Regulation method for promoting body color silvering of rainbow trout

Abstract

A regulation method for promoting body color silvering of rainbow trout. Before harvesting rainbow trout, the rainbow trout are cultured for at least thirty days by means of at least one of the following two measures: 1) mounting an LED light source above a rainbow trout culture pond to change the water color in the culture pond; and 2) mounting a water pump in the rainbow trout culture pond to change the water flow velocity in the culture pond. The regulatory effects of lighting and water flow velocity on body color silvering of rainbow trout are investigated, and by means of special lighting and water flow velocity control, regulation of body color silvering of rainbow trout is achieved. In addition, an exercise training mode is created by controlling the water flow velocity, thereby further promoting development and stability of skin pigment cells in rainbow trout, promoting muscle growth to a certain extent, and further improving the nutritional and economic value of the rainbow trout.

Description

A regulatory method to promote silvering of rainbow trout body color Technical Field

[0001] This invention relates to the field of aquaculture technology, specifically to a method for regulating the silvering of rainbow trout body color. Background Technology

[0002] Rainbow trout originated in the Pacific coast of North America and the Kamchatka Peninsula. Since its introduction to China in 1959, rainbow trout farming has spread to more than 20 provinces, municipalities, and autonomous regions in China. It has high economic value, with tender, delicious, and non-fishy meat. It contains small bones, so scaling is unnecessary before consumption. Rainbow trout meat is rich in unsaturated fatty acids and amino acids, which are beneficial for human absorption and nutritional balance. It has now become a high-end aquatic product highly favored by the consumer market.

[0003] The popular silvery-white color of rainbow trout is primarily related to the iris cells within their skin. The coloration of these iris cells is a result of multilayer thin-film interference. Alternating layers of transparent materials with different refractive indices form an alternating layer. When the optical thickness (the product of physical thickness and refractive index) of this alternating layer is comparable to the wavelength of light, it acts as a reflector. When incident light interacts with the reflector, the reflected light undergoes constructive or destructive interference, thus producing different colors.

[0004] Several processes during rainbow trout farming can affect their body color. For example, rainbow trout have high water quality requirements; changes in water temperature and dissolved oxygen during farming can alter their color, causing them to lose their luster. A lack of astaxanthin or lutein in the feed can lead to insufficient pigment synthesis, resulting in a dull color. Harvesting and transportation can cause stress in rainbow trout, causing the pigment cells on their skin to shrink, leading to a darkening of color and even the appearance of spots in a short period. High stocking densities, due to overfeeding or untimely manure disposal, can lead to excessive suspended solids in the water and even the formation of toxic substances, also causing stress and altering their body color. The most popular rainbow trout color on the market is a bright silver. If the rainbow trout have a dull, spotted color or exhibit other colors, it will significantly reduce their market acceptance, leading to decreased sales or lower prices, resulting in economic losses for rainbow trout farmers and hindering the industrialization of rainbow trout farming. Summary of the Invention

[0005] The purpose of this invention is to provide a simple and low-cost method for promoting silvering of rainbow trout body color.

[0006] This invention is achieved through the following technical solution: a method for regulating the silvering of rainbow trout body color, wherein rainbow trout are cultured for at least thirty days using at least one of the following two measures before harvesting:

[0007] (1) Install LED light sources above the rainbow trout breeding pond to change the color of the water in the breeding pond;

[0008] (2) Install water pumps in rainbow trout breeding ponds to change the water flow rate in the breeding ponds.

[0009] The working principle of this technical solution is as follows: pigment cells (melanocytes, erythrocytes, xanthophyllocytes, and iris cells) in the dermal chromatin units that control changes in fish body color can respond to external light signals, altering the fish's body color by changing the size, number, and arrangement of these pigment cells. Simultaneously, iris cells associated with silver coloration exhibit structural coloration through the reflection of light by reflective plates composed of guanine crystals; therefore, their color-developing mechanism is closely related to guanine synthesis and related metabolic pathways. Exercise can upregulate the expression of the PKA signaling pathway related to iris cell survival and color development, while also promoting muscle growth and development in fish. The combination of these two factors can better promote silvering of rainbow trout body color and, to some extent, promote growth.

[0010] To better implement the method of the present invention, further, in measure (1), the color of the purple-red LED light source installed above the rainbow trout breeding pond is at least one of red, blue, purple, and purple-red.

[0011] To better implement the method of the present invention, in further measure (1), the illuminance of the LED light source installed above the rainbow trout breeding pond is 1000LX to 2000LX.

[0012] To better implement the method of the present invention, further, in measure (1), the lighting power of the LED light source installed above the rainbow trout breeding pond is not less than 5W / m2.

[0013] To better implement the method of the present invention, in further measure (1), the LED light source installed above the rainbow trout breeding pond provides illumination for 12 hours per day.

[0014] To better implement the method of the present invention, in further measure (2), a water pump is installed in the rainbow trout breeding pond to make the water flow velocity in the breeding pond 1.2bl / s to 2.4bl / s.

[0015] To better implement the method of the present invention, in further measure (2), the water pump installed in the rainbow trout breeding pond operates for 20 hours a day.

[0016] To better implement the method of the present invention, the internal volume of the rainbow trout breeding pond is further 283 m³. 3 Each breeding pond is stocked with 100 healthy rainbow trout that meet market size.

[0017] To better implement the method of the present invention, the breeding parameters in the rainbow trout breeding pond are further as follows: dissolved oxygen 7 mg / L to 8 mg / L, temperature 16℃ to 18℃, pH 6.5 to 6.8, and ammonia nitrogen content not greater than 0.0075 mg / L.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] (1) This invention provides a method for regulating the silvering of rainbow trout body color by installing a purple-red LED light source to change the number and arrangement of pigment cell clusters in rainbow trout skin through light color, and by controlling the water flow rate to create a movement effect, thereby regulating the silvering of rainbow trout body color.

[0020] (2) This invention creates a sports training mode by controlling the water flow rate, which further promotes the development and stability of rainbow trout skin pigment cells, and also promotes muscle growth to a certain extent.

[0021] (3) This invention explores the regulatory effects of light and water flow velocity on the silvering of rainbow trout. By using special light combined with water flow velocity control, the silvering of rainbow trout can be regulated. The process is simple and low-cost, but the economic benefits are significant and it is suitable for widespread application. Attached Figure Description

[0022] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0023] Figure 1 is a bar chart showing the changes in the cross-sectional area of ​​rainbow trout muscle fibers in different breeding ponds in Example 5 of the present invention;

[0024] Figure 2 shows the body color of rainbow trout before cultivation using the control method of the present invention;

[0025] Figure 3 shows the body color of rainbow trout cultured using the control method of the present invention. Detailed Implementation

[0026] To make the objectives, process conditions, and advantages of the present invention clearer, the present invention will be further described in detail with reference to the following embodiments. However, the embodiments of the present invention are not limited thereto. Various substitutions and modifications can be made based on common technical knowledge and conventional means in the art without departing from the above-described technical concept of the present invention, and all such substitutions and modifications should be included within the scope of the present invention. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0027] Example 1:

[0028] This embodiment demonstrates the effect of light on the silvering of rainbow trout bodies, specifically through the following experiments:

[0029] (1) Experimental materials

[0030] The experiment was conducted in an indoor breeding pond, using rainbow trout that were obtained entirely through artificial breeding.

[0031] (2) Experimental procedure

[0032] Two identical breeding ponds were set up, each with a volume of 283 m³. 3 One hundred healthy rainbow trout of marketable size are placed in each breeding pond.

[0033] Each culture pond was kept under identical conditions, all conducted indoors, and fed twice daily with standard commercial feed. Dissolved oxygen levels in the ponds were maintained at 7-8 mg / L, temperatures at 16-18℃, pH at 6.5-6.8, and ammonia nitrogen levels not exceeding 0.0075 mg / L. One pond served as the control group, and the other as the light-exposed group.

[0034] The control group used natural light inside the greenhouse, while the illumination group had a purple-red LED light with an intensity of 1500 Lx added about 1 m above the breeding pond, and the illumination time was controlled to 12 hours.

[0035] Finally, the color change of rainbow trout in each breeding pond was measured. The color change was divided into six levels: -1, -2, -3, 0, +1, +2, and +3. Among them, 0 represents the initial color, "-" represents the mixed color (towards black or brown), "+" represents the degree of silvering of the color, and "1-3" represents the gradual increase in the degree of change. The results are shown in Table 1 below:

[0036] Table 1. Silvering status of each group

[0037] (3) Experimental conclusions

[0038] As shown in Table 1, rainbow trout exhibit a better silvering effect after being irradiated with a purplish-red LED light source. The main reason for this is that the color of the light alters the composition of the pigment clusters in the rainbow trout's skin cells, resulting in a change in the reflected light and a higher silvering effect.

[0039] Example 2:

[0040] Based on the above embodiments, this embodiment further verifies the influence of light color on the silvering of rainbow trout body color, and specifically conducts the following experiments:

[0041] (1) Experimental materials

[0042] Same as the above embodiments.

[0043] (2) Experimental procedure

[0044] Six identical breeding ponds were set up, each with a volume of 283 m3. 100 healthy rainbow trout of marketable size were placed in each breeding pond.

[0045] The breeding conditions in each breeding pond are the same, and all are carried out in an indoor breeding workshop.

[0046] Different colors of light with an intensity of 1500 Lx were set above each breeding pond. One breeding pond used natural light from inside the greenhouse as a control group and was irradiated for 12 hours a day.

[0047] The other feeding and rearing processes were the same as those provided in Example 1. Finally, the changes in body color of rainbow trout in each rearing pond were measured using the same measurement standards as in Example 1. The results are shown in Table 2 below:

[0048] Table 2. Silvering status for each group

[0049] (3) Experimental conclusions

[0050] As shown in Table 2, compared to the control group under natural light, light color can significantly affect the body color of rainbow trout.

[0051] In addition, different light groups have different effects on the silvering of rainbow trout body color, indicating that the pigment cell clusters in the rainbow trout skin respond differently to different light colors. The purple and red light groups have the most significant effects on the silvering of rainbow trout body color, and these two light colors can be used to regulate the silvering of rainbow trout body color.

[0052] Example 3:

[0053] Based on the above embodiments, this embodiment further verifies the effect of light intensity on the silvering of rainbow trout body color, and specifically conducts the following experiments:

[0054] (1) Experimental materials

[0055] Same as the above embodiments.

[0056] (2) Experimental procedure

[0057] Seven identical culture ponds were set up, each with a volume of 283 m³. 3 One hundred healthy rainbow trout of marketable size are placed in each breeding pond.

[0058] The breeding conditions in each breeding pond are the same, and all are carried out in an indoor breeding workshop.

[0059] Purple-red LED lights were installed above each breeding pond. Different breeding ponds were illuminated according to the light intensity gradient. One breeding pond used natural light from the greenhouse as a control group and was irradiated for 12 hours a day.

[0060] The other breeding processes are the same as those provided in Example 1. Finally, the changes in body color of rainbow trout in each breeding pond are measured, and the measurement standards are the same as in Example 1. The results are shown in Table 3 below:

[0061] Table 3. Silvering status for each group

[0062] (3) Experimental conclusions

[0063] As shown in Table 3, rainbow trout exhibit the best silvering effect at light intensities of 1500 Lx and 1750 Lx. Insufficient light intensity has little or no impact on silvering, while excessive light intensity reduces the silvering effect. Since 1500 Lx and 1750 Lx light intensities yield the best silvering results, and considering cost-effectiveness, 1500 Lx is selected as the most suitable light intensity for controlling rainbow trout silvering.

[0064] Example 4:

[0065] Based on the above embodiments, this embodiment further verifies the effect of water flow velocity on the silvering of rainbow trout body color, and specifically conducts the following experiments:

[0066] (1) Experimental materials

[0067] Same as the above embodiments.

[0068] (2) Experimental procedure

[0069] Three identical breeding ponds were set up, each with a volume of 283 m³. 3 One hundred healthy rainbow trout of marketable size are placed in each breeding pond.

[0070] The breeding conditions in each breeding pond are the same, and all are carried out in an indoor breeding workshop.

[0071] Each rearing pond is equipped with a 1500 Lx purple-red LED light, providing 12 hours of illumination daily. The water flow rate in each pond is regulated by a water pump; one pond uses natural water flow, another has a flow rate of 1.2 bl / s, and the third has a flow rate of 2.4 bl / s. Water flow control is stopped during feeding times (9:00-11:00 and 18:00-20:00) to keep the water still and facilitate feeding for the rainbow trout.

[0072] The other breeding processes are the same as those provided in Example 1. Finally, the change in body color of rainbow trout in each breeding pond is measured, and the measurement standard is the same as in Example 1. The results are recorded as shown in Table 4 below:

[0073] Table 4: Silvering status for each group

[0074] (3) Experimental conclusions

[0075] As shown in Table 4, rainbow trout exhibit the best silvering effect when exposed to a purple-red LED light source at a water flow velocity of 1.2 bl / s. Moderate water flow velocity provides the rainbow trout with sufficient exercise stimulation, promoting gene expression related to the growth and development of pigment cells such as iris cells, and better reflecting external light sources, thus contributing to improved body color. Excessive water flow velocity has the opposite effect on silvering, possibly because the higher flow velocity forces the rainbow trout under stronger exercise stress, producing stress and affecting body color changes.

[0076] Example 5:

[0077] This embodiment, based on the above embodiments, further verifies the effect of water flow velocity on rainbow trout muscle growth, specifically by conducting the following experiments:

[0078] (1) Experimental materials

[0079] Same as the above embodiments.

[0080] (2) Experimental procedure

[0081] Different rearing ponds have their water flow rates regulated by water pumps. One pond uses natural water flow, another has a flow rate of 1.2 bl / s, and the third has a flow rate of 2.4 bl / s. Water flow control is stopped during feeding times (9:00-11:00 and 18:00-20:00) to keep the water still for rainbow trout to feed. All rearing conditions are identical and conducted in an indoor rearing facility.

[0082] The other breeding processes were the same as those provided in Example 1. Finally, the changes in the cross-sectional area of ​​rainbow trout muscle fibers in each breeding pond were measured. The results are shown in Figure 1.

[0083] (3) Experimental conclusions

[0084] As shown in Figure 1, the cross-sectional area of ​​rainbow trout muscle fibers increases significantly at a water flow rate of 1.2 bl / s. At a water flow rate of 2.4 bl / s, the promoting effect on the increase in muscle fiber cross-sectional area is less pronounced than at a flow rate of 1.2 bl / s.

[0085] Example 6:

[0086] Based on the experimental results of the above embodiments, this embodiment provides a complete method for regulating the silvering of rainbow trout body color, as follows:

[0087] Install purple-red LED lights with a power of no less than 5 watts / square meter and an illuminance of 1500 Lx above the rainbow trout rearing pond. Simultaneously, regulate the water flow rate in the pond to 1.2 bl / s using a water pump. Maintain dissolved oxygen levels of 7-8 mg / L, temperature of 16-18℃, pH of 6.5-6.8, and ammonia nitrogen content no greater than 0.0075 mg / L in the pond. Illuminate the rainbow trout in the pond with purple-red LED light for 12 hours daily. Stop controlling the water flow during feeding times of 9:00-11:00 and 18:00-20:00 daily to keep the water still for optimal feeding. Feed the trout twice daily with standard commercial feed. After at least thirty days of this rearing process, harvest the rainbow trout.

[0088] The body color of rainbow trout before cultivation is shown in Figure 2, and the body color of rainbow trout after cultivation is shown in Figure 3.

[0089] It is evident that by installing a purplish-red LED light source to alter the number and arrangement of pigment cell clusters in the rainbow trout's skin through light color, and by controlling the water flow rate to create a movement effect, the silvering of the rainbow trout's body color can be regulated significantly, noticeably improving the rainbow trout's appearance and increasing its economic value.

[0090] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for regulating the silvering of rainbow trout body color, characterized in that, Rainbow trout should be cultured for at least thirty days using at least one of the following two methods before harvesting: (1) Install LED light sources above the rainbow trout breeding pond to change the color of the water in the breeding pond; (2) Install water pumps in rainbow trout breeding ponds to change the water flow rate in the breeding ponds.

2. The method for regulating the silvering of rainbow trout body color according to claim 1, characterized in that, In measure (1), the color of the purple-red LED light source installed above the rainbow trout breeding pond is at least one of red, blue, purple, and purple-red.

3. The method for regulating the silvering of rainbow trout body color according to claim 1 or 2, characterized in that, In measure (1), the illuminance of the LED light source installed above the rainbow trout breeding pond is 1000LX to 2000LX.

4. A method for regulating the silvering of rainbow trout body color according to claim 1 or 2, characterized in that, In measure (1), the lighting power of the LED light source installed above the rainbow trout breeding pond shall not be less than 5W / m. 2 .

5. A method for regulating the silvering of rainbow trout body color according to claim 1 or 2, characterized in that, In measure (1), the LED light source installed above the rainbow trout breeding pond provides illumination for 12 hours a day.

6. A method for regulating the silvering of rainbow trout body color according to claim 1 or 2, characterized in that, In measure (2), a water pump is installed in the rainbow trout breeding pond to make the water flow velocity in the breeding pond 1.2bl / s to 2.4bl / s.

7. A method for regulating the silvering of rainbow trout body color according to claim 1 or 2, characterized in that, In measure (2), the water pump installed in the rainbow trout breeding pond operates for 20 hours a day.

8. A method for regulating the silvering of rainbow trout body color according to claim 1 or 2, characterized in that, The internal volume of the rainbow trout breeding pond is 283m³. 3 Each breeding pond is stocked with 100 healthy rainbow trout that meet market size.

9. A method for regulating the silvering of rainbow trout body color according to claim 1 or 2, characterized in that, The breeding parameters in the rainbow trout breeding pond are: dissolved oxygen 7 mg / L to 8 mg / L, temperature 16℃ to 18℃, pH 6.5 to 6.8, and ammonia nitrogen content not exceeding 0.0075 mg / L.

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