Method and device for inducing and domesticating bias swimming ability of large yellow croaker

Abstract

The invention discloses a method and a device for inducing and domesticating bias swimming ability of large yellow croakers, and belongs to the technical field of marine biological resource conservation. The device comprises a lateral swimming ability induction domestication water tank; a T-shaped domestication swim lane is arranged in the domestication area and comprises a starting arm, a left arm area, a right arm area, a left fish collection area and a right fish collection area, wherein the left arm area and the right arm area are located on the two sides of the starting arm respectively. The left arm area and the right arm area are provided with first movable doors used for being communicated with or separated from the corresponding fish collecting areas respectively. A second movable door communicated with or separated from the temporary culture area is arranged on the starting arm; the flow generation area is provided with a flow generator and a flow equalizing pore plate, and the flow equalizing pore plate is arranged at the end part, far away from the temporary culture area, of the starting arm. The invention further provides a corresponding induction and domestication method, after the released juvenile fish is domesticated for a period of time, the lateral swimming capacity of the released juvenile fish in a natural sea area is improved, the predation efficiency of the released juvenile fish is improved, the predation risk of the released juvenile fish is reduced, and therefore the survival rate of the released juvenile fish is increased.

Description

Technical Field

[0001] The invention relates to the technical field of marine biological resource conservation, and in particular to a method and a device for inducing and domesticating the lateralized swimming ability of large yellow croaker. Background Art

[0002] Marine fish are a key component of marine biodiversity and play an important role in maintaining the marine food chain and ecological balance. Marine fish are also high-quality protein resources for humans, and are related to the food supply and security of human social development. Due to climate change and overfishing, marine fish natural resources are facing a situation of continuous decline, among which large yellow croaker is the most seriously declining marine fish. Large yellow croaker (Larimichthys crocea) is the most important marine economic fish in my country, with high economic and ecological value. A large number of large yellow croakers have been released in the southeast coast of my country. However, at present, wild large yellow croakers still cannot form a large-scale resource. Restoring and rebuilding large yellow croaker resources in natural sea areas has also become a hot topic of concern for national and local governments.

[0003] The fish seedlings released for reproduction are all obtained through artificial breeding, and the survival rate of the seedlings is improved through an ideal artificially controllable environment, such as regular feeding and no risk of predation. However, after the fry are released into the natural sea, there are many uncertainties in their living environment. In order to improve the survival rate of the released fry in the natural sea, it is necessary to enhance their ability to prey and escape from enemies. There is no method or device for inducing and domesticating the lateralized swimming ability of large yellow croaker in the current prior art. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems in the prior art and provide a method and device for inducing and domesticating the lateralized swimming ability of large yellow croaker. After a period of domestication in the device of the present invention, the released large yellow croaker fry can improve their lateralized swimming ability in natural sea areas, improve their predation efficiency, and reduce the risk of being preyed on, thereby improving the survival rate after release.

[0005] The device for inducing and taming the lateralized swimming ability of large yellow croaker of the present invention comprises a lateralized swimming ability inducing taming water tank, wherein the lateralized swimming ability inducing taming water tank comprises independently separated temporary rearing areas and taming areas in sequence along the length direction;

[0006] A T-shaped acclimation swimming lane is provided in the acclimation area, and the T-shaped acclimation swimming lane includes a starting arm and a left arm area and a right arm area respectively located on both sides of the starting arm. The left arm area, the starting arm and the inner wall of the lateralized swimming ability inducing acclimation water tank of the acclimation area form a left fish gathering area, and the right arm area, the starting arm and the inner wall of the lateralized swimming ability inducing acclimation water tank form a right fish gathering area. The left arm area and the right arm area are respectively provided with first movable doors for connecting or separating with their respective corresponding fish gathering areas; the starting arm is provided with a second movable door for connecting or separating with the temporary holding area.

[0007] As a preferred embodiment, the length of the starting arm is at least 4 times the length of the fish body, and the width of the starting arm is at least 2 times the length of the fish body.

[0008] As a preferred embodiment, the widths of the left arm region and the right arm region are the same as the width of the starting arm.

[0009] As a preferred embodiment, the starting arm is 60 cm long and 30 cm wide.

[0010] As a preferred embodiment, a flow-making area is further provided on the side of the acclimation area away from the temporary breeding area, the flow-making area is provided with a flow maker, and a flow-equalizing orifice plate is provided at the end of the starting arm away from the temporary breeding area to form a uniform flow field in the starting arm.

[0011] As a preferred embodiment, the flow maker is a power-adjustable flow maker to meet the flow-seeking characteristics of large yellow croaker fry at different stages.

[0012] The present invention also discloses a method for inducing and domesticating the lateralized swimming ability of the large yellow croaker, which comprises: constructing a water tank for domesticating the lateralized swimming ability of the fish;

[0013] Construct a device to induce and train lateralized swimming ability;

[0014] Inducing lateralized swimming behavior; during induction, the yellow croaker fry is introduced into the starting arm of the T-shaped domestication swimming lane. Under the stimulation of the water flow, the yellow croaker fry swims forward upstream along the water flow of the starting arm. When it swims to the selection area between the left arm area and the right arm area, it cannot continue to move forward, so it must turn left or right and swim to the left arm area and the right arm area; without any external stimulation, the yellow croaker fry is induced to freely choose to swim left or right into the left arm area or the right arm area in the selection area. Once the yellow croaker fry enters the left arm area and the right arm area, the movable door of the corresponding fish gathering area is opened, and the yellow croaker fry is introduced into the fish gathering area, and one lateralized swimming behavior domestication is completed;

[0015] After 10 trainings, if the same yellow croaker fry swims in the same direction 8 to 10 times, it is considered to have lateralized swimming ability.

[0016] The lateralized swimming ability of large yellow croaker fry is subjected to lateralized domestication until at least 60% of the large yellow croaker fry in the fish school show the same lateralized characteristics as those induced by the lateralization, thus completing the induction and domestication of the lateralized swimming ability of large yellow croaker.

[0017] As a preferred method, the lateralized swimming ability is characterized by the endogenous lateralization index Li:

[0018] Li=[ / ]*100%; when │Li│≥60%, it indicates that the fry has the ability of lateralization, Li>0 indicates right lateralization, and Li<0 indicates left lateralization.

[0019] As a preferred method, when performing lateralized domestication on young yellow croakers with lateralized swimming ability, the width of the left arm area and the right arm area of ​​the T-shaped domestication swimming lane is doubled, a discrimination midline is set at the middle position of the bottom of the left arm area and the right arm area, and a net cage is set in front of the flow generator, and a ferocious predator fish is set in the net cage;

[0020] When the domesticated large yellow croaker fry swims forward to the judgment center line, if it continues to swim forward and crosses the judgment center line and reaches the vicinity of the net cage, it is considered a failure and is directly fished out, punished with a few seconds of air exposure, and then moved to a new temporary holding pond;

[0021] If the large yellow croaker fry during domestication turns sideways and swims into the left arm area or the right arm area before reaching the discrimination midline, the large yellow croaker fry will be introduced into the corresponding fish gathering area; according to the results of the above-mentioned lateralization induction, the large yellow croaker fry with the same induction results will be fed with bait as a reward, while the large yellow croaker fry with the opposite results will not be rewarded with bait; thereafter, all the large yellow croaker fry will be moved back to the temporary holding area, and after 1 day of adaptation, they will be domesticated again; the domestication will be repeated until at least 80% of the large yellow croaker fry show the same lateralization characteristics as those caused by the lateralization induction.

[0022] Compared with the prior art, the beneficial effect of the present invention is that the device for inducing and taming the lateralized swimming ability of released yellow croaker fry of the present invention comprises an taming area and a temporary rearing area, and a T-shaped taming swimming lane is designed in the taming area. When the yellow croaker fry swims upstream with the starting arm to the selection area, it has to make a choice of left or right. After multiple induction and taming, the lateralized swimming ability of the yellow croaker fry can be effectively improved.

[0023] In terms of the induction and domestication methods, the present invention first performs lateralization induction domestication on large yellow croaker fry until the large yellow croaker fry exhibits lateralization ability, and then performs lateralization ability training under predation pressure. By comparing the lateralization ability domestication results under predation pressure with the calculation results of the endogenous lateralization index Li, the effectiveness of the lateralization ability domestication under predation pressure is improved.

[0024] The device for inducing and taming the lateralized swimming ability of juvenile yellow croaker of the present invention is used to effectively taming the lateralized swimming ability of released juvenile yellow croaker, significantly improving the lateralized swimming ability of juvenile yellow croaker in natural sea areas, improving its predation efficiency, and reducing the risk of being preyed on, thereby improving the survival rate after release. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a lateralized swimming ability training tank according to an embodiment of the present invention.

[0026] Figure 2 Schematic diagram of the structure of a T-shaped acclimation swimming lane in an embodiment of the present invention.

[0027] Figure 3 It is a schematic structural diagram of a lateralized swimming ability acclimation tank during predation pressure acclimation according to an embodiment of the present invention.

[0028] Figure 4 The lateralization index results of 50 large yellow croaker fry in the embodiment of the present invention;

[0029] Figure 5 The embodiment of the present invention is the result of domestication of large yellow croaker fry to form endogenous lateralized physiological characteristics.

[0030] Description of reference numerals:

[0031] 1. Lateralized swimming ability acclimatization tank, 11. Temporary holding area, 12. Acclimatization area, 13. Flow-making area, 2. T-shaped acclimatization swimming lane, 21. Starting arm, 22. Left arm area, 23. Right arm area, 24. Left fish gathering area, 25. Right fish gathering area, 26. First movable gate, 27. Second movable gate, 3. Flow maker, 4. Flow equalizing orifice plate. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0033] Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with ordinary skills in the field to which the present disclosure belongs. "First", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of "including" or "comprising" cover the elements or objects listed after "including" or "comprising" and their equivalents, and do not exclude other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0034] The rapid "C"-shaped lateralized swimming behavior of yellow croaker is the most effective behavior for predation and escape from prey. Accurate and rapid lateralized attack on prey or lateralized escape to reduce predation (quickly turning to the left or right) can greatly improve the survival rate of released yellow croaker fry. Therefore, it is necessary to develop corresponding methods to improve the lateralized swimming ability of yellow croaker fry and improve the survival rate and proliferation effect of yellow croaker fry after proliferation and release.

[0035] In order to acclimate the lateralized swimming ability of young yellow croaker, the present embodiment designs a lateralized swimming ability induction acclimatization water tank 1, which comprises a temporary holding area 11 and an acclimatization area 12, wherein the acclimatization area 12 comprises a T-shaped acclimatization swimming lane 2 and a left fish gathering area and a right fish gathering area. As an example, for example, the width of the lateralized swimming ability induction acclimatization water tank 1 can be 3m; the present embodiment designs the temporary holding area and the induced acclimatization together, which can reduce the stress response of the fish transfer process.

[0036] The temporary rearing area 11 and the acclimation area 12 are separated by a second movable door 27. The T-shaped acclimation swimming lane 2 comprises a starting arm 21, a left arm area 22, a right arm area 23 and a middle selection area. The protruding part of the starting arm 21 is 60 cm long and 30 cm wide, which is 15 cm of 4 times and 2 times the length of the fish body respectively. If the length of the fish body changes, the size will be changed accordingly. The critical swimming speed of the large yellow croaker fry is 2-3.1 times the body length. In order to ensure the adaptability in the starting arm and reduce the stress response, the minimum setting is 4 times the body length, and if conditions permit, it is as long as possible. The width of 2 times the body length is to ensure that the fish is not restricted when turning around in the starting arm. The left arm area 22 and the right arm area 23 of the acclimation swimming lane are both 30 cm wide and 130 cm long. The width of the left arm area 22 and the right arm area 23 is the same as that of the starting arm 21. The same width improves adaptability. The left arm area 22 and the right arm area 23 are both provided with movable doors to communicate with the left fish gathering area and the right fish gathering area. A flow generator 3 is set in front of the starting arm 21, and a uniform flow field is formed in the starting arm 21 through a uniform opaque perforated plate. By adjusting the power of the flow generator 3, the water flow speed generated can achieve upstream swimming of large yellow croaker.

[0037] During induction, the second movable door 27 is opened, and a yellow croaker fry in the temporary rearing area 11 is introduced into the starting arm 21 of the T-shaped swimming lane. Under the stimulation of the water flow, the yellow croaker fry swims forward upstream along the water flow of the starting arm 21. When the yellow croaker fry swims to the selection area, it cannot continue to move forward, so it must turn left or right and swim to the left arm area 22 or the right arm area 23. In the absence of any external stimulation, the yellow croaker fry is induced to freely choose to swim left or right into the left arm area 22 or the right arm area 23 in the selection area. Once the yellow croaker fry enters the left arm area 22 or the right arm area 23, the movable door of the fish gathering area is opened to introduce the yellow croaker fry into the fish gathering area, and the domestication of lateralized swimming behavior is completed. Figure 1 As shown, the arrow is a schematic diagram of the swimming direction of the fish.

[0038] After 10 domestications, if the same yellow croaker fry swims in the same direction 8 to 10 times, it is considered to have lateralized swimming ability and is characterized by the endogenous lateralization index Li:

[0039] Li = [number of times you swam to the right - number of times you swam to the left / number of times you swam to the right + number of times you swam to the left] * 100%;

[0040] When │L i│≥60%, it means that the large yellow croaker fry has the ability of lateralization, Li>0 indicates right lateralization, and Li<0 indicates left lateralization;

[0041] In this embodiment, by recording the induction results of 50 large yellow croaker fry, it was found that 34% (17 / 50) of the fish were left-lateralized and 4% (2 / 50) were right-lateralized; after inducing large yellow croaker fry with the induction and acclimation device and method of this embodiment, it was found that the large yellow croaker fry had obvious left-lateralized behavioral characteristics.

[0042] like Figure 4 The following table shows the lateralization index results of 50 large yellow croaker juveniles. An index greater than 0.6 indicates lateralization. A positive number indicates right lateralization, and a negative number indicates left lateralization. Figure 4 The case where the lateralization index is 0 is included. There is no bar graph when the lateralization index is 0. The specific data of the lateralization index results of 50 large yellow croaker juveniles are shown in Table 1:

[0043] Table 1

[0044]

[0045]

[0046]

[0047] Lateralized swimming ability training under predation pressure: The width of the left arm area 22 and the right arm area 23 of the T-shaped training lane 2 is doubled, a judgment center line is set at the middle position of the bottom of the left arm area 22 and the right arm area 23, and a net cage is set in front of the flow generator 3, and a ferocious predator fish, such as an adult black sea bream, is set in the net cage. When the yellow croaker fry swims forward to the boundary of the virtual selection area of ​​the judgment center line, if it continues to swim forward directly after crossing the judgment center line and reaches the vicinity of the net cage, it is considered to have failed and been preyed on, and is directly fished out, punished by air exposure for a few seconds, and then moved to a temporary holding pond. If it turns sideways and swims into the left or right arm area, the yellow croaker fry is introduced into the left arm area 22 or the right arm area 23. According to the results of the above lateralized induction, the yellow croaker fry with the same induction results are given bait feeding as a reward, while the yellow croaker fry with the opposite results are not given bait feeding rewards. Afterwards, all the yellow croaker fry were re-transferred to the temporary rearing area 11, adapted for 1 day, and then acclimated again. The acclimation was repeated until 60% of the yellow croaker fry showed the same lateralization characteristics as those induced by lateralization.

[0048] The method can be directly applied to the domestication of a single large yellow croaker fry or any number of groups. At the same time, the domestication tank of the present embodiment can also be replaced with a cage of the same structure and directly used for domestication at sea to improve the lateralized swimming ability of the large yellow croaker fry to avoid enemies after proliferation and release.

[0049] like Figure 5As shown, the ordinate represents the number of experimental days, and the abscissa represents the lateralization index of large yellow croaker fry. In this embodiment, 10 fish are grouped together. In this embodiment, when 80% of the fish enter the left side, it is considered that the domestication is successful. From the 16th day, the fish group begins to show obvious left lateralized cluster swimming behavior. The experimental results show that by artificially domesticating large yellow croaker fry to form endogenous lateralized physiological characteristics, the rapid response of fry when encountering enemies can be improved. Specific data are shown in Table 2:

[0050] Table 2

[0051]

[0052]

[0053] As a more preferred method, in the early stage of domestication, an artificial disturbance can be directly applied to the right side, such as underwater noise, to reduce the number of fish entering the right side, thereby quickly improving the domestication effect of left-lateralized swimming ability.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for inducing and domesticating the lateralized swimming ability of large yellow croaker, characterized in that: The invention comprises a lateralized swimming ability inducing acclimation water tank (1), wherein the lateralized swimming ability inducing acclimation water tank (1) comprises independently separated temporary holding areas (11) and acclimation areas (12) in sequence along the length direction; a T-shaped acclimation swimming lane (2) is arranged in the acclimation area (12), and the T-shaped acclimation swimming lane (2) comprises a starting arm (21) and a left arm area (22) and a right arm area (23) respectively located on both sides of the starting arm (21); the left arm area (22), the starting arm (21) and the right arm area (23) of the acclimation area (12) The inner wall of the lateralized swimming ability induction acclimation water tank (1) encloses a left fish collection area (24); the right arm area (23), the starting arm (21) and the inner wall of the lateralized swimming ability induction acclimation water tank (1) enclose a right fish collection area (25); the left arm area (22) and the right arm area (23) are respectively provided with a first movable door (26) for connecting with or separating from the corresponding fish collection area; the starting arm (21) is provided with a second movable door (27) for connecting with or separating from the temporary rearing area (11).

2. The device for inducing and taming the lateralized swimming ability of large yellow croaker as claimed in claim 1, characterized in that: The length of the starting arm (21) is at least 4 times the length of the fish body, and the width of the starting arm (21) is at least 2 times the length of the fish body.

3. The device for inducing and taming the lateralized swimming ability of large yellow croaker as claimed in claim 1, characterized in that: The widths of the left arm region (22) and the right arm region (23) are the same as the width of the starting arm.

4. The device for inducing and taming the lateralized swimming ability of large yellow croaker as claimed in claim 2, characterized in that: The starting arm (21) is 60 cm long and 30 cm wide.

5. The device for inducing and taming the lateralized swimming ability of large yellow croaker as claimed in claim 1, characterized in that: A flow-making area (13) is also provided on the side of the acclimation area (12) away from the temporary rearing area (11), and the flow-making area (13) is provided with a flow generator (3). An equalizing orifice plate (4) is provided at the end of the starting arm (21) away from the temporary rearing area (11) to form a uniform flow field in the starting arm (21).

6. The device for inducing and taming the lateralized swimming ability of large yellow croaker as claimed in claim 5, characterized in that: The flow generator (3) is a flow generator with adjustable power, so as to meet the flow-seeking characteristics of large yellow croaker fry at different stages.

7. A method for inducing and taming the lateralized swimming ability of large yellow croaker using the device for inducing and taming the lateralized swimming ability of large yellow croaker as claimed in claim 1, characterized in that: include: Construct the device for inducing and taming lateralized swimming ability according to claim 1; Inducing lateralized swimming behavior; during induction, the yellow croaker fry is introduced into the starting arm (21) of the T-shaped domestication swimming lane (2); under the stimulation of the water flow, the yellow croaker fry swims forward upstream along the water flow of the starting arm (21); when it reaches the selection area between the left arm area (22) and the right arm area (23), it cannot continue to move forward and must turn left or right to swim to the left arm area (22) and the right arm area (23); in the absence of any external stimulation, the yellow croaker fry is induced to freely choose to swim left or right into the left arm area (22) or the right arm area (23) in the selection area; once the yellow croaker fry enters the left arm area (22) and the right arm area (23), the movable door of the corresponding fish gathering area is opened, and the yellow croaker fry is introduced into the fish gathering area, and the domestication of lateralized swimming behavior is completed; After 10 trainings, if the same yellow croaker fry swims in the same direction 8 to 10 times, it is considered to have lateralized swimming ability. The lateralized swimming ability of large yellow croaker fry is subjected to lateralized domestication until at least 60% of the large yellow croaker fry in the fish school show the same lateralized characteristics as those induced by the lateralization, thus completing the induction and domestication of the lateralized swimming ability of large yellow croaker.

8. The method for inducing and taming the lateralized swimming ability of large yellow croaker as claimed in claim 7, characterized in that: The lateralized swimming ability is characterized by the endogenous lateralization index Li: Li=[(number of times it swims to the right-number of times it swims to the left) / (number of times it swims to the right+number of times it swims to the left)]*100%; when │Li│≥60%, it indicates that the fry has the ability of lateralization, Li>0 indicates right lateralization, and Li<0 indicates left lateralization.

9. The method for inducing and taming the lateralized swimming ability of large yellow croaker as claimed in claim 7, characterized in that: When performing lateralized domestication on young yellow croaker fish with lateralized swimming ability, the widths of the left arm area (22) and the right arm area (23) of the T-shaped domestication swimming lane (2) are doubled, a discrimination center line is set at the middle position of the bottom of the left arm area (22) and the right arm area (23), and a net cage is set in front of the flow generator (3), and a ferocious predator fish is set in the net cage; When the domesticated large yellow croaker fry swims forward to the judgment center line, if it continues to swim forward and crosses the judgment center line and reaches the vicinity of the net cage, it is considered a failure and is directly fished out, punished with a few seconds of air exposure, and then moved to the temporary holding area (11); If the large yellow croaker fry being domesticated turns sideways and swims into the left arm area (22) or the right arm area (23) before reaching the discrimination midline, the large yellow croaker fry is introduced into the corresponding fish gathering area; based on the result of the above-mentioned lateralization induction to determine the left or right deviation, the large yellow croaker fry with the same induction result is fed with bait as a reward, while the large yellow croaker fry with the opposite result is not fed with bait as a reward; then all the large yellow croaker fry are moved back to the temporary holding area (11), adapted for 1 day, and then domesticated again; the domestication is repeated until at least 60% of the large yellow croaker fry show the same lateralization characteristics as the lateralization induction.

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