A method for constructing a deep learning model based on otolith embedding and age identification of Sardinella fareastensis

Abstract

The present invention discloses a method for constructing a deep learning model based on otolith embedding and age identification of Far Eastern Sardines. The process of otolith embedding includes the steps of soaking, cleaning, drying, embedding, photographing and retaining. The otoliths of Far Eastern Sardines are embedded and fixed on a glass slide, photographed and retained by a microscope camera under the irradiation of transmitted light of an optical microscope, and the ring patterns are analyzed and judged. The identified age data and the biological data corresponding to each tail are used as training samples to input the constructed deep learning model. The accuracy of the model after training is greatly improved. In the present invention, otolith embedding realizes the clear visualization of the annual rings of Far Eastern Sardines, avoids the interference of interfering rings on the annual rings, makes the annual rings easier to identify and judge, and the construction of a deep learning model based on age identification improves the accuracy of age identification of Far Eastern Sardines. The efficiency of age identification of Far Eastern Sardines is greatly improved, and otolith samples can be preserved for a long time.

Description

Technical Field

[0001] The present invention relates to the field of aquatic product age identification, and in particular to a method for constructing a deep learning model based on otolith embedding and age identification of Sardinella fareastensis. Background Art

[0002] The Far Eastern Sardines are one of the main fish species caught commercially in my country's high seas. The abundance of their resources fluctuates greatly. Accurately grasping the relevant growth parameters of the Far Eastern Sardines and their age composition are extremely important basic work for the rational use of these resources.

[0003] Otoliths are the sensory organs of fish. Because of their fixed migration routes, their habitats have obvious seasonal changes. Therefore, the otoliths have alternating light and dark bands, which together form annual rings. Therefore, the age of the fish can be roughly determined based on the number of light and dark band rings in the otoliths. Therefore, accurate reading of the ring patterns can accurately identify its age.

[0004] Using otolith surface ring patterns to determine the age of fish is a common method, but the light and dark bands on the untreated otolith surface are not obvious, and there will be more interference rings when observed under an optical microscope, which often leads to incorrect readings and misjudgment of age. Since the otoliths of Far Eastern Sardines are relatively thin and brittle, the use of traditional otolith processing methods will lead to large errors and difficulties in otolith grinding or age interpretation. The otoliths processed by the method of the present invention can increase the light transmittance of the otoliths, and the alternation of light and dark bands is clearer, reducing the influence of interference rings, greatly improving the recognition of ring patterns, and thus increasing the accuracy of age identification of Far Eastern Sardines.

[0005] Deep learning is a new direction in the field of machine learning. Deep Neural Networks (DNN) are the basis of deep learning and are currently widely used in various fields. The application provides a deep learning model, which is an automatic method for distinguishing the age of fish based on multiple factors (fork length, body weight, and otolith weight). The deep learning model (Linear-Rule) of this application has a higher degree of matching with the data. At the same time, softmax is used for dimensional changes, making the biological data characteristics between different ages more obvious, thereby achieving the effect of improving the efficiency and accuracy of Far Eastern Sardinella age identification. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for constructing a deep learning model based on otolith embedding and age identification of Far Eastern Sardinella, which can effectively improve the accuracy and efficiency of age identification of Far Eastern Sardinella.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A method for constructing a deep learning model based on otolith embedding and age identification of Far Eastern Sardinella, comprising the following steps:

[0009] (1) The growth rings of the otolith samples of Sardinella serrata were manually identified, and the ages of Sardinella serrata were obtained as follows: 0+, 1+, 2+, 3+, 4+, 5+, 6+;

[0010] (2) using the age of the otolith samples identified in step (1) as a validation set and the biological parameters of each fish as a training set to construct a deep learning model;

[0011] (3) The original three-dimensional data of fish fork length, fish weight and otolith weight are upgraded to 700 dimensions through Linear operation;

[0012] (4) Use the linear activation function (ReLU) method to change the output of some neurons to 0, making the network sparse, while reducing the interdependence of parameters and alleviating model overfitting;

[0013] (5) Call the Linear operation to increase the model to 2048 dimensions to make the model features more obvious;

[0014] (6) Add a ReLU operation to increase the dimension of the model to 4096 dimensions, achieving the most obvious feature effect;

[0015] (7) Perform dimensionality reduction on the model, reducing the 4096-dimensional model to 1024-dimensional model, so that the features of the model can be integrated;

[0016] (8) Perform two linear operations to reduce the model to its seven dimensions corresponding to 0+, 1+, 2+, 3+, 4+, 5+, and 6+;

[0017] (9) After N experiments, the output seven-dimensional results are compared with 0+, 1+, 2+, 3+, 4+, 5+, and 6+ in the verification set. If the results are the same as those in the verification set, they are considered to be correct results. If the comparison results are different, they are considered to be incorrect results.

[0018] As a preferred embodiment, the specific steps of manually identifying the otolith growth rings in step (1) are:

[0019] (11) Soaking: Soak the otolith sample of Sardinella fareastensis in a reagent containing 75% alcohol for 24 h to remove the thin film on the surface of the otolith;

[0020] (12) Cleaning: Place the cleaned otolith sample into an ultrasonic cleaner and clean it for 10 min to remove any residual film and organic tissue on the surface of the otolith.

[0021] (13) Drying: Place the otolith samples cleaned by ultrasonic cleaning in an oven at 45°C for 24 h to remove moisture from the otolith surface;

[0022] (14) Embedding: Place the dried otolith with the sulcus side facing downward on a glass slide. Wrap the entire otolith with shadowless glue and irradiate it with ultraviolet light for 3 seconds to fix the otolith on the glass slide.

[0023] (15) Place the slide on the stage of a Leica DM750 optical microscope, adjust the brightness of the LED light so that the transmitted light illuminates the sample and the annual rings of the otoliths are clearly visible. Use a 10x objective to take photos from the core to the tail of the otolith, and identify the annual rings in the photos.

[0024] As a preferred embodiment, the specific steps of the annual ring identification in step (15) are:

[0025] (151) The otolith produces calcium carbonate crystals from the core and embeds them into the protein matrix to form a ring structure. The ring formed by the calcium carbonate crystals is relatively narrow, corresponding to the slow growth period of the otolith, and appears as a transparent zone under the incident light of the microscope.

[0026] (152) The protein matrix forms a relatively wide ring, which corresponds to the period of rapid growth of the otoliths and appears as a translucent zone under the incident light of the microscope;

[0027] (153) The broad opaque protein matrix and the narrow transparent calcium carbonate crystals together form the whorls of otolith growth;

[0028] (154) When judging, we usually look from the core to the outside. The first obvious ring pattern is not counted and is regarded as the young ring 7;

[0029] (155) The ring pattern is the interface between the translucent ring and the opaque ring. A complete transparent ring and a translucent ring form a complete annual ring.

[0030] (156) The translucent ring must appear continuously on the surface of the otolith. If the translucent ring merges with another ring or fails to appear on the entire surface of the otolith, it is considered a false ring.

[0031] (157) The outermost opaque ring does not count as a complete ring structure unless another opaque ring can be observed outside it;

[0032] (158) Count the translucent bands 1, 2, and 3. The number of translucent bands is the age;

[0033] (159) Each otolith of the Far Eastern Sardinella was examined and counted by two people independently. If the two people counted the same number of rings, the age was considered correct and the result was accepted. If the two people counted different numbers of growth rings, they would re-examine and count and discuss the final structure. If they reached a consensus, the result would be accepted; otherwise, it would be abandoned.

[0034] As a preferred embodiment, the otoliths of Sardinella orientalis in step (1) are made of calcium carbonate crystalline material, and the otolith sample should be completely wrapped with shadowless glue to increase the overall light transmittance.

[0035] As a preferred embodiment, the shadowless glue, also known as UV curing glue, is a type of adhesive that must be cured by ultraviolet light. The adhesive has the characteristics of high strength, high efficiency, high transparency, etc. It will not cause harm to the human body and is safe and easy to use.

[0036] As a preferred embodiment, the biological parameters of each fish in step (2) are fork length, body weight, and otolith weight.

[0037] As a preferred embodiment, the otolith samples of each fish are sampled at a fork length interval of 5 mm, and the biological parameters of each fish are fork length 0.1 cm, body weight 0.1 g, and otolith weight 0.01 mg.

[0038] As a preferred embodiment, during embedding in step (14), the otolith is placed with the sulcus facing downwards, so that it is not easy to slide when covered with shadowless glue, and the stability is higher;

[0039] As a preferred embodiment, in step (14), after the otoliths are completely wrapped with the shadowless glue, it is necessary to leave it to stand for 3 minutes, during which time the bubbles in the glue are expelled using a dissecting needle to avoid affecting the overall light transmission effect.

[0040] As a preferred embodiment, in step (15), when identifying age, under the irradiation of transmitted light, the core position of the otolith surface appears opaque brown-black, and from the core to the bottom of the otolith, transparent rings and opaque rings are arranged alternately, and the complete appearance of transparent rings and opaque rings is regarded as a complete annual ring.

[0041] Beneficial effects: The present invention uses biological parameters (fork length, body weight, and otolith weight) as a training set, thereby improving the recognition of otolith annual rings and the accuracy of age identification, avoiding the influence of otolith surface interference rings on age identification, and the construction and application of deep learning models greatly improve the efficiency of Far Eastern Sardines age identification, making the identification work more accurate and efficient. This method does not require cutting Far Eastern Sardines otoliths, is more efficient, has better effects, and greatly improves the accuracy and efficiency of Far Eastern Sardines age identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The figure is a schematic diagram of the overall appearance structure of the otolith of Sardinella sardinae of the present invention.

[0043] Figure 2 The figure is a schematic diagram of the appearance structure of the otolith sample of Sardinella orientalis after being processed according to the present invention.

[0044] Figure 3 Schematic diagram of the process of the deep learning model of the present invention.

[0045] Figure 4 This is an electron microscope image of the otolith of the Far Eastern Sardinella in Example 1 of the present invention.

[0046] Figure 5 This is an electron microscope image of the otolith of the Far Eastern Sardinella in Example 2 of the present invention.

[0047] Figure 6 This is an electron microscope image of the otolith of the Far Eastern Sardinella in Example 3 of the present invention.

[0048] Figure 7 This is an electron microscope image of the otolith of the Far Eastern Sardinella in Example 4 of the present invention. DETAILED DESCRIPTION

[0049] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings: This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0050] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0051] like Figure 1-3 , which is a schematic diagram of the overall appearance structure of the Far Eastern Sardinella otolith of the present invention.

[0052] 1. First, embed the otoliths, including the following steps:

[0053] 1) Soaking: After the otoliths are taken out of the fish, they are soaked in alcohol reagent to remove the thin film on the surface of the otoliths;

[0054] 2) Cleaning: Place the cleaned otolith sample into an ultrasonic cleaning machine and start cleaning to clean the remaining film and organic tissue on the surface of the otolith;

[0055] 3) Drying: The otolith samples cleaned with an ultrasonic cleaner were placed in an oven at 45°C for drying to remove moisture from the otolith surface;

[0056] 4) Embedding: First, number the slide, which should be consistent with the number of the Far Eastern Sardinella sample. Place the dried otolith with the sulcus side facing downward on the slide steadily. The total length and maximum width of the otolith should correspond to the length and width of the slide. Wrap the entire otolith with shadowless glue, and use a dissecting needle to pick out the bubbles. After the bubbles are completely eliminated, irradiate with ultraviolet light, and the otolith will be fixed on the slide.

[0057] 5) Photography: Place the embedded otolith slide on the stage of the Leica DM750 optical microscope, so that the otolith is located in the light transmission hole, adjust the light source to achieve the best observation light in the imaging system. Use a 10x objective lens, adjust the coarse focusing screw and the fine focusing screw to make the otolith ring pattern clearly visible, and use the microscope's built-in imaging system to take photos for preservation.

[0058] Through the above five steps, the otolith sample of Far Eastern Sardinella was processed, and the otolith sample with high transparency was placed under an optical microscope and illuminated by transmitted light. Figure 2 shown.

[0059] 2. Age identification of Sardinella sardinellae by otolith patterns

[0060] 1) The difference between otoliths and scales is that the formation of otoliths begins in the embryonic period, and the mineral bases are combined to form an independent core8

[0061] 2) Calcium carbonate crystals are generated from the core and embedded in the protein matrix to form a ring structure. The ring formed by calcium carbonate crystals is relatively narrow, corresponding to the slow growth period of otoliths, and appears as transparent zones 4, 5, and 6 under the incident light of the microscope;

[0062] 3) The protein matrix forms a relatively wide ring, which corresponds to the rapid growth period of the otolith and appears as translucent zones 1, 2, and 3 under the incident light of the microscope;

[0063] 4) The broad opaque protein matrix and the narrow transparent calcium carbonate crystals together form the whorls of otolith growth;

[0064] 5) When judging, usually look from the core to the outside, the first obvious wheel pattern is not counted and is regarded as the young wheel 7;

[0065] 6) The ring pattern is the interface between the translucent ring and the opaque ring. A complete transparent ring and a translucent ring form a complete annual ring.

[0066] 7) The translucent ring must appear continuously on the surface of the otolith. If the translucent ring merges with another ring or fails to appear on the entire surface of the otolith, it is considered a false ring.

[0067] 8) The outermost opaque ring is not considered a complete ring structure unless another opaque ring can be observed outside the outermost ring;

[0068] 9) Count the number of translucent zones 1, 2, and 3, and the number of translucent zones is the age. Each otolith of the Far Eastern Sardinella is judged and counted by two people. If the two people count the same number of rings, the age is considered correct and the result is accepted; if the two people count different numbers of annual rings, they will re-judge and count, and discuss the final structure. If they reach a consensus, they will accept the result, otherwise they will give up.

[0069] 3. Construction of age identification method based on deep learning model, such as Figure 3 described.

[0070] 1) The original 3D data of fish fork length, fish weight and otolith weight are upgraded to 700 dimensions through Linear operation;

[0071] 2) Use the linear activation function (ReLU) method to change the output of some neurons to 0, making the network sparse, while reducing the interdependence of parameters and alleviating model overfitting;

[0072] 3) Call the Linear operation to increase the model to 2048 dimensions to make the model features more obvious;

[0073] 4) Add a ReLU operation to increase the dimension of the model to 4096 dimensions, achieving the most obvious feature effect;

[0074] 5) Perform dimensionality reduction on the model, reducing the 4096 dimension to 1024 dimension, so that the features of the model can be integrated;

[0075] 6) Perform two linear operations to reduce the model to its 7 dimensions corresponding to 0+, 1+, 2+, 3+, 4+, 5+, 6+;

[0076] 7) Compare the output 7-dimensional results with the validation set to obtain the final results of the model.

[0077] Embodiment 1:

[0078] like Figure 4 , which is a schematic diagram of the overall appearance structure of the Far Eastern Sardinella otolith of the present invention.

[0079] 1. First, embed the otoliths, including the following steps:

[0080] 1) Soaking: After the otoliths are taken out of the fish, they are soaked in a reagent with 75% alcohol for 24 hours to remove the thin film on the surface of the otoliths;

[0081] 2) Cleaning: Place the cleaned otolith sample into an ultrasonic cleaner and clean it for 10 minutes to remove any residual film and organic tissue on the surface of the otolith;

[0082] 3) Drying: The otolith samples cleaned with an ultrasonic cleaner were placed in an oven at 45°C for 24 hours to remove moisture from the otolith surface;

[0083] 4) Embedding: First, number the slides to be consistent with the number of the Far Eastern Sardinella sample, place the dried otoliths on the slide with the sulcus side facing down, and place them steadily. The total length and maximum width of the otoliths should correspond to the length and width of the slide. Use shadowless glue to wrap the entire otolith, use a dissecting needle to pick out the bubbles, and after the bubbles are completely eliminated, use ultraviolet light to irradiate for 3 seconds, and the otoliths will be fixed on the slide;

[0084] 5) Photography: Place the embedded otolith slide on the stage of the Leica DM750 optical microscope, so that the otolith is located in the light transmission hole, adjust the light source to achieve the best observation light in the imaging system. Use a 10x objective lens, adjust the coarse focusing screw and the fine focusing screw to make the otolith ring pattern clearly visible, and use the microscope's built-in imaging system to take photos for preservation.

[0085] Through the above five steps, the otolith sample of Far Eastern Sardinella was processed, and the otolith sample with high transparency was placed under an optical microscope and illuminated by transmitted light. Figure 4 shown.

[0086] 2. Age identification of Sardinella sardinellae by otolith patterns

[0087] like Figure 4 Count the translucent bands 9, 10, and 11, and the number of translucent bands is the age. Each Far Eastern Sardinella otolith is judged and counted by two people. If the two count the same number of annual rings, the age is considered correct and the result is accepted; if the two count the number of annual rings differently, the judgment and count are repeated, and the final structure is discussed. If a consensus is reached, the result is accepted, otherwise it is abandoned and the age of the otolith sample is judged to be 3+.

[0088] The biological parameters of the otolith are fork length, body weight, and otolith weight, which are 175 mm, 46.6 g, and 0.002 mg, respectively. Substituting the three biological parameters into the model, Figure 3 As shown, if the model judges it to be 3+ and the result is consistent with the human judgment, it is considered to be the correct result.

[0089] Embodiment 2:

[0090] like Figure 5 , which is a schematic diagram of the overall appearance structure of the Far Eastern Sardinella otolith of the present invention.

[0091] 1. First, embed the otoliths, including the following steps:

[0092] 1) Soaking: After the otoliths are taken out of the fish, they are soaked in a reagent with 75% alcohol for 24 hours to remove the thin film on the surface of the otoliths;

[0093] 2) Cleaning: Place the cleaned otolith sample into an ultrasonic cleaner and clean it for 10 minutes to remove any residual film and organic tissue on the surface of the otolith;

[0094] 3) Drying: The otolith samples cleaned with an ultrasonic cleaner were placed in an oven at 45°C for 24 hours to remove moisture from the otolith surface;

[0095] 4) Embedding: First, number the slides to be consistent with the number of the Far Eastern Sardinella sample, place the dried otoliths on the slide with the sulcus side facing down, and place them steadily. The total length and maximum width of the otoliths should correspond to the length and width of the slide. Use shadowless glue to wrap the entire otolith, use a dissecting needle to pick out the bubbles, and after the bubbles are completely eliminated, use ultraviolet light to irradiate for 3 seconds, and the otoliths will be fixed on the slide;

[0096] 5) Photography: Place the embedded otolith slide on the stage of the Leica DM750 optical microscope, so that the otolith is located in the light transmission hole, adjust the light source to achieve the best observation light in the imaging system. Use a 10x objective lens, adjust the coarse focusing screw and the fine focusing screw to make the otolith ring pattern clearly visible, and use the microscope's built-in imaging system to take photos for preservation.

[0097] Through the above five steps, the otolith sample of Far Eastern Sardinella was processed, and the otolith sample with high transparency was placed under an optical microscope and illuminated by transmitted light. Figure 5 shown.

[0098] 2. Age identification of Sardinella sardinellae by otolith patterns

[0099] like Figure 5 Count the translucent zones 12 and 13, and the number of translucent zones is the age. Each Far Eastern Sardinella otolith is judged and counted by two people. If the two count the same number of rings, the age is considered correct and the result is accepted; if the two count the number of annual rings differently, the judgment and count are repeated, and the final structure is discussed. If a consensus is reached, the result is accepted, otherwise it is abandoned and the age of the otolith sample is judged to be 2+.

[0100] The biological parameters of the otolith are fork length, body weight, and otolith weight, which are 155 mm, 32.3 g, and 0.0014 mg, respectively. Substituting the three biological parameters into the model, Figure 3 As shown, if the model judges it to be 2+ and the result is consistent with the human judgment, it is considered to be the correct result.

[0101] Embodiment 3:

[0102] like Figure 6 , which is a schematic diagram of the overall appearance structure of the Far Eastern Sardinella otolith of the present invention.

[0103] 1. First, embed the otoliths, including the following steps:

[0104] 1) Soaking: After the otoliths are taken out of the fish, they are soaked in a reagent with 75% alcohol for 24 hours to remove the thin film on the surface of the otoliths;

[0105] 2) Cleaning: Place the cleaned otolith sample into an ultrasonic cleaner and clean it for 10 minutes to remove any residual film and organic tissue on the surface of the otolith;

[0106] 3) Drying: The otolith samples cleaned with an ultrasonic cleaner were placed in an oven at 45°C for 24 hours to remove moisture from the otolith surface;

[0107] 4) Embedding: First, number the slides to be consistent with the number of the Far Eastern Sardinella sample, place the dried otoliths on the slide with the sulcus side facing down, and place them steadily. The total length and maximum width of the otoliths should correspond to the length and width of the slide. Use shadowless glue to wrap the entire otolith, use a dissecting needle to pick out the bubbles, and after the bubbles are completely eliminated, use ultraviolet light to irradiate for 3 seconds, and the otoliths will be fixed on the slide;

[0108] 5) Photography: Place the embedded otolith slide on the stage of the Leica DM750 optical microscope, so that the otolith is located in the light transmission hole, adjust the light source to achieve the best observation light in the imaging system. Use a 10x objective lens, adjust the coarse focusing screw and the fine focusing screw to make the otolith ring pattern clearly visible, and use the microscope's built-in imaging system to take photos for preservation.

[0109] Through the above five steps, the otolith sample of Far Eastern Sardinella was processed, and the otolith sample with high transparency was placed under an optical microscope and illuminated by transmitted light. Figure 6 shown.

[0110] 2. Age identification of Sardinella sardinellae by otolith patterns

[0111] like Figure 6 Count the number of translucent bands 14, and the number of translucent bands is the age. Each Far Eastern Sardinella otolith is judged and counted by two people. If the two count the same number, the age is considered correct and the result is accepted; if the number of annual rings counted by the two people is different, the judgment and counting are re-performed, and the final structure is discussed. If a consensus is reached, the result is accepted, otherwise it is abandoned and the age of the otolith sample is judged as 1+.

[0112] The biological parameters of the otolith are fork length, body weight, and otolith weight, which are 145 mm, 30.7 g, and 0.0011 mg, respectively. Substituting the three biological parameters into the model, Figure 3 As shown, if the model judges it to be 1+ and the result is consistent with the human judgment, it is considered to be the correct result.

[0113] Embodiment 4:

[0114] like Figure 7 , which is a schematic diagram of the overall appearance structure of the Far Eastern Sardinella otolith of the present invention.

[0115] 1. First, embed the otoliths, including the following steps:

[0116] 1) Soaking: After the otoliths are taken out of the fish, they are soaked in a reagent with 75% alcohol for 24 hours to remove the thin film on the surface of the otoliths;

[0117] 2) Cleaning: Place the cleaned otolith sample into an ultrasonic cleaner and clean it for 10 minutes to remove any residual film and organic tissue on the surface of the otolith;

[0118] 3) Drying: The otolith samples cleaned with an ultrasonic cleaner were placed in an oven at 45°C for 24 hours to remove moisture from the otolith surface;

[0119] 4) Embedding: First, number the slides to be consistent with the number of the Far Eastern Sardinella sample, place the dried otoliths on the slide with the sulcus side facing down, and place them steadily. The total length and maximum width of the otoliths should correspond to the length and width of the slide. Use shadowless glue to wrap the entire otolith, use a dissecting needle to pick out the bubbles, and after the bubbles are completely eliminated, use ultraviolet light to irradiate for 3 seconds, and the otoliths will be fixed on the slide;

[0120] 5) Photography: Place the embedded otolith slide on the stage of the Leica DM750 optical microscope, so that the otolith is located in the light transmission hole, adjust the light source to achieve the best observation light in the imaging system. Use a 10x objective lens, adjust the coarse focusing screw and the fine focusing screw to make the otolith ring pattern clearly visible, and use the microscope's built-in imaging system to take photos for preservation.

[0121] Through the above five steps, the otolith sample of Far Eastern Sardinella was processed, and the otolith sample with high transparency was placed under an optical microscope and illuminated by transmitted light. Figure 6 shown.

[0122] 2. Age identification of Sardinella sardinellae by otolith patterns

[0123] like Figure 7Count the number of translucent bands 15, and the number of translucent bands is the age. Each Far Eastern Sardinella otolith is judged and counted by two people. If the two count the same number of rings, the age is considered correct and the result is accepted; if the two count the number of annual rings differently, the judgment and count are repeated, and the final structure is discussed. If a consensus is reached, the result is accepted, otherwise it is abandoned and the age of the otolith sample is judged as 1+.

[0124] The biological parameters of the otolith are fork length, body weight, and otolith weight, which are 170 mm, 51.5 g, and 0.0016 mg, respectively. Substituting the three biological parameters into the model, Figure 3 As shown, if the model judges it as 2+ and the result is inconsistent with the human judgment, it is considered to be an erroneous result.

[0125] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for constructing a deep learning model based on otolith embedding and age identification of Far Eastern Sardinella, characterized in that: The following steps are involved: (1) The growth rings of the otolith samples of the Far Eastern Sardinella were manually identified, and the ages of the Far Eastern Sardinella were obtained as follows: 0+, 1+, 2+, 3+, 4+, 5+, 6+; (2) using the age of the otolith samples identified in step (1) as a validation set and the biological parameters of each fish as a training set to construct a deep learning model; (3) The original three-dimensional data of fish fork length, fish weight and otolith weight are upgraded to 700 dimensions through Linear operations; (4) Use the linear activation function method to change the output of some neurons to 0, making the network sparse, while reducing the interdependence of parameters and alleviating model overfitting; (5) Call the Linear operation to increase the model to 2048 dimensions to make the model features more obvious; (6) Add a ReLU operation to increase the dimension of the model to 4096 dimensions, achieving the most obvious feature effect; (7) Perform dimensionality reduction on the model, reducing the 4096 dimension to 1024 dimension, so that the features of the model can be integrated; (8) Perform two linear operations to reduce the model to its seven dimensions corresponding to 0+, 1+, 2+, 3+, 4+, 5+, 6+; (9) After N experiments, the output seven-dimensional results are compared with the validation set to obtain the final result of the deep learning model; The specific steps of manually identifying the otolith growth rings in step (1) are as follows: (11) Soaking: Soak the otolith samples of Sardinella sardinae in a reagent with 75% alcohol content for 24 hours to remove the thin film on the surface of the otoliths; (12) Cleaning: Place the cleaned otolith sample into an ultrasonic cleaner and clean it for 10 min to remove any remaining film and organic tissue on the surface of the otolith. (13) Drying: Place the otolith samples cleaned by ultrasonic cleaning machine in an oven at 45°C and dry for 24 hours to remove moisture from the otolith surface. (14) Embedding: Place the dried otolith with the sulcus side facing downward on a glass slide. Wrap the entire otolith with shadowless glue and irradiate it with ultraviolet light for 3 seconds to fix the otolith on the glass slide. (15) Place the slide on the stage of a Leica DM750 optical microscope, adjust the brightness of the LED light so that the transmitted light illuminates the sample and the annual rings of the otolith are clearly visible, use a 10x objective lens to take a photo of the otolith core to the tail end, and identify the annual rings in the photo; The specific steps of the annual ring identification in step (15) are: (151) The otolith produces calcium carbonate crystals from the core and embeds them into the protein matrix to form a ring structure. The ring formed by the calcium carbonate crystals is relatively narrow, corresponding to the slow growth period of the otolith, and appears as a transparent zone under the incident light of the microscope. (152) The protein matrix forms a relatively wide ring, which corresponds to the period of rapid growth of the otoliths and appears as a translucent zone under the incident light of the microscope; (153) Broad opaque protein matrix and narrow transparent calcium carbonate crystals together form the whorls of otolith growth; (154) When judging, we usually look from the core to the outside. The first obvious ring pattern is not counted and is regarded as a young ring (7); (155) The ring pattern is the interface between the translucent ring and the opaque ring. A complete transparent ring and a translucent ring form a complete annual ring. (156) The translucent ring must appear continuously on the surface of the otolith. If the translucent ring merges with another ring or fails to appear on the entire surface of the otolith, it is considered a false ring. (157) The outermost opaque ring does not count as a complete ring structure unless another opaque ring can be observed outside it; (158) Count the translucent bands (1), (2), and (3). The number of translucent bands is the age; (159) Each otolith of the Far Eastern Sardinella was examined and counted by two people independently. If the two people counted the same number of rings, the age was considered correct and the result was accepted. If the two people counted different numbers of growth rings, they would re-examine and count and discuss the final structure. If they reached a consensus, the result would be accepted; otherwise, it would be abandoned.

2. The method for constructing a deep learning model based on otolith embedding and age identification of Sardinella far easternensis according to claim 1, characterized in that: The otoliths of Sardinella sardegna in step (1) are made of calcium carbonate crystalline material, and the otolith sample should be completely wrapped with shadowless glue to increase the overall light transmittance.

3. The method for constructing a deep learning model based on otolith embedding and age identification of Sardinella far easternensis according to claim 1, characterized in that: The shadowless glue, also known as UV curing glue, is a type of adhesive that must be cured by ultraviolet light.

4. The method for constructing a deep learning model based on otolith embedding and age identification of Sardinella far easternensis according to claim 1, characterized in that: Otolith samples were taken from each fish at intervals of 5 mm fork length, and the biological parameters of each fish were fork length 0.1 cm, body weight 0.1 g, and otolith weight 0.01 mg.

5. The method for constructing a deep learning model based on otolith embedding and age identification of Sardinella far easternensis according to claim 1, characterized in that: In the step (14), when embedding, the atrium sulcus of the otolith is placed downward, so that it is not easy to slide when covered with shadowless glue, and the stability is higher.

6. The method for constructing a deep learning model based on otolith embedding and age identification of Sardinella far easternis according to claim 1, characterized in that: In step (14), after the otoliths are completely wrapped with the shadowless glue, it needs to be left to stand for 3 minutes, during which time the bubbles in the glue are expelled using a dissecting needle to avoid affecting the overall light transmission effect.

7. The method for constructing a deep learning model based on otolith embedding and age identification of Sardinella far easternensis according to claim 1, characterized in that: In the step (15), when the age is identified, under the irradiation of transmitted light, the core position of the otolith surface appears opaque brown-black, and from the core to the bottom of the otolith, transparent rings and opaque rings are arranged alternately. The complete appearance of transparent rings and opaque rings is regarded as a complete annual ring.

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