Environment enlarging device and method for enrichment culture of juvenile sebastes schlegeli

Abstract

The invention discloses an environment enlarging device for enrichment culture of sebastes schlegeli juvenile fish, which is characterized in that the device comprises a first box body (1), four side walls of the first box body (1) are respectively connected with transparent pipes (2), the bottom ends of the transparent pipes (2) are connected with top plates of second box bodies (3), the bottom end surfaces of the four second box bodies (3) are coplanar, and the bottom end surfaces of the transparent pipes (2) are connected with top plates of the second box bodies (3). A camera (4) is arranged on the bottom face of the first box body (1), a plurality of food intake holes (5) distributed at equal intervals are formed in the side wall of the transparent pipe (2), turning plates (6) matched with the food intake holes (5) are hinged to the interior of the transparent pipe (2), the outline of each turning plate (6) is larger than the hole diameter of the corresponding food intake hole (5), and the food intake holes (5) are located on the lower side of the transparent pipe (2). And a screen (7) is arranged at the joint of the transparent tube (2) and the second box body (3).

Description

Technical Field

[0001] The invention relates to the research field of marine fish breeding, in particular to an environmental enrichment device for enrichment breeding of young jack mackerel, and a method for environmental enrichment and domestication using the device. Background Art

[0002] In order to improve the breeding effect, breeders hope that the breeding environment and conditions can be as consistent as possible with the bait habitat in natural waters to enhance the breeding effect of young fish. Therefore, in the traditional breeding process, live bait is put into the breeding container according to the above principles. However, when the live bait is directly fed, the live bait will be concentrated and eaten by the young fish during feeding. The remaining live bait is affected by the fish school and cannot form a multi-layer random distribution in the water like in the marine environment. Therefore, it is impossible to achieve the purpose of simulating the feeding of young fish in the wild environment. At the same time, when the young fish compete for the live bait, they may bite each other's body and gills, which will cause injury or even death to the young fish.

[0003] Therefore, a method or device capable of solving the above problems is now needed. Summary of the invention

[0004] The present invention aims to solve the above-mentioned deficiencies in the prior art and proposes an environmental enrichment device with a simple structure, ingenious design and reasonable layout. The present invention also discloses a domestication method for enriching and cultivating fry of Hystrix schrenckii using the device, thereby achieving the purpose of reducing its aggressive behavior and alleviating the pressure in the cultivation environment. The method can significantly improve its antioxidant capacity and the levels of brain cell proliferation and neural transfer, thereby improving the fish welfare of Hystrix schrenckii fry and improving the cultivation quality of Hystrix schrenckii fry.

[0005] The technical solution of the present invention is: an environmental enrichment device for enrichment and breeding of juvenile scorpionfish, characterized in that: the device comprises a first box body 1, the four side walls of the first box body 1 are respectively connected to a transparent tube 2, the bottom end of the transparent tube 2 is connected to the top plate of a second box body 3, the bottom end surfaces of the four second boxes 3 are coplanar, and a camera 4 is arranged on the bottom surface of the first box body 1, The side wall of the transparent tube 2 is provided with a plurality of feeding holes 5 distributed at equal intervals, a flap 6 matching the feeding holes 5 is hinged in the transparent tube 2, and the outline of the flap 6 is larger than the aperture of the feeding holes 5, the feeding holes 5 are located on the lower side of the transparent tube 2, and a screen 7 is provided at the connection between the transparent tube 2 and the second box body 3. A plurality of escape holes 8 are provided on the side wall of the second box body 3. The device is placed in a breeding container 9 , and is equipped with a water circulation system together with the breeding container 9 . The outlet of the water inlet pipe 10 in the water circulation system is connected to the first box body 1 .

[0006] The four second boxes 3 are distributed at the four corners of the breeding container 9 .

[0007] The feeding hole 5 has a diameter ranging from 0.3 to 0.4 cm, and the avoiding hole 8 has a diameter ranging from 3 to 4 cm.

[0008] The screen 7 is rotatably connected to the transparent tube 2 via a rotating shaft, and a stopper 10 matching the screen 7 is provided at the end of the transparent tube 2. Under the action of the stopper 10, the screen 7 can only swing toward the inner side of the transparent tube 2, and the width of the gap that can be opened by the screen 7 is in the range of 0.3-0.4 cm.

[0009] A method for enriching and cultivating juvenile flathead mullet, characterized in that the method is carried out according to the following steps: A. Inject filtered seawater into the culture container 9, use air stones to continuously aerate, suck the bottom once a day, change the water once a day, and change the water once a day, with a daily water change of 50%. B. According to the above method, an experimental group culture container 9 and a control group culture container 9 were constructed, wherein the experimental group was divided into experimental group 1 and experimental group 2, and the control group was divided into control group 1 and control group 2. Young scorpionfish with a body length of 2.45±0.55 cm were respectively released into the above culture containers 9, wherein ten scorpionfish were released into both the experimental group 1 and the control group 1, and six scorpionfish were released into both the experimental group 2 and the control group 2. C. At 8:00 and 14:00 every day, the control group 1 and the control group 2 were fed with sediment pellet bait, and the average diameter of the sediment pellet bait was 2 mm. During the feeding process, the feeding state of the juvenile scorpionfish was observed, and the feeding was stopped when they showed a state of satiation. Starting from 8:00 every day, live bait was fed to the experimental group 1 and the experimental group 2. The live bait was whiteleg shrimp with a body length of 10.1 ± 0.3 mm. During feeding, feeding was carried out through the first box 3, and 8 whiteleg shrimps were fed in each transparent tube 2. The experimental group 1 and the experimental group 2 were checked every three hours, and the number of surviving whiteleg shrimps in each transparent tube 2 was checked. If the number was less than 8, it was supplemented to 8. The acclimation period was 56 days. D. Clean the enrichment device every 7 days. E. After the first feeding of each day, the aggressive behavior of the juveniles of the experimental and control groups during feeding was filmed using camera 4 for 30 minutes. At 16:30 each day, the aggressive behavior of the juveniles of the experimental and control groups when not feeding was filmed using camera 4 for 30 minutes.

[0010] Compared with the prior art, the present invention has the following advantages: When using traditional methods to culture young flounder, live bait is directly fed into the culture container. However, this method causes the residual bait to be too dispersed in the water, so it needs to be cleaned frequently, which affects the domestication of the young fish, and the omission of residual bait will cause water quality deterioration. When live bait is directly fed, the live bait will be concentratedly eaten by the young fish during feeding, and the remaining live shrimp will be affected by the fish school and cannot meet the multi-layer random distribution in the water in the marine environment, and cannot simulate the feeding characteristics of wild young fish in the marine environment. In addition, there is a risk of fighting with each other, biting the fish body and gills, causing the fish body to be injured or even killed. The environmental enrichment device disclosed in the present invention, and the method for social enrichment culture of juvenile scorpionfish using the device, wherein the bait habitat is simulated according to the feeding characteristics of scorpionfish, and the size of the group also reflects the natural changes seen in the wild, thereby providing a living environment similar to that of wild groups for its early cultivation. The method can not only reduce the influence of stress factors on juvenile scorpionfish during the cultivation process, but also domesticate the juveniles, reduce their aggressive behavior, relieve the pressure in the cultivation environment, and improve their antioxidant capacity and brain cell proliferation and neural transfer, thereby improving the fish welfare of juvenile scorpionfish and the cultivation quality of juvenile scorpionfish. The method has low cost and is easy to operate, and can be widely used in large-scale cultivation and breeding, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 2 is a top view of an embodiment of the present invention.

[0012] Figure 2 yes Figure 1 AA section view in.

[0013] Figure 3 yes Figure 2 Enlarged view of part B in .

[0014] Figure 4 yes Figure 2 Enlarged view of section C in . DETAILED DESCRIPTION

[0015] The specific implementation of the present invention will be described below with reference to the accompanying drawings. Figures 1 to 4 As shown: an environmental enrichment device for enrichment and breeding of young jack mackerel, the device comprises a first box 1, four side walls of the first box 1 are respectively connected to transparent tubes 2, the bottom end of the transparent tube 2 is connected to the top plate of a second box 3, the bottom end surfaces of the four second boxes 3 are coplanar, and a camera 4 is arranged on the bottom surface of the first box 1. The side wall of the transparent tube 2 is provided with a plurality of feeding holes 5 distributed at equal intervals, a flap 6 matching the feeding holes 5 is hinged in the transparent tube 2, and the outline of the flap 6 is larger than the aperture of the feeding holes 5, the feeding holes 5 are located on the lower side of the transparent tube 2, and a screen 7 is provided at the connection between the transparent tube 2 and the second box body 3. A plurality of escape holes 8 are provided on the side wall of the second box body 3. The device is placed in a breeding container 9 , and is equipped with a water circulation system together with the breeding container 9 . The outlet of the water inlet pipe 10 in the water circulation system is connected to the first box body 1 .

[0016] The four second boxes 3 are distributed at the four corners of the breeding container 9 .

[0017] The feeding hole 5 has a diameter ranging from 0.3 to 0.4 cm, and the avoiding hole 8 has a diameter ranging from 3 to 4 cm.

[0018] The screen 7 is rotatably connected to the transparent tube 2 via a rotating shaft, and a stopper 10 matching the screen 7 is provided at the end of the transparent tube 2. Under the action of the stopper 10, the screen 7 can only swing toward the inner side of the transparent tube 2, and the width of the gap that can be opened by the screen 7 is in the range of 0.3-0.4 cm.

[0019] When using the above-mentioned environmental enrichment device for enrichment culture of juvenile scorpionfish, follow the steps below: First, filter seawater is injected into the culture container 9, and air is continuously inflated using an air stone. The bottom is sucked once a day and the water is changed once a day. The daily water change volume is 50%. According to the above method, an experimental group culture container 9 and a control group culture container 9 were constructed, wherein the experimental group was divided into experimental group 1 and experimental group 2, and the control group was divided into control group 1 and control group 2. Young scorpionfish with a body length of 2.45±0.55 cm were respectively released into the above culture containers 9, wherein ten scorpionfish were released into both the experimental group 1 and the control group 1, and six scorpionfish were released into both the experimental group 2 and the control group 2. At 8:00 and 14:00 every day, the control group 1 and the control group 2 were fed with sediment pellet bait, and the average diameter of the sediment pellet bait was 2 mm. During the feeding process, the feeding state of the juvenile flatfish was observed, and the feeding was stopped when they showed a state of satiation. From 8:00 every day, live bait was fed to the experimental group 1 and the experimental group 2. The live bait was whiteleg shrimp with a body length of 10.1 ± 0.3 mm. When feeding, feeding was carried out through the first box 3, and 8 whiteleg shrimps were fed in each transparent tube 2. The experimental group 1 and the experimental group 2 were checked every three hours, and the number of surviving whiteleg shrimps in each transparent tube 2 was checked. If the number was less than 8, it was supplemented to 8. The acclimation period was 56 days. Since all the feeding holes 5 are located on the lower side of the transparent tube 2, the flap 6 will automatically buckle on the inner side of the feeding hole 5 under the action of gravity to close it. At the same time, since the flipping direction of the flap 6 is opposite to the water flow direction, the flap 6 will also be pressed against the feeding hole 5 under the action of water pressure to close it. When the experimental group is feeding, since all the live baits enter the transparent tube 2, the young scorpionfish will try to enter the transparent tube 2 under the attraction of the live baits, and they will push open the flap 6. However, since the aperture size of the feeding hole 5 is relatively small (0.3-0.4 cm), it can only accommodate the mouth of the young scorpionfish. Therefore, the young scorpionfish will put its mouth into the transparent tube 2 and catch the swimming live bait. When the young scorpionfish is not feeding, the flap 6 will automatically close. Similarly, the young scorpionfish entering the second box body 3 through the escape hole 8 will also push open the screen 7 driven by the feeding instinct. However, due to the angle limit of the screen 7, only the mouth of the young scorpionfish can penetrate into the transparent tube 2 and catch the swimming live bait. When the young scorpionfish does not feed, the screen 7 is automatically closed under the action of water pressure. During the above acclimation process, the enrichment device was cleaned every 7 days. After the first feeding of each day, the camera 4 was used to film the aggressive behaviors of the juveniles of the experimental group and the control group during the feeding process, and the filming time was 30 minutes. At 16:30 each day, the camera 4 was used to film the aggressive behaviors of the juveniles of the experimental group and the control group when they were not feeding, and the filming time was 30 minutes. By analyzing the captured video footage, we can draw the following conclusions: The frequency of intraspecific aggressive behavior of the juveniles of the experimental group fed with live bait (including experimental group 1 and experimental group 2) was significantly lower than that of the control group fed with sediment pellet bait (including control group 1 and control group 2). In addition, the frequency of aggressive behavior of the juveniles of the experimental group 1 with ten juveniles was also significantly lower than that of the experimental group 2 with six juveniles. That is, behavioral observations show that the aggressive behavior of juvenile redfish groups that have undergone environmental enrichment and domesticated breeding has decreased and the environmental pressure they are exposed to has been reduced.

[0020] After the domestication operation, live baits were placed in the control group (including control group 1 and control group 2) that had not undergone environmental enrichment and domestication. The live baits were shrimps and algae. After observation, it was found that when the juvenile flathead mullet groups in the control group were fed with shrimp bait, their predation times were relatively few and there was escape behavior; when they were fed with algae bait, they would attack each other for food; at the same time, the groups in the control group would have multiple intraspecific attacks under non-feeding conditions; Live baits were placed in the experimental groups (including experimental groups 1 and 2) that had undergone environmental enrichment and domestication. The live baits were shrimps and shellfish. After observation, it was found that after the live bait was placed in the transparent tube 2, the juvenile scorpionfish group would quickly rush to the live bait and actively push open the flap 6 and the screen 7 to feed, but the number of attacks on each other was relatively small. At the same time, the number of intraspecific attacks in the experimental groups under non-feeding conditions was also relatively small. That is, behavioral observations showed that the predatory behavior of the juvenile Scorpionfish group that had undergone environmental enrichment and domestication was significantly enhanced, and the intraspecific aggressive behavior caused by competing for food during feeding and the intraspecific aggressive behavior during non-feeding were reduced compared with the control group. After the environmental enrichment and acclimatization, three juveniles of the experimental group and the control group were taken, a total of 12 juveniles of the flathead scorpionfish, and the cortisol and MDA concentrations and CAT, GSH-Px, SOD activities and gene expressions were measured. The results showed that: Compared with the control group, the experimental group significantly reduced CAT activity (16.34%), GSH-Px activity (50.12%), SOD activity (12.55%), and the frequency of aggressive behavior during feeding (62.91%) and when idle (53.51%) were reduced, and the coefficient of variation of body weight (28.06%), brain pcna (182.75%), dcx (86.7%) and neurod (154.19%) gene expressions were enhanced; Compared with experimental group 2 (small-scale group), experimental group 1 (large-scale group) significantly reduced the MDA content (27.4%), and the frequency of aggressive behavior during feeding (31.91%) and the frequency of aggressive behavior during leisure (32.09%) were reduced. The basal cortisol level (11.11%), dcx (78.34%) and neurod (72.54%) gene expressions were enhanced; the activity of CAT (52.56%), GSH-Px (57.78%), and SOD (51.73%) were increased. The above results show that after using this species of environmental enrichment device for domestication, not only can the impact of stress factors on the fry of Xu's flatfish be reduced during the breeding process, but also the aggressive behavior of the fry of Xu's flatfish can be reduced, the stress in the breeding environment can be eliminated, and its antioxidant capacity and brain cell proliferation and neural transfer levels can be improved, thereby improving the fish welfare of the fry of Xu's flatfish, improving the breeding quality of the fry of Xu's flatfish, and also improving the adaptability of the fry for reproduction and release.

Claims

1. An environmental enrichment device for enrichment and aquaculture of juvenile scorpionfish, characterized in that: The device comprises a first box (1), wherein four side walls of the first box (1) are respectively connected to transparent tubes (2), the bottom end of the transparent tube (2) is connected to the top plate of a second box (3), the bottom end surfaces of the four second boxes (3) are coplanar, and a camera (4) is arranged on the bottom surface of the first box (1). The side wall of the transparent tube (2) is provided with a plurality of feeding holes (5) distributed at equal intervals. A flap (6) matching the feeding holes (5) is hingedly connected inside the transparent tube (2), and the outline of the flap (6) is larger than the aperture of the feeding holes (5). The feeding holes (5) are located on the lower side of the transparent tube (2). A screen (7) is provided at the connection between the transparent tube (2) and the second box body (3). A plurality of escape holes (8) are provided on the side wall of the second box body (3). The device is placed in a breeding container (9) and is equipped with a water circulation system together with the breeding container (9). The outlet of the water inlet pipe (10) in the water circulation system is connected to the first box body (1).

2. The environmental enrichment device for enrichment and aquaculture of juvenile flathead mullet according to claim 1, characterized in that: The four second boxes (3) are distributed at the four corners of the breeding container (9).

3. The environmental enrichment device for enrichment and aquaculture of juvenile flathead mullet according to claim 1, characterized in that: The feeding hole (5) has a diameter ranging from 0.3 to 0.4 cm, and the avoiding hole (8) has a diameter ranging from 3 to 4 cm.

4. The environmental enrichment device for enrichment and aquaculture of juvenile flathead mullet according to claim 1, characterized in that: The screen (7) is rotatably connected to the transparent tube (2) via a rotating shaft, and a stopper (10) matching the screen (7) is provided at the end of the transparent tube (2). Under the action of the stopper (10), the screen (7) can only swing in the direction of the inner side of the transparent tube (2), and the width of the gap that can be opened by the screen (7) is in the range of 0.3-0.4 cm.

5. A method for enriching and cultivating juvenile flatfish, characterized in that: The method described is carried out according to the following steps: A. Inject filtered seawater into the culture container (9), use an air stone to continuously aerate, suck the bottom once a day, and change the water once a day, with a daily water change of 50%. B. According to the above method, an experimental group culture container (9) and a control group culture container (9) were constructed, wherein the experimental group was divided into experimental group 1 and experimental group 2, and the control group was divided into control group 1 and control group 2. Young scorpionfish with a body length of 2.45±0.55 cm were released into the above culture containers (9), wherein ten scorpionfish were released into both experimental group 1 and control group 1, and six scorpionfish were released into both experimental group 2 and control group 2. C. At 8:00 and 14:00 every day, the control group 1 and the control group 2 were fed with sediment pellet bait, and the average diameter of the sediment pellet bait was 2 mm. During the feeding process, the feeding state of the juvenile scorpionfish was observed, and the feeding was stopped when the juvenile scorpionfish showed a state of satiation. Starting from 8:00 every day, live bait was fed to the experimental group 1 and the experimental group 2. The live bait was whiteleg shrimp with a body length of 10.1 ± 0.3 mm. During the feeding, the live bait was fed through the first box (3), and 8 whiteleg shrimp were fed in each transparent tube (2). The experimental group 1 and the experimental group 2 were checked every three hours, and the number of surviving whiteleg shrimp in each transparent tube (2) was checked. If the number was less than 8, it was supplemented to 8. The acclimation period was 56 days. D. Clean the enrichment device every 7 days. E. After the first feeding of each day, the camera (4) was used to film the aggressive behavior of the juveniles of the experimental and control groups during the feeding process. The filming time was 30 minutes. At 16:30 each day, the camera (4) was used to film the aggressive behavior of the juveniles of the experimental and control groups when they were not feeding. The filming time was 30 minutes.

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