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

Abstract

The application discloses a method and device for inducing and domesticating the swimming ability of one-side of large yellow croaker, and belongs to the technical field of marine biological resource conservation. The application comprises a water tank for inducing and domesticating the swimming ability of one-side of large yellow croaker; a T-shaped domestication swimming channel is arranged in the domestication area, the T-shaped domestication swimming channel comprises a starting arm and left and right arm areas respectively arranged on both sides of the starting arm, a left fish gathering area and a right fish gathering area; first movable doors for communicating with or separating the left and right arm areas from the corresponding fish gathering areas are respectively arranged on the left and right arm areas; a second movable door for communicating with or separating the starting arm from a temporary breeding area is arranged on the starting arm; a flow maker and a flow equalizing orifice plate are arranged in a flow making area, and the end of the starting arm away from the temporary breeding area is provided with the flow equalizing orifice plate. The application also provides corresponding inducing and domesticating methods. The device of the application can improve the swimming ability of one-side of large yellow croaker in natural sea areas after the juvenile fish is released and domesticated for a period of time, so that the predation efficiency of the juvenile fish is improved, the risk of being preyed on is reduced, and the survival rate after release is improved.

Description

Technical Field

[0001] This invention relates to the field of marine biological resource conservation technology, specifically to a method and apparatus for inducing and training the lateral swimming ability of large yellow croaker. Background Technology

[0002] Marine fish are a key component of marine biodiversity, playing a vital role in maintaining the marine food chain and ecological balance. They are also a high-quality protein resource for humans, impacting food supply and security for human society. Due to climate change and overfishing, marine fish resources are facing continuous decline, with the large yellow croaker being one of the most severely affected species. The large yellow croaker (Larimichthys crocea) is one of my country's most important marine economic fish species, possessing high economic and ecological value.

[0003] Fish fry released for stock enhancement are all obtained through artificial breeding, with survival rates improved through artificially controlled ideal environments such as timed feeding and freedom from predation. However, once released into natural marine environments, the fry face numerous uncertainties in their survival. To enhance their survival rate in natural waters, it is essential to strengthen their predator-hunting and predator-avoidance abilities. Currently, there are no methods or devices for inducing and training large yellow croaker to swim laterally. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems in the prior art and provide a method and apparatus for inducing and training the lateral swimming ability of large yellow croaker. This allows released juvenile large yellow croaker to undergo a period of training within the apparatus of this invention, thereby improving their lateral swimming ability in natural sea areas, increasing their predation efficiency, reducing the risk of predation, and ultimately improving their survival rate after release.

[0005] The present invention provides a device for inducing and acclimatizing the lateral swimming ability of large yellow croaker, comprising a lateral swimming ability induction and acclimatization tank, wherein the lateral swimming ability induction and acclimatization tank comprises, along its length, an independently separated temporary holding area and an acclimatization area.

[0006] The acclimatization area is equipped with a T-shaped acclimatization lane, which includes a starting arm and a left arm area and a right arm area located on both sides of the starting arm. The left arm area, the starting arm, and the inner wall of the lateral swimming ability induction acclimatization tank of the acclimatization area form a left fish collection area, and the right arm area, the starting arm, and the inner wall of the lateral swimming ability induction acclimatization tank form a right fish collection area. The left arm area and the right arm area are respectively provided with a first movable door for communicating with or separating from their respective fish collection areas; the starting arm is provided with a second movable door for communicating with or separating from the temporary holding area.

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

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

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

[0010] As a preferred embodiment, the acclimatization zone is further provided on the side away from the temporary holding zone, the flow-generating zone is provided with a flow generator, and the end of the starting arm away from the temporary holding zone is provided with a flow equalization orifice plate to form a uniform flow field within the starting arm.

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

[0012] The present invention also discloses a method for inducing and acclimatizing the lateral swimming ability of the large yellow croaker, the method comprising: constructing a lateral swimming ability acclimatization tank for the fish.

[0013] Construct a device for inducing and training lateral swimming ability;

[0014] Lateral swimming behavior induction was performed. During induction, juvenile large yellow croakers were introduced into the starting arm of the T-shaped training lane. Stimulated by the water flow, the juvenile large yellow croakers swam upstream along the water flow of the starting arm. When they reached the selection area between the left and right arm areas, they could not continue forward and had to turn left or right to swim into the left or right arm areas. Without any external stimulation, the juvenile large yellow croakers were induced to freely choose to swim to the left or right arm areas in the selection area. Once the juvenile large yellow croakers entered the left or right arm areas, the activity gate of the corresponding fish gathering area was opened, and the juvenile large yellow croakers were introduced into the fish gathering area. One lateral swimming behavior training session was completed.

[0015] If a juvenile large yellow croaker swims sideways in the same direction 8-10 times after 10 acclimatizations, it is considered to have the ability to swim sideways.

[0016] Lateralization training was conducted on juvenile large yellow croaker with lateralization swimming ability until at least 60% of the juvenile large yellow croaker in the fish group showed the same lateralization characteristics as those induced by lateralization. This completed the induction and training of lateralization swimming ability in large yellow croaker.

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

[0018] Li = [ / ] * 100%; When |Li| ≥ 60%, it indicates that the juvenile large yellow croaker has lateralization ability. Li > 0 indicates right lateralization, and Li < 0 indicates left lateralization.

[0019] As a preferred method, when acclimatizing juvenile large yellow croaker with lateral swimming ability, the width of the left and right arm areas of the T-shaped acclimatization channel is doubled, a discrimination midline is set at the middle position of the bottom of the left and right arm areas, and a net cage is set in front of the flow generator, with ferocious predator fish inside the net cage.

[0020] When the domesticated juvenile large yellow croaker swims forward to the midline of identification, if it continues to swim forward and crosses the midline to reach the vicinity of the net cage, it is considered a failure and is immediately scooped out. After being punished with a few seconds of air exposure, it is transferred to a new temporary holding pond.

[0021] If the juvenile large yellow croakers in the domestication process turn sideways and swim into the left or right arm area before reaching the midline, they are introduced into the corresponding fish gathering area. Based on the results of the lateralization induction, the juvenile large yellow croakers with the same induction results are given food as a reward, while those with the opposite results are not given food as a reward. Afterward, all the juvenile large yellow croakers are moved back to the temporary holding area and allowed to adapt for 1 day before being domesticated again. The domestication is repeated until at least 80% of the juvenile large yellow croakers exhibit the same lateralization characteristics as those induced by lateralization.

[0022] Compared with the prior art, the beneficial effects of the present invention are: the device for inducing and acclimatizing the lateral swimming ability of released juvenile large yellow croaker includes an acclimatization area and a temporary holding area, and a T-shaped acclimatization lane is designed in the acclimatization area. When the juvenile large yellow croaker swims upstream to the selection area at the starting arm, it has to make a choice to go left or right. After repeated induction and acclimatization, the lateral swimming ability of the juvenile large yellow croaker can be effectively improved.

[0023] In terms of induction and domestication methods, this invention first induces and domesticates lateralization in juvenile large yellow croaker until the juvenile large yellow croaker exhibits lateralization ability, and then trains lateralization ability under predation pressure. By comparing the domestication results of lateralization ability under predation pressure with the calculation results of the endogenous lateralization index Li, the effectiveness of lateralization ability domestication under predation pressure is improved.

[0024] The device for inducing and training the lateral swimming ability of juvenile large yellow croaker of the present invention is used to effectively train the lateral swimming ability of released juvenile fish, significantly improve the lateral swimming ability of juvenile large yellow croaker in natural sea areas, improve their predation efficiency, reduce the risk of being preyed upon, and thus improve the survival rate after release. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the lateral swimming ability training tank according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the T-shaped training lane according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the structure of the lateral swimming ability training tank during predation pressure training according to an embodiment of the present invention.

[0028] Figure 4 The results of lateralization index of 50 juvenile large yellow croakers in this embodiment of the invention;

[0029] Figure 5 This is the result of the domestication of juvenile large yellow croaker to form endogenous lateralization physiological characteristics in an embodiment of the present invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Lateral swimming ability training tank, 11. Temporary holding area, 12. Training area, 13. Current generation area, 2. T-shaped training lane, 21. Starting arm, 22. Left arm area, 23. Right arm area, 24. Left fish collection area, 25. Right fish collection area, 26. First movable gate, 27. Second movable gate, 3. Current generator, 4. Flow equalization plate. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0033] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly.

[0034] The rapid "C"-shaped lateral swimming behavior of the large yellow croaker is the most effective way to hunt and escape predation. Accurate and rapid lateral attack on prey or lateral escape to reduce predation (quickly choosing to turn left or right) can greatly improve the survival rate of released juvenile large yellow croaker. Therefore, it is necessary to develop corresponding methods to improve the lateral swimming ability of juvenile large yellow croaker, thereby enhancing their survival rate and propagation effect after stock enhancement.

[0035] To cultivate the ability of juvenile large yellow croaker to swim laterally, this embodiment designs a lateral swimming ability induction and training tank 1. This tank 1 includes a temporary holding area 11 and a training area 12, wherein the training area 12 includes a T-shaped training lane 2, a left fish collection area, and a right fish collection area. As an example, the width of this lateral swimming ability induction and training tank 1 can be 3m. This embodiment combines the temporary holding area and the training area to reduce stress during fish transfer.

[0036] The temporary holding area 11 and the acclimatization area 12 are separated by a second active gate 27. The T-shaped acclimatization lane 2 includes an initial arm 21, a left arm area 22, a right arm area 23, and a central selection area. The protruding part of the initial arm 21 is 60cm long and 30cm wide, which are 4 times and 2 times the fish's body length, respectively (15cm). If the fish's body length changes, the dimensions must be adjusted accordingly. The critical swimming speed for juvenile large yellow croaker is 2-3.1 times its body length. To ensure adaptability within the initial arm and reduce stress response, the minimum speed is set to 4 times the body length, and it should be as long as possible if conditions permit. The width of 2 times the body length ensures that the fish is not restricted when turning direction within the initial arm. The left arm section 22 and right arm section 23 of the training lane are both 30cm wide and 130cm long. The width of the left arm section 22 and right arm section 23 is the same as that of the starting arm 21. The same width improves adaptability. Both the left arm section 22 and right arm section 23 are equipped with movable gates that connect to the left and right fish gathering areas, respectively. A flow generator 3 is installed directly in front of the starting arm 21, and a uniform flow field is formed within the starting arm 21 through a uniform opaque perforated plate. By adjusting the power of the flow generator 3, the generated water flow speed can be adjusted to enable the large yellow croaker to swim upstream.

[0037] During induction, the second active gate 27 opens, introducing a juvenile large yellow croaker from the temporary holding area 11 into the starting arm 21 of the T-shaped swimming lane. Stimulated by the water flow, the juvenile swims upstream along the current of the starting arm 21. When the juvenile reaches the selection area, unable to continue forward, it must turn left or right to swim to the left arm area 22 or the right arm area 23. Without any external stimulation, the juvenile is induced to freely choose to swim left or right into the left arm area 22 or the right arm area 23 within the selection area. Once the juvenile enters the left arm area 22 or the right arm area 23, the active gate of the fish collection area is opened, introducing the juvenile into the fish collection area, thus completing one cycle of lateral swimming behavior training. Figure 1As shown, the arrows indicate the direction of the fish's swimming.

[0038] If a juvenile large yellow croaker exhibits lateral swimming in the same direction 8-10 times after 10 domestication cycles, it is considered to have lateral swimming ability, which is characterized by the endogenous lateralization index Li.

[0039] Li = [Number of swims to the right - Number of swims to the left / Number of swims to the right + Number of swims to the left] * 100%;

[0040] When |Li|≥60%, it indicates that the juvenile large yellow croaker has lateralization ability. Li>0 indicates right lateralization, and Li<0 indicates left lateralization.

[0041] This embodiment recorded the induction results of 50 juvenile large yellow croakers and found that 34% (17 / 50) of the fish were lateralized to the left and 4% (2 / 50) were lateralized to the right. After inducing the juvenile large yellow croakers with the induction and domestication device and method of this embodiment, it was found that the juvenile large yellow croakers had obvious left lateralization behavior characteristics.

[0042] like Figure 4 The image shows the lateralization index results for 50 juvenile large yellow croakers. An index greater than 0.6 indicates lateralization. Positive numbers indicate right lateralization, and negative numbers indicate left lateralization. It should be noted that... Figure 4 This includes cases where the lateralization index is 0, for which there is no bar chart. Specific data on the lateralization index of 50 juvenile large yellow croakers are shown in Table 1.

[0043] Table 1

[0044]

[0045] Lateralization swimming ability training under predation pressure: The width of the left arm zone 22 and right arm zone 23 of the T-shaped training lane 2 is doubled. A discrimination midline is set at the middle position of the bottom of the left arm zone 22 and right arm zone 23. A net cage is placed in front of the flow generator 3, containing predatory fish such as adult black sea bream. When the juvenile large yellow croaker swims forward to the boundary of the virtual selection area of ​​the discrimination midline, if it continues to swim directly across the discrimination midline and reaches the vicinity of the net cage, it is considered a failure and is preyed upon. It is then immediately removed, given a few seconds of air exposure as a penalty, and transferred to a temporary holding tank. If it turns sideways and swims into the left or right arm zone, the juvenile large yellow croaker is introduced into the left arm zone 22 or right arm zone 23. Based on the results of the above lateralization induction, the juvenile large yellow croaker with the same induction results are rewarded with food, while the juvenile large yellow croaker with the opposite results are not rewarded with food. All the juvenile large yellow croakers were then moved back to temporary holding area 11 and allowed to acclimatize for one day before being acclimatized again. This acclimatization process was repeated until 60% of the juvenile large yellow croakers exhibited the same lateralization characteristics as those induced by lateralization.

[0046] This method can be directly applied to the domestication of individual juvenile large yellow croakers or any number of groups. At the same time, the domestication tank in this embodiment can be replaced with a net cage of the same structure for direct use in marine domestication, thereby improving the lateral swimming ability of the released juvenile large yellow croakers to avoid predators.

[0047] like Figure 5 As shown, the vertical axis represents the number of experimental days, and the horizontal axis represents the lateralization index of juvenile large yellow croaker. In this example, 10 fish were used as a group. Successful domestication was considered achieved when 80% of the fish entered the left side of the fish. From day 16 onwards, the fish began to exhibit obvious left-lateralized gregarious swimming behavior. The experimental results demonstrate that artificially inducing juvenile large yellow croaker to develop endogenous lateralization physiological characteristics can improve their rapid response to predators. Specific data are shown in Table 2.

[0048] Table 2

[0049]

[0050] As a better approach, an artificial disturbance, such as underwater noise, can be applied directly to the right side during the early stages of acclimatization to reduce the number of fish entering the right side and quickly improve the acclimatization effect of left-leaning swimming ability.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art 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 appended claims and their equivalents.

Claims

1. A method for inducing and domesticating the swimming ability of one-sided Larimichthys crocea, characterized in that, The application relates to a device for inducing and domesticating lateralized swimming ability, which comprises a lateralized swimming ability inducing and domesticating tank (1) sequentially comprising an independent separated temporary breeding area (11) and a domesticating area (12) along the length direction; a T-shaped domesticating swimming channel (2) is arranged in the domesticating area (12), the T-shaped domesticating swimming channel (2) comprises a starting arm (21) and left and right arm areas (22, 23) arranged on the two sides of the starting arm (21) respectively, the left arm area (22), the starting arm (21) and the inner wall of the lateralized swimming ability inducing and domesticating tank (1) form a left fish collecting area (24), the right arm area (23), the starting arm (21) and the inner wall of the lateralized swimming ability inducing and domesticating tank (1) form a right fish collecting area (25), and the left and right arm areas (22, 23) are respectively provided with first movable doors (26) for communicating or separating with the corresponding fish collecting areas; and the starting arm (21) is provided with a second movable door (27) for communicating or separating with the temporary breeding area (11). The device is used for inducing lateralized swimming behavior, and the induction is as follows: the large yellow croaker larvae are introduced into the starting arm (21) of the T-shaped domesticating swimming channel (2), under the stimulation of water flow, the large yellow croaker larvae swim forward along the starting arm (21) against the water flow, when reaching the selection area between the left and right arm areas (22, 23), the large yellow croaker larvae must turn to the left or right arm area (22, 23) because they cannot continue to swim forward, under the condition of no external stimulation, the large yellow croaker larvae freely choose to swim into the left or right arm area (22, 23), once the large yellow croaker larvae enter the left or right arm area (22, 23), the movable door of the corresponding fish collecting area is opened, the large yellow croaker larvae are introduced into the fish collecting area, and the lateralized swimming behavior domestication is completed. If the same large yellow croaker larvae swim in the same direction for 8-10 times, the large yellow croaker larvae are considered to have lateralized swimming ability. The large yellow croaker larvae with lateralized swimming ability are domesticated until at least 60% of the large yellow croaker larvae in the fish group show the same lateralized characteristics as the large yellow croaker larvae with lateralized swimming ability. 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.

2. The method for inducing and domesticating the swimming ability of P. major according to claim 1, wherein, The left and right arm areas (22, 23) have the same width as the starting arm.

3. The method for inducing and training the lateral swimming ability of large yellow croaker as described in claim 1, characterized in that, The length of the starting arm (21) is 60 cm, and the width is 30 cm.

4. The method for inducing and training the lateral swimming ability of large yellow croaker as described in claim 2, characterized in that, The domesticating area (12) is further provided with a flow generating area (13) away from the temporary breeding area (11), the flow generating area (13) is provided with a flow generator (3), and the end of the starting arm (21) away from the temporary breeding area (11) is provided with a uniform flow hole plate (4) to form a uniform flow field in the starting arm (21).

5. The method for inducing and training the lateral swimming ability of large yellow croaker as described in claim 1, characterized in that, The flow generator (3) is a flow generator with adjustable power to meet the flow seeking characteristics of the large yellow croaker larvae at different stages.

6. The method for inducing and training the lateral swimming ability of large yellow croaker as described in claim 5, characterized in that, ​ 7. The method for inducing and training the lateral swimming ability of large yellow croaker as described in claim 1, characterized in that, The biased lateralization swimming ability is characterized by an endogenous lateralization index Li: Li=[(number of swimming to the right-number of swimming to the left) / (number of swimming to the right+number of swimming to the left)]*100%; when |Li|≥60%, it indicates that the large yellow croaker larvae have the ability of lateralization, Li>0 indicates right lateralization, and Li<0 indicates left lateralization.

8. The method for inducing and domesticating the swimming ability of P. major according to claim 1, wherein the P. major is P. major of 100-150 g in weight. When the large yellow croaker larvae with the ability of lateralization swimming are subjected to lateralization domestication, the width of the left arm area (22) and the right arm area (23) of the T-shaped domestication channel (2) is increased by 1 times, a middle 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 the net cage is provided with fierce predator fish; When the large yellow croaker larvae in domestication swim forward to the middle line, if they directly continue to swim forward to the net cage after passing the middle line, they are considered to fail, and are directly fished out, punished by air exposure for a few seconds, and then moved to the temporary breeding area (11); If the large yellow croaker larvae in domestication turn their bodies and swim into the left arm area (22) or the right arm area (23) before reaching the middle line, the large yellow croaker larvae are introduced into the corresponding fish collecting area; according to the results of the above-mentioned lateralization induction of left or right bias, the large yellow croaker larvae with the same induction results are given bait feeding as a reward, and the large yellow croaker larvae with opposite results are not given bait feeding reward; then all the large yellow croaker larvae are re-moved to the temporary breeding area (11), and after 1 day of adaptation, they are domesticated again; the domestication is repeated until at least 60% of the large yellow croaker larvae show the same lateralization characteristics as the lateralization induction.

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