Method and system for rapidly, nondestructively and accurately monitoring female fish ovary development state

Abstract

The invention belongs to but is not limited to the field of biodiversity protection and aquaculture, and particularly relates to a method and system for nondestructively monitoring ovarian development of female fish, and the method comprises the following steps: S1, anesthetizing experimental fish by adopting anesthetic MS-222; s2, placing the anesthetized experimental fish in a GE workstation 7503.0 T magnetic resonance imager (MRI) for scanning, and after scanning is finished, performing post-processing in a magnetic resonance imaging data analysis system (GE AW4.7 workstation) so as to obtain axial surface image data of the ovary of each female fish, and measuring data of the ovary and the fish body volume; s3, judging the development stage of the ovary by observing the morphological characteristics of the ovary of the female fish and calculating the fish body volume ratio data of the ovary; and S4, putting the experimental fish subjected to anesthesia scanning into clear water, and resuscitating the experimental fish. The method can quickly and accurately identify the ovarian development stage of the female fish under the condition of not damaging the fish, and reduces the monitoring time and economic cost.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the fields of biodiversity protection and aquaculture, and in particular relates to a method and system for rapidly, non-destructively and accurately monitoring the ovarian development status of female fish. Background Art

[0002] Fish are an important component of the ecosystem and play a vital role in maintaining the stability of the ecosystem. At the same time, fish are also an important source of high-quality protein for humans. Therefore, it is crucial to protect wild fish resources and promote the sustainable development of the aquaculture industry. In recent years, due to climate change and the impact of human activities (water pollution, water conservancy project construction, and overfishing, etc.), the protection of wild fishery resources and the sustainable development of farmed fish aquaculture have faced many challenges. Two of the major challenges are the obstruction of ovarian maturation in female fish and the asynchronous development of the ovaries of male and female broodstock, which results in low broodstock rates (reproduction rate, hatching rate, and seedling survival rate), which in turn leads to the depletion of wild fishery resources and insufficient supply of high-quality farmed fish seedlings. In response to the above problems, the maturation of the ovaries of female fish can be monitored at high frequencies, and targeted and effective measures can be taken to regulate the maturation of the ovaries of female fish, thereby improving the three rates of broodstock.

[0003] At present, the technical means of evaluating the ovarian maturity of fish can be summarized into two categories: invasive and non-invasive. Invasive techniques include observation of ovarian morphology after dissection, ovarian histological examination, and determination of ovarian sex-to-body ratio indicators. Although the above invasive methods can accurately determine the maturity of the ovaries, they are time-consuming and inevitably cause harm to fish or even death, thereby increasing the cost of breeding. Non-invasive techniques include B-type ultrasound scanning, computed tomography (CT) scanning, and magnetic resonance imaging (MRI) scanning. Although B-type ultrasound scanning and computed tomography (CT) scanning can avoid the death of fish, they have the problem of poor accuracy, and CT technology has radiation, which will affect the health of fish. Compared with B-type ultrasound scanning and computed tomography (CT) scanning, magnetic resonance imaging technology has high soft tissue resolution and no radiation, and has been successfully used to monitor the ovarian development status of long-finned goby. However, the existing magnetic resonance imaging technology still has the problem of too long scanning time (461 seconds), which will increase the economic cost of scanning monitoring and the mortality rate of scanned fish.

[0004] In view of the above analysis, the technical problem that urgently needs to be solved in the existing technology for monitoring the ovarian development status is: to reduce the scanning time of the existing magnetic resonance imaging technology without reducing the accuracy of the existing non-destructive technology. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a method for rapidly and non-destructively monitoring the ovarian development status of female fish, which can realize rapid and non-destructive detection of the ovarian development stage of female fish, improve the accuracy and efficiency of identifying the ovarian development stage of female fish, make up for the shortcomings of the prior art, greatly reduce the scanning monitoring time and economic cost, and provide a new method with lower economic cost for the protection of wild fishery resources and the sustainable development of farmed fish aquaculture.

[0006] The present invention is achieved by a method for non-destructively monitoring the ovarian development of female fish, comprising the following steps:

[0007] S1, experimental fish were anesthetized using the anesthetic MS-222;

[0008] S2, the anesthetized experimental fish were placed in a GE Discovery MR 7503.0T magnetic resonance imager (MRI) for scanning, and after the scanning, the MRI data analysis system (GEAW4.7 workstation) was used for post-processing to obtain the axial image data of the ovary of each female fish, and the data of the ovary and fish body volume were measured;

[0009] S3, the ovarian development stage was determined by observing the morphological characteristics of the female fish ovaries and calculating the ovary-to-body volume ratio data;

[0010] S4, put the anesthetized and scanned experimental fish into clean water and allow them to recover.

[0011] Furthermore, in step S1, after the fish is anesthetized, excess water on the body surface is removed and wiped off before scanning.

[0012] Furthermore, in step S1, the scanning time is 140 seconds.

[0013] Furthermore, in step S3, the specific morphological characteristics of the magnetic resonance imaging (MRI) image of the female fish ovary are as follows: in stage I, the ovary is string-shaped and thin; in stage II, the ovary is flat and band-shaped; in stage III, the ovary is mass-shaped, and the area occupied by the ovary in the abdominal cavity increases; in stage IV, the ovary is cystic and elongated, occupying most of the abdominal cavity; in stage V, the ovary occupies almost all of the abdominal space, and the abdomen of the experimental fish obviously protrudes outward, and the ovary volume reaches its maximum at this time; in stage VI, the space occupied by the ovary in the abdominal cavity decreases, the length and width of the ovary are significantly reduced, and the ovary gradually degenerates.

[0014] The results obtained by magnetic resonance imaging were used to calculate the ovarian fish body volume ratio index (%). The formula for the ovarian fish body volume ratio index (%) is:

[0015] Ovarian to fish volume ratio index (%) = (ovarian volume [cm3] / fish body volume [cm3]) × 100

[0016] Another object of the present invention is to provide a female fish ovarian development stage monitoring system, comprising: an anesthesia device (Xitianlong brand plastic box, length, width and height: 489×347×283 mm), using MS-222 (150 ppm, Shanghai Aladdin Biochemical Technology Co., Ltd, China, anesthesia time 673±18 seconds) to anesthetize experimental fish; a magnetic resonance imager (Discovery MR750; General Electric Medical Systems, Milwaukee, WI, USA) and a magnetic resonance imaging data analysis system (GEAW4.7 workstation), used to scan the anesthetized experimental fish and obtain its ovarian axial plane image and ovary and fish body volume data; and a waking device (Xitianlong brand plastic box, length, width and height: 489×347×283 mm), in which clean water is placed to help the experimental fish wake up, and the waking time is 744±31 seconds.

[0017] Furthermore, the scanning time of the magnetic resonance imaging device is 140 seconds to ensure that sufficiently clear and detailed ovarian image data are obtained.

[0018] Furthermore, the analysis device determines the stage of ovarian development based on the following morphological features of ovarian magnetic resonance images: stage I ovaries are string-shaped; stage II ovaries are flat and ribbon-shaped; stage III ovaries are block-shaped; stage IV ovaries are cystic and elongated; stage V ovaries almost occupy all abdominal space; and stage VI ovaries gradually degenerate and the space occupied in the abdominal cavity decreases.

[0019] Table 1. Distribution range of ovary sex to body ratio and ovary to body volume ratio of Channa argus

[0020]

[0021]

[0022] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0023] First, the present invention provides a method for quickly, non-destructively and accurately monitoring the ovarian development of female fish, which belongs to the field of fishery resource protection and aquaculture technology. The present invention uses magnetic resonance imaging technology to scan female fish through a magnetic resonance imaging instrument to identify the stages of female fish ovarian development status. The present invention can quickly and accurately identify the ovarian development status of female fish without harming the fish, without damaging the fish, improving the survival rate of fish, and reducing monitoring time and economic costs. This method can accurately identify the state of ovarian development, so as to take targeted measures to improve the three rates of parent fish, and then to a certain extent help alleviate the problems faced by the depletion of wild fishery resources and the sustainable development of farmed fish aquaculture.

[0024] Second, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0025] (1) The expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0026] The technical solution of the present invention can improve the three rates of parent fish after transformation, thereby helping to alleviate the problems faced by the depletion of wild fishery resources and the sustainable development of farmed fish aquaculture to a certain extent, and has high ecological protection value and economic value.

[0027] (2) The technical solution of the present invention fills the technical gap in the industry at home and abroad:

[0028] The technical solution of the present invention fills the technical gap in the domestic and foreign industry technologies for rapid, non-destructive and accurate monitoring of female fish ovarian development.

[0029] (3) The technical solution of the present invention solves the technical problems that people have been eager to solve but have never been able to solve successfully:

[0030] The technical solution of the present invention solves the technical problem of non-destructive, rapid and accurate monitoring of the ovarian development status of female fish in the domestic and foreign industries: a method for rapid, non-destructive and accurate monitoring of the ovarian development of female fish.

[0031] Third, the method of non-destructive monitoring of female fish ovarian development of the present invention solves many problems in the prior art regarding monitoring of fish ovarian development by introducing magnetic resonance imaging (MRI) technology, and has achieved significant technical progress in industrial applications. Specifically, it is manifested in the following aspects:

[0032] 1) Solved the invasiveness problem of traditional methods

[0033] In the prior art, the ovaries of female fish are usually observed and analyzed by dissection or other invasive methods. These methods not only lead to the death of experimental fish, but also make it impossible to conduct multiple observations. The present invention uses MRI technology to achieve non-destructive monitoring of the ovarian development of female fish. It does not require any destructive operation on the experimental fish and will not cause harm to the health of the fish. Through non-invasive methods, the ovarian development dynamics of the same fish can be monitored multiple times, providing more complete and continuous data for research.

[0034] 2) Improved monitoring accuracy and image resolution

[0035] MRI technology can generate high-resolution soft tissue images, which is particularly suitable for observing internal organs such as fish ovaries. Compared with traditional imaging methods such as ultrasound and X-rays, MRI has a higher resolution for soft tissues and can clearly show the morphological characteristics of the ovaries. By analyzing MRI images, the volume and morphological changes of the ovaries can be accurately measured, and the ovarian development stage of female fish can be determined.

[0036] 3) Realizes the automation of real-time dynamic monitoring and data processing

[0037] By combining with the MRI data analysis system, the acquired images can be automatically post-processed and data measured. This technology automatically generates the ratio of the fish ovary to the fish body volume, and can quickly and accurately determine the development status of the ovary in combination with morphological characteristics. This automated data processing greatly reduces the errors caused by manual operations and improves the efficiency and accuracy of data analysis.

[0038] 4) Reduced interference with experimental fish and enhanced the sustainability of the experiment

[0039] Traditional ovarian development research usually requires sacrificing experimental fish, resulting in excessive consumption of fish resources, limiting the sustainability of the experiment and the sample size. The present invention monitors fish through anesthesia and MRI scanning technology, and the experimental fish can be revived and continue to survive after the monitoring is completed, which not only greatly reduces the consumption of experimental fish, but also allows the same fish to be observed multiple times to achieve dynamic monitoring, which has great advantages in fish reproduction and physiological research.

[0040] The technical progress of the present invention in industrial application is reflected in the following aspects:

[0041] Environmental protection and sustainability: The use of non-destructive monitoring methods reduces the consumption of experimental fish resources and contributes to the sustainable development of fishery breeding and biological research.

[0042] Improvement of experimental efficiency: Through MRI's high-resolution imaging and automated data analysis system, the present invention greatly improves the efficiency of the experiment and the accuracy of the data, providing a more convenient and reliable tool for fish reproductive physiology research.

[0043] Broad application prospects: This technology is not only suitable for laboratory research, but can also be applied to reproduction monitoring and management in the aquaculture industry, helping to improve the breeding quality and efficiency of aquatic resources.

[0044] In summary, the nondestructive monitoring method of the present invention solves the problems of invasiveness and data discontinuity in the existing technology for monitoring fish ovarian development, and significantly improves the accuracy, efficiency and sustainability of monitoring through technological innovation, and has important industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of a method for non-destructive monitoring of ovarian development of female fish provided by an embodiment of the present invention.

[0046] Figure 2 : This is a graph showing the relationship between the gonadal index (GSI) and the ovary-to-body volume ratio of the two sequences provided in the embodiments of the present invention. (A) The fish body is scanned by the 3D CUBE T1WI sequence; (B) The fish body is scanned by the 3D-FSE-Cube-Flex T2WI sequence.

[0047] Figure 3 The following are representative axial magnetic resonance images of the female Channa argus ovary at different maturation stages provided by the embodiment of the present invention (Ov, ovary). DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] The method for non-destructive monitoring of female fish ovarian development provided by the present invention comprises the following steps:

[0050] S1, experimental fish were anesthetized using the anesthetic MS-222;

[0051] S2, the anesthetized experimental fish were placed in a GE Discovery MR 7503.0T magnetic resonance imager (MRI) for scanning, and after the scanning, the MRI data analysis system (GEAW4.7 workstation) was used for post-processing to obtain the axial image data of the ovary of each female fish, and the data of the ovary and fish body volume were measured;

[0052] S3, the ovarian development stage was determined by observing the morphological characteristics of the female fish ovaries and calculating the ovary-to-body volume ratio data;

[0053] S4, put the anesthetized and scanned experimental fish into clean water and allow them to recover.

[0054] The method of the present invention for non-destructive monitoring of female fish ovarian development realizes accurate monitoring of female fish ovarian development through magnetic resonance imaging (MRI) technology without causing damage to the experimental fish. Its working principle is divided into the following steps:

[0055] 1) Anesthesia: During the monitoring process, in order to prevent the movement of the experimental fish from interfering with the MRI scan, the experimental fish were first anesthetized with the anesthetic MS-222. This anesthetic can quickly put the fish into an anesthetized state, which is convenient for subsequent scanning operations and has little impact on the health of the fish.

[0056] 2) Magnetic resonance imaging scan: The anesthetized experimental fish were placed in a GE Discovery MR 7503.0T magnetic resonance imaging (MRI) for scanning. Through MRI technology, high-resolution image data of the experimental fish ovaries can be obtained, especially the axial image of the fish ovaries. MRI technology is non-destructive and will not cause physical damage to the fish body. At the same time, it can clearly display soft tissue structures such as ovaries.

[0057] 3) Data analysis and measurement: The acquired MRI image data is post-processed through the magnetic resonance imaging data analysis system (GEAW4.7 workstation) to generate detailed image data of the experimental fish ovaries. The analysis system will also automatically measure the ovarian volume and body volume of the female fish, and infer the development stage of the ovaries by calculating the ratio of ovarian volume to body volume. At the same time, researchers can also use the morphological characteristics of the ovaries in the image to assist in judging the development of the ovaries.

[0058] 4) Experimental fish recovery: After the scan, the experimental fish were placed in clean water to allow them to recover naturally. Since the effect of MS-222 anesthetic is short, the fish can quickly wake up in clean water and resume normal activities, thus ensuring the health of the fish and the non-destructiveness of the experiment.

[0059] Through the above steps, this method can non-destructively and accurately monitor the development of female fish ovaries and provide effective technical support for ovarian development research.

[0060] Furthermore, in step S1, after the fish is anesthetized, excess water on the body surface is removed and wiped off before scanning.

[0061] Furthermore, in step S1, the scanning time is 140 seconds.

[0062] Furthermore, in step S3, the specific morphological characteristics of the magnetic resonance imaging (MRI) image of the female fish ovary are as follows: in stage I, the ovary is string-shaped and thin; in stage II, the ovary is flat and band-shaped; in stage III, the ovary is mass-shaped, and the area occupied by the ovary in the abdominal cavity increases; in stage IV, the ovary is cystic and elongated, occupying most of the abdominal cavity; in stage V, the ovary occupies almost all of the abdominal space, and the abdomen of the experimental fish obviously protrudes outward, and the ovary volume reaches its maximum at this time; in stage VI, the space occupied by the ovary in the abdominal cavity decreases, the length and width of the ovary are significantly reduced, and the ovary gradually degenerates.

[0063] The specific application field of the present invention is in the field of biodiversity protection and aquaculture.

[0064] Figure 2.Relationship between the gonadal index (GSI) and the ovary-to-body volume ratio of the two sequences. (A) The fish body was scanned by the 3D CUBET1WI sequence; (B) The fish body was scanned by the 3D-FSE-Cube-Flex T2WI sequence. The data were collected from 36 experimental fish in the same batch. GSI = (gonad weight [g] / experimental fish weight [g]) × 100; ovary-to-body volume ratio = (ovary volume [cm 3 ] / Experimental fish body volume [cm 3 ])×100.

[0065] Figure 3 .Representative axial magnetic resonance images of the ovary of Channa argus at different developmental stages. (Ov, ovary).

[0066] Table 2. Sex ratio (%) and ovarian fish volume ratio (%) at different developmental stages of Channa argus

[0067]

[0068] Industrial Application Example 1: Reproduction Monitoring in Aquaculture

[0069] In aquaculture farms, monitoring the ovarian development of female fish is crucial for optimizing the reproductive cycle and increasing the yield of fry. The non-destructive monitoring method of the present invention can be applied to fish breeding management. By regularly performing MRI scans on female fish, the development status of the ovaries and the fish body volume ratio data can be obtained, thereby accurately judging the reproductive maturity of female fish. Farm managers can adjust the breeding plan based on these data, choose the best time for breeding, avoid too early or too late breeding arrangements, and improve fish yield and breeding efficiency.

[0070] Industrial application example 2: Research on fish reproductive biology in scientific research institutions

[0071] In the study of fish reproductive biology, understanding the effects of different environmental factors on the ovarian development of female fish is one of the key points of the study. The method of the present invention can be widely used in scientific research institutions to conduct fish development research, without the need for traumatic operations on experimental fish, thus avoiding the impact on experimental data. Researchers can regularly scan and analyze ovarian development, explore the effects of environmental factors such as temperature, bait, and light on ovarian development, obtain continuous development data, and provide accurate and non-destructive technical support for fish reproductive regulation research.

[0072] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for non-destructive monitoring of ovarian development in female fish, characterized in that: The steps include: S1, the experimental fish were anesthetized with anesthetics; S2, placing the anesthetized experimental fish in a magnetic resonance imaging device MRI for scanning, and performing post-processing on a magnetic resonance imaging data analysis system workstation after the scanning, thereby obtaining axial plane image data of the ovary of each female fish, and measuring the volume data of the ovary and the fish body; S3, the ovarian development stage was determined by observing the morphological characteristics of the female fish ovaries and calculating the ovary-to-body volume ratio data; S4, put the anesthetized and scanned experimental fish into clean water and allow them to recover.

2. The method for non-destructive monitoring of female fish ovarian development as claimed in claim 1, characterized in that: In step S1, after the fish is anesthetized, excess water on the body surface is removed and wiped off before scanning.

3. The method for non-destructive monitoring of ovarian development of female fish as claimed in claim 1, characterized in that: In step S1, the scanning time is 140 seconds.

4. The method for non-destructive monitoring of ovarian development in female fish as claimed in claim 1, characterized in that: In step S3, the specific morphological characteristics of the magnetic resonance image of the female fish ovary are as follows: the ovary in stage I is string-shaped and thin; the ovary in stage II is flat and band-shaped; the ovary in stage III is mass-shaped, and the area occupied by the ovary in the abdominal cavity increases; the ovary in stage IV is cystic and elongated, occupying most of the abdominal cavity; the ovary in stage V occupies almost all of the abdominal space, and the abdomen of the experimental fish obviously protrudes outward, and the ovary volume reaches its maximum at this time; in stage VI, the space occupied by the ovary in the abdominal cavity decreases, the length and width of the ovary are significantly reduced, and the ovary gradually degenerates.

5. A female fish ovarian development monitoring system, characterized in that: include: Anesthesia device, using MS-222 for anesthetizing the experimental fish; Magnetic resonance imager and magnetic resonance imaging data analysis system (GE AW4.7 workstation), used to scan the anesthetized experimental fish and obtain axial images of the ovaries and volume data of the ovaries and fish body; and awakening device, put clean water in the plastic box to help the experimental fish wake up, and the awakening time is 744±31 seconds.

6. The female fish ovarian development monitoring system according to claim 5, characterized in that: A wiping device is also included to remove the experimental fish after anesthesia is completed and wipe excess moisture from its body surface to allow for more accurate scanning.

7. The female fish ovarian development monitoring system according to claim 5, characterized in that: The scanning time of the magnetic resonance imaging apparatus is 140 seconds to ensure that sufficiently clear and detailed ovarian image data are obtained.

8. The female fish ovarian development monitoring system according to claim 5, characterized in that: The analysis device specifically determines the ovarian development stage based on the following morphological features of the ovarian magnetic resonance images: stage I ovaries are string-shaped; stage II ovaries are flat and ribbon-shaped; stage III ovaries are block-shaped; stage IV ovaries are cystic and elongated; stage V ovaries almost occupy the entire abdominal space; and stage VI ovaries gradually degenerate and the space occupied in the abdominal cavity decreases.

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