A sampling device for the crawling stage of shellfish larvae

Abstract

This invention discloses a sampling device for the crawling stage of shellfish larvae, comprising a hollow tube, a one-way valve at the front end of the hollow tube, a sample storage bottle located below the front end of the hollow tube, and an adjustable air valve and piston located at the rear end of the hollow tube. The use of this device will greatly assist shellfish seedling cultivation, saving time and manpower: for large seedling ponds, sampling personnel no longer need to enter the water; for deep water, there is no need to drain the water for sampling; the sampling area is precisely controllable; there is no longer concern that the water volume in the collected sample will be much larger than the target material (bottom mud, sediment, etc.); at the same time, the impact of sampling on the seedling water body is minimized.

Description

Technical Field

[0001] This invention relates to a sampling device for the crawling stage of shellfish larvae, belonging to the field of aquatic artificial seedling cultivation. Background Technology

[0002] Burrowing mollusks undergo several stages from fertilized egg to larvae: Male and female gametes combine in the water to form a suspended fertilized egg, which cleaves to form an embryo, developing into a motile larva and gradually beginning to feed; at this stage, the larvae live a planktonic life. After a period of further development, the legs gradually form and begin to function, at which point the larvae transition to a benthic life, known as the crawling stage. Accurately determining the developmental stage of mollusks larvae is extremely helpful in guiding a series of tasks in seedling cultivation, such as feed selection and environmental maintenance. In actual seedling cultivation, the limited area and depth of the seedling pond make direct sampling of the water and sediment from the bottom extremely difficult. Current methods mainly involve using long tubes for suction or extended containers for retrieval. These operations collect large amounts of samples from other water bodies and may even lead to the loss of samples from the target area, resulting in significant uncertainty and unsatisfactory results. Furthermore, the sediment in the seedling pond is only a thin layer of floating mud, making collection difficult and easily causing significant disturbance to the sediment, which is detrimental to seedling cultivation. Patent application "Application No.: 201611045302.6, Invention Title: A Sampling and Observation Device for Buried Mollusk Juveniles and Its Manufacturing and Usage Method" describes a method of obtaining samples by blocking and releasing the pipe opening with a finger to allow water to flow into the pipe, followed by filtration of the water. However, ordinary pipes are insufficient for deep water, and in large water bodies, staff may need to enter the nursery pond for operation. These situations limit sampling efficiency and cause significant disturbance to the water body, especially the substrate where juvenile mollusks inhabit, which is detrimental to nursery work. Therefore, there is an urgent need for a sampling device for mollusk larvae during the crawling stage that solves the problem of difficult sampling and observation after larvae sink to the bottom (crawling stage), improves efficiency, and reduces workload. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a sampling device for the crawling stage of shellfish larvae.

[0004] Technical solution: The present invention provides a sampling device for the crawling stage of shellfish larvae, comprising a hollow tube, a one-way valve disposed at the front end of the hollow tube, a sample storage bottle disposed below the front end of the hollow tube, and an adjustable air valve and piston disposed at the rear end of the hollow tube.

[0005] The one-way valve is fixed to the inner wall of the hollow tube to prevent the obtained water sample from flowing out of the opening at the front end of the device.

[0006] The sample storage bottle has an opening at the bottom and is covered with a filter screen to filter out the water inside the bottle and capture particles of the target size.

[0007] The filter screen is fixed to the bottom of the sample storage bottle by the bottle cap.

[0008] The hollow tube is equipped with a one-way valve at the connection between it and the sample storage bottle to prevent the water sample collected in the sample storage bottle from flowing out again.

[0009] The adjustable air valve is a combination of a glass bead and a rubber tube, with the glass bead located inside the rubber tube and having a larger inner diameter than the rubber tube. Under normal conditions, the rubber tube remains sealed; when the glass bead is squeezed, a gap is created in the rubber tube. Squeezing adjusts the airtightness of the sampling device for the crawling stage of shellfish larvae, and the pressure difference drives the water sample to flow within the device.

[0010] The hollow tube has an opening on its side at the tail end, and an adjustable air valve is connected to the opening.

[0011] The hollow tube is a telescopic tube, which allows for flexible adjustment of the device length to adapt to different usage scenarios.

[0012] The hollow tube has a roller at its extended end, which is located on the same side as the sample storage bottle, making it convenient for the sampling device to move along the bottom of the water during the crawling stage of shellfish larvae.

[0013] The larvae mentioned are burrowing bivalve larvae. This device can be used for sampling once these larvae transition from a planktonic to a benthic, crawling stage. It mainly includes most species of the Veneridae order of bivalve mollusks that are already artificially bred, as well as some organisms with similar habits from the Bivalvia and Gastropoda classes.

[0014] The core pain points of existing technologies lie in the difficulty of long-distance sampling and the difficulty of effectively preserving the collected water samples. This invention addresses these two problems with the following design: 1. An air valve device consisting of a rubber tube and a glass bead is added to the end of the long tube (handheld side), with full consideration given to the airtightness of the device. By squeezing the glass bead, the pressure inside the tube is changed, drawing the water sample into the tube and preserving it. 2. A container device is added to the front end of the long tube (sampling side) and connected to the tube, creating space to accommodate the collected water sample. An openable bottle cap is designed at the bottom of the container for easy removal of the collected water sample.

[0015] In this invention, both the air valve 8 and the piston 9 must be present. If only the air valve 8 is present, the operation of the one-way valve 3 and the one-way valve 4 cannot be accurately controlled; if only the piston 9 is present, the amount of water drawn in is entirely related to the movement of the piston. In order to draw in the same amount of water, the range of movement of the piston needs to be greatly extended. Moreover, once the device starts working, the pressure inside the device is entirely regulated by the piston, and the gas volume is completely fixed.

[0016] In addition, two one-way valves are installed inside the pipe, and a piston is installed in front of the piston at the end of the long pipe (handheld side) to allow for more flexible control of the pressure and water flow direction in the pipe. A telescopic module is added to the middle section of the pipe to facilitate application in various scenarios. Since this device uses pressure to extract water, the threads of the telescopic component in the middle section of pipe 7 must be tightly engaged for a strict airtight seal; the diameter of the rubber tube of the air valve 8 must be suitable for the diameter of the glass bead, with the glass bead diameter slightly larger than the inner diameter of the rubber tube. The rubber tube must be tightly fitted onto the air nozzle of the pipe for a strict airtight seal, similar to an alkaline burette; the diameter of the piston 9 must match the inner diameter of pipe 7 for a strict airtight seal.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The use of this device will greatly assist the shellfish seedling cultivation work, saving time and manpower: When facing a large seedling pond, sampling personnel no longer need to enter the pond to work; when facing deep water, there is no need to drain water for sampling; the collection area is precise and controllable; there is no longer any concern that the water volume in the collected sample is much larger than the target object (bottom mud, sediment, etc.); at the same time, the impact of sampling work on the seedling water body is minimized. Attached Figure Description

[0018] Figure 1 This is a sampling device for the crawling stage of shellfish larvae. Detailed Implementation

[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0020] like Figure 1As shown, the main body of the sampling device for the crawling stage of shellfish larvae is a hollow tube 7. The hollow tube 7 is telescopic, allowing for flexible adjustment of the device length to adapt to different usage scenarios. The front end of the hollow tube 7 has an opening 1 for drawing water samples. A one-way valve 3 is located at the front end of the hollow tube, fixed to the inner wall of the hollow tube 7, 1-2 cm from the opening 1, to prevent the collected water sample from flowing out of the front opening. An opening is located at the bottom of the front end of the hollow tube 7, connecting to a sample storage bottle 5, where the collected water sample can be temporarily stored. The bottom of the sample storage bottle 5 has an opening covered with a filter screen. Since the juvenile shellfish grow, the pore size of the filter screen is not fixed, and the filter screen can be replaced at any time. The pore sizes of the filter screen are mainly divided into 300 micrometers, 400 micrometers, 500 micrometers, 750 micrometers, and 1000 micrometers. The filter screen is fixed to the bottom of the sample storage bottle 5 by a bottle cap 6. The inner wall of the cap 6 is threaded, complementing the threads on the outer ring of the sample storage bottle 5, ensuring that the cap 6 can be fixed to the bottom of the sample storage bottle 5. The bottom of the cap 6 is completely hollow, exposing the filter screen, which filters out the water in the sample storage bottle 5 and captures particles of the target size. A one-way valve 4 is provided at the connection between the hollow tube 7 and the sample storage bottle 5 to prevent the water sample collected in the sample storage bottle from flowing out again. A roller 2 is provided at the extension of the tube opening 1 of the hollow tube 7, located on the same side as the sample storage bottle 5, to facilitate the movement of the sampling device for the crawling stage of shellfish larvae along the bottom of the water. The tail end of the hollow tube 7 has an opening, which is connected to an adjustable air valve 8. A combination of glass beads and rubber tubing is used, where the glass beads are slightly larger in diameter than the rubber tubing. Under normal conditions, the rubber tubing remains sealed. When the glass beads are squeezed, a gap is created in the rubber tubing. By squeezing, the airtightness of the sampling device for the crawling stage of shellfish larvae is adjusted, and the water sample is driven to flow within the device by the pressure difference. A piston 9 is located at the opening of the hollow tube 7. This piston changes the internal pressure of the device, driving the water sample to flow within it. In conjunction with the one-way valve 3, the water sample ultimately flows into the sample storage bottle. The piston 9 has a certain range of motion. Initially, the piston 9 is at the deepest point of the hollow tube 7. After water flows into the device under the control of the adjustable air valve 8, the adjustable air valve 8 is closed. The piston 9 is then moved outward from the deepest point to draw in more water. The piston 9 is then moved to the deepest point again. At this point, the one-way valve 3 is closed and the one-way valve 4 is opened, allowing water to flow into the sample storage bottle 5. After filtration, some water flows out of the device, while the desired sample is retained on the filter screen 6. Additionally, if needed, the adjustable air valve 8 can be opened, and the piston 9 can be moved to adjust the internal pressure of the device without changing the amount of water inside. The device pressure and the water-to-gas ratio can be flexibly adjusted according to requirements.

[0021] During use, when the sampling device for the crawling stage of shellfish larvae is submerged in water, the entire device is airtight, preventing large amounts of water from entering. When the tube opening 1 reaches the target sampling site, the air inside the device is connected to the atmosphere through a rubber tube, and water naturally flows into the hollow tube 7 under atmospheric pressure. Adjust the hollow tube 7 to the appropriate length, hold the end and probe the front end to the bottom of the water, using the roller to assist the tube opening 1 in moving along the bottom. Submerge the tube opening 1 completely into the bottom, and once it touches the bottom, open the adjustable air valve 8 to allow water to be naturally drawn into the tube. When the piston 9 is at the deepest point of the hollow tube 7, and the adjustable air valve 8 is closed, the air pressure prevents large amounts of water from entering the hollow tube 7 when the tube opening 1 is submerged. Upon reaching the target sampling point, open the air valve 8, allowing a large amount of water to enter the hollow tube 7. After stabilization, adjust the air valve 8 to move the piston 9 from the deepest point outwards, further increasing the water volume inside the device. Pushing further into the deepest part, the water flow forces the one-way valve 3 to close and the one-way valve 4 to open, allowing the water to enter the sample storage bottle 5. After passing through the bottle cap 6 for filtration, some water flows out of the device, while the required sample (i.e., shellfish seedlings) will be completely trapped on the filter screen of the sample storage bottle cap. The sample is then removed and collected for the next step.

[0022] In response to four seedling ponds (clams) Cyclina sinensis In the practical application of this invention, to verify its effectiveness, two traditional methods and a new device were used to assist in seedling cultivation in each pond. Relevant data were recorded, and the results are as follows: ① After 15 aspirations using the long tube from the previous patent application (application number: 201611045302.6), a 1L beaker was filled with water samples. After filtration, the target sample was aspirated into two 5mL pipettes, yielding approximately 2mL of effective sample. A drop was examined under a microscope, revealing over 110 juvenile shellfish (live + empty shells). ② The bottom sediment was directly scooped from the seedling pond. Extreme caution was required during this process; the bottom mud needed to be thoroughly stirred before stepping in. Due to the thin bottom sediment, collection was extremely difficult. Five 100cm sections of sediment were collected. 2 Approximately 14 mL of actual effective sample was collected from the area. One drop was examined under a microscope, revealing over 90 juvenile clam shells (live and empty). ③ Using the device designed in this invention, sampling was performed, covering an area of ​​approximately 120 cm² of the seabed in one minute. 2 Approximately 8 mL of actual effective sample was collected. One drop was examined under a microscope, and more than 140 juvenile clam shells (live and empty) were found.

[0023] Table 1. Water volume, time, and effect of different methods for collecting 1 mL of effective sample

[0024] Note: ① Data is derived from the average of samples taken from four nursery ponds. ② Since water sampling and filtration are both completed within the device, the water sample volume collected by the device is not recorded. ③ The number of juvenile shellfish is the number of all identifiable juvenile shellfish in 1 mL of valid sample, including live and empty shells, counted under a microscope. ④ Time is recorded from the start of sampling until the valid sample is dropped onto the slide.

Claims

1. A device for sampling the creeping stage of bivalve larvae, characterized in that, It includes a hollow tube (7), a one-way valve (3) located at the front end of the hollow tube (7) (1), a sample storage bottle (5) located below the front end of the hollow tube (7), an adjustable gas valve (8) located at the rear end of the hollow tube (7), and a piston (9).

2. A device for sampling the creeping stage of bivalve larvae according to claim 1, characterised in that, The one-way valve (3) is fixed on the inner wall of the hollow tube (7).

3. The device for sampling of the larval spat stage of shellfish according to claim 1, characterized in that, The bottom of the sample bottle (5) is provided with an opening and covered with a filter screen.

4. The sampling device for the crawling stage of shellfish larvae according to claim 3, characterized in that, The filter screen is fixed to the bottom of the sample bottle (5) by the bottle cap (6).

5. The sampling device for the crawling stage of shellfish larvae according to claim 1, characterized in that, A one-way valve (4) is provided at the connection between the hollow tube (7) and the sample bottle (5).

6. The sampling device for the crawling stage of shellfish larvae according to claim 1, characterized in that, The adjustable air valve (8) is a combination of a glass bead and a rubber tube, with the glass bead located inside the rubber tube and having a larger inner diameter than the rubber tube.

7. The sampling device for the crawling stage of shellfish larvae according to claim 1, characterized in that, The hollow tube (7) has an opening on the side of its tail end, and an adjustable air valve (8) is connected to the opening.

8. The sampling device for the crawling stage of shellfish larvae according to claim 1, characterized in that, The hollow tube (7) is a telescopic tube.

9. The sampling device for the crawling stage of shellfish larvae according to claim 1, characterized in that, The hollow tube (7) has a roller (2) at the extension of the tube opening (1), which is located on the same side as the sample bottle (5).

10. The sampling device for the crawling stage of shellfish larvae according to claim 1, characterized in that, The larvae mentioned are larvae of burrowing bivalve mollusks.

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