CN111896066A - A method for rapid and accurate determination of the shell cavity volume of bivalve molluscs - Google Patents

Abstract

The invention provides a method for rapidly and accurately measuring the volume of bivalve mollusk shell cavity, which relates to the field of aquatic shellfish breeding. The shell cavity of bivalve mollusks is filled with agar gel, which can describe the details in the shell cavity. By measuring the density of the agar gel and weighing to obtain the weight of the gel filled in the shell cavity, it is convenient to calculate and obtain bivalve mollusks. The exact volume of the shell cavity. The invention can process a large number of samples at one time, has high throughput, the used agar can be recycled and reused, all required are conventional equipment, and it has universal applicability to the rapid and efficient determination of the shell cavity volume of bivalve molluscs, The relevant shell cavity volume data can be used to quickly and accurately obtain the condition index traits of bivalve molluscs, and provide an effective method for the rapid and accurate acquisition of relevant traits in shellfish breeding.

Description

A method for rapid and accurate determination of the shell cavity volume of bivalve molluscs

technical field

The invention relates to the field of aquatic shellfish breeding, in particular to a method for rapidly, efficiently and accurately measuring the shell cavity volume of bivalve molluscs.

Background technique

The bivalve mollusks have various shapes and are generally irregular. When the bivalve is closed, it is difficult to measure the volume of the shell cavity due to the existence of the soft body. In shellfish breeding, bivalve mollusks often use the plumpness index to describe the plumpness of the soft body. The plumpness index, also called the condition index, is generally expressed as the ratio of the dry matter mass of the soft body to the volume of the shell cavity. It is an important reference for the breeding process of bivalve mollusks, such as harvesting and egg collection, and is also an important breeding indicator. Accurately obtaining the shell cavity volume of bivalve mollusks is a necessary prerequisite for obtaining an accurate plumpness index.

The methods used in the volume measurement of bivalve mollusks in the past include the drainage method, the weighing method, and the exhaust method. In addition, there are also methods to measure the volume of bivalve mollusks by means of salt filling method, but these methods have the disadvantage of being complicated to operate and unable to obtain a large amount of data quickly, efficiently and accurately. The drainage method was more commonly used in the early days, and the volume of the whole oyster or shell can be directly obtained by measuring the drainage volume. Due to the human error of the operator and the accuracy of measuring the container, this method is gradually replaced by the weighing method combined with the liquid discharge (ZL 201310612214.X), and the method of obtaining the volume by subtracting the shell volume from the total volume is subject to weighing The accuracy and range are limited, the error is large, and due to the limitation of the container, it is difficult to measure large individuals or special-shaped shellfish.

Therefore, the development of a rapid and accurate method to measure the shell cavity volume of bivalve molluscs is an important factor to improve the efficiency of obtaining condition index in shellfish breeding.

SUMMARY OF THE INVENTION

The invention provides a method for rapidly and accurately measuring the shell cavity volume of bivalve molluscs. The method uses agar gel to directly shape the shell cavity of bivalve mollusks, and obtains bivalve mollusks quickly and accurately by weighing. Shell cavity volume.

For achieving the above purpose, the concrete technical scheme adopted in the present invention is as follows:

(1) Preparation of agar gel: use distilled water to prepare agar gel with a concentration of 1%, heat and boil for 5min-6 on high heat (heating and boiling at 90-100℃), heat on low heat (heating at 70-80℃) for 10-12min fully Stir and let stand for 5-10 minutes to discharge the air bubbles in the agar gel. After no air bubbles remain, put the standard volume container with the pre-approved volume (V _mark ) and weighing weight (W _mark ) that is not suitable for thermal deformation into the agar gel middle;

(2) Treatment of the sample to be tested: After dissecting the bivalve sample to be tested, remove the soft body, combine the remaining bivalves, and use a thread (thin thread such as scouring thread, fish silk thread, etc.) to wrap the outer part of the bivalve shell to make It is fixed, and the tightness of the binding is subject to the opening ability of 1-5mm after the double shells are combined at the part farthest from the twisted part;

(3) Immersion of agar gel: Use tweezers to place the twisted part of the bivalve sample to be tested downward, slowly immerse it into agar gel with a temperature higher than 85°C, and after the air in the shell cavity is exhausted, the bundled thin wires are closed. Immediately after the bivalves are tightly merged, sink into the agar gel. According to the volume of the container and the gel, multiple samples of bivalve mollusks can be simultaneously immersed;

(4) Determination of the density of the agar gel: heat the gel again to a slight boiling state for 1-2 minutes, and use tweezers to turn the bivalve mollusk sample (about 3-8 minutes) to exhaust the remaining air in the shell cavity, and then cool the agar After the gel is melted to room temperature, the bivalve mollusk samples are taken out from the agar gel, and the agar gel filled in the shell cavity is peeled off; at the same time, the standard volume container is peeled off from the agar gel, and the surface agar is removed. Then, weigh the weight again (W _{(mark + gel)} ), the weight of the agar gel in the standard volume container W _gel = W _{(mark + gel)} - W _mark , calculate the agar gel density ρ _gel = W _gel /V _mark (unit: g/cm ³ );

(5) Calculation of shell cavity volume: weigh the agar gel filled in the shell cavity in step (4) on an electronic balance, and weigh W _{shell cavity gel} (unit: g); calculate the shell cavity volume V _{Shell cavity} = W _{shell cavity gel} /ρ _gel (unit: cm ³ ).

The agar gel concentration in the step (1) is suitable, taking into account the fluidity of the hot melt adhesive and the hardness after cooling, fully stirring, and discharging air bubbles after standing to ensure uniform gel density;

The processing of the sample to be tested in the step (2) ensures that the double shell maintains a small gap, which is convenient for gas discharge;

The method of immersing the agar gel in the step (3): adding and keeping the temperature of the agar gel at not lower than 85°C, when the sample is immersed, the twisted part needs to be slowly immersed into the gel;

The determination of the density of the agar gel in the step (4): due to the influence of the heating time, etc., a standard volume container of known weight needs to be put in each time, and the standard volume gel is obtained by weighing the total weight after the agar gel is filled. The weight of the gel, the final density ρ of the agar gel can be obtained;

The advantages of the present invention:

The technical method provided by the invention is to fill the shell cavity of bivalve mollusks with agar gel by using the characteristics of high concentration agar gel flowing at high temperature and low temperature solidification, and filling the gel with the density of the gel and the shell cavity. to obtain the exact volume of the bivalve shell cavity. The technical principle is simple and reliable, and the operation is simple and easy. The required equipment and containers are all conventional equipment in laboratories or seedling enterprises. The agar used is non-toxic and harmless, and can be recycled and reused. It is suitable for a wide variety of bivalve mollusks and a large size range, which is not limited by the size of the measuring container; it has wide applicability.

The gel in the present invention has the advantages of low price and various proportions and concentrations. The price of 500 g of agar is only tens of yuan. The gel of 1% can be configured with 50 L of gel, which is enough to fill 1250 samples with an average shell cavity volume of 40 ml. , the average cost per sample is only a few cents; due to the characteristics of agar gel, it has good fluidity and immersion after heating, and can be heated and dissolved in an induction cooker or microwave oven, and the operation is simple; after solidification, it is easy to peel off from the sample to be tested, use It can be recycled later, and the density is uniform and controllable.

Other software such as plasticine, rubber, sludge, etc. need to be manually filled into the shell cavity due to the characteristics of solids during use. Due to the operation and extrusion of different personnel, it is easy to cause uneven density of the software, and due to the unevenness of the shell cavity. rules, resulting in poor measurement accuracy, complex operation, high density, low measurement speed and poor accuracy. Although cement, resin and other fluids have fluidity and invasiveness, they are one-time molding materials with complicated operation and long setting time; not only cannot be recycled after use, but also inconvenient to peel due to their strong adhesion properties.

Description of drawings

Figure 1 is a picture of a sample of oysters with closed double shells peeled off after being immersed in agar gel and cooled.

Figure 2 is a picture of the agar gel filled and solidified in the cavity of the oyster shell after peeling off the double shell.

Detailed ways

Example 1

The following examples take oysters as objects, and further illustrate the present invention, and the present invention can also be used for the rapid and accurate determination of the shell cavity volume of other bivalve molluscs:

1. Prepare electric furnace, 2L beaker, agar powder, distilled water, balance, 5ml standard container, thin wire;

2. Use distilled water to prepare 1% agar gel, heat at 95°C until the agar powder is fully melted for 5 minutes, heat at 80°C for 10 minutes, stir evenly, and let stand for 8 minutes to remove air bubbles; weigh 5ml standard container to 27.58g, put into agar gel glue;

3. 6 oysters to be tested, dissect and remove the soft body, after cleaning, match the left and right shells, wrap the thin wire around the shell and double shells, and bundle the outer shells, so that the tightness of the binding is 1mm from the part farthest from the twisted part after the double shells are combined. The opening capacity of the oyster gel shall prevail, the twisted part is immersed downward into the agar gel to discharge the air in the cavity, and then the thin wire is tightened; slowly heat and stir again, so that the agar gel is fully immersed in the oyster shell cavity, and the possible remaining air is discharged, and cooled. After the agar gel is melted to room temperature, the bivalve mollusk sample is taken out from the agar gel, and the agar gel filled in the shell cavity is peeled off;

4. Cool the agar gel, after peeling off the oyster shell and the standard container, after cleaning the standard container surface agar, the weighing weight is 30.67g; Calculate this agar density ρ _gel =0.978 (g/cm ⁾ ;

5. Open the oyster shell, carefully peel off the agar gel in the cavity of each oyster shell and weigh it separately;

6. Calculate each oyster shell cavity volume V _oyster . The following table:

The existing methods for measuring the volume of the shell cavity of bivalve mollusks mostly use the drainage method and the weighing method. Reference [Xu Fei, et al. Comparison of two measurement methods for the volume of the oyster shell cavity [J]. Ocean Science, 2007, 31( 7): 15-19], one is to measure the volume of the liquid discharged after the oyster is immersed in the liquid by directly using the measuring device. This method is limited by the shape of the oyster or other bivalve molluscs, and the capacity requirements of the measuring device vary greatly, and a large number of The measurement accuracy of the measuring device cannot be guaranteed, resulting in low measurement accuracy, and it is not suitable for direct measurement of the volume of the shell cavity. The weighing method or the indirect weighing method (ZL 201310612214.X) uses an electronic balance to directly measure the change in the weight of the discharged water after immersing oysters or bivalve molluscs in liquid to directly and indirectly obtain the volume of the oyster shell and the volume of the shell cavity. Due to the changes in the airtightness of bivalve shells after dissection, related methods cannot directly and accurately obtain the shell cavity volume data.

The method of filling in the shell cavity has also been reported, [Yang Hongwei, et al. Measurement of the shell cavity volume of bivalve mollusks using the salt filling method [J]. Environmental Science Guide, 2013, 32(05): 10-13. ], using the method of measuring the volume of shellfish shell cavity with table salt as the filling (salt filling method), and using the "water volume method" to verify. Each sample measured by this type of method needs to be determined that the salt particles are adequately filled in the shellfish cavity and that there are no leaks in order to ensure the accuracy of the measured data. The operation is complicated, the throughput is low, and the measurement cannot be carried out quickly and in large quantities.

Compared with the above methods, this method innovatively utilizes the characteristics of agar gel flow at high temperature and low temperature solidification, and fills the shell cavity of bivalve mollusks with agar gel by the immersion method, which can describe the characteristics of the agar gel in the shell cavity. For details, by measuring the density of the agar gel and weighing to obtain the weight of the gel filled in the shell cavity, it is convenient to calculate the accurate volume of the shell cavity of bivalve mollusks. The invention can process a large number of samples at one time, has high throughput, the used agar can be recycled and reused, all required are conventional equipment, and it has universal applicability to the rapid and efficient determination of the shell cavity volume of bivalve molluscs, The relevant shell cavity volume data can be applied to the rapid and accurate acquisition of the condition index traits of bivalve molluscs, which provides an effective method for the rapid and accurate acquisition of the relevant traits of shellfish breeding.

The above are specific embodiments of the invention, but the design concept of the present invention is not limited to the measurement of the cavity volume of oyster shells, and has applicability to the measurement of the cavity volume of bivalve mollusks. Insubstantial changes shall be regarded as acts infringing the protection scope of the present invention.

Claims (5)

1. A method for rapidly and accurately measuring the volume of a bivalve shell cavity is characterized in that: the method comprises the following steps:

(1) preparation of agar gel: preparing 1% agar gel with distilled water, boiling at 90-100 deg.C for 5-6min, heating at 70-80 deg.C for 10-12min, stirring, standing for 5-10 min to discharge bubbles in agar gel, and checking volume (V)_{Sign board}) And weighing (W)_{Sign board}) Into agar gel in a standard volume container;

(2) treatment of a sample to be tested: dissecting the to-be-detected bivalve shellfish sample, removing the soft part, combining the rest bivalves, winding the outer part of the bivalve shellfish with a wire to fix the bivalve shellfish, wherein the binding tightness degree is based on the opening capacity of 1-5mm after the bivalve shellfish at the position farthest from the twisting part is combined;

(3) immersion of agar gel: using a pair of tweezers to enable the twisting part of the bivalve shellfish sample to be detected to be downward, slowly immersing the bivalve shellfish sample into the agar gel with the temperature higher than 85 ℃, removing air in the shell cavity, tightening the binding thin lines until the bivalve shellfish sample is tightly combined, and then sinking the binding thin lines into the agar gel;

(4) determination of agar gel density: heating the gel again to boiling state for 1-2min, turning over bivalve shellfish sample with tweezers to discharge residual air in the shell cavity, cooling agar gel to room temperature, and collecting bivalve shellfish sampleTaking out the agar gel, and stripping the agar gel filled in the shell cavity; at the same time, the standard volume container was peeled off the agar gel, and after removing the surface agar, the weight was again measured (W)_{(Label + gel)}) Weight W of agar gel in Standard volume vessel_Gel＝W_{(Label + gel)}-W_{Sign board}And calculating to obtain the density rho of the agar gel_Gel＝W_Gel/V_{Sign board}(unit: g/cm)³)；

(5) Calculation of the volume of the shell cavity: weighing the agar gel filled in the shell cavity in the step (4) on an electronic balance, and weighing W_{Shell cavity gel}(unit: g); calculating to obtain the volume V of the shell cavity_{Shell cavity}＝W_{Shell cavity gel}/ρ_Gel(unit: cm)³)。

2. The method for rapidly and accurately measuring the volume of the bivalve shellfish shell cavity as recited in claim 1, wherein: the concentration of the agar gel in the step (1) is 1 percent; heating at 70-80 deg.C for 10min, stirring, standing for 8min to ensure the discharge of bubbles in the gel.

3. The method for rapidly and accurately measuring the volume of the bivalve shellfish shell cavity as recited in claim 1, wherein: in the step (2), the binding tightness degree is based on the opening capacity of 1mm after the two shells are combined, so that the air in the shell cavity is conveniently discharged.

4. The method for rapidly and accurately measuring the volume of the bivalve shellfish shell cavity as recited in claim 1, wherein: the method for immersing the agar gel into the shell cavity in the step (3) comprises the following steps: slowly immersing the shell twisted part downwards into agar gel at the temperature of 90 ℃, discharging air in the shell cavity, and tightening the thin line until the two shells are tightly combined.

5. The method for rapidly and accurately measuring the volume of the bivalve shellfish shell cavity as recited in claim 1, wherein: and (3) simultaneously sinking a plurality of bivalve shellfish samples according to the container and the gel volume.

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