JP5641460B1 - Artificial egg-laying equipment for medaka - Google Patents

Abstract

The present invention relates to a medaka egg-laying bed that can be procured and efficiently collected for observation and research because a large number of eggs and egg-laying beds are required for medaka observation and research conducted in elementary school. [Means for solving the problems] By using the habits of medaka, we found the conditions of the egg-laying bed that would like to lay eggs and created an artificial egg-laying bed. We provide an artificial egg-laying device for medaka that is easy to collect eggs and is useful for observation and research by connecting to a support frame with easy floating members. [Selection] Figure 1

Description

The present invention relates to an artificial egg-laying apparatus for medaka, and in particular, for collecting eggs of medaka for observation and research in elementary school, it is easy to concentrate and lay eggs using the habit of medaka, and eggs laid. The present invention relates to an artificial egg-laying apparatus for medaka that is easy to collect eggs and is small and easy to use.
The present invention relates to an artificial egg-laying apparatus for medaka that can be easily obtained and created without a shortage of the artificial egg-bed required for observation and research at the same time.

To collect medaka, there is a method of capturing the medaka that has been embraced and collecting fertilized eggs directly on the belly (hidden genital ostium) by hand or brush. However, the method of capturing the medaka that has been laid and collecting it from the belly is likely to hurt the fish body and may cause the medaka to be weakened and die if stressed repeatedly. It is difficult to adopt for elementary school learning because it is an advanced method carried out in an institute.

Traditional methods used as a spawning bed for medaka include taking and collecting water spider water hyacinths floating on the surface of the water and spawning on the roots that protrude below the surface of the water. Is used as a method of placing in water and laying eggs on leaves and stems. Many of these methods have been incorporated into science studies conducted by fifth graders.
However, in those methods, water hyacinths, pine trees, etc. used in plants are plants and grow, change shape, and depending on the season, it is difficult to obtain uniform shapes, and in winter, they die. There was a problem that the plant was broken by handling and damaged the plant.

In addition, there is a palm fiber as a material for the egg-laying bed, and there is a method of bundling and shaping, placing it on the surface of the water or in the water, taking out eggs spawned on a large number of fiber parts, and collecting eggs. When not, some enthusiasts procure and use similar natural palm fiber as a substitute.
However, it is difficult to procure shell fibers as raw materials, and there is a substitute natural palm fiber, but there is a problem that it is difficult to process such as scattering at the time of modeling.

Further, Patent Document 1 discloses a structure in which a floating spawning bed in which a skeleton is made of bamboo or wood and a palm skin or the like is laminated and integrated is used for a river.

In Patent Document 2, it is proposed to use a magic tape (registered trademark) or a part of the filter that is fluffy as a root of the pseudo water hyacinth, and is proposed as a substitute for a period without natural water hyacinth.

In Patent Document 3, an acrylic wool yarn is used as a floating member and an acrylic wool yarn is attached to a lower part of a filamentary bundle that is bundled in a spherical shape, and a weight is attached to the lower part to constitute a spawning part. A medaka egg-collecting device provided with a net for use has been proposed for science use by fifth graders in elementary school.

Furthermore, Patent Document 4 proposes a spawning bed for medaka in which loop members, holes, and the like are formed by firmly connecting a net member to a floating member of foamed polystyrene.

JP 2000-188991 PR JP 2004-337140 A Registered Utility Model No. 3158213 Public Information JP 2010-07187 PR

Capturing medaka and collecting eggs from the abdomen is easy to hurt the fish, and if performed many times, stress may weaken the medaka and cause it to die. It is an advanced method that is difficult to incorporate into elementary school learning.

Water hyacinth water hyacinths and pine trees are plants that grow and change shape, and depending on the season, it is difficult to obtain and procure a uniform shape, and it will wither in the winter, and it is difficult to cut and damage plants by handling. was there.

Although there is a substitute natural palm fiber that is difficult to procure as a raw material, there is a problem that it is difficult to process such as scattering at the time of modeling.

The floating egg-laying bed disclosed in Patent Document 1 has a large structure and is not suitable for use in medaka observation or research.

The pseudo water hyacinth of Patent Document 2 is provided for proliferation and ornamental use, and the pseudo water hyacinth leaves and stems obstruct the line of sight from the upper surface of the water surface and are not suitable for observation or research.

In the medaka egg collection device of Patent Document 3, the acrylic wool that is the egg-laying bed member may lose the color of the dye, which may cause the water to become cloudy and lint entangled with the egg, hindering observation and research. May end up.

In the spawning bed for medaka of Patent Document 4, a loop or hole is formed in the net-like spawning floor member and is firmly connected to the floating member, and is used as one body, and the floating part is difficult to handle in observation and research. .

The present invention has been made based on the technical background as described above, and achieves the following objects.
An object of the present invention is to provide an artificial egg-laying apparatus for medaka that can clearly observe the medaka's habits for observation and research in elementary school classes, and for biological research, and that medaka can easily lay eggs. is there.
Another object of the present invention is to provide an artificial egg-laying apparatus for medaka that can easily lay eggs of medaka eggs that have been laid without loss.
Still another object of the present invention is to provide an artificial egg-laying apparatus for medaka that can be easily used and can be easily used.

The present invention 1 is a donut-shaped (ring-shaped) floating member that floats on water, a bridge-type support frame that extends downward from both ends of the floating member, and a connection that is provided upward in the central portion of the support frame. An artificial spawning bed device for medaka, comprising: a member; and an artificial spawning bed having a weight at a lower portion thereof detachably connected to the connecting member and provided with a fitting portion.
With the above configuration, since the floating member has a hollow portion, the inside of the artificial spawning bed can be observed from above and the artificial spawning bed is detachably supported by the support frame upward, so that the observation is possible. It can be easily replaced without any hindrance, and can be reduced in size and weight to reduce the work load after the next process.

Further, the present invention 2 is the artificial laying bed apparatus for medaka of the present invention 1, wherein the artificial laying bed is a plurality of sheet-like members (synthetic resin cloth or A spawning bed can be formed with a mesh cloth or net), a spherical weight and a tying tool, and the two or more of the above-mentioned multiple sheets are overlapped and wrapped around the spherical weight at the center to resemble the appearance of a corolla It is characterized by being an artificial spawning bed. Synthetic resinous sheet-like members corresponding to many petals overlap, and many occlusions, constrictions, gaps, and entrances are formed from the central part to the outer periphery, and egg-laying spots (what are egg-laying spots? A collective of preferred places for laying eggs).

In addition, the present invention 3 is the artificial laying bed apparatus for medaka of the present invention 1, wherein the connecting member connects the fitting portion at the lower part of the artificial laying bed with an elastic material.
By connecting using an elastic material, the structure becomes simple and the artificial spawning bed can be freely attached and detached, and egg collection and movement are facilitated.

Further, the present invention 4 is the artificial laying bed apparatus for medaka of the present invention 1, wherein the support frame is one or a plurality.
Basically, one support frame is sufficient as shown in FIG. 1, but in order to make it more stable, the two support frames can be cross-shaped or further increased.

By using a donut-shaped (ring-shaped) floating member in the present invention, it is possible to observe the swimming state, egg-laying state, etc. of the medaka in the artificial spawning bed located in the lower part thereof. Easy to observe.
The artificial egg-laying bed of the present invention is upward, the lower part is bound and the upper part is open, so that the medaka is easy to enter from the upper part to the lower part, the spawning rate is improved, and at the same time it is detachable from the support frame for egg collection. It is easy to exchange and move the information.
Furthermore, since the artificial spawning bed for medaka of the present invention can be easily prepared by using a commercially available product that is easily available, the required amount can be easily compensated.
As described above, the problems of the prior art are solved.

It is a perspective view of the artificial spawning bed apparatus for medaka of the present invention. (Outline drawing when spawning beds are connected) It is a side view of the artificial egg-laying bed modeled by the modeling method of the present invention. It is sectional drawing of AA 'of FIG. 2 of this invention. It is an expansion partial perspective view of the 3a connection member of FIG. 1 of this invention. It is sectional drawing of connection member BB 'of FIG. 4 of this invention. It is the schematic of the state which floated on the water surface the artificial spawning bed apparatus for medaka of this invention. It is a figure showing the temperature change of the day inside the medaka breeding water tank which set the artificial egg-laying apparatus of this invention.

In the present invention, the following various studies have been repeated in order to develop an artificial egg-laying apparatus for medaka that achieves the present invention.

Table 1 is a table of 10 items selected from daily necessities that can be used as substitutes for artificial spawning beds. These are used as a substitute for bundling spawning beds, and the presence or absence of spawning is confirmed.
As a result, a material with strong buoyancy as a material for an artificial egg-laying bed does not become a natural state in water, and a material with smooth skin is not suitable as it is because it is difficult to attach eggs. No. in Table 1 With the exception of 2 packing tape, the other materials were found to be able to substitute for two-digit spawning. In particular, No. 1 in Table 1. The kitchen drainage net of No. 3 is judged to be a familiar material from the viewpoint of appropriate flexibility, shape retention in water, etc., making it easy to attach medaka eggs and easy to collect at the time of egg collection. Special care must be taken with substitute materials, such as products containing abrasives that may cause damage to medaka, or materials that contain harmful detergents or chemicals that are exposed to the outside. It must not be done.

FIG. 7 shows the daily water temperature change in the aquarium at the time of spawning, and the water temperature is measured at regular intervals in an 80 L aquarium, divided into an upper layer and a bottom immediately below the water surface at a depth of 40 cm. As a result, if the upper layer just below the water surface maintains a high water temperature and lays eggs under good conditions as a habit of the medaka, it is estimated that eggs lay in the layer immediately below the water surface where fry will hatch as soon as possible. It is. Moreover, in the nature, medaka often sees swimming around the surface of the water. At the critical level, it can take in a lot of oxygen and prey on small insects that fall from the sky. On the other hand, there are many mud, sediment sediments, miscellaneous fungi and foreign enemies at the bottom, and the bottom is judged to be bad for medaka eggs.

Table 2 shows trial data in which the same number of spawning beds are installed at the bottom and the bottom of the water surface and the number of spawns is compared. As a result, the number of eggs laid in the spawning bed installed just below the water surface in the upper layer was large, and the advantage of a high egg-laying rate was seen at 75.5% of the whole. Therefore, it can be determined that medaka prefers to lay eggs in the upper layer, which is directly below the water surface.

It is judged that it is necessary to include the ability to maintain a position just below the water surface as an essential item for installing a spawning bed.

Table 3 shows a rounded resin net with a total length of 30 cm, which is conically shaped, with an entrance diameter of 5 cm, narrowed gently toward the back, and the egg-laying bed in the shape where the innermost part becomes a point-like blockage. This is the data that was tried. The data was divided into three parts and 10 trials from the entrance opening, 10 cm to 20 cm in the middle, and 2 trials from the back 20 cm to the closing point.
The result was a high egg-laying rate of 60.2% on the constricted back side. It can be seen that the medaka penetrates close to the constricted obstruction as a habit and lays many eggs.

Table 4 shows data obtained by rounding a synthetic resin net into a cylindrical shape, having a diameter of 5 cm and a total length of 15 cm, crushing one side into a line, closing the constriction, and holding it in place immediately below the water surface. Since the data was shortened, the data was divided at the center of the entire length, and 7.5 cm from the entrance was the entrance side, and the narrow constriction portion 7.5 cm from the center was the back side. The result showed that the back side had a high egg-laying rate of 88.6%.

Table 5 shows 10 pieces of vinyl tape for gardening with a width of 3 cm (1, 1 in Table 1, thickness 0.5 mm, eye size 2 x 3 mm) cut to a total length of 20 cm, and centered on the center to radiate. This is the data that was obtained by trying to hold the bundle in a position just below the surface of the water. Data division was performed by dividing the tape from the center of the overlapped portion into the inner portion and separating the outer end of the tape from the outer portion. The result was a high egg-laying rate of 82.3% on the inner side near the center where the tapes overlapped. Medaka eggs and newly hatched larvae are preyed by adult medaka fish and other foreign enemies, but there are instincts that survive life as a place to lay eggs, a space that can be protected from external enemies, that is, a gap that can protect eggs and fry It is determined that eggs will be laid in a narrow area where no external enemies can enter, such as overgrown areas and overlapping aquatic plants.

From FIG. 7 and the results of Tables 2 to 5, etc., in order to create such an artificial spawning bed of a medaka, there are many overlapping gaps, and the state where the back is closed and the back is closed. In addition to the structure “spawning spot” like a state where aquatic plants thrive, there is a demand for a material that has a tension that can hold its shape while being flexible and that has protrusions and depressions on the skin surface where eggs can easily adhere.

Table 6 shows the total length of the female medaka in the spawning state. The smallest is a female who starts laying eggs after three months of birth, and is about 2.5 cm in length and 0.5 cm in height. Female medaka over 3 years old is large with a total length of about 5cm and a height of 1cm. As an item required for an artificial spawning bed, it is necessary that the medaka that has been laid is able to enter the spawning bed. In this case, there is a need for a gap for the largest female medaka to enter, and it is a numerical value that becomes a necessary standard for weaving as a measure of the frontage and depth dimensions of the spawning bed to be created.

As a measure of the size of the egg-laying bed to be created, the maximum length of the medaka is 5 cm, the minimum frontage where a medaka with a body height of 1 cm can enter is 1 cm × 1 cm, and the depth is 5 cm. It is necessary to have a form in which a large number of structures are formed on the outer periphery from the center in a state where this is constricted and closed in the back. However, the center is the center of the bundle and requires 1 to 2 cm. Assuming 2 cm as the assumption, the size of the outer circumference is 2 cm in the center plus 5 cm × 2 on both sides of the front side and the opposite side, and a three-dimensional image of the spawning bed of about 12 cm in total is created.

The shape embodied in the result of repeatedly examining the image over and over again by combining the necessary items for the egg-laying bed created from the above-mentioned data etc., many petals overlap, many gaps and stenosis points from the center to the outer periphery, In the back, FIG. 2 shows a model that is an assembly of “laying spots” such as a closed state. It became an artificial spawning bed created by a corolla shape resembling a flower shaped by a substitute member. If the color is dark black or the like, the eggs will stand out, but they are not specified.

3 is a cross-sectional view taken along the line AA ′ of FIG. 8 sheets of sheet-like member (4b), which is an artificial egg-laying member, are stacked, and a spherical weight (6) is placed in the center, and the wrapped base is fixed with a binding tool (8), and then one sheet-like member (4b) is placed. It is a cross section when one sheet is opened and shaped. In the sheet-like member (4b), No. No. 3 synthetic resin draining net is used, the thickness is 0.15 mm, and the eye size is 1.5 × 3.5 mm.

Medaka eggs are about 1mm to 1.5mm in diameter, but the circumference is covered with sparse hair of about 0.2mm, and the attached yarn from 10mm to 20mm is bundled from one place. If it sticks, it will not fall easily. In nature, they are laid on floating grass and aquatic plants that are stuck to the water and stick to the attached yarn to hatch. The medaka egg is a sedimenting egg that sinks to the bottom of the water and becomes unfavorable, so the attached yarn plays a role in preventing the fall on the object.

In order for eggs to hatch, warm water with a temperature of 20 ° C or higher and fresh water containing oxygen are necessary. In normal breeding, the water temperature is suitable for the egg-laying season, but fresh water containing oxygen. In order to ensure that the egg lays continuously around the egg, the artificial spawning bed is required to be made of a material that is easy to attach to and keeps its shape, allowing it to contact with the surrounding water, such as aquatic plants and algae. However, as a corresponding material, the synthetic resin net is judged to be the best structural material.

Table 7 shows a comparison of the spawning beds of the same size with different net sizes. The result of the evaluation is that the number of eggs laid is superior only from 0.1 mm to 5 mm. If the eye size exceeds that, the number of eggs laid will decrease, and if the eye size becomes larger, the egg-laying place will be extremely close to the root of the bundle. It was a result. Artificial spawning beds used for observation and research are optimal as a result of examining not only the number of eggs laid but also the detailed requirements including flexibility, shape retention, ease of processing, water resistance, and workability during egg collection. The nets were some kind of kitchen draining nets and farm harvest nets. There was a screen door net as a familiar one, but this comparison is a one-step decision because the material is hard and the thread loosens from the cut end. Therefore, the best net size here is 1.5 mm x 2.5 mm, 1.5 mm x 3.5 mm, 2 mm x 4 mm, and 3 mm x 5 mm, and the minimum size to the maximum size is 1.5 mm. From 5 mm. (Comparison of substitute materials within the range where general commercial products can be procured.)

The function of the spherical weight (6) of the artificial spawning bed in FIG. 3 will be described below in (a) to (e).
(A) A function that serves as a basis for collecting sheet-like members as the center of a bundle for modeling.
(B) The function of the (7) spherical weight part of FIG. 2 as a male fitting part for connection to be inserted into the connection member.
(C) Function to protect the spawning bed part when it is dropped into the aquarium. (Because the weight falls and sinks, the egg-laying part protects the egg without being soiled with mud and excrement on the bottom)
(D) A function as a balance weight that balances the floating support frame and the float when connected to stabilize the entire body in order to use this spawning bed.
(E) In the summer, when the temperature rises, use a fine mesh-like member for the spawning bed in the sun, and if it is kept in that state for several hours in the aquarium, air bubbles attached to the mesh or algae generated inside the aquarium The generated gas accumulates and enlarges, causing a phenomenon that the egg-laying bed floats.

The material of the spherical weight is a glass sphere (marble) used for the trial production, and its diameter is around 16mm and weighs 6g (depending on the manufacturer or individual, there is a variation of ± 1mm in diameter and ± 1g in weight). Is. It is inexpensive and easy to obtain, but any other stainless steel or rubber ball that is water resistant can be used.

The binding tool of (8) artificial spawn bed in FIGS. 2 and 3 is a binding band or a rubber band, but it is still better if there is a dedicated molded product such as a synthetic resin or a binding tool such as stainless steel or aluminum.

Hereinafter, specific embodiments for carrying out the present invention will be described.
[Floating member and overall configuration]

FIG. 1 shows a donut-shaped floating member (1) for holding the created artificial spawning bed (4a) in a fixed position below the surface of the water (1) A support frame extending in a reverse arch shape downward from both ends of the central portion of the floating member (1) This is an artificial egg-laying apparatus for medaka in which (2) and the connecting member (3a) provided at the center of the support frame (2) are integrated. This also plays an important role in stably supporting an artificial spawning bed in a layer superior to spawning by trial data. (4a) depicts the external shape when the created artificial egg-laying beds are connected.

The following (A) to (D) are the reasons why the floating member has a donut shape.
(B) The hollow part was opened so that the line of sight of the observation could reach from the upper part.
(B) A passage opening through which a hollow part is passed to connect and detach a spawning bed.
(C) Even if the main body rotates on the surface of the water in the aquarium, it always has the same shape and is beautiful.
(D) Even when approaching the aquarium, the outer part of the donut floats guards without crushing the spawning bed and plays a role as an outer shell.

FIG. 1 is an overall view of the artificial spawning bed apparatus of the present invention. (1) is a donut-shaped floating member having a hollow portion (opening) in the center. In the conventional artificial spawning bed, the upper part is covered with a floating part, and it becomes a hiding place for medaka and is stable and stable. This is believed to be because medaka is timid and sensitive to upper movements. However, the medaka is a medaka that feeds every day regularly, and if it is not surprised by quick movements, it waits for feeding and eats it directly from their hands. Acts that surprise the surroundings are prohibited for medaka. If there is no other good laying bed target in the aquarium, the female medaka that has been laid will be sure to lay eggs on the laying bed in one good condition, and when it is necessary to collect eggs for observation or research By placing only one artificial spawning bed without putting other aquatic plants in the aquarium, eggs can be laid and collected.

Here, the shape of the floating member and the definition of the donut shape will be described.
A shape with a hole in the center is defined as a shape that becomes a donut shape when the image is visually rotated regardless of symmetry or asymmetry. Therefore, even a design with a flower shape or decoration is a donut shape if it meets this definition.

The material of the donut-shaped floating member is a foamed synthetic resin plate material having a thickness of 2 mm and a total thickness of 7 mm. These two sheets have a structure in which both ends of the band plate of the support frame member are sandwiched and fixed, and this is a safety measure for bringing in the cut portion of the band plate. The color of the prototype is blue, and a green color that matches the image is preferable, but it is not specified.

The full length (diameter) of the donut-shaped floating member (1) in FIG. 1 forms the outline of the connected artificial spawning bed (4a), and is found by the mutual relationship between the spawning bed used and the water tank. is there. The artificial egg-laying bed (4a) has a circular maximum diameter of about 12 cm from the total length of the female medaka, and the donut-shaped floating member (1) needs to be larger than that. On the other hand, it is necessary to fit within the inner dimensions of the tank used at school. For general aquariums, the standard aquarium size is 45cm and it is for 30L (Yokoba x Okuyuki x Takasa) 45x24x30cm (depth is about 23cm), 60cm is 60x30x36cm (depth) The inner size is about 29 cm). Medaka is the smallest fish in Japan and does not require a large tank. Therefore, the size of the smaller aquarium varies slightly depending on the manufacturer, but the small aquarium of the shark manufacturer is for L size 23L (45 × 25 × 28cm) M size 18L (36 × 22 × 26cm) S size 12L ( 31 × 18 × 24 cm) and the minimum inner dimension is about 17 cm, so 17 cm was determined as the maximum diameter of the donut-shaped float. The donut-shaped floating member has a diameter of 17 cm and an opening diameter of 12 cm, and the width of the floating member is 2.5 cm. Of course, if it is to be used in a large water tank, it may be determined in consideration of the above matters. Although it was determined to be the optimum size comprehensively and determined as the size of the prototype, it is likely that the size of the artificial spawning bed and the opening become a passage port and the size can be reduced by 1 to 2 cm. However, it goes without saying that the diameter of the floating member (1) can be changed as necessary.

The material of the support frame (2) in FIG. 1 was a synthetic resin, the prototype was made of a polypropylene strip, and the color was blue with the same color as the float. Using two members with a thickness of 0.5 mm and a width of 15 mm, several parts are heat welded to maintain the strength to hold the artificial spawning bed (4a). The mold is a reverse arch bridge type, and a strip formed by two sheets is a pillar and is fixed at both ends of the floating member (1). When fixed, the radius is 8.5 cm, and the central water surface is 8.5 cm. In addition, a connecting member (3a) having a function of holding and detaching the artificial spawning bed (4a) upright in the center by one sheet on the upper side of the band plate material is prepared and installed. There is no specification or restriction on color. Of course, the support frame (2) may be integrally formed of the same material as the floating member (1).

Connecting member of FIG. 1 (3a), the artificial spawning beds (4a) lifting member such when the need to move when such a large amount use or when eggs egg retrieval daily observation and research (1), ( 2) Separated from (3a), only the artificial spawning bed (4a) is provided so that it can be used efficiently. As a result, the bulk of the leaves and stems is eliminated and the handling becomes much easier than when the water hyacinth has been used. Therefore, if only this artificial spawning bed (4a) is replaced and identified every day, and stored as it is in a container, it is possible to compare changes in daily eggs side by side in a small storage space. is there.

FIG. 4 is a partial perspective view of the connecting member (3a), and the material is a polypropylene strip material similar to that of the support frame (2). This strip material has moderate tension and elasticity, and the skin surface is anti-slip processed. A cylinder with a diameter of 30 mm is made of the same material, and both ends thereof are heated and held by sandwiching the cylinder in a form that is lifted by about 5 mm from the base portion of the support frame (2) by the same material arm. The connecting part (female fitting part) (3b), which is the insertion port part of the spherical weight part (male fitting part) (7) of the artificial spawning bed (4a), is provided with an elastic material (5) to be expanded and contracted. It is a simple structure that bites the constricted part of the spherical weight part (male fitting part) (7) of the artificial spawning bed (4a).

FIG. 5 is a cross-sectional view of the connecting member (3a) taken along the line BB ′. When the cylindrical part is pressed with fingers from both sides, the cylindrical entrance part opens slightly, and the entrance part that has been shrunk by the elastic material (5) becomes circular, so the spherical weight part of the artificial spawning bed (4a), (male fitting part ) Turn (7) and return the finger holding the cylindrical part to bite the constricted part. If it is bitten, it will need to be confirmed because it will not fall even if the connected artificial spawning bed device is inverted or shaken. The diameter of the connecting portion (3b) before insertion is 15 mm and the maximum diameter is expanded to 30 mm, but the allowable range of the biting ability is about 17 mm at the minimum and 25 mm at the maximum in the spherical weight.

The elastic material (5) of the connecting portion (3b) of the connecting member (3a) used for the prototype was a rubber band. If it is used underwater for about 5 months per season, it will grow slightly and material deterioration will begin, so it will need to be replaced, but it can be easily replaced with a crochet. If more durability is desired, other materials such as rubber, spring, etc. having high weather resistance, or a connecting device in synthetic resin molding, etc., are better.

FIG. 6 is a schematic side view of the artificial spawning bed device connected with the artificial spawning bed (4a) when it floats on the water surface. A space where medaka can swim around the artificial spawning bed (4a) is always secured.

[Artificial spawning bed]
(A) A method for forming an artificial egg-laying bed (4a) (an example of a sheet-like member) will be described in the following (a) to (h).
(I) Water-proof, moderately tensioned, flexible and easy to attach eggs to the kitchen Triangle corner draining net for kitchen (No. 3 in Table 1, black, made of polyethylene), marbles, binding tool in advance To do.
(B) The dimensions of the triangular corner draining net are approximately 250 mm × 280 mm bags (thickness 0.15, eye size is 1.5 × 3.5 mm). Since one side is thermally welded linearly at the bag binding portion, this portion is cut into a straight line by about 10 mm.
(C) When the crease portions at both ends are cut into two straight lines, two sheet-like members of 240 mm × 280 mm are obtained.
(D) If these two sheets are cut in half and cut into four, and further cut in half and cut into eight, the sheet-like member is about 120 mm × 140 mm.
(E) Each of the eight sheet-like members (4b) is superposed in a radial direction by alternately changing the angle from the center, such as alternately in the vertical and horizontal directions, or in the vertical and horizontal directions, diagonally and vertically and horizontally.
(F) Put a spherical weight (about 16mm in diameter) (6) in the center of eight sheets, wrap it with eight sheet-like members (4b), and wrap it up along one side to resemble the wrinkles of the umbrella Arrange.
(G) When the root containing the spherical weight (6) is tightened and fixed with the tying tool (8), it can be bundled with the ball wrapped with the sheet-like member, and this is the spherical weight part (male) inserted into the connecting part (3b) This is where the constricted part is bitten by the mold fitting part (7).
(H) Carefully open the petals one by one from the outside of the bundled member, create a “spawning spot” where the medaka enters, rotate all the pieces to rotate, check the entire surroundings, arrange the corolla of the sheet-like member If you can, it is complete. The size can be made the same, and other methods such as nylon bath towels, laundry nets, harvest nets used by farmers, etc. can be formed by this method. (The number is increased or decreased depending on the diameter of the spherical weight.)

(B) A method for forming an artificial egg-laying bed (an example of a narrow tape-shaped member) is described in the following (a) to (e).
(A) A mesh gardening tape (No. 1 in Table 1 above, thickness 0.5 mm, width 30 mm, eye size 2 × 3 mm, made of polyethylene), marbles, and a binding tool are prepared in advance.
(B) Cut ten pieces of tape into a length of 200 mm and prepare 10 pieces.
(C) All the 10 sheets are overlapped at equal angles radially from the center with the center aligned and intersected vertically and horizontally or obliquely vertically and horizontally.
(D) Put the spherical weight (6) in the center and wrap it with 10 tapes (4b), and stop the root with the tying tool (8).
(E) When the tape-shaped member (4b) can be crowned by carefully opening and rotating all the pieces one by one from the outside of the bundled members, rotating and inspecting them, it is completed. In this case, the “spawning spot” is the overlapping part on the center side. If other members are similar, they can be created by this method. (The number is increased or decreased depending on the diameter of the spherical weight.)

(C) The number of eggs is limited by the thickness of the egg-laying floor member (sheet-like, tape-like member, etc.). The number of sheets is the limit and 6 to 10 sheets is the optimum number. Although it is limited to the range of the diameter of the spherical weight and the maximum bite diameter of the connecting member, the bite allowable range is about 17 mm to 25 mm. Therefore, when the diameter of the spherical weight is 15 mm, the outer diameter of the sphere wrapped with the sheet-like member has an allowable range of 10 mm at the maximum, but when wrapped, the wrinkle thickness of the member is added to the outer diameter, so that the thickness increases. Since the diameter is enlarged, when a new member is used, it is necessary to actually create it once and confirm the diameter of the spherical weight portion. There are few thick and hard materials, so it is good to make a moderate notch in the petal part inside the corolla after shaping. The color should be black or dark, but not specified.

To use the medaka artificial spawning bed apparatus of the present invention is simply there than the person Engineering laying bed apparatus can laying spawn if Ukabere the water surface in the water tank or the like in the conventional breeding methods, observation and research In order to obtain more eggs for and to obtain the effect, there are some points that overlap with the general breeding method.

[Selection of implementation time, etc.]
Medaka lays eggs every day from mid-April to around September in areas near Tokyo, so the observational research period is from May to July in elementary schools. The number of laying eggs has been declining to exceed the limit, and since elementary school is in summer vacation, the best time for observation and research is judged from May to June.
In laboratories that are kept indoors all year round, various devices that prepare the same environmental conditions as during the season are necessary and devised, but when temporarily raising and observing in the classroom during the season, It is judged that the place where the sunlight is temporarily in the window is good at the temperature condition of 20 ℃ to 28 ℃ for 13 hours or more. It is preferable to study in advance about better breeding methods.

[Preparation stage]
The points to be noted in the preliminary preparation stage are described in (a) to (f) below.
(B) Before observing or starting research, medaka breeding should be accustomed to the aquarium for a week or more. This is because medaka is not used and stable egg-laying and egg-collecting cannot be performed. (B) A medaka is more stable if it is bred to 1 or less per 1L of aquarium. This is because overcrowded breeding is limited by lack of oxygen and the range of action and is not stable by stress. For example, in a 20L aquarium, the number of animals should be 20 or less.
(C) The female medaka ratio is slightly higher than 50%. Example: 20 in total, 12 female medakas, 8 male medakas. This is to improve the egg-laying rate. This is because when the male medaka increases, food is often fed or mated, and the feeding behavior is disturbed, reducing the number of eggs produced by female medaka.
(D) It is better to give the bait divided in 2-3 times a day in an amount that can be eaten in 1-2 minutes. This is because if you give too much food, the remaining amount of food will rot, the water will worsen, and the medaka will weaken.
(E) The oxygen supply by the pump is not necessary unless it is overcrowded. If an oxygen pump is used, it is sufficient that the water flow in the tank cannot be made at a minimum. This is because if a strong water current is applied to a medaka for a long time, it will be weakened by the stress of swimming for a long time and will die the worst.
(F) Remove all aquatic plants that are spawning objects in the aquarium. One artificial spawning bed is used in one tank to concentrate on one artificial spawning bed to be used and promote spawning.

[Observation in the aquarium and replacement of artificial spawning beds]
Hereinafter, describe the considerations for replacement implementation of observation and the artificial spawning beds in the aquarium from (g) to (k).
(G) Check every day to check for changes in the state of the medaka. It is time to use an artificial spawning bed after confirming an egg on the belly of a female medaka, but it is necessary to try it in the aquarium for the first time. First of all, the artificial spawning bed device is put in the corresponding aquarium to see how it looks.
(H) The next day, to grasp the time when the medaka in the aquarium lays eggs and finishes laying eggs. Ordinary medaka egg laying ends early in the morning in the morning, but it is to grasp and confirm the timing when all the eggs on the belly of the female medaka in the aquarium are gone.
(L) Once the timing is known, the artificial spawning bed is recovered and replaced at that timing. If there are two artificial spawning bed devices in advance, one can be prepared, so replacement is smooth.
(Nu) When replacing the artificial spawning bed, check the floating support frame, wash the eggs with a toothbrush etc. and clean them with a toothbrush, clean them, and replace with a new artificial spawning bed. Therefore, it is preferable to encourage. When removing the artificial spawning bed from the aquarium, medaka may sometimes lurk inside the spawning bed, so if you check and slowly remove it, you can safely remove it without damaging it. It is.
(L) Observe in the same manner as described above, and when there are no eggs in the belly of all female medakas at approximately the same time every day, collect the artificial spawning bed and replace it with a new one. Eggs are laid on the collected artificial egg-laying beds, so they must be individually placed in a container for identification and storage, and tap water should be put at the beginning of egg storage. This is because the disinfectant's Kalki component serves to protect the egg from germs. If you are worried, you can drop a few drops of water to make the water light blue with the special ornamental fish disinfectant methylene blue. Since fertile eggs are cloudy, if you leave them as they are, other eggs will be spoiled with water mold and so on, so use a dropper to remove them.

[Removal stage at the end of observation and research, cleaning of artificial spawning bed equipment, etc.]
When the observation and research are completed, the artificial laying bed apparatus for medaka is collected, separated from the laying bed, washed with a toothbrush, etc., disinfected with methylene blue aqueous solution, dried, and stored in a box or the like. In addition, it replaces | exchanges, if the elastic material (rubber rubber) (5) of a connection part (3b) deteriorates. Use a crochet for smooth replacement. Let's return the medaka to a biotope.

[Ascertain usage limits by checking artificial spawning beds]
Artificial egg-laying beds can be reused by washing them with water and disinfecting them in the sun. If there are so many deformations that the medaka can not enter and the number of spawning spots decreases, it is the limit of use and it is to replace with a new artificial spawning bed.

[Use for breeding]
When using for breeding, daily artificial spawning beds need not be replaced. Periodically replace the artificial spawning bed in 3-4 days and keep it in a separate nursery container. One to two weeks after hatching, it is transferred to a separate container, and the difference in growth between individuals appears. This is because medakas of fast-growing and large individuals can eat freshly hatched fry if they are left as they are. Since nursery containers are easily contaminated with water mold and the like, regular replacement and regular cleansing are one of the effective means of growing fry and improving the reproduction rate. For breeding, it is not necessary to remove the egg from the artificial spawning bed and it can be moved as it is, so there is less pain and it can be reused for one season, but it should be lightly washed and dried in a timely manner as well as inspection.

(1) Apparatus for implementation The apparatus for implementation is as follows.
The artificial egg-laying bed used was the one in paragraph [0063] (A).
That is, the sheet-like member is No. 1 in Table 1. 3 Using a kitchen draining net (thickness 0.15 mm, eye size 1.5 × 3.5 mm), the net is cut to produce eight sheet-like members of about 120 × 140 mm. The eight sheet-like members are alternately arranged vertically and horizontally, vertically and horizontally, diagonally vertically and horizontally, etc., and the angles are evenly overlapped from the center, and are superimposed radially. A spherical weight (marble, approximately 16 mm in diameter) is placed in the center of the 8 sheets. Wrapped with 8 sheet-like members, stopped with a binding tool, opened petals, and arranged in a shape similar to a corolla to constitute an artificial spawning bed.
As shown in FIG. 1, the artificial laying bed apparatus for medaka in which the floating member (17 cm in diameter, 12 cm in inner diameter) is attached to the connecting member of the support frame (depth 8.5 cm below the water surface). It is.
(2) Settings and results for implementation The tank used for 20L was used, and the water was drawn from well water and allowed to stand for one day to reach the normal water temperature. The place is 2 meters below the eaves, which is 80 cm overhanging, on the 50 cm deck, and a steel net cover is set in the aquarium as a countermeasure against foreign enemies. The sunshine duration was 13 hours or more, and the water temperature was 23 to 26 ° C. as in FIG. Moreover, the direct sunlight of the place is a place facing south from 9:00 to 13:00. Use commercial bait.
The artificial spawning bed apparatus is floated in one aquarium, and 12 females and 8 males of about 3 cm aged 1 year old are kept in a stable period of one week after breeding the main aquarium and continuously observed for 10 days during the season. For this purpose, 10 artificial spawn beds are prepared, and it is confirmed that all female medakas have laid eggs at a fixed time every day, and the artificial spawn beds are defined in the paragraphs “0069” (G) to (L). Replacement was performed according to Regarding the observation visibility, it has been confirmed from several times that the female medaka has observed the action observed by turning the fish body and laying it. Table 8 shows the egg collection results. It was confirmed that the artificial egg-laying apparatus functions and can collect medaka eggs necessary for observation and research. Moreover, Table 9 has confirmed that it can be used without a problem by the result after one season using 10 artificial spawning bed apparatuses about durability.

The artificial spawning bed apparatus for medaka of the present invention can be sold as it is in an assembled state in consideration of industrial use, and can contribute to elementary school students, researchers and the like.
Further, it is possible to contribute only to a spawning bed having a large number of uses as a single unit, and to use only a floating support frame as a single unit.
Furthermore, the artificial spawning bed apparatus for medaka of the present invention can be assembled and disassembled, so that the creative ability of elementary school students and the like can be obtained by selling the disassembled floating member, support frame, artificial spawning bed, etc. as a set. Can contribute to nourish.
In addition, the material specification of each part etc. can be changed. For example, the elastic material of the connecting member can be made from a rubber band to a metal spring, can be made into a component as a connecting device made of synthetic resin, the connecting member can be a magnet, and the weight of the artificial spawning bed can be adsorbed.
In addition, the apparatus of the present invention can be diverted to a size suitable for target fish and small organisms such as other fishes and used as a spawning bed and a breeding apparatus.
Furthermore, it can also be used as a design object for underwater flowers and water surface flowers as underwater art.

1. 1. floating member Support frame 3a. Connecting member 3b. Connecting part (female fitting part)
4a. Artificial spawning bed 4b. 4. Sheet-like member Elastic material6. 6. spherical weight Spherical weight (male fitting)
8). Tying tool

Claims (4)

A donut-shaped (ring-shaped) floating member that floats on the water, a bridge-shaped support frame that extends downward from both ends of the floating member, a connecting member that is provided upward in a central portion of the supporting frame, and the connection An artificial egg-laying bed apparatus for medaka, comprising an artificial egg-laying bed having a weight at a lower portion and a fitting portion detachably connected to a member. The artificial laying bed apparatus for medaka according to claim 1, wherein the artificial laying bed includes a plurality of sheet-like members (synthetic resin cloth or mesh cloth or net), and the plurality of sheets are 2 to 12 sheets , An artificial egg-laying apparatus for medaka, which is an artificial egg-laying bed that is shaped like the shape of a corolla by wrapping a spherical weight at the center. The artificial laying bed apparatus for medaka according to claim 1, wherein the connecting member connects the lower fitting portions of the artificial laying bed with an elastic material. The artificial laying bed apparatus for medaka according to claim 1, wherein the support frame is one or a plurality.

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