Method for distinguishing good crabs according to shell color change
By changing the photoperiod, the color of the shell of the combative crab is lighter, combined with light experiments and fighting experiments, the reduction of immunity and environmental pollution caused by combat behavior in high-density pond breeding was solved, efficient screening and molecular breeding were achieved, and the yield and quality of Chinese mitten crabs were improved.
Patent Information
- Application Number
- CN202510464381.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-14
- Publication Date
- 2025-07-11
AI Technical Summary
Under high-density pond breeding conditions, the fighting behavior of Chinese mitten crabs leads to a decrease in immune ability, a decrease in foraging efficiency and mating success rate, and a lack of appendages or serious physical damage, which affects survival, growth, quality and economic value, and the bait at the bottom of the pond is accumulated to pollute the environment.
By changing the light cycle, the shell color of the combative crabs will be lighter quickly. The shell color changes will be used to identify the combative crabs. Combined with light experiments, mirror experiments and fighting experiments, the combat crabs will be screened and molecular breeding will be carried out.
It has achieved efficient screening of combative crabs, improved the yield and quality of Chinese mitten crabs, reduced economic losses caused by fighting, and provided group materials for molecular breeding, improving unit price and breeding efficiency.
Smart Images
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Abstract
Description
Technical Field
[0001] This application relates to the technical field of the production and breeding of Chinese mitten crabs, and specifically relates to a method for distinguishing aggressive and non-aggressive Chinese mitten crabs by shell color. Background Art
[0002] In recent years, the breeding of Chinese mitten crabs has transformed from lake enclosure culture to pond ecological culture, opening a new model of "green transformation". However, under the conditions of high-density pond culture, the fighting behavior of Chinese mitten crabs has intensified. The loss of their appendages or physical injuries will lead to a decline in immune ability, a reduction in foraging efficiency and mating success rate, and cannibalism, thus seriously affecting their survival, growth, quality and economic value.
[0003] In addition, due to the inability to feed normally due to the loss of appendages, a large amount of bait accumulates at the bottom of the pond, polluting the breeding environment and further reducing the level of green ecological culture. Chinese mitten crabs are naturally aggressive, and significant individual differences within the population prompt the emergence of aggressive and non-aggressive groups. The fighting behavior of aggressive crabs often causes more energy loss, more serious limb breakage and even death.
[0004] Therefore, it becomes particularly important to screen out aggressive individuals. By utilizing the characteristics and habits of aggressive crabs, on the one hand, screening can be carried out by visually observing the shell color, and non-aggressive crab populations of Chinese mitten crabs can also be obtained by means of image digitization for related molecular breeding. And through aggression verification, aggressive individuals can be efficiently screened out. This method is simple, efficient and reliable, and can be widely applied to production practice and scientific research, which is beneficial to the improvement of the yield and quality of Chinese mitten crabs. Summary of the Invention
[0005] The present invention provides a method for distinguishing aggressive crabs based on shell color changes. The purpose is to rapidly lighten the shell color of aggressive crabs by changing the photoperiod, so as to achieve the purpose of distinguishing aggressive crabs.
[0006] The present invention is achieved through the following technical solutions:
[0007] A method for distinguishing aggressive crabs based on shell color changes specifically includes the following operating steps:
[0008] (1) Screening Chinese mitten crabs and adjusting shell color:
[0009] Select Chinese mitten crabs with a body weight of 30-40 g and intact limbs, and breed them in a laboratory water tank. After irradiating with LED lights for a certain period of time, the shell color of individual Chinese mitten crabs becomes lighter. Some individual Chinese mitten crabs will show uneven fading, presenting an abnormal shell color with dark patches. Before proceeding to the next operating step of the lighting experiment, the individual Chinese mitten crabs with abnormal shell color need to be removed;
[0010] (2) Conduct a light experiment:
[0011] Under laboratory conditions, the photoperiod was adjusted to constant light for 24 hours, and the light source was still a 240 lm LED lamp. There was no shelter like structure in the single-culture water tank, so that Eriocheir sinensis was under the influence of light for 24 hours. Other breeding conditions remained unchanged. Under this condition, they were cultured singly for 7 days. Before and after the light experiment, high-definition pictures of the backs of all Eriocheir sinensis individuals were taken separately by a high-definition camera. By taking pictures under artificial light in the laboratory, the color tone changes caused by environmental conditions were controlled.
[0012] (3) Analyze the shell color:
[0013] Classify the shell color of Eriocheir sinensis according to the high-definition pictures of the backs of the Eriocheir sinensis individuals taken.
[0014] (4) Test aggression, conduct fighting experiments and distinguish aggressive crabs:
[0015] After the light experiment, mirror experiments and fighting experiments were conducted on the light-colored crab group and the dark-colored crab group respectively to obtain the aggression and aggressive behavior data of the two groups. By analyzing the aggression and aggressive behavior of the dark-colored crab group and the light-colored crab group, the correlation between the shell color depth and aggressive personality of Eriocheir sinensis was found. The results showed that there was a positive correlation between the shell color gray value and aggression or aggressive behavior. The relationship and its interaction among the shell color depth, gender, aggression and aggressive behavior were measured by a generalized linear model. It was assumed that the conditional distribution of the response variable Y belonged to the exponential distribution family, and its probability density function (or probability mass function) could be expressed as:
[0016]
[0017] Among them: θ is the natural parameter, which determines the specific shape of the distribution, Φ is the scale parameter, usually related to the variance of the distribution, b(θ) and c(y,Φ) are known functions, used to ensure that the integral (or summation) of the probability density function or probability mass function is 1. All analysis methods were carried out on SPSS Statistics 26.0.
[0018] (5) Draw conclusions: Gender has nothing to do with whether an individual is aggressive. The shell color depth, aggression and aggressive personality are significantly correlated. At the same time, there is a significant interaction between the shell color depth and aggression. The lighter the shell color, the more aggressive the individual. Therefore, light-colored crabs are aggressive crabs and dark-colored crabs are non-aggressive crabs. Conversely, by comparing the carapace gray values of aggressive crabs and non-aggressive crabs before and after the light experiment, it was found that the shell color of aggressive crabs would become lighter under the influence of light, while the shell color of non-aggressive crabs would not be affected by light.
[0019] As a preferred embodiment, in step (1), the Chinese mitten crabs are placed in an opaque circular water tank with a diameter of 30 cm. The natural light cycle is simulated by a 240 lm LED lamp placed directly above the water tank, with a light-dark ratio of 1:1. Under this condition, the crabs are cultured individually for 7 days to adjust the shell color to be stable. The LED lamp in the laboratory will make the shell color of all individuals lighter to a certain extent, and culturing individually for 7 days is sufficient to make the shell color of all individuals stable.
[0020] As a preferred embodiment, in step (2), the light cycle is adjusted to 24-hour constant illumination, and the light source is still a 240 lm LED lamp. There is no shelter similar to a shelter in the single-culture water tank, so that the Chinese mitten crabs are under the influence of light for 24 hours, and other culture conditions remain unchanged. Under this condition, the crabs are cultured individually for 7 days. Before and after the light experiment, high-definition pictures of the backs of all individuals are taken by a high-definition camera respectively, and the hue changes caused by environmental conditions are controlled by taking pictures under artificial light in the laboratory.
[0021] As a preferred embodiment, in step (3), first, the shell color is simply divided into light-colored crabs and dark-colored crab populations manually. The shell color difference caused by continuous illumination is visible to the naked eye. Those light-shelled crabs are aggressive crabs, and this characteristic will simplify the screening steps and facilitate its wide application.
[0022] As a preferred embodiment, in step (3), for the screening of aggressive crabs required for fine research, the shell color can be quantitatively measured so as to have more accurate specific data support. The specific operation is as follows: Use ImageJ software (NIH) to analyze and quantitatively measure the shell color of Chinese mitten crabs. Five square areas of the same size are divided on the picture, and the gray values of the five square areas on the individual carapace are analyzed. The gray value range is 0-255. The larger the value, the lighter the shell color. Since the shooting environment is indoor artificial light, light reflection is unavoidable. When obtaining the gray value, the square areas with severe light reflection need to be removed, and the average value of the gray values of other areas is taken. The gray value range of light-colored crabs is 62.469-104.679, and these are the aggressive crabs.
[0023] As a preferred embodiment, the device for the mirror experiment in step (4) includes a square water tank (23×18×30 cm) and a plane mirror (20×10 cm) closely attached to one side of the square water tank. The number of interactions between the crab and the plane mirror is counted to quantify the aggressiveness of the crab. The interaction behaviors include approaching, touching, and raising the chelipeds. The sum of the three interaction behaviors is recorded as the number of aggressive behaviors. The larger the number, the stronger the aggressiveness. The fighting experiment uses a conventional crab fighting device, and mainly records the number of aggressive behaviors (grabbing, pushing, approaching directly, intimidating, stretching, and patrolling) that occur during the fighting process of two individuals. The number of aggressive behaviors is sufficient to judge the aggressiveness of an individual.
[0024] Technical principle of the present invention: Under the influence of short-term continuous light, there will be obvious differences in the shell colors between aggressive crabs and non-aggressive crabs. This difference is very significant and can be observed with the naked eye. Under non-laboratory conditions, by setting up a continuous light source at night for 7 days and reducing shelters, individuals with lighter shell colors in the group can be observed. At this time, removing the light-colored crabs (aggressive crabs) can achieve the purpose of reducing the fighting of Chinese mitten crabs under high-density farming. Under laboratory conditions, more precise screening methods are required. In addition to qualitative comparison, quantitative measurement also needs to be carried out through ImageJ software (NIH). Through mirror experiments and fighting experiments, the distinction of aggressive crabs can be made more precise, and finally, in-depth research can be carried out on the group of aggressive crabs.
[0025] Beneficial effects:
[0026] (a) A method for distinguishing aggressive and non-aggressive Chinese mitten crab populations according to the present invention further differentiates and analyzes the gene polymorphisms between aggressive crabs and non-aggressive crabs, identifies single nucleotide polymorphism (SNP) loci associated with the fighting behavior of Chinese mitten crabs, provides important population materials for the molecular breeding of Chinese mitten crabs, and finally new varieties of Chinese mitten crabs (non-aggressive crabs) can be cultivated and used as the main farming objects. At the same time, according to the characteristics of aggressive crabs and non-aggressive crabs, different farming environments are selected for separate farming. For example, high-density pond farming is carried out for non-aggressive crab populations to increase production; low-density cage farming or single farming is carried out for aggressive crab populations to further improve the individual quality and increase the unit price.
[0027] (b) The shell color is an easily distinguishable characteristic of Chinese mitten crabs. In this application, by changing the photoperiod, the shell color of aggressive crabs can be quickly lightened, thus achieving the purpose of distinguishing aggressive crabs. This method can be widely applied to production practice.
[0028] (c) Except for experimental conditions, when the light treatment is carried out in a glass tank for 7 days, there will also be differences in shell colors among individuals. This change in shell color is related to the light cycle, but the speed of shell color change is slower than that under experimental conditions. Therefore, in actual production, the aggressive group with lightened shell colors can be screened out by turning on the light at night and reducing shelters, reducing the economic losses caused by the fighting of aggressive crabs during the farming process. Description of the drawings
[0029] Figure 1 It is a schematic structural diagram of the light experiment device in an embodiment of the present invention.
[0030] Figure 2 It is a schematic diagram of five square areas for analyzing the gray value of the carapace of Chinese mitten crabs by ImageJ software (NIH) in an embodiment of the present invention.
[0031] Figure 3 It is a schematic structural diagram of the mirror experiment device in an embodiment of the present invention.
[0032] Figure 4 This is a coordinate graph showing the changes in the shell color of aggressive crabs and non-aggressive crabs before and after the light experiment in an embodiment of the present invention.
[0033] Figure 5 This is a schematic diagram showing the shell color differences between aggressive crabs and non-aggressive crabs before and after the light experiment in an embodiment of the present invention. Detailed implementation manners
[0034] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings: These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.
[0035] A method for identifying aggressive crabs based on shell color changes specifically includes the following operation steps:
[0036] I. Screening and shell color adjustment of Eriocheir sinensis:
[0037] Select Eriocheir sinensis with intact limbs and a body weight of 30 - 40 g. Place them in an opaque circular water tank with a diameter of 30 cm, and simulate the natural light cycle (light-dark ratio 1:1) through a 240 lm LED lamp placed directly above the water tank. Under this condition, keep them in single culture for 7 days to adjust the shell color of Eriocheir sinensis to be stable. The LED lamp in the laboratory will make the shell color of all individuals become lighter to a certain extent, and 7 days of single culture is sufficient to make the shell color of all individuals stable. In addition, during the process of the shell color becoming lighter, some individuals will show uneven fading, presenting dark patches. Such individuals with abnormal shell color need to be removed before the light experiment.
[0038] II. Light experiment:
[0039] As Figure 1 shown, under laboratory conditions, adjust the light cycle to 24-hour constant light, and the light source is still a 240 lm LED lamp. There is no shelter-like covering in the single-culture water tank, so that Eriocheir sinensis is under the influence of light for 24 hours, and other breeding conditions remain unchanged. Keep them in single culture for 7 days under this condition. Before and after the light experiment, take high-definition pictures of the backs of all individuals through a high-definition camera, and control the color tone changes caused by environmental conditions by taking pictures under the artificial light in the laboratory.
[0040] III. Shell color analysis:
[0041] Classify the shell colors of Chinese mitten crabs according to the captured high-definition back pictures. First, simply divide the shell color shades manually to obtain groups of light-colored crabs and dark-colored crabs. The purpose of this patent is to serve the front line of production. The shell color differences caused by continuous light are visible to the naked eye. Those light-shelled crabs are aggressive crabs, and this characteristic will simplify the screening steps and facilitate their wide application. For the screening of aggressive crabs required for fine research, quantitative measurement of the shell color can be carried out to have more accurate specific data support. The specific operation is as follows: Use ImageJ software (NIH) to analyze and conduct quantitative measurement of the shell color of Chinese mitten crabs. As Figure 2 shown, divide five square areas on the picture. Each square area has the same size. Analyze the grayscale values of the five square areas on the individual carapace. The grayscale value range is 0 - 255. The larger the value, the lighter the shell color. Since the shooting environment is indoor artificial light and light reflection is unavoidable, when obtaining the grayscale value, it is necessary to remove the square areas with serious light reflection and take the average grayscale value of other areas. The grayscale value range of light-colored crabs is 62.469 - 104.679, and these are the aggressive crabs.
[0042] IV. Aggressiveness test, fighting experiment and differentiation of aggressive crabs:
[0043] After the light experiment, conduct mirror experiments and fighting experiments on the groups of light-colored crabs and dark-colored crabs respectively to obtain the aggressiveness and aggressive behavior data of the two groups. The device for the mirror experiment includes a square water tank (23×18×30 cm) and a plane mirror (20×10 cm) closely attached to one side of the square water tank. Count the number of interactions between the crab and the plane mirror to quantify the aggressiveness of the crab. The interaction behaviors include approaching, touching, and raising the chelipeds. Record the sum of the three interaction behaviors as the number of aggressive times. The larger the number, the stronger the aggressiveness. As Figure 3 shown. The fighting experiment uses a conventional crab fighting device and mainly records the number of aggressive behaviors (grabbing, pushing, approaching directly, intimidating, stretching, and patrolling) that occur during the fight between two individuals. The number of aggressive behaviors is sufficient to judge the aggressiveness of an individual.
[0044] As Figure 4 shown, by analyzing the aggressiveness and aggressive behavior of the dark-colored crab and light-colored crab groups, find the correlation between the shell color depth and aggressive personality of Chinese mitten crabs. The results show that there is a positive correlation between the grayscale value of the shell color and aggressiveness or aggressive behavior. Use the generalized linear model to measure the relationship and its interaction effects among shell color depth, gender, aggressiveness, and aggressive behavior. Assume that the conditional distribution of the response variable Y belongs to the exponential distribution family, and its probability density function (or probability mass function) can be expressed as:
[0045]
[0046] Among them: θ is the natural parameter that determines the specific shape of the distribution. Φ is the scale parameter, which is usually related to the variance of the distribution. b(θ) and c(y,Φ) are known functions used to ensure that the integral (or summation) of the probability density function or probability mass function is 1. All the analysis methods were carried out on SPSS Statistics 26.0. As Figure 5 shown, the results indicate that gender has no relation with whether an individual is aggressive, and there is a significant correlation between the shell color depth, aggression, and the aggressive personality. At the same time, there is a significant interaction between the shell color depth and aggression. The lighter the shell color, the more aggressive the individual. Therefore, light-colored crabs are aggressive crabs, and dark-colored crabs are non-aggressive crabs. Conversely, by comparing the carapace gray-scale values of aggressive crabs and non-aggressive crabs before and after illumination, it was found that the shell color of aggressive crabs would become lighter under the influence of illumination, while the shell color of non-aggressive crabs would not be affected by illumination.
[0047] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.
Claims
1. A method for identifying aggressive crabs based on shell color changes, characterized in that, Specifically, the following operation steps are included: (1) Screening Eriocheir sinensis and adjusting shell color: Select Eriocheir sinensis with a body weight of 30 - 40 g and intact limbs, and culture them in the laboratory sink. After irradiating with LED lights for a certain period of time, the shell color of individual Eriocheir sinensis becomes lighter. Some individuals of Eriocheir sinensis will show uneven fading, presenting an abnormal shell color with dark patches. Before proceeding to the next operation step of the light experiment, the individuals of Eriocheir sinensis with abnormal shell color need to be removed; (2) Conducting the light experiment: Under laboratory conditions, adjust the photoperiod to 24 - hour constant light, and the light source is still a 240 - lm LED lamp. There is no shelter similar to a refuge in the single - culture water tank, so that Eriocheir sinensis is under the influence of light for 24 hours, and other culture conditions remain unchanged. Under this condition, culture them singly for 7 days. Before and after the light experiment, take high - definition pictures of the backs of all Eriocheir sinensis individuals through a high - definition camera, and control the color - tone changes caused by environmental conditions by taking pictures under laboratory artificial light; (3) Analyzing the shell color: Classify the shell color of Eriocheir sinensis according to the high - definition pictures of the backs of the Eriocheir sinensis individuals taken; (4) Testing aggression, conducting fighting experiments, and differentiating aggressive crabs: After the light experiment, conduct mirror experiments and fighting experiments on the light - colored crab group and the dark - colored crab group respectively to obtain the aggression and aggressive behavior data of the two groups. By analyzing the aggression and aggressive behavior of the dark - colored crab group and the light - colored crab group, find the correlation between the shell color depth of Eriocheir sinensis and the aggressive character. The results show that there is a positive correlation between the shell color gray - scale value and aggression or aggressive behavior. Use the generalized linear model to measure the relationship and its interaction among shell color depth, gender, aggression, and aggressive behavior. Assume that the conditional distribution of the response variable Y belongs to the exponential distribution family, and its probability density function can be expressed as: where: θ is the natural parameter that determines the specific shape of the distribution, Φ is the scale parameter, usually related to the variance of the distribution, b(θ) and c(y, Φ) are known functions used to ensure that the integral of the probability density function or probability mass function is 1. All analysis methods are carried out on SPSS Statistics 26.0; (5) Draw conclusions that gender has nothing to do with whether an individual is aggressive, the shell color depth, aggression, and aggressive character are significantly correlated, and there is a significant interaction between the shell color depth and aggression. The lighter the shell color, the more aggressive the individual. Therefore, light - colored crabs are aggressive crabs and dark - colored crabs are non - aggressive crabs. Conversely, by comparing the carapace gray - scale values of aggressive crabs and non - aggressive crabs before and after the light experiment, it is found that the shell color of aggressive crabs will become lighter under the influence of light, while the shell color of non - aggressive crabs will not be affected by light.
2. The method for identifying aggressive crabs based on shell color change according to claim 1, characterized in that, In step (1) above, place Eriocheir sinensis in an opaque circular water tank with a diameter of 30 cm, and simulate the natural light cycle with a 240 - lm LED lamp placed directly above the water tank, with a light - to - dark ratio of 1:
1. Under this condition, culture them singly for 7 days to adjust the shell color of Eriocheir sinensis to be stable. The LED lights in the laboratory will make the shell color of all individuals lighter to a certain extent, and culturing them singly for 7 days is sufficient to make the shell color of all individuals stable.
3. A method for identifying aggressive crabs based on shell color change according to claim 1, characterized in that In step (2), the photoperiod was adjusted to 24-hour constant light, and the light source was still a 240-lm LED lamp. There was no shelter-like object in the single-culture tank, so that Eriocheir sinensis was under the influence of light for 24 hours. Other breeding conditions remained unchanged. Under this condition, they were cultured singly for 7 days. Before and after the light experiment, high-definition pictures of the backs of all individuals were taken by a high-definition camera respectively. Photos were taken under artificial light in the laboratory to control the color tone changes caused by environmental conditions.
4. A method for identifying aggressive crabs based on shell color change according to claim 1, characterized in that In step (3), first, the shell color was simply divided into light-colored and dark-colored crab groups manually. The shell color difference caused by continuous light was visible to the naked eye. Those light-shelled crabs were aggressive crabs, and this characteristic would simplify the screening steps and facilitate its wide application.
5. A method for identifying aggressive crabs based on shell color change according to claim 1, characterized in that, In step (3), for the screening of aggressive crabs required for fine research, quantitative measurement of the shell color could be carried out so as to have more accurate specific data support. The specific operation was as follows: The ImageJ software was used to analyze and quantitatively measure the shell color of Eriocheir sinensis. Five square areas of the same size were divided on the picture, and the gray values of the five square areas on the individual carapace were analyzed. The gray value range was 0-255. The larger the value, the lighter the shell color. Since the shooting environment was indoor artificial light and light reflection was inevitable, the square areas with serious light reflection needed to be removed when obtaining the gray values, and the average gray value of other areas was taken. The gray value range of light-colored crabs was 62.469-104.679, and these were the aggressive crabs.
6. A method for identifying aggressive crabs based on shell color change according to claim 1, characterized in that, In step (4), the device for the mirror experiment included a square water tank and a plane mirror closely attached to one side of the square water tank. The number of interactions between the crab and the plane mirror was counted to quantify the aggressiveness of the crab. The interaction behaviors included approaching, touching, and raising the chelipeds. The sum of the three interaction behaviors was recorded as the number of aggressive behaviors. The more the number, the stronger the aggressiveness. The fighting experiment used a conventional crab fighting device, and mainly recorded the number of aggressive behaviors that occurred during the fighting process of two individuals. The number of aggressive behaviors was sufficient to judge the aggressiveness of an individual.