Regulation method for gonadal development in acipenser sinensis broodfish

Abstract

A regulation method for the gonadal development in Acipenser sinensis broodfish. The regulation process comprises the following steps: 1) at a daily feeding amount of 0.5-1.0% and a daily feeding frequency of 2 times / day, carrying out gonadal activation cultivation on Acipenser sinensis broodfish at stage II of gonadal development, to obtain broodfish at stage III of gonadal development; 2) at the daily feeding amount of 0.5-1.0%, the daily feeding frequency of 2 times / day, and a noise limit in aquaculture environment of 60 dB, carrying out near-maturation cultivation on the broodfish at stage III of gonadal development, to obtain broodfish at the early stage IV of gonadal development; and 3) carrying out reduced-feeding cultivation on the broodfish at the early stage IV of gonadal development, to obtain broodfish having reproductive capacity. By using the regulation method provided in the present application, the gonadal activation rate of the Acipenser sinensis broodfish can be effectively increased, and refined cultivation is carried out on key Acipenser sinensis broodfish at stage III of gonadal development, to regulate the normal gonadal development of the key Acipenser sinensis broodfish to enter stage IV and achieve maturation.

Description

Method for regulating gonadal development of Chinese sturgeon broodfish

[0001] The present application claims priority to the Chinese patent application No. 202410586041.7 filed on May 11, 2024, and entitled "Method for regulating gonadal development of Chinese sturgeon broodfish", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to a method for regulating gonadal development of Chinese sturgeon broodfish, and belongs to the field of biotechnology. BACKGROUND

[0003] Chinese sturgeon (Acipenser sinensis) is a fish belonging to the class of Osteichthyes, the order of Acipenseriformes, the family of Acipenseridae, and the genus of Acipenser. It is a national first-class protected animal, an endangered species (EN) of the International Union for Conservation of Nature (IUCN), and an appendix II protected species of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Historically, Chinese sturgeon was distributed in the Yangtze River, the Pearl River, the Minjiang River, the Qiantang River, the Yellow River, the Yellow Sea, and the East China Sea, and had the habit of anadromous migration. At present, Chinese sturgeon has disappeared in the Minjiang River, the Qiantang River, the Yellow River, and the Pearl River, and only exists in the Yangtze River. Chinese sturgeon was an important fishery resource in the Yangtze River basin, but due to overfishing and environmental pollution, the wild population of Chinese sturgeon has been declining.

[0004] In order to carry out species protection and supplement the number of wild populations of Chinese sturgeon, the Chinese Sturgeon Institute researched and broke through the artificial breeding technology of Chinese sturgeon in 1984, and has carried out artificial induced spawning, fry culture, and restocking of wild Chinese sturgeon every year since then. Since the mid-1990s, the Chinese Sturgeon Institute has started to carry out restocking of large-size Chinese sturgeon fry. In 2009, the Chinese Sturgeon Institute took the lead in breaking through the research of full-artificial breeding of Chinese sturgeon, and the second-generation Chinese sturgeon entered the restocking sequence. So far, more than 7 million Chinese sturgeon fry of various sizes have been released through restocking, of which more than 6 million have been released by the Chinese Sturgeon Institute.

[0005] However, Chinese sturgeon broodfish takes a long time to mature, and it requires a large amount of financial, material, and human resources to cultivate them to sexual maturity in an artificial environment. Under the background of low gonadal transformation rate of Chinese sturgeon broodfish, key broodfish whose gonadal development has entered phase III are particularly valuable. However, the degeneration of mature broodfish is a high-difficulty problem that has plagued Chinese sturgeon breeding. Once the gonads of key broodfish in phase III degenerate, the breeding opportunity will be missed, and the degenerated broodfish will take another 3 years or even more years to mature again.

[0006] Therefore, how to improve the Chinese sturgeon gonad starting rate and carry out fine breeding on the Chinese sturgeon key brood fish with gonad development entering the III stage, and regulate the normal development of gonad into the IV stage and maturity is an important link for the establishment and practice of the whole artificial breeding system of Chinese sturgeon.

[0007] SUMMARY

[0008] The application provides a Chinese sturgeon brood fish gonad development regulation method, which can significantly improve the Chinese sturgeon gonad starting rate and reduce the Chinese sturgeon gonad degeneration, and is helpful to realize the establishment and practice of the whole artificial breeding system of Chinese sturgeon.

[0009] The application provides a Chinese sturgeon brood fish gonad development regulation method, and the regulation process comprises the following steps:

[0010] 1) According to the daily feeding amount of 0.5-1.0% and the daily feeding frequency of 2 times / d, the Chinese sturgeon brood fish with gonad development II is subjected to gonad starting cultivation, and the brood fish with gonad development III is obtained;

[0011] 2) According to the daily feeding amount of 0.5-1.0%, the daily feeding frequency of 2 times / d, and the noise limit value of 60 dB of the breeding environment, the brood fish with gonad development III is subjected to near-mature cultivation, and the brood fish with gonad development IV in the early stage is obtained;

[0012] 3) The female brood fish with gonad development IV in the early stage is subjected to first reduced feeding type cultivation, so that the daily feeding amount of the female brood fish is reduced to 0 within 3 months and maintained; the male brood fish with gonad development to the late stage IV is subjected to second reduced feeding type cultivation, so that the daily feeding amount of the male brood fish is reduced to 0 within 30 days and maintained, the noise limit value of the breeding environment is 40 dB, and the brood fish with reproductive ability is obtained;

[0013] In the process of steps 2) and 3), the water temperature of the breeding water is 10-27℃, and the breeding density is not higher than 5 kg / m 3 .

[0014] The daily feeding time interval of the regulation process is 8-12 h, the daytime light intensity is 3000-5000 Lx, and the nighttime light intensity is <20 Lx.

[0015] In the regulation method, in step 1), the breeding density is 5-8 kg / m 3 .

[0016] In the regulation method, in steps 2) and 3), the breeding density is 2-3 kg / m 3 .

[0017] The feeding amount at 8:00 in steps 2) and 3) of the regulation method is 60%-70% of the daily feeding amount, and the feeding amount at 16:00 is 30-40% of the daily feeding amount.

[0018] The first reduced feeding cultivation in step 3) of the regulation method comprises the following steps:

[0019] The daily feeding amount of the female brood fish is reduced by 0.0017%-0.0067% per day in the first month, and / or the daily feeding amount is reduced by 0.0067%-0.0150% per day in the second and third months;

[0020] The second reduced feeding cultivation comprises the following steps:

[0021] The daily feeding amount of the male brood fish is reduced by 0.017%-0.033% per day, and the daily feeding amount is reduced to 0 on the 30th day and maintained.

[0022] The first reduced feeding cultivation in step 3) of the regulation method comprises the following steps:

[0023] The daily feeding amount of the female brood fish is reduced by 0.0083-0.0333% per time in the first month, and the daily feeding amount is maintained for 5 days after reduction, and then reduced by the first reduction amount again, and the cycle is repeated until the daily feeding amount is 0.

[0024] The daily feeding amount is reduced by 0.0333-0.075% per time in the second and third months, and the daily feeding amount is maintained for 5 days after reduction, and then reduced by the second reduction amount again, and the cycle is repeated until the daily feeding amount is 0.

[0025] The second reduced feeding cultivation comprises the following steps:

[0026] The daily feeding amount of the male brood fish is reduced by 0.1-0.2% per time, and the daily feeding amount is maintained for 5 days after reduction, and then reduced by 0.1-0.2% per time again, and the cycle is repeated until the daily feeding amount is 0 and maintained.

[0027] In steps 2) and 3) of the regulation method, the water flow rate is 0.0-0.3 m / s during the gonadal development stage III to the middle of the gonadal development stage IV, and the water flow rate is 0.5-1.0 m / s after the middle of the gonadal development stage IV.

[0028] In step 1) of the regulation method, the daily change of water temperature is not higher than 3℃;

[0029] And / or, in steps 2) and 3), the daily change of water temperature is not higher than 1℃.

[0030] The feed nutritional composition in the regulation process includes crude protein ≥ 42.0 wt%, crude fat ≥ 10.0 wt%, crude fiber ≤ 5.0 wt%, crude ash ≤ 16.0 wt%, total phosphorus ≥ 1.2 wt%, and lysine ≥ 2.5 wt%.

[0031] The regulation method as described above, the DO of the breeding water is > 7.5 mg / L, NH4 + < 0.5 mg / L, NO2 － < 0.05 mg / L, and the pH value is 7.5-8.0.

[0032] The application provides a regulation method for the gonadal development of Chinese sturgeon brood fish, which regulates the feeding rules, controls the light intensity, the breeding water temperature, and the environmental parameters in stages, and cooperatively realizes the effective regulation of the gonadal development of Chinese sturgeon brood fish. The regulation method greatly improves the gonadal starting rate of Chinese sturgeon brood fish and reduces the gonadal degeneration rate of Chinese sturgeon brood fish, and lays a solid foundation for the large-scale breeding and large-scale release of Chinese sturgeon. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a column chart of the feeding amount change in step 1) in an embodiment of the application;

[0034] Figure 2 is a regulation curve of the breeding water temperature in step 1) in an embodiment of the application;

[0035] Figure 3 is a feeding amount-time curve diagram of the reduced feeding type cultivation of female brood fish in step 3) in an embodiment of the application;

[0036] Figure 4 is a regulation curve of the breeding water temperature in step 2) and step 3) in an embodiment of the application;

[0037] Figure 5 is a graph of the relationship between different breeding densities of female brood fish and the degeneration rate in the application. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the application more clear, the technical scheme in the embodiments of the application will be described clearly and completely in combination with the embodiments of the application. Obviously, the described embodiments are some embodiments of the application, not all the embodiments. Based on the embodiments in the application, all the other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0039] The application provides a regulation method for the gonadal development of Chinese sturgeon brood fish, which includes the following steps:

[0040] 1) According to the daily feeding amount of 0.5-1.0%, the daily feeding frequency of 2 times / d, the Chinese sturgeon parent fish in the gonadal development stage II is gonadal starting cultivation, and the parent fish in the gonadal development stage III is obtained;

[0041] 2) According to the daily feeding amount of 0.5-1.0%, the daily feeding frequency of 2 times / d, and the noise limit of 60dB in the breeding environment, the parent fish in the gonadal development stage III is near-mature cultivation, and the parent fish in the early gonadal development stage IV is obtained;

[0042] 3) The first reduced feeding type cultivation is carried out on the female parent fish in the early gonadal development stage IV, so that the daily feeding amount of the female parent fish is reduced to 0 within 3 months and maintained, the second reduced feeding type cultivation is carried out on the male parent fish in the late gonadal development stage IV, so that the daily feeding amount of the male parent fish is reduced to 0 within 1 month and maintained, the noise limit of the breeding environment is 40dB, and the parent fish with reproductive ability is obtained;

[0043] In the process of steps 2) and 3), the water temperature of the breeding water is 10-27℃, the breeding density is not higher than 5kg / m 3 ;

[0044] The interval of the daily feeding process is 8-12h, the light intensity in the daytime is 3000-5000Lx, and the light intensity at night is <20Lx.

[0045] The Chinese sturgeon parent fish is detected by B-ultrasound method and puncture method, and the gonadal development stage of the Chinese sturgeon parent fish is judged.

[0046] Specifically, in step 1), the Chinese sturgeon parent fish in the gonadal development stage II is cultivated according to the daily feeding amount of 0.5-1.0% and the daily feeding frequency of 2 times / d, and the parent fish in the gonadal development stage III is obtained.

[0047] In detail, the daily feeding amount of the present application refers to the ratio of the daily feeding amount of feed to the average mass of the Chinese sturgeon parent fish, for example, if the average mass of the Chinese sturgeon parent fish is 100kg, the daily feeding amount of 0.5-1.0% refers to the daily feeding amount of 0.5-1kg.

[0048] It can be understood that there are individual differences in the feeding amount of the parent fish in the breeding device during feeding, and there are also differences in the daily feeding amount of each parent fish.

[0049] The daily feeding amount is 0.5-1.0%, for example, the daily feeding amount includes but is not limited to 0.50%, 0.55%, 0.60%, 0.65%, 0.70%, 0.75%, 0.80%, 0.85%, 0.90%, 0.95%, 1.0% or a range formed by any two of them.

[0050] During the feeding process, the feeding condition of the Chinese sturgeon brood fish needs to be observed, and the feeding amount is adjusted in the above daily feeding amount range in time according to the feeding condition of the Chinese sturgeon brood fish. FIG. 1 is a column chart of the feeding amount change in an embodiment, wherein the feeding amount is calculated according to the weight of 100 kg per tail of the Chinese sturgeon brood fish.

[0051] The daily feeding frequency of 2 times / d means that the feeding is performed twice a day.

[0052] The time interval between each feeding in step 1) of the present application is 8-12 h. For example, the feeding time interval includes but is not limited to 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0 or a range formed by any two of them.

[0053] For example, in an embodiment, the first feeding is performed at 8:00 am, and the second feeding is performed at 16:00 pm.

[0054] The present application does not limit the feeding amount of the two feedings, and the feeding amount can be adjusted in time according to the feeding condition of the Chinese sturgeon brood fish and the water temperature, growth state and the like. For example, taking 1.0% of the daily feeding amount as an example, the feeding amount of the first feeding is 0.5%, and the feeding amount of the second feeding is 0.5%.

[0055] It can be understood that in step 1), the culture water needs to be in a suitable flow rate range, and the present application does not limit the specific range of the flow rate of the culture water during step 1), and a suitable flow rate range can be selected according to the actual situation. For example, the flow rate of the culture water is 0.2-0.5 m / s.

[0056] The present application does not limit the specific range of the water temperature of the culture water in step 1), and a suitable water temperature range can be selected according to the actual situation, for example, 10-27℃. FIG. 2 is a water temperature regulation curve of the culture water in an embodiment.

[0057] In step 2), the Chinese sturgeon brood fish in the gonadal development stage III is subjected to near-mature cultivation according to the daily feeding amount of 0.5-1.0%, the daily feeding frequency of 2 times / d, and the environmental noise limit of 60 dB, and the Chinese sturgeon brood fish in the gonadal development stage IV is obtained.

[0058] Specifically, the same feeding rule as in step 1) is maintained in step 2), and the Chinese sturgeon brood fish in the gonadal development stage III is subjected to near-mature cultivation, and the Chinese sturgeon brood fish in the gonadal development stage IV is obtained.

[0059] At the same time, the culture environment needs to be strictly controlled in a relatively quiet atmosphere in step 2). The environmental noise limit in the present application refers to the maximum noise decibel value generated by a sound source within a linear distance of 20 m from the culture device. The noise can be detected by a noise detector.

[0060] In step 3), the female parent fish in the early stage of gonadal development stage IV is subjected to first reduced feeding type cultivation, so that the daily feeding amount of the female parent fish is reduced to 0 within 3 months and kept, the male parent fish in the late stage of gonadal development stage IV is subjected to second reduced feeding type cultivation, so that the daily feeding amount of the male parent fish is reduced to 0 within 1 month and kept, the noise limit of the breeding environment is 40 dB, and the parent fish with reproductive ability is obtained.

[0061] The parent fish with reproductive ability in the present application refers to the parent fish of Chinese sturgeon which can artificially induce spawning to lay eggs or sperm and reproduce offspring through artificial insemination.

[0062] Specifically, the first reduced feeding type cultivation and the second reduced feeding type cultivation in the present application refer to gradually reducing the daily feeding amount during cultivation, so that the daily feeding amount of the female parent fish is reduced to 0 within 3 months, the daily feeding amount of the male parent fish is reduced to 0 within 1 month, and then the daily feeding amount is kept at 0, so that the parent fish of Chinese sturgeon is subjected to fasting cultivation until the parent fish with reproductive ability is obtained.

[0063] The present application does not limit the specific way of reducing the daily feeding amount, and it can be understood that the reduction range of the daily feeding amount should not be too large, and the daily feeding amount needs to be reduced by a relatively appropriate lower range, so that the parent fish of Chinese sturgeon gradually adapts to the lower daily feeding amount.

[0064] In a specific embodiment, the daily feeding amount of the female parent fish is reduced every day within 3 months until it is reduced to 0; in another specific embodiment, the daily feeding amount is reduced in steps, that is, it is reduced once, kept for a period of time, reduced again and kept for a period of time, until it is reduced to 0. The daily feeding amount of the male parent fish is reduced every day within 1 month until it is reduced to 0; in another specific embodiment, the daily feeding amount is reduced in steps, that is, it is reduced once, kept for a period of time, reduced again and kept for a period of time, until it is reduced to 0.

[0065] During step 3), the noise limit of the breeding environment is 40 dB.

[0066] For example, the noise decibel number of the breeding environment includes but is not limited to 40 dB, 35 dB, 30 dB, 25 dB, 20 dB, 15 dB, 10 dB, 0 dB or a range formed by any two of them.

[0067] In addition, during steps 2) and 3), the water temperature of the breeding water is 10-27℃, and the breeding density is not higher than 5 kg / m 3 .

[0068] In detail, the water temperature of the aquaculture water is 10-27℃, for example, the water temperature of the aquaculture water includes but is not limited to 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃ or a range consisting of any two of them.

[0069] It can be understood that the water temperature of the aquaculture water conforms to the natural rhythm change, that is, the water temperature will be adjusted with the change of seasons, and the water temperature in winter is in the low temperature section, and the water temperature in summer is in the high temperature section.

[0070] In a specific embodiment, the temperature in steps 2) and 3) is 10-15℃ from December to early April of the next year, 15-20℃ from early April to early May and from mid-October to December, and 20-27℃ from early May to mid-October.

[0071] The stocking density refers to the ratio of the total mass of the Chinese sturgeon parent fish in the aquaculture device to the volume of the aquaculture water. The stocking density is not more than 5 kg / m 3 , for example, the stocking density includes but is not limited to 5.0 kg / m 3 , 4.5 kg / m 3 , 4.0 kg / m 3 , 3.5 kg / m 3 , 3.0 kg / m 3 , 2.5 kg / m 3 , 2.0 kg / m 3 , 1.5 kg / m 3 , 1.0 kg / m 3 or any range not more than 5 kg / m 3 .

[0072] The light intensity also needs to be controlled during the regulation process, and the light intensity during the day is 3000-5000Lx, and the light intensity at night is <20Lx.

[0073] In detail, the light intensity during the day includes but is not limited to 3000Lx, 3500Lx, 4000Lx, 4500Lx, 5000Lx or a range consisting of any two of them.

[0074] The light intensity at night includes but is not limited to 19Lx, 18Lx, 16Lx, 14Lx, 12Lx, 10Lx, 8Lx, 6Lx, 4Lx or any range less than 20Lx.

[0075] The light intensity in the present application conforms to the natural light intensity rule, and the light intensity at different times in a day is different, and will be adjusted with the change of seasons.

[0076] This application achieves good results by cultivating Chinese sturgeon broodstock at different stages of gonadal development in stages and controlling feeding rules, water temperature, environmental noise limits, and light intensity at different stages of cultivation.

[0077] Furthermore, in one specific embodiment of this application, in step 1), the stocking density is 5-8 kg / m². 3 .

[0078] In detail, the stocking density for raising Chinese sturgeon broodstock in gonadal development stage II to obtain Chinese sturgeon broodstock in gonadal development stage III is 5-8 kg / m³. 3 For example, stocking density includes, but is not limited to, 5 kg / m³. 3 5.5kg / m 3 6kg / m 3 6.5kg / m 3 7kg / m 3 7.5kg / m 3 8kg / m 3 Or a range consisting of any two of them.

[0079] Through a series of creative experiments, the applicant discovered that when breeding Chinese sturgeon broodstock in stage II of gonadal development to obtain Chinese sturgeon broodstock in stage III of gonadal development, a stocking density within the aforementioned range is more conducive to the initiation of gonadal development in the Chinese sturgeon broodstock. This is because the aforementioned stocking density range allows for effective utilization of the breeding facilities while exhibiting a significant group feeding effect, marked feeding desire and behavior, and vigorous feeding, which is conducive to the accumulation and storage of nutrients, laying the nutritional foundation and conditions for the initiation of gonadal development. At the same time, this density range will not cause environmental, space, or food stress to the Chinese sturgeon broodstock in stage II of gonadal development, thus meeting their growth and development needs.

[0080] Furthermore, in one specific embodiment of this application, in steps 2) and 3), the stocking density is 2-3 kg / m². 3 .

[0081] In detail, the stocking density of Chinese sturgeon broodstock in stage III of gonadal development to reproductive capacity is 2-3 kg / m³. 3 For example, stocking density includes, but is not limited to, 2.0 kg / m³. 3 2.1kg / m 3 2.2kg / m 3 2.3kg / m 3 2.4kg / m 3 2.5kg / m 3 2.6kg / m3 2.7 kg / m 3 2.8 kg / m 3 2.9 kg / m 3 3.0 kg / m 3 or a range consisting of any two of them.

[0082] The applicant, through a large number of creative experiments, controls the different breeding densities of female parent fish of Chinese sturgeon, explores the gonadal degeneration rate under different breeding densities, and specifically as shown in Figure 5, it can be seen that when the breeding density meets the above range, the gonadal degeneration rate of the obtained Chinese sturgeon parent fish is lower, and has excellent reproduction effect. The reason is that the Chinese sturgeon parent fish in the gonadal development stage III is sensitive to environmental, spatial and other factors, and the above breeding density can reduce the competition and pressure of nutrition, environment, space and other conditions between Chinese sturgeon parent fish, reduce the stress factors, make the living environment more stable and comfortable, thereby promoting the growth and development of Chinese sturgeon parent fish, maintaining the normal function of its reproductive system, and improving the reproduction effect.

[0083] Further, in a specific embodiment of the present application, in steps 2) and 3), the feeding amount at 8:00 is 60%-70% of the daily feeding amount, and the feeding amount at 16:00 is 30-40% of the daily feeding amount.

[0084] Specifically, the Chinese sturgeon parent fish in the gonadal development stage III feeds 60%-70% of the daily feeding amount at 8:00 and 30-40% of the daily feeding amount at 16:00 during the process of developing into parent fish with reproductive capacity.

[0085] In a specific embodiment, the daily feeding amount is 1.0%, the feeding amount at 8:00 is 0.6-0.7%, and the feeding amount at 16:00 is 0.3-0.4%.

[0086] When the above feeding rules are adopted, the feeding needs of Chinese sturgeon parent fish at different time periods can be better met, and the nutritional balance of Chinese sturgeon parent fish can be maintained, and its metabolism can be promoted, thereby reducing the risk of gonadal degeneration and improving the reproduction effect, and better realizing the regulation of gonadal development of Chinese sturgeon parent fish.

[0087] Further, in a specific embodiment of the present application, step 3) first reduced feeding type cultivation includes the following steps:

[0088] the first month of female parent fish daily feeding amount reduction rate is 0.0017%-0.0067% / day; and / or, the second and third months of daily feeding amount reduction rate is 0.0067%-0.0150% / day;

[0089] And / or, the second reduced feeding breeding comprises the following steps: the male parent fish daily feeding amount reduction amplitude is 0.017%-0.033% / day, 30 days to daily feeding amount is 0 and remains.

[0090] The daily feeding amount reduction amplitude in the present application refers to the decrease value of daily feeding amount per unit of time. Taking the daily feeding amount of 0.0017% / day and the initial daily feeding amount of 0.5% as an example, the first day daily feeding amount decreases by 0.0017%, and decreases to 0.4983%. The fifth day daily feeding amount decreases by 5 times of 0.0017% compared with the initial daily feeding amount, i.e. decreases by 0.0085%, and decreases to 0.4915%.

[0091] In detail, the first month daily feeding amount of the female parent fish at the early stage of gonadal development stage IV is bred according to the reduction amplitude of 0.0017%-0.0067% per day. For example, the reduction amplitude includes but is not limited to 0.0017% / day, 0.0020% / day, 0.0025% / day, 0.0030% / day, 0.0035% / day, 0.0040% / day, 0.0045% / day, 0.0050% / day, 0.0055% / day, 0.0060% / day, 0.0067% / day or a range formed by any two of them.

[0092] The second and third month daily feeding amount reduction amplitude is 0.0067%-0.0150% / day. For example, the reduction amplitude includes but is not limited to 0.0067% / day, 0.0070% / day, 0.0075% / day, 0.0080% / day, 0.0085% / day, 0.0090% / day, 0.0095% / day, 0.0010% / day, 0.0015% / day or a range formed by any two of them.

[0093] The male parent fish at the late stage of gonadal development stage IV is bred according to the daily feeding amount reduction amplitude of 0.017%-0.033% / day, and the daily feeding amount is reduced to 0 and remains for 30 days.

[0094] For example, the daily feeding amount reduction amplitude is 0.017% / day, 0.020% / day, 0.025% / day, 0.030% / day, 0.033% / day or a range formed by any two of them.

[0095] It can be understood that the male parent fish at the early stage of gonadal development stage IV to the late stage of gonadal development stage IV remains the original feeding rule unchanged.

[0096] In a specific embodiment, the daily feeding amount reduction is shown in FIG. 3, in which the third month is the early stage of gonadal development stage IV, the third to fourth month is the first month, and the fourth to sixth month is the second and third month.

[0097] When the reduction amplitude meets the above range, on the one hand, the female parent fish of Chinese sturgeon can gradually adapt to less food intake, effectively avoiding the adverse effects of sudden reduction of daily feeding amount on its growth and health, and on the other hand, the nutritional status of the female parent fish of Chinese sturgeon can be better managed, the risk of gonadal degeneration can be reduced, and the reproductive effect and survival quality can be improved.

[0098] Further, in a specific embodiment of the present application, the step 3) of reducing feeding type cultivation comprises the following steps: the daily feeding amount of the female parent fish in the first month is reduced by 0.0083-0.0333% per time according to the first reduction amount, the daily feeding amount is kept unchanged for 5 days after the reduction, then the daily feeding amount is reduced again according to the first reduction amount, and the cycle is repeated until the daily feeding amount is 0.

[0099] And / or, the daily feeding amount in the second and third months is reduced by 0.0333-0.075% per time according to the second reduction amount, the daily feeding amount is kept unchanged for 5 days after the reduction, then the daily feeding amount is reduced again according to the second reduction amount, and the cycle is repeated until the daily feeding amount is 0.

[0100] When the male parent fish is in the late stage of gonadal development stage IV, the daily feeding amount is reduced by 0.1-0.2% per time according to the reduction amount, the daily feeding amount is kept unchanged for 5 days after the reduction, then the daily feeding amount is reduced again by 0.1-0.2% per time, and the cycle is repeated until the daily feeding amount is 0 and kept.

[0101] The first reduction amount and the second reduction amount in the present application refer to the difference between the daily feeding amount before each reduction and the daily feeding amount after the reduction.

[0102] When the female parent fish of Chinese sturgeon enters the early stage of gonadal development stage IV, the daily feeding amount is reduced in a stepwise manner.

[0103] Specifically, for the female parent fish, the daily feeding amount in the first month is reduced by 0.0083-0.0333% per time according to the first reduction amount, the daily feeding amount is kept unchanged for 5 days after the reduction, then the daily feeding amount is reduced again according to the first reduction amount, and the cycle is repeated until the daily feeding amount is 0.

[0104] The first reduction amount is 0.0083-0.0333% per time, for example, the first reduction amount includes but is not limited to 0.0083% per time, 0.0085% per time, 0.0090% per time, 0.0095% per time, 0.0100% per time, 0.0150% per time, 0.0200% per time, 0.0250% per time, 0.0300% per time, 0.0333% per time, or a range composed of any two of them.

[0105] For example, the initial feeding amount is 1%, the first reduction amount is 0.0333% per time, the daily feeding amount is reduced to 0.9667% on the first day of the first month, the daily feeding amount of 0.9667% is maintained for 5 days, then the daily feeding amount is reduced to 0.9334%, the daily feeding amount of 0.9334% is maintained for 5 days, the first reduction with the first reduction amount is taken as the first cycle, and a total of 6 cycles are performed, and the daily feeding amount is reduced to 0.8002% in the sixth cycle, and the daily feeding amount of 0.8002% is maintained for 5 days.

[0106] The daily feeding amount in the second and third months is reduced by 0.0333-0.075% per time according to the second reduction amount, the daily feeding amount is maintained for 5 days after reduction, and then the second reduction amount is reduced again, and the cycle is performed 12 times to the daily feeding amount of 0.

[0107] The second reduction amount is 0.0333-0.075% per time, for example, the second reduction amount includes but is not limited to 0.0333% per time, 0.0350% per time, 0.040% per time, 0.045% per time, 0.050% per time, 0.055% per time, 0.060% per time, 0.065% per time, 0.070% per time, 0.075% per time, or a range formed by any two of them.

[0108] For example, the initial daily feeding amount in the second month is 0.9%, and the second reduction amount is 0.075% per time, the daily feeding amount is reduced to 0.825% on the first day of the second month, the daily feeding amount of 0.825% is maintained for 5 days, then the daily feeding amount is reduced to 0.75%, the daily feeding amount of 0.75% is maintained for 5 days, the first reduction with the second reduction amount is taken as the first cycle, and a total of 12 cycles are performed, and the daily feeding amount is reduced to 0 in the 12th cycle.

[0109] For male parent fish, the daily feeding amount is reduced by 0.1-0.2% per time according to the reduction amount, the daily feeding amount is maintained for 5 days after reduction, and then the reduction of 0.1-0.2% per time is performed again, and the cycle is performed until the daily feeding amount is 0 and maintained.

[0110] For example, the initial daily feeding amount is 1.0%, and the reduction amount is 0.2%, the daily feeding amount is reduced to 0.8% on the first day of the second month, the daily feeding amount of 0.8% is maintained for 5 days, the first reduction with the reduction amount of 0.2% is taken as the first cycle, and a total of 6 cycles are performed, and the daily feeding amount is reduced to 0 and maintained in the 6th cycle.

[0111] When the daily feeding amount is reduced according to the above reduction method, on the one hand, the Chinese sturgeon parent fish can gradually adapt to less food intake, effectively avoiding the adverse effects of sudden reduction of daily feeding amount on their growth and health, on the other hand, the nutritional status of the Chinese sturgeon parent fish can be better managed, the risk of gonadal degeneration can be reduced, and the reproductive effect and survival quality can be improved.

[0112] Further, in a specific embodiment of the present application, in steps 2) and 3), the flow rate of the breeding water is 0.0-0.3 m / s during the period from gonadal development stage III to mid-gonadal development stage IV, and the flow rate of the breeding water is 0.5-1.0 m / s after the period from gonadal development stage IV to mid-gonadal development stage IV.

[0113] In detail, during the period from gonadal development stage III to mid-gonadal development stage IV, the flow rate of the breeding water is 0.0-0.3 m / s, for example, the flow rate of the breeding water includes but is not limited to 0.0 m / s, 0.05 m / s, 0.10 m / s, 0.15 m / s, 0.20 m / s, 0.25 m / s, 0.3 m / s, or a range formed by any two of them.

[0114] After the period from gonadal development stage IV to mid-gonadal development stage IV, the flow rate of the breeding water is 0.5-1.0 m / s, for example, the flow rate of the breeding water includes but is not limited to 0.50 m / s, 0.55 m / s, 0.60 m / s, 0.65 m / s, 0.70 m / s, 0.75 m / s, 0.80 m / s, 0.85 m / s, 0.90 m / s, 0.95 m / s, 1.0 m / s, or a range formed by any two of them.

[0115] The present application does not limit the control mode of the flow rate of the breeding water, and the flow rate control mode commonly used in the art can be selected, for example, the flow rate can be controlled by increasing the water inflow and the water inflow direction or by using a flow generating pump to generate flow.

[0116] When the flow rate of the breeding water in steps 2) and 3) is within the above range, the gonadal stability of the Chinese sturgeon brood fish can be better stimulated, and the gonadal degeneration rate is reduced. The reason is that water flow is extremely important for the maturation of reproductive gonads and spawning of anadromous fish. Generally, anadromous fish can only produce high energy metabolism during the process of returning to the river, stimulate the synthesis and release of sex hormones, and make the gonads fully develop and mature. When the gonads develop to stage IV, the flow stimulation plays an important role in the further development and maturation of the gonads. During the breeding period of the brood fish, frequent water flow or appropriate water flow stimulation before spawning can promote the development, maturation, and spawning of the gonads and improve the fertilization rate.

[0117] Further, in a specific embodiment of the present application, in step 1), the daily change of the water temperature of the breeding water is not higher than 3℃; and / or, in steps 2) and 3), the daily change of the water temperature of the breeding water is not higher than 1℃.

[0118] The daily change of the water temperature in the present application refers to the difference between the maximum value and the minimum value of the water temperature per day.

[0119] When the daily change of the water temperature of the breeding water is within the above range, the stress caused by temperature change can be minimized, and the gonadal initiation and gonadal stability of the Chinese sturgeon brood fish can be improved.

[0120] Further, in an embodiment of the present application, the feed nutritional composition in the regulation process comprises crude protein ≥ 42.0 wt%, crude fat ≥ 10.0 wt%, crude fiber ≤ 5.0 wt%, crude ash ≤ 16.0 wt%, total phosphorus ≥ 1.2 wt%, and lysine ≥ 2.5 wt%.

[0121] The crude protein in the present application refers to the total nitrogen-containing substances in the feed, including soluble protein and insoluble protein, which can provide the required amino acids and nitrogen source for the Chinese sturgeon parent fish, and support the metabolism and tissue growth in the Chinese sturgeon parent fish.

[0122] The crude fat in the present application refers to the fat in the feed, which provides energy and essential fatty acids for the Chinese sturgeon parent fish, and helps to maintain the health of the fish and promote growth and development.

[0123] The crude fiber in the present application refers to the insoluble fiber in the feed, mainly from plant raw materials such as chaff and soybean meal.

[0124] The crude ash in the present application refers to the content of inorganic substances in the feed, which is mainly composed of minerals and other inorganic substances, such as calcium, phosphorus, magnesium, etc.

[0125] The total phosphorus in the present application refers to the total content of all forms of phosphorus in the feed, such as inorganic phosphorus, organic phosphorus, etc.

[0126] When the nutritional composition of the feed meets the above range, the cultivation of the Chinese sturgeon parent fish can be achieved, and the gonadal development of the Chinese sturgeon parent fish can be effectively regulated.

[0127] Further, in an embodiment of the present application, the DO of the breeding water during the regulation process is > 7.5 mg / L, NH4 + < 0.5 mg / L, NO2 － < 0.05 mg / L, and the pH value is 7.5-8.0.

[0128] The DO in the present application refers to the concentration of dissolved oxygen in water, for example, DO is 8 mg / L, which means that 1 L of water dissolves 8 mg of oxygen.

[0129] The present application does not limit the testing method of DO, NH4 + , NO2 － , and pH in the breeding water, which can use the common testing method in the art, for example, water quality automatic analyzer or handheld water quality analyzer or titration method can be used to determine the water quality indexes such as DO, NH4 + , NO2 － , and pH.

[0130] The present application also does not limit the testing method of DO, NH4 + , NO2 －, the control mode of pH, for example, the DO content in the breeding water can be increased by using the oxygen supply mode or the air aeration mode of the breeding pond, and the water quality indexes such as NH4 + , NO2 － , pH and the like can be controlled by water exchange, sewage and the like.

[0131] When the water quality parameters of the breeding water meet the above ranges, not only the survival rate of the Chinese sturgeon parent fish can be improved, but also the gonadal regulation of the Chinese sturgeon parent fish can be further realized.

[0132] Hereinafter, the regulation method of the gonadal development of the Chinese sturgeon parent fish provided in the present application is described in detail through specific examples.

[0133] The Chinese sturgeon parent fish in the present application is from the first generation parent fish self-bred and self-raised by the Chinese Sturgeon Research Institute.

[0134] Example 1

[0135] The regulation process of the gonadal development of the Chinese sturgeon parent fish in the present embodiment includes the following steps:

[0136] 1) The Chinese sturgeon female parent fish in the gonadal development stage II is gonadal starting cultured according to the daily feeding amount of 0.5-1.0% and the daily feeding frequency of 2 times / d, and the parent fish in the gonadal development stage III is obtained;

[0137] In the culture process, the water temperature meets the natural rhythm change, as shown in FIG. 4, and the daily change of the water temperature in the breeding water is not higher than 3℃; the breeding density is 5-8 kg / m 3 .

[0138] 2) The parent fish in the gonadal development stage III is near-mature cultured according to the daily feeding amount of 0.5-1.0%, the daily feeding frequency of 2 times / d, and the breeding environment noise limit of 60 dB, and the parent fish in the early gonadal development stage IV is obtained;

[0139] The flow rate of the breeding water is 0.0-0.3 m / s; the water temperature in the culture process is 10-27℃ and meets the natural rhythm change, as shown in FIG. 3, the daily change of the water temperature in the breeding water is not higher than 1℃, the breeding density is 2-3 kg / m 3 , and the breeding environment noise limit is 60 dB.

[0140] 3) the parent fish in the early stage of gonadal development stage IV is subjected to the reduced feeding type cultivation, the reduced feeding type cultivation of the female parent fish is as follows: in the first month, the feeding amount per day is reduced by the first reduction amount of 0.0083-0.0333% per time, the feeding amount per day is kept unchanged for 5 days after the reduction, then the feeding amount per day is reduced again by the first reduction amount, and the cycle is repeated for 6 times; in the second and third months, the feeding amount per day is reduced by the second reduction amount of 0.0333-0.075% per time, the feeding amount per day is kept unchanged for 5 days after the reduction, then the feeding amount per day is reduced again by the second reduction amount, and the cycle is repeated until the feeding amount per day is 0, and the noise limit of the breeding environment is 40dB, so that the female parent fish with the breeding ability is obtained;

[0141] the reduced feeding type cultivation of the male parent fish is as follows: the feeding amount per day of the male parent fish is kept at 0.5-1.0%, the male parent fish in the late stage of gonadal development stage IV is reduced by the reduction amount of 0.1-0.2% per time, the feeding amount per day is kept unchanged for 5 days after the reduction, then the feeding amount per day is reduced again by 0.1-0.2% per time, and the cycle is repeated until the feeding amount per day is 0 and kept unchanged, and the noise limit of the breeding environment is 40dB, so that the male parent fish with the breeding ability is obtained.

[0142] In the cultivation process, the water temperature is 10-27℃ and meets the natural rhythm change, the daily change of the water temperature of the breeding water is not higher than 1℃, the breeding density is 2-3kg / m 3 .

[0143] In the early stage of gonadal development stage IV to the middle stage of gonadal development stage IV, the flow rate of the breeding water is 0.0-0.3m / s, and after the middle stage of gonadal development stage IV, the flow rate of the breeding water is 0.5-1.0m / s.

[0144] The nutritional composition of the feed includes crude protein ≥42.0wt%, crude fat ≥10.0wt%, crude fiber ≤5.0wt%, crude ash ≤16.0wt%, total phosphorus ≥1.2wt%, and lysine ≥2.5wt%; the feeding amount at 8:00 per day is 60%-70% of the daily feeding amount, and the feeding amount at 16:00 per day is 30-40% of the daily feeding amount; the light intensity during the day is 3000-5000Lx, the light intensity at night is <20Lx, and the flow rate of the breeding water is 0.2-0.5m / s; the water quality parameters of the breeding water are DO >7.5mg / L, NH4 + <0.5mg / L, NO2 － <0.05mg / L, and pH value is 7.5-8.0.

[0145] Example 2

[0146] The gonadal development regulation process of the Chinese sturgeon parent fish in this example is basically the same as that in Example 1, and the difference is as follows:

[0147] Step 3) In the reduced feeding type cultivation, the female broodstock is reduced by 0.0017%-0.0067% per day in the first month, and by 0.0067%-0.0150% per day in the second and third months, and the daily feeding amount is reduced to 0;

[0148] The male broodstock is maintained at a daily feeding amount of 0.5-1.0%, and the broodstock in the late stage of gonadal development stage IV is reduced by 0.017%-0.033% per day, and the feeding amount is reduced to 0 and maintained.

[0149] Example 3

[0150] The gonadal development regulation process of the Chinese sturgeon broodstock in this example is basically the same as that in Example 1, except that:

[0151] In step 1), the stocking density is 10 kg / m 3 .

[0152] Example 4

[0153] The gonadal development regulation process of the Chinese sturgeon broodstock in this example is basically the same as that in Example 1, except that:

[0154] In steps 2 and 3), the stocking density is 4 kg / m 3 .

[0155] Example 5

[0156] The gonadal development regulation process of the Chinese sturgeon broodstock in this example is basically the same as that in Example 1, except that:

[0157] In steps 2 and 3), the feeding amount at 8:00 is 50% of the daily feeding amount, and the feeding amount at 16:00 is 50% of the daily feeding amount.

[0158] Example 6

[0159] The gonadal development regulation process of the Chinese sturgeon broodstock in this example is basically the same as that in Example 1, except that:

[0160] In step 3) of the reduced feeding type cultivation, the female broodstock is reduced by 0.0055%-0.0111% in the first three months;

[0161] The male broodstock is started at a daily feeding amount of 0.5-1.0% in the late stage of gonadal development stage IV, and in the one-month reduced feeding period, the feeding amount is reduced by 0.017% per day for the first ten days, and by 0.017%-0.042% per day for the last twenty days.

[0162] Example 7

[0163] The process of regulating the gonadal development of the Chinese sturgeon parent fish in this example is basically the same as that in Example 1, except that:

[0164] In step 3), the flow rate of the culture water is 0.4 m / s after the middle of the IV period of gonadal development.

[0165] Example 8

[0166] The process of regulating the gonadal development of the Chinese sturgeon parent fish in this example is basically the same as that in Example 1, except that:

[0167] In step 1), the daily variation of the culture water temperature is 4℃.

[0168] In steps 2) and 3), the daily variation of the culture water temperature is 2℃.

[0169] Example 9

[0170] The process of regulating the gonadal development of the Chinese sturgeon parent fish in this example is basically the same as that in Example 1, except that:

[0171] The nutritional composition of the feed includes 40wt% of crude protein, 6-8wt% of crude fat, 6wt% of crude fiber, 17wt% of crude ash, ≥1.2wt% of total phosphorus, and 2wt% of lysine.

[0172] Example 10

[0173] The process of regulating the gonadal development of the Chinese sturgeon parent fish in this example is basically the same as that in Example 1, except that:

[0174] The DO is 6 mg / L, the pH is 6.5-7.0, the NH4 + <0.5mg / L, and the NO2 － is 0.06-0.1 mg / L.

[0175] Comparative Example 1

[0176] The process of regulating the gonadal development of the Chinese sturgeon parent fish in this example includes the following steps:

[0177] 1) The Chinese sturgeon parent fish in the II period of gonadal development is cultured according to the daily feeding amount of 0.5-1.0% and the daily feeding frequency of 1 time / d, with freshwater fish as the main bait source, artificial stocking is carried out with the constant flow of river water, and the annual regulation of water temperature is carried out according to the annual variation of the water temperature of the river water, the DO of the culture water is >5.5 mg / L, the NH4 + <0.5mg / L, the NO2 － <0.1mg / L, and the pH value is 6.5, to obtain the parent fish in the III period of gonadal development;

[0178] 2) in the process of the gonad development from the stage III to the beginning of the stage IV, the flow rate of the breeding water is controlled to be 0.2-0.5 m / s, and after the gonad development to the stage IV, the flow rate of the breeding water is controlled to be 1.0-1.5 m / s.

[0179] Comparative Example 2

[0180] The regulation process of the gonad development of the Chinese sturgeon parent fish in the comparative example comprises the following steps:

[0181] The gonad development of the Chinese sturgeon parent fish in the stage II is cultivated, and the parameters in the cultivation process are as follows:

[0182] Referring to the annual change of the water temperature of the downstream section of the Gezhouba Dam in Yichang of the Yangtze River, the water temperature of the breeding water is controlled to be 6-28.5℃; the nutritional composition of the feed includes: crude protein≥40.0wt%, crude fat 6-8wt%, crude fiber≤6.0wt%, crude ash≤17.0wt%, calcium≤5wt%, total phosphorus≥1.2wt%, lysine≥2wt%, and water content≤12wt%;

[0183] During the low water temperature period when the water temperature of the breeding water is below 12℃, low daily feeding of 1% or below is used for winterization feeding regulation, and when the gonad development of the offspring Chinese sturgeon parent fish reaches the stage III or above, the daily feeding rate is strictly controlled to be within 1% to ensure the stable development of the gonad of the parent fish;

[0184] The water quality parameters of the breeding water are as follows: DO is 6 mg / L, pH is 6.5-7.0, NH4 + ≤0.5 mg / L, and NO2 － ≤0.11 mg / L.

[0185] The light intensity for the parent fish in the stage III or above of gonad development is controlled to be within 10000 Lx;

[0186] In the process of the gonad development of the parent fish in the stage III to the beginning of the stage IV, the flow rate of the breeding water is controlled to be 0.2-0.5 m / s, and after the gonad development to the stage IV, the flow rate of the breeding water is controlled to be 0.5-1.0 m / s.

[0187] Comparative Example 3

[0188] The regulation process of the gonad development of the Chinese sturgeon parent fish in the comparative example is basically the same as that in Example 1, and the difference is that:

[0189] Step 3) does not perform the reduced feeding type cultivation, and the daily feeding amount is still maintained to be 0.5-1.0%.

[0190] Comparative Example 4

[0191] The regulation process of the gonad development of the Chinese sturgeon parent fish in the comparative example is basically the same as that in Example 1, and the difference is that:

[0192] The daily feeding frequency is 1 time / d.

[0193] Comparative Example 5

[0194] The regulation process of the gonadal development of the parent fish of the Chinese sturgeon in this comparative example is basically the same as that in Example 1, except that:

[0195] The environmental noise of the culture is > 90 dB.

[0196] Comparative Example 6

[0197] The regulation process of the gonadal development of the parent fish of the Chinese sturgeon in this comparative example is basically the same as that in Example 1, except that:

[0198] The daily feeding time interval is 6 h.

[0199] Comparative Example 7

[0200] The regulation process of the gonadal development of the parent fish of the Chinese sturgeon in this comparative example is basically the same as that in Example 1, except that:

[0201] In steps 2) and 3), the culture density is 6 kg / m 3 .

[0202] Comparative Example 8

[0203] The regulation process of the gonadal development of the parent fish of the Chinese sturgeon in this comparative example is basically the same as that in Example 1, except that:

[0204] In steps 2) and 3), the water temperature of the culture water reaches 28℃.

[0205] Comparative Example 9

[0206] The regulation process of the gonadal development of the parent fish of the Chinese sturgeon in this comparative example is basically the same as that in Example 1, except that:

[0207] The light intensity during the day is 5500-10000 Lx, and the light intensity at night is < 20 Lx.

[0208] Test Example

[0209] The parent fish of the Chinese sturgeon obtained by culturing in Examples 1-10 and Comparative Examples 1-9 were tested by stages according to the method of B-ultrasonic detection, and the gonadal development starting rate and the gonadal maturation rate were counted, as shown in Table 1. Among them, the success rate refers to the ratio of the number of parent fish with reproductive capacity to the number of parent fish in the gonadal development stage II.

[0210] Table 1

[0211] The male parent fish cultivated by the method of Example 1-10 and Comparative Example 1-9 were tested by B-ultrasonic detection, and the starting rate of gonadal development and the mature rate of gonadal were counted, as shown in Table 2. The success rate refers to the ratio of the number of parent fish with reproductive capacity to the number of parent fish in the gonadal development stage II.

[0212] Table 2

[0213] After years of research and practice, the starting rate of gonadal development of female parent fish of Chinese sturgeon has significantly increased, with an average starting rate of 20.58%, up from the initial 3.25%, and the highest starting rate reaching 27.59%. The average starting rate of gonadal development of male parent fish of Chinese sturgeon has increased from the initial 12.77% to 26.40%, which is much higher than the industry standard of 4-6% of the starting rate of gonadal development of Chinese sturgeon. In particular, the number of Chinese sturgeon parent fish in stage II to stage III has increased significantly since 2020-2023. At the same time, the number and proportion of parent fish with reproductive capacity have increased significantly. The average rate of female parent fish with reproductive capacity has increased steadily from the initial 37.50% to more than 71.41%. In particular, according to the regulation method of Example 1, the gonadal degeneration rate of female parent fish of Chinese sturgeon has decreased to 8.33%, and the rate of parent fish with reproductive capacity has increased to 91.67%. The rate of male parent fish with reproductive capacity has increased steadily from the initial 33.33% to 93.33%, which lays a solid foundation for the large-scale breeding and release of Chinese sturgeon and plays an important role and significance in the protection of Chinese sturgeon species.

[0214] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto. Although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for part or all of the technical features thereof. 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 application.

Claims

1. A method for regulating the gonadal development of Chinese sturgeon broodfish, wherein, The regulation process comprises the following steps: 1) According to the daily feeding amount of 0.5-1.0%, the daily feeding frequency of 2 times / d, the Chinese sturgeon parent fish in the gonadal development phase II is subjected to gonadal start-up cultivation, and the parent fish in the gonadal development phase III is obtained; 2) According to the daily feeding amount of 0.5-1.0%, the daily feeding frequency of 2 times / d, and the limit value of the noise of the breeding environment of 60 dB, the parent fish in the gonadal development phase III is subjected to near-mature cultivation, and the parent fish in the early gonadal development phase IV is obtained; 3) The female parent fish in the early gonadal development phase IV is subjected to the first reduced feeding type cultivation, so that the daily feeding amount of the female parent fish is reduced to 0 within 3 months and maintained; the male parent fish in the late gonadal development phase IV is subjected to the second reduced feeding type cultivation, so that the daily feeding amount of the male parent fish is reduced to 0 within 30 days and maintained, and the limit value of the noise of the breeding environment is 40 dB, and the parent fish with the breeding ability is obtained; In the step 2) and step 3), the water temperature of the breeding water is 10-27℃, and the breeding density is not higher than 5kg / m 3 ; The daily feeding time interval of the regulation process is 8-12 h, the light intensity in the daytime is 3000-5000 Lx, and the light intensity at night is <20 Lx.

2. The method of modulation according to claim 1, wherein, In step 1), the stocking density is 5-8 kg / m 3 .

3. The method of modulation according to any one of claims 1 or 2, wherein, In steps 2) and 3), the farming density is 2-3 kg / m 3 .

4. The method of modulation according to any one of claims 1-3, wherein, In steps 2) and 3), the feeding amount at 8:00 is 60%-70% of the daily feeding amount, and the feeding amount at 16:00 is 30-40% of the daily feeding amount.

5. The method of modulation according to any one of claims 1-4, wherein, The first reduced feeding type cultivation in step 3) comprises the following steps: The daily feeding amount reduction rate of the female parent fish in the first month is 0.0017%-0.0067% / day; and / or, the daily feeding amount reduction rate of the female parent fish in the second and third months is 0.0067%-0.0150% / day; And / or, the second reduced feeding type cultivation comprises the following steps: The daily feeding amount reduction rate of the male parent fish is 0.017%-0.033% / day, and the daily feeding amount is reduced to 0 and maintained.

6. The method of modulation according to any one of claims 1-5, wherein, The first reduced feeding type cultivation in step 3) comprises the following steps: The daily feeding amount of the female parent fish is reduced by 0.0083-0.0333% / time in the first month according to the first reduction amount, the daily feeding amount is maintained for 5 days after the reduction, then the daily feeding amount is reduced again according to the first reduction amount, and the cycle is repeated until the daily feeding amount is 0; And / or, the daily feeding amount of the female parent fish is reduced by 0.0333-0.075% / time in the second and third months according to the second reduction amount, the daily feeding amount is maintained for 5 days after the reduction, then the daily feeding amount is reduced again according to the second reduction amount, and the cycle is repeated until the daily feeding amount is 0; And / or, the second reduced feeding type cultivation comprises the following steps: The daily feeding amount of the male parent fish is reduced by 0.1-0.2% / time, the daily feeding amount is maintained for 5 days after the reduction, then the daily feeding amount is reduced again by 0.1-0.2% / time, and the cycle is repeated until the daily feeding amount is 0 and maintained.

7. The method of modulation according to any one of claims 1-6, wherein, In steps 2) and 3), the water flow rate during the gonadal development phase III to the middle of the gonadal development phase IV is 0.0-0.3 m / s, and the water flow rate after the middle of the gonadal development phase IV is 0.5-1.0 m / s.

8. The method of modulation according to any one of claims 1-7, wherein, In step 1), the daily change of the water temperature of the breeding water is not higher than 3℃; And / or, in steps 2) and 3), the daily change of the water temperature of the breeding water is not higher than 1℃.

9. The method of modulation according to any one of claims 1-8, wherein, The feed nutrient composition in the regulation process includes crude protein ≥ 42.0wt%, crude fat ≥ 10.0wt%, crude fiber ≤ 5.0wt%, crude ash ≤ 16.0wt%, total phosphorus ≥ 1.2wt%, and lysine ≥ 2.5wt%.

10. The method of modulation according to any one of claims 1-9, wherein, The DO in the process is more than 7.5 mg / L, NH4 + <0.5 mg / L, NO2 － <0.05 mg / L, and the pH value is 7.5-8.0.

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