CN115104558A - Device and method for evaluating swimming capacity of large yellow croaker population - Google Patents

Abstract

A device and method for evaluating the group swimming ability of large yellow croaker belong to the technical field of biological measurement. The device includes swimming lanes, water pumps, PVC water pipes, frequency converters, rectifiers, blocking nets, and cameras; water is injected into the swimming lanes; the water pump is connected to the PVC water pipes and placed inside the swimming lanes to form a circulation; It is placed at the head end of the swimming lane to form laminar flow; the blocking net is placed at the inner end of the swimming lane; the camera is placed directly above the swimming lane. Method: First, the water pump forms a circulating flow inside the swimming lane, and the rectifier is used to generate a stable laminar flow. The test large yellow croaker group is put into the swimming lane, and the water flow speed in the swimming lane is controlled by the frequency converter to adjust the power of the pump, and it will rush to the tail end due to fatigue When the large yellow croaker on the block is fished out, the swimming ability of the fish is known, and the camera records the whole process. The swimming ability evaluation of a large number of large yellow croaker groups can be carried out in a short time, with low equipment cost, high efficiency and wide application.

Description

A device and method for evaluating the group swimming ability of large yellow croaker

technical field

The invention belongs to the technical field of biological measurement, and in particular relates to a device and method for evaluating the swimming ability of large yellow croaker groups.

Background technique

Large yellow croaker (Larimichthys crocea) is an important marine economic aquaculture species in my country. The "nearshore cage" is the main breeding mode. Due to the disadvantages of poor water exchange and serious environmental pollution, this model leads to frequent aquatic diseases. Mortality rates remain high. Therefore, the large yellow croaker aquaculture industry is trying to turn to the "far-reaching sea cage" breeding mode. However, deep-sea cages have more complex current conditions, with more rapids and turbulence, and have higher requirements on the swimming ability of the cultured objects. The swimming ability of fish is considered to be an important indicator for evaluating fish growth and survival, and is closely related to fish robustness. In this context, it is particularly important to develop a device and method for selecting the swimming ability of large yellow croaker groups under specific aquaculture scenarios in combination with the deep-sea farming methods and characteristics of large yellow croaker, starting with the swimming ability of fish.

Among the evaluation methods of fish swimming ability, critical swimming speed (U _crit ) is the most common and widely used index, and is considered as the standard for evaluating fish swimming ability. The critical swimming speed is calculated from the speed and duration when the fish swims continuously at a fixed time and speed increment, and finally reaches a state of fatigue. This method was first established by Canadian scholar Brett in 1964 and is still in use today. To this end, Brett built the first "fish respiration meter" that can be used to measure the critical swimming speed of fish. The device places the experimental fish to be tested in the swimming lane and forms a closed loop of the water circuit, and changes the interior of the swimming lane by controlling the power of the water pump. The water flow velocity, thereby measuring the critical swimming speed of the experimental fish, is also the model basis for the later fish swimming ability measurement device. Since then, research on the swimming ability of fish has become popular, and the experimental device has also been improved on the basis of the "Brett type". Stobutzki built a swimming lane device for measuring the swimming ability of coral reef fish in 1997. The device consists of 6 independent swimming lanes, powered by a pump, and an "inverted U-shaped" tank is set up at the front of the swimming lane to stabilize the water flow, which can measure 6 fish at the same time. Experimental fish swimming ability. In addition, a swimming lane device for measuring the swimming ability of fish was built by Loligo Company. It consists of a single swimming lane, powered by a paddle-type engine, and the speed of the water flow in the swimming lane is controlled by a controller. It is the most successful commercial fish swimming ability measurement. device.

Although a lot of measurement devices for fish swimming ability have been developed, unfortunately, the existing measurement devices still have obvious drawbacks, such as: limited number of individuals that can be measured, complicated measurement technology, few production application scenarios, etc. , these limitations make the current fish swimming ability measurement device unfeasible for industrial application in production.

Therefore, a device and method for evaluating the swimming ability of large yellow croaker groups are provided, which can quickly and in large quantities select robust large yellow croakers with strong swimming ability for production and breeding, thereby saving production costs and production time, and bringing benefits to the large yellow croaker aquaculture industry. Real economic benefits, and provide solutions for the selection of robust large yellow croaker individuals with strong swimming ability in specific aquaculture scenarios such as offshore deep seas, and help the sustainable development of the aquaculture industry.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a device and method for evaluating the swimming ability of a large yellow croaker group, which can efficiently and quickly select strong swimming ability and robust individuals from the large yellow croaker group, aiming at the problems existing in the prior art.

A device for evaluating the swimming ability of large yellow croaker groups, including: swimming lanes, water pumps, PVC water pipes, frequency converters, rectifiers, blocking nets, cameras; The water inlet and the PVC water inlet are parallel to the bottom surface of the swimming lane, and make it form a stable circulation inside the swimming lane; the frequency converter is connected to the water pump, and the water flow inside the swimming lane is controlled by changing the power of the pump; the rectifier is placed at the head end of the swimming lane to form a laminar flow ; The blocking net is placed at the inner end of the swimming lane to block the large yellow croaker; the camera is placed directly above the swimming lane to record the swimming behavior of the large yellow croaker in the swimming lane, which can be further analyzed through video.

Preferably, the size of the swimming lane is variable, so as to be suitable for fish of different sizes.

Preferably, the maximum power of the water pump is variable to achieve the required maximum water flow rate.

Preferably, the PVC water pipe is made of hard material, which is not easily deformed, and can stabilize the direction of the water flow.

Preferably, the rectifier is made of corrosion-resistant stainless steel, which is not easily corroded, and is honeycomb-shaped, which is prone to laminar flow.

Preferably, the blocking net is made of nylon soft material, which is not easy to cause damage to the fish body, and the aperture should be much smaller than the measured size of the large yellow croaker to prevent the large yellow croaker from escaping.

A method for evaluating the swimming ability of large yellow croaker groups, wherein the specific steps are as follows:

1) Put the evaluation large yellow croaker population into the swimming lane with low flow rate (0.5BL.s ^-1 ) to adapt to 30min, and the adaptation time can be extended until all evaluation large yellow croakers show normal swimming behavior;

2) Swimming lane water flow speed is increased by 0.5BL.s ^-1 by frequency converter at every interval 5min;

3) After 6 stages, every interval 15min is increased by 1BL.s ^-1 of swimming lane water flow speed;

4) During the whole evaluation period, the large yellow croaker that has reached the fatigue state is quickly taken out, and the fatigue time and the water flow speed when fatigued are recorded. The fatigue state means that the large yellow croaker is unable to perform top-current swimming behavior and is washed to the end of the swimming lane by the current. Can't leave on the block for more than 5s;

5) The swimming ability U _crit of the individual large yellow croaker is obtained by the following formula:

U _crit =V ₁ +(t ₁ /T)V

Among them, V ₁ is the water flow velocity of the individual large yellow croaker in the pre-fatigue stage; V is the increment of the water flow velocity; T is the time interval; t ₁ is the swimming time of the large yellow croaker in the fatigue stage.

The invention provides a device and method for evaluating the swimming ability of large yellow croaker groups. Compared with the existing fish swimming ability evaluation device, the invention has at least the following advantages and technical effects:

1. The device has low construction cost, large evaluation scale, high evaluation efficiency, and has industrial application prospects;

2. The method has low technical difficulty, and can complete the swimming ability evaluation of large quantities of large yellow croakers in a short time without causing damage to the fish.

Description of drawings

Fig. 1 is the structural representation of the device for evaluating the swimming ability of large yellow croaker groups provided by the present invention;

2 is a schematic diagram of the method for evaluating the swimming ability of large yellow croaker groups provided by the present invention;

Figure 3 shows the distribution of swimming ability of the 3-month-old group of large yellow croaker.

The marks in the figure are: 1-swimming lane; 2-water pump; 3-PVC pipe water outlet; 4-PVC pipe water inlet; 5-frequency converter; 6-rectifier; 7-blocking net; 8-camera; 10- Measured large yellow croaker.

Detailed ways

In order to make the technical solutions of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the implementation of the present invention. examples, but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1: A device for evaluating the swimming ability of large yellow croaker groups

Referring to FIG. 1, the present embodiment provides a device for evaluating the swimming ability of large yellow croaker groups, including: swimming lane 1, water pump 2, PVC pipe water outlet 3, PVC pipe water inlet 4, frequency converter 5, rectifier 6, net 7, camera 8. Evaluation area 9.

Swimming lane 1 is placed on a horizontal plane, and seawater with a certain depth is injected into it; water pump 2 is connected to a PVC water pipe and placed in the swimming lane. The PVC pipe water outlet 3 and the PVC pipe water inlet 4 are parallel to the bottom surface of the swimming lane 1, and make it form a stable circulation inside the swimming lane; frequency converter 5. Connect the water pump 2, and control the size of the water flow in the swimming lane 1 by changing the power of the water pump 2; ; The camera 8 is placed just above the center of the swimming lane 1 to record the swimming behavior of the large yellow croaker in the swimming lane 1, which can be further analyzed through the video.

When in use, inject seawater into the swimming lane 1, turn on the water pump 2, the water flow enters the water pump 2 from the PVC pipe water inlet 4, and then flows out from the PVC pipe water outlet 3, forming a stable circulation inside the swimming lane 1. By changing the output frequency of the frequency converter 5, the output power of the water pump 2 is controlled to adjust the speed of the water flow inside the swimming lane 1. The water flow velocity corresponding to each output frequency can be measured by the flow meter.

The evaluation area 9 inside the swimming lane 1 is used to place the large yellow croaker 10 under test. The rectifier 6 forms a laminar flow in the evaluation area 9 , and the blocking net 1 prevents the large yellow croaker 10 under test from leaving the evaluation area 9 . Camera 8 records the swimming behavior of 9 large yellow croakers in the evaluation area throughout the whole process.

The swimming lane 1 used in this embodiment is made of acrylic, and is circular, with a height of 30 cm, an outer diameter of 80 cm, and an inner diameter of 40 cm. It should be noted that the use of acrylic material, circular ring, height 30cm, outer diameter 80cm, inner diameter 40cm swimming lane, is only a preferred implementation of this embodiment, the present invention is not limited to this, in other implementations Other sizes of lanes may also be used in the example.

The brand of the water pump 2 used in this embodiment is Sunsun, and the model is HLS-370. It should be noted that the use of a water pump with a brand of Sunsun and a model of HLS-370 is only a preferred implementation of this embodiment, and the present invention is not limited to this, and other brands and models of water pumps may also be used in other embodiments. water pump.

The brand of the frequency converter 5 used in this embodiment is Delta, and the model is EV4300-0.75G1. It should be noted that the use of a frequency converter whose brand is Delta and whose model is EV4300-0.75G1 is only a preferred implementation of this embodiment, and the present invention is not limited to this, and other brands may also be used in other embodiments. and models of inverters.

The aperture of the rectifier 6 used in this embodiment is 6.8 mm. It should be noted that the use of a rectifier with an aperture of 6.8 mm is only a preferred implementation of this embodiment, and the present invention is not limited to this. In other embodiments, the aperture of the rectifier can also be changed according to the size of the swimming lane.

Example 2: A method for evaluating the swimming ability of large yellow croaker groups

The swimming ability U _crit measurement scheme is shown in Figure 2, and the present embodiment provides a method for evaluating the swimming ability of large yellow croaker groups, wherein the specific steps are as follows:

1) Put the evaluation large yellow croaker population into the swimming lane with low flow rate (0.5BL.s ^-1 ) after adapting for 30min;

2) Swimming lane water flow speed is increased by 0.5BL.s ^-1 by frequency converter at every interval 5min;

3) After 6 stages, every interval 15min is increased by 1BL.s ^-1 of swimming lane water flow speed;

4) Quickly fish out the large yellow croaker that has reached the fatigue state during the evaluation period, and record the fatigue time and the water flow speed when fatigued;

5) The swimming ability U _crit of the individual large yellow croaker is obtained by the following formula:

U _crit =V ₁ +(t ₁ /T)V

Among them, V ₁ is the water flow velocity of the individual large yellow croaker in the pre-fatigue stage; V is the increment of the water flow velocity; T is the time interval; t ₁ is the swimming time of the large yellow croaker in the fatigue stage.

In addition, a specific embodiment will be given below in combination with the device provided in Embodiment 1 and the method provided in Embodiment 2, and the specific embodiment also describes the operation process of the device provided in Embodiment 1 in detail.

Using 3-month-old large yellow croaker (Larimichthys crocea) as the fish used, the specific steps are as follows:

1) Connect and energize the components of a device for evaluating the swimming ability of large yellow croaker groups as required, inject 20cm deep seawater into swimming lane 1, turn on water pump 2 and frequency converter 5, wait for a stable circulation to form in swimming lane 1, and pass the flow meter Measure the corresponding water flow speed inside swimming lane 1 under each output frequency of inverter 5;

2) Use a tripod to fix the camera 8 just above the evaluation area 9, and during the entire evaluation period, the evaluation area 9 is recorded by the camera 8 throughout the whole process;

3) Select 100 3-month-old large yellow croakers with a body weight (BW) of 2.30±0.43g and a body length (BL) of 5.86±0.50cm;

4) Adjust the output frequency of the frequency converter 5 so that the water flow speed in the swimming lane 1 is 0.5BL/s, that is, 3cm/s, and then place 100 large yellow croaker groups in the evaluation area 9 for 30 minutes;

5) After the adaptation, adjust the output frequency through the frequency converter 5 every 5min to increase the speed of the water flow in the swimming lane 1 by 0.5BL/s;

6) After repeating step 2) for 6 stages, the output frequency is adjusted by the frequency converter 5 every 15min, so that the water flow speed in the swimming lane 1 is increased by 1BL/s;

7) During the whole evaluation period, the large yellow croaker that has reached a state of fatigue (that is, the large yellow croaker cannot continue to do top-current swimming behavior, is washed by the current to the end of swimming lane 1 and blocked on the net 7 and cannot leave for more than 5s) will be quickly fished out and recorded. Fatigue time and water flow speed when fatigued;

8) The swimming ability U _crit of the individual large yellow croaker is obtained by the following formula:

U _crit =V ₁ +(t ₁ /T)V

Among them, V ₁ is the water flow velocity of the individual large yellow croaker in the pre-fatigue stage; V is the increment of the water flow velocity; T is the time interval; t ₁ is the swimming time of the large yellow croaker in the fatigue stage.

9) The swimming ability of 100 3-month-old large yellow croaker groups can be obtained through the calculation formula, see Figure 3.

The above-mentioned embodiments are only preferred embodiments of the present invention, and should not be construed as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still belong to the scope of the patent of the present invention.

Claims (9)

1. a device for evaluating the swimming ability of large yellow croaker groups, is characterized in that comprising: swimming lane, water pump, PVC water pipe, frequency converter, rectifier, blocking net, camera; swimming lane is placed on a horizontal plane, and injected into seawater; The PVC water outlet and PVC water inlet are parallel to the bottom surface of the swimming lane, and make it form a stable circulation inside the swimming lane; the frequency converter is connected to the water pump, and the water flow inside the swimming lane is controlled by changing the power of the pump; the rectifier is placed at the head end inside the swimming lane to form Laminar flow; the net is placed at the inner end of the swimming lane to block the large yellow croaker; the camera is placed directly above the swimming lane to record the swimming behavior of the large yellow croaker in the swimming lane, and further analysis is performed through the video. 2. A device for evaluating the swimming ability of large yellow croaker groups as claimed in claim 1, wherein the swimming lane is a circular ring, and the material is an acrylic plate. 3. A device for testing and evaluating the swimming ability of large yellow croaker groups according to claim 1, wherein the water pump adopts a land water pump, and the maximum power is variable to achieve the required maximum water flow speed. 4 . The device for evaluating the swimming ability of large yellow croaker groups according to claim 1 , wherein the power of the frequency converter is greater than the power of the water pump. 5 . 5. A device for evaluating the swimming ability of large yellow croaker groups according to claim 1, characterized in that the PVC water pipe is made of hard material, is not easily deformed, and can stabilize the direction of the water flow. 6. A device for evaluating the swimming ability of large yellow croaker groups according to claim 1, characterized in that the rectifier is made of corrosion-resistant stainless steel, and the shape is honeycomb, so as to facilitate the generation of laminar flow. 7 . The device for evaluating the swimming ability of large yellow croaker groups according to claim 6 , wherein the honeycomb-shaped aperture of the rectifier is 6.8 mm. 8 . 8. a kind of device of testing and evaluating large yellow croaker group swimming ability as claimed in claim 1 is characterized in that described blocking net adopts nylon soft material, to reduce the damage to fish body, and blocking net aperture is less than the measured large yellow croaker size, so as to avoid large yellow croaker. escape. 9. a method for evaluating the swimming ability of large yellow croaker group is characterized in that the steps are as follows: 1) Put the evaluation large yellow croaker group into the swimming lane at a low flow rate of 0.5BL.s ^-1 to adapt for 30 minutes, and the adaptation time can be extended until all evaluation large yellow croakers show normal swimming behavior; 2) Swimming lane water flow speed is increased by 0.5BL.s ^-1 by frequency converter at every interval 5min; 3) After 6 stages, every interval 15min is increased by 1BL.s ^-1 of swimming lane water flow speed; 4) During the whole evaluation period, the large yellow croaker that has reached the fatigue state is quickly taken out, and the fatigue time and the water flow speed when fatigued are recorded. The fatigue state means that the large yellow croaker is unable to perform top-current swimming behavior and is washed to the end of the swimming lane by the current. Can't leave on the block for more than 5s; 5) The swimming ability U _crit of the individual large yellow croaker is obtained by the following formula: U _crit =V ₁ +(t ₁ /T)V Among them, V ₁ is the water flow velocity of the individual large yellow croaker in the pre-fatigue stage; V is the increment of the water flow velocity; T is the time interval; t ₁ is the swimming time of the large yellow croaker in the fatigue stage.

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