A grading device for raising juvenile fish

Abstract

This invention relates to a grading device for juvenile fish rearing, addressing the problem of cannibalism among juvenile fish during rearing, leading to injury or even mass mortality. The device features a cylindrical central pool at the center of the rearing pond. A first pool and a second pool are located on either side of the central pool. These pools are separated, allowing water to pass through but not fish. Fish-passing plates with holes are installed on the side walls of the central pool, corresponding to the first and second pools. A rotating shaft connects to a rotating drive net plate at the central axis of the central pool. A swinging intercepting net plate is installed on the inner side of the central pool wall, beside the fish-passing plates. When retracted, the swinging intercepting net plate rests against the pool wall; when extended, its inner end abuts against a central pillar. This invention separates smaller juvenile fish during rearing, reducing stocking density and minimizing cannibalism.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, and in particular to a grading device for raising juvenile fish. Background Technology

[0002] In the process of marine aquaculture, fish such as brown scorpionfish, yellow croaker, small yellow croaker, silverfish and mandarin fish need to be raised in a concentrated manner to avoid natural predators, increase the survival rate of juvenile fish and increase production.

[0003] The rearing of juvenile fish is completed in the hatchery. Due to asynchronous development, cannibalism may occur among the juveniles in the hatchery. This behavior is influenced by various factors, including stocking density, hunger, feeding methods, and differences in individual size. Especially when juveniles are hungry, they are more likely to kill each other, with weaker individuals often becoming targets, resulting in damage to their eyes, abdomen, fins, and even mass mortality. Therefore, during the rearing process, it is necessary to closely monitor the growth of the juveniles, feed them promptly, maintain a reasonable stocking density, and separate smaller juveniles in a timely manner to reduce cannibalism. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that juvenile fish may kill each other during the juvenile fish breeding process, resulting in damage or even mass mortality of juvenile fish. It provides a breeding and grading device for juvenile fish, which feeds the juvenile fish in a concentrated manner in the early stage of growth, and then grades the juvenile fish according to their size after they reach a certain growth stage. This frees up space, reduces stocking density, separates smaller juvenile fish, and reduces cannibalism among juvenile fish.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: a grading device for raising juvenile fish, including a seedling pond, a cylindrical central pool at the center of the seedling pond, a first pool and a second pool respectively on the two sides of the outer side of the central pool, the pool wall of the central pool is mesh-like, a fixed isolation mesh plate is provided between the first pool and the second pool, fish passage plates are respectively provided on the two side walls of the central pool corresponding to the first pool and the second pool, the fish passage plates are provided with several fish passage holes, and a gate plate can be inserted and pulled out at the fish passage holes; a rotating shaft is provided at the central axis of the central pool, and a rotating driving mesh plate is radially connected to the rotating shaft; a swinging intercepting mesh plate is provided on the inner side of the pool wall of the central pool on the side of the fish passage plate, the outer end of the swinging intercepting mesh plate is hinged to the pool wall of the central pool, the swinging intercepting mesh plate is close to the pool wall of the central pool when it is retracted, and the inner end of the swinging intercepting mesh plate abuts against the central column when it is extended.

[0006] In this device, the central pool of the nursery is formed by a central net bucket. The first and second pools are separated by a fine, fixed isolation net. Water can circulate in the three spaces of the nursery, and the water level cannot exceed the height of the partition structure between the central pool, the first pool, and the second pool. However, juvenile fish larger than the mesh of the central net bucket and the fixed isolation net cannot pass through. At the beginning of the breeding process, all juvenile fish are placed in the central pool for feeding. At this time, the swinging intercepting net is attached to the wall of the central pool, and the rotating driving net is stationary, rolled up, or not installed with the rotating shaft. After the juvenile fish grow to a certain stage and individual differences appear, the rotating driving net is lowered or installed with the rotating shaft. The smallest juvenile fish are separated first, and the side of the fish passage plate with the smaller fish passage hole size is set to correspond to the first pool. Multiple fish passage holes are evenly distributed on the fish passage plate, and they are arranged from top to bottom. The gate is pulled out, and the swinging intercepting net is spread out so that the inner end of the swinging intercepting net is against the central column. Then the rotating driving net is rotated. Using a screen, the juvenile fish are driven towards the side of the screen with the smaller fish passage opening. This method of intercepting on one side and driving on the other concentrates the juvenile fish near the screen, allowing those smaller than the fish passage opening to pass through and enter the first outer pool. After a period of time, the screen is swung back to fit against the wall of the central pool, and the screen is rotated again until the fish have passed the screen area. Then, the screen is swung open again so that the inner end of the screen rests against the central pillar, and the screen is rotated again to drive the juvenile fish. This process is repeated several times to separate the smallest juvenile fish into the first pool. Then, the same method is used to separate the medium-sized juvenile fish into the second pool, leaving the largest juvenile fish in the central pool. After the juvenile fish have grown for a period of time, they are separated according to size to reduce stocking density and minimize cannibalism.

[0007] Preferably, the upper side of the swinging intercepting net and the rotating driving net is a rigid rod, and a flexible net surface is suspended below the rigid rod, with a weight attached to the bottom of the net surface. The flexible net surface does not harm the fish and is easy to store and install.

[0008] Preferably, both the swinging intercepting net and the rotating driving net are arc-shaped nets when viewed from above. The arc of the swinging intercepting net is smaller than that of the rotating driving net. When the inner end of the rotating driving net is close to the inner end of the swinging intercepting net, the outer ends of the rotating driving net and the swinging intercepting net open in a funnel shape, with the fish passage plate located within the funnel opening. The use of arc-shaped structures with different arcs in the swinging intercepting net and the rotating driving net naturally forms a funnel opening, preventing the juvenile fish from being squeezed during the driving process.

[0009] Preferably, the outer hinge of the swinging intercepting net panel is provided with a torsion spring having a swing-out preload, and a traction rope is provided between the inner end of the swinging intercepting net panel and the bank of the seedling pond. The traction rope holds the swinging intercepting net panel against the wall of the central pond, and the torsion spring drives the swinging intercepting net panel to swing open. The traction rope can be operated manually or driven by a motor.

[0010] Preferably, there is a gap between the outer end of the rotating repellent net and the wall of the central pool. This allows some juvenile fish to pass through the gap between the outer end of the rotating repellent net and the wall of the central pool, preventing the juvenile fish from being pinched or injured.

[0011] Preferably, a central column is provided at the central axis of the central water tank, and the rotating shaft is rotatably sleeved on the central column. A mounting plate is detachably provided on the top of the central column, and a motor is mounted on the mounting plate. The motor and the rotating shaft are connected by gear transmission. A drive component for the rotating shaft is provided at the upper end of the central column.

[0012] Preferably, the top of the rotating drive net plate is a rigid insert rod, which is inserted and fixed to the side wall of the rotating shaft.

[0013] Preferably, the upper part of the outer side of the fish passage is equipped with a one-way swing rod that can swing outward in one direction. The fish passage allows juvenile fish to pass through in one direction, preventing smaller juvenile fish from re-entering the central pool through the fish passage.

[0014] Preferably, the upper end of the unidirectional rocker arm is a swing seat, and a cleaning nozzle is provided at the swing seat. This ensures that the swing seat can swing flexibly.

[0015] Preferably, the fish passage holes on one side of the central pool are larger than those on the other side. The size difference between the fish passage holes on both sides separates juvenile fish of different sizes.

[0016] In the process of fish fry rearing, this invention uses a mesh partition to divide the rearing pond into multiple spaces. The fry are first fed in one space. When the fry grow to a certain stage and differences in size occur, the mesh is used to drive them to a fish board, allowing the smaller fry to pass through the fish board into another space. This achieves the separation of smaller fry during the fry rearing process, reduces stocking density, and reduces cannibalism among fry. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 This is a planar structural diagram of a swing interceptor mesh plate storage according to the present invention.

[0019] Figure 2 This is a planar structural diagram of a side-swinging interceptor mesh panel according to the present invention.

[0020] Figure 3 This is the invention Figure 1 The K-direction view in the image.

[0021] Figure 4 This is the invention Figure 1 AA section view in the image.

[0022] Figure 5 This is the invention Figure 3 A schematic diagram of the fish passage structure at point F.

[0023] Figure 6 This is the invention Figure 5 A schematic diagram of the cross-section of the fish hole.

[0024] In the diagram: 1. Bankside, 2. Water surface, 3. Nursery pond, 3.1. Central pond, 3.2. First pond, 3.3. Second pond, 4. Central net bucket, 5. Fixed isolation net plate, 6. Swinging interception net plate, 7. Hinge seat, 8. Torsion spring, 9. Pulling and fixing rope, 10. Central column, 11. Rotating shaft, 12. Mounting plate, 13. Motor, 14. Gear, 15. Rotating driving net plate, 16. Fish passage plate, 17. Fish passage hole, 18. One-way swing rod, 19. Swing rod seat, 20. Cleaning nozzle, 21. Gate, 22. Weight, 23. Trumpet mouth, 24. Cleaning pipeline. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0026] Example: A grading device for juvenile fish rearing, such as... Figure 1 , 3As shown. This device includes a seedling pond 3, with a cylindrical central pool 3.1 at its center. The central pool is directly formed by a central net bucket 4, the walls of which are made of fine mesh, allowing water to pass through but not fish. A first pool 3.2 and a second pool 3.3 are respectively located on the outer sides of the central pool. A fixed isolation net plate 5 is provided between the first and second pools, also with a fine mesh, allowing water to pass through but not fish. The water level 2 in the seedling pond 3 is no higher than the height of the central net bucket 4 and the fixed isolation plate 5. Fish-passing plates 16 are provided on both sides of the central pool 3.1, corresponding to the first pool 3.2 and the second pool 3.3 respectively. Several fish-passing holes 17 are provided on the fish-passing plates 16, and gates 21 can be pulled out and inserted at the fish-passing holes. A central column 10 is installed at the central axis of the central pool 3.1. A rotating shaft 11 is rotatably sleeved on the upper end of the central column 10. A shaft gear is installed at the upper end of the rotating shaft. A mounting plate 12 is detachably installed on the top of the central column 10. A motor 13 is installed on the mounting plate. A gear 14 is installed on the output shaft of the motor 13. The motor and the rotating shaft are driven by the meshing of the gear 14 and the shaft gear. A rotating driving net plate 15 is radially connected to the rotating shaft 11. There is a gap between the outer end of the rotating driving net plate 15 and the pool wall of the central pool 3.1, which allows juvenile fish to swim through. The top of the rotating driving net plate is a rigid insert rod, which is inserted and fixed to the side wall of the rotating shaft. A swinging intercepting net plate 6 is installed on the inner side of the pool wall of the central water tank 3.1, next to the fish passage plate 16. The outer end of the swinging intercepting net plate 6 is connected to the pool wall of the central water tank by a hinge seat 7. A torsion spring 8 with a swing-out preload is installed at the hinge point of the outer end of the swinging intercepting net plate 6. A traction fixing rope 9 is installed between the inner end of the swinging intercepting net plate and the bank side 2 of the seedling pond 3. When the swinging intercepting net plate 6 is retracted, it is against the pool wall of the central water tank 3.1. When the swinging intercepting net plate is extended, its inner end abuts against the central column 10.

[0027] like Figure 4 As shown, the upper side of the swinging intercepting net plate 6 and the rotating driving net plate 15 is a rigid rod, and a flexible net surface is suspended below the rigid rod. The mesh of the net surface is fine, allowing water to pass through but not fish. A weight 22 is hung at the bottom of the net surface.

[0028] like Figure 1 , 2 As shown, both the swinging interception net plate 6 and the rotating driving net plate 15 are arc-shaped nets when viewed from above. The arc of the swinging interception net plate 6 is smaller than that of the rotating driving net plate 15. When the inner end of the rotating driving net plate is close to the inner end of the swinging interception net plate, the outer end of the rotating driving net plate and the outer end of the swinging interception net plate unfold in a funnel shape. The fish passage plate is located within the funnel opening 23.

[0029] like Figure 5 , 6As shown, the fish passage plate has multiple fish passage holes evenly arranged from top to bottom. The fish passage holes 17 on the same fish passage plate are all the same size, and the size of the fish passage hole corresponding to the first pool 3.2 is less than or equal to the size of the fish passage hole corresponding to the second pool 3.3. A one-way swing rod 18 that can swing outward in one direction is provided on the upper part of the outer side of the fish passage hole 17. The upper end of the one-way swing rod 18 is a swing seat 19, and a cleaning nozzle 20 is provided at the swing seat 19. The cleaning nozzle is supplied with water through the cleaning pipe 24.

[0030] When starting to raise livestock, such as Figure 1 As shown, first, all the fry are placed in the central pond for feeding. At this time, the swinging intercepting net is placed against the wall of the central pond, and the rotating driving net remains stationary with the net surface rolled up. After the fry grow to a certain stage and individual differences appear, the rotating driving net is lowered. The smallest fry are separated first. The side of the fish passage plate with the smaller fish passage hole size is set to correspond to the first pond. Multiple fish passage holes are evenly distributed on the fish passage plate, and they are arranged from top to bottom. The gate is then removed, as shown. Figure 2 As shown, the swinging intercepting net is spread out so that its inner end rests against the central pillar. Then, the net is rotated to drive the juvenile fish towards the side of the fish passage with the smaller opening. This method of intercepting on one side and driving on the other concentrates the juvenile fish near the fish passage, allowing those smaller than the opening to pass through and enter the first outer pool. After a period of time, the swinging intercepting net is swung back to the wall of the central pool, and the rotation continues until the fish have passed the area marked by the net. Then, the net is spread out again so that its inner end rests against the central pillar, and the rotation continues to drive the juvenile fish. This process is repeated several times to separate the smallest juvenile fish into the first pool. Then, the same method is used to separate the medium-sized juvenile fish into the second pool, leaving the largest juvenile fish in the central pool.

Claims

1. A rearing staging device for the hatchery rearing of juvenile fish, comprising a hatchery tank, characterised in that: The center of the breeding pond is provided with a cylindrical center pool, and the outer sides of the center pool are respectively provided with a first pool and a second pool; the pool wall of the center pool is mesh-shaped, a fixed isolation net plate is arranged between the first pool and the second pool, and the two side pool walls of the center pool are respectively provided with fish passing plates corresponding to the first pool and the second pool; a plurality of fish passing holes are formed in the fish passing plates, and a gate plate is inserted in the fish passing holes and can be pulled out; a rotating shaft is arranged at the central axis of the center pool, and the rotating shaft is connected with a rotating driving net plate in the radial direction; a swinging intercepting net plate is arranged on the inner side of the pool wall of the center pool and beside the fish passing plate, the outer end of the swinging intercepting net plate is hinged to the pool wall of the center pool, the swinging intercepting net plate is attached to the pool wall of the center pool when it is stored, and the inner end of the swinging intercepting net plate abuts against the center column when it swings out. The swinging intercepting net plate and the rotating driving net plate are both arc-shaped nets from the perspective of the top view, the arc of the swinging intercepting net plate is smaller than the arc of the rotating driving net plate, when the inner end of the rotating driving net plate is close to the inner end of the swinging intercepting net plate, the outer end of the rotating driving net plate and the outer end of the swinging intercepting net plate are trumpet-shaped, and the fish passing plate is located in the trumpet range; there is a gap between the outer end of the rotating driving net plate and the pool wall of the center pool.

2. A rearing staging device for the hatchery culture of juvenile fish according to claim 1 characterised in that: The upper side of the swinging intercepting net plate and the rotating driving net plate is a rigid rod, and a flexible net surface is hung below the rigid rod, and a heavy drop is hung at the bottom end of the net surface.

3. A rearing staging device for the hatchery culture of juvenile fish according to claim 1 characterised in that: A torsional spring with a swing pre-tightening force is arranged at the hinged position of the outer end of the swinging intercepting net plate, and a pulling fixing rope is arranged between the inner end of the swinging intercepting net plate and the bank side of the breeding pond.

4. A rearing staging device for the hatching of juvenile fish according to claim 1, characterised in that: A center column is arranged at the central axis of the center pool, the rotating shaft is rotatably sleeved on the center column, a mounting plate is detachably arranged at the top of the center column, a motor is arranged on the mounting plate, and gear transmission is adopted between the motor and the rotating shaft.

5. A rearing staging device for the hatching of juvenile fish according to claim 1, characterised in that: The top of the rotating driving net plate is a rigid insertion rod, and the insertion rod is fixedly inserted with the side wall of the rotating shaft.

6. A rearing staging device for the hatching of juvenile fish according to claim 1, characterised in that: The upper part of the outside of the fish passing hole is provided with a one-way swinging rod which can swing outward in one direction.

7. A rearing staging device for the hatching of juvenile fish according to claim 6, characterised in that: The upper end of the one-way swinging rod is a swinging seat, and a cleaning nozzle is arranged at the swinging seat.

8. A rearing staging device for the hatching of juvenile fish according to claim 1, characterised in that: The fish passing holes of the fish passing plate on one side of the center pool are larger than the fish passing holes of the fish passing plate on the other side of the center pool.

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