

7. The control method according to claim 1, characterized in that, In step 1), the selection of broodstock includes: selecting healthy scallops with a shell height >10cm from 2-3 year old scallops as broodstock; temporarily culturing the broodstock in seawater with a water temperature of 3-5℃ and a salinity of 30-40‰; the broodstock culturing density is 15-20 scallops / m². 3 ; Preferably, the male-to-female ratio of the parent shellfish is 5-6:

1.

8. A method for inducing spawning and fertilization in the scallop, characterized in that, The method includes the regulation method described in any one of claims 1-7, and further includes the steps of inducing spawning and fertilization: when the regulation method described in any one of claims 1-7 results in an effective accumulated temperature of 60-70 °C·d, female and male shellfish are randomly sampled, and the gonad color and gonad index (GI) are recorded; when the gonad colors of the sampled individuals are bright and the GI is >18%, synchronous spawning and fertilization are performed.

9. The method for inducing labor and fertilization according to claim 9, characterized in that, The spawning induction process is as follows: the parent oysters awaiting spawning at a constant temperature are removed and placed in a cool, dry place to air dry for 30-40 minutes, until the edge of the mantle slightly shrinks but is not completely dry; then the air-dried parent oysters are placed in flowing seawater at 10-12℃ and kept in the dark for 1-2 hours; the fertilization process is as follows: when the spawning density of the parent oysters reaches 40-50 eggs / mL, the parent oysters are removed, and microscopic examination is performed to control 3-5 sperm cells around each egg. The mixed sperm are evenly sprinkled and stirred to complete fertilization.

10. The application of the control method according to any one of claims 1-7 in the reproduction of Yesso scallop.

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