JP6723816B2 - Small fish guiding member and small fish collecting device - Google Patents

Description

The present invention relates to a small fish guiding member and a small fish collecting device for efficiently collecting small fish cultivated in a cage or the like.

In order to achieve sustainable use of marine resources represented by fish, it has been attempted to cultivate large migratory fish such as yellowtail and tuna as well as conventional cultured fish such as flounder, Thailand, and puffer fish. Among these, the consumption of tuna has been increasing all over the world in recent years, and the problem of depletion has become a particular problem. Regarding aquaculture of tuna, in the past, the mainstream was livestock breeding by catching undeveloped tuna fish in the open sea, but in recent years, complete aquaculture of raising eggs to adult tuna has been reported and realized (for example, Patent Document 1.).

In aquaculture of fish, larvae hatched from eggs are grown in aquaculture tanks for a certain period of time, and after growing to fry of a certain size, they may be transferred to large-scale aquaculture tanks or aquaculture in open ocean cages. In that case, it is necessary to collect the fry in the aquaculture tank. For the collection of juvenile fish, in the case of conventional cultured fish such as puffer fish and Thailand, for example, a guide for sucking fish together with water from the opening at the tip end and sending out from the opening at the base end end as disclosed in Patent Document 2. Fry can be efficiently sucked and recovered by inserting the member into the aquaculture tank and sucking the conduit connected to this with a pump or by making a difference in water level and using the siphon principle. .. Patent Document 2 describes that such a guiding member is preferably a trumpet-shaped or conical guiding member that is colored with blue or green paint and has no metallic luster.

On the other hand, juvenile tuna has a problem that it is more easily debilitated and has a higher mortality rate than juveniles of other fish. In addition, tuna, a migratory fish, has the property of swimming against the flow of water. Therefore, if you try to suction and collect juvenile tuna with water using the principle of the pump and siphon using the conventional guiding member, it is necessary to enhance the suction force or forcefully drive the fish to the small fish guiding member. .. The fragile tuna fry tend to be damaged by the rapid flow of a large suction force and forcible forcing, causing collision with the inner walls of the nets and conduits and damaging them. There is a risk that it will not be able to grow smoothly after shifting to aquaculture.

JP, 2007-222150, A Japanese Patent Laid-Open No. 2003-14409

As described above, it has been substantially impossible to recover juvenile tuna using the above-described guiding member and the principle of the pump and the siphon. Therefore, in order to collect delicate and stress- and injured juveniles without letting them die and without damaging them, one by one, scoop fry one by one with a taro net, and transport several waters each with a bucket or the like. In reality, it takes a lot of time and manpower, and there was a problem that the collection work was inefficient.

Against this background, there is an urgent need to develop a technique for efficiently recovering juvenile fish such as tuna without debilitating them.
Therefore, an object of the present invention is to provide a small fish guiding member and a small fish collecting device capable of collecting small fish such as tuna efficiently and safely.

As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that small fish, such as small fish, are timid, and if the guide member is colored, it becomes difficult to approach it. By using a light-transmissive member for the introduction part of the guide member, it becomes easier for small fish such as fish to enter the inside of the guide member. The present invention has been accomplished by discovering that the transfer can be performed without causing the transfer.

That is, the small fish guiding member of the present invention includes an introduction part having an opening through which a small fish to be cultivated enters, a connection part having an opening to which suction means is connected, and a flow path connecting the introduction part and the connection part. It is characterized in that at least the introduction portion is made of a light transmissive member.

According to the small fish guide member of the present invention, at least the introduction portion is formed of the light-transmissive member, so that the inside of the introduction portion becomes bright and the existence of the introduction portion can be reduced for small fish. Therefore, it is possible to diminish the caution of small fish, so it is not necessary to forcibly push small fish into the back of the guide member, so there is no need to suck in a strong water flow that is debilitating, and small fish can be collected. be able to.

There are no particular restrictions on the small fish to be collected, and all small fish of the aquaculture species are targeted. As fish, for example, yellowtail, yellowtail exemplified by yellowtail, amberjack, amberjack exemplified by amberjack, trevally, red sea bream, red sea bream, taidai exemplified by sea bream, bluefin tuna, bluefin tuna, southern bluefin tuna, yellowfin, Bigeye, albacore, cosinaga, Atlantic tuna, bonito, suma, flat tuna, tuna exemplified by Marsuda, mackerel, mackerel exemplified by sesame mackerel, hagatsuo, exemplified by tuna, mackerel, mackerel Salmons, salmon, salmons exemplified by trout, flounder, flounder, flounders exemplified by Ushinoshita, and the like.
Includes mackerel fish as collection targets. The mackerel fish refers to a fish that is classified in the Perciformes mackerel subfamily Mackeridaceae. Mackerel fishes include the Hagatsuo, Sawara, Saba, and Tuna. The Hagatsuo group includes the genus Isuna and Hagatsuo, the Sawara group includes the Kamasawara genus, Nijosaba and Sawara, the Saba group includes the Glucuma and Saba genus, and the Tuna group includes the Sodahatsu and Suma species. Genus, bonito and tuna are included. For bluefin tuna, bluefin tuna, redfin tuna, redfin tuna, red-tailed tuna, red-tailed mackerel, red-headed mackerel, swallow-tailed mackerel, mackerel and sesame mackerel The genus includes bonito, bonito in the genus Bonito, and bluefin tuna, bluefin tuna, southern bluefin tuna, yellowfin, bigeye, bigeye tuna, albacore, koshinaga, and northern tuna. Among the mackerel fishes, small fish of the genus Tuna are easily debilitated and are therefore one of the objects of the present invention.

There is no limitation on the size of the fish to be collected, and for example, cultivated fish such as larvae of 30 cm or less, 20 cm or less, and 10 cm or less, fry, and juvenile may be targeted as small fish.

The small fish guide member of the present invention includes an introduction portion, a main body portion, and a connection portion. However, the introduction part, the main body part and the connection part do not necessarily have to be separate members, and the introduction part and the main body part are integrated, the main body part and the connection part are integrated, the introduction part It also includes a body, a body, and a connecting part that are integrated.

In the small fish guiding member of the present invention, the main body may also be formed of a light transmissive member. By doing so, not only the introduction part for the small fish, but also the inside of the main body becomes brighter, so the presence of the main part can be diminished, so that the caution of the small fish can be diminished and more efficiently. A small fish can be attracted to the back side of the guide member.

Further, the connecting portion may be made of a light-transmissive member, so that the entire connection may be light-transmissive. By doing so, the entire small fish guiding member of the present invention becomes brighter for the small fish, and a sense of security can be further provided, so that the small fish is more efficiently attracted to the back side of the guiding member. be able to.

In the small fish guide member, there is no limitation on the length of the introduction portion (length of the transparent portion), and when the total length of the introduction portion and the main body portion is 100%, for example, 50% or more, for example, 70% Above, for example, 85% or more (including 100%). It should be noted that 100% of the length of the introduction portion means that the introduction portion and the main body portion are integrated.

The light-transmissive member may be any member that allows light that the small fish perceives to pass through, and may include a case that the light transmissive member is visually colorless, and a case that the light transmissive member is colored if the light perceived by the small fish passes through. Further, the light transmission member, as long as it is transparent to light and at least the inside of the introduction portion is bright, for example, like a louver, the outside cannot be seen from the inside of the introduction portion, but the structure is such that light is inserted, It may also be a mesh member.
When the light transmissive member is a transparent member, it may be an inorganic material such as glass, or may be a transparent resin. When a transparent resin is used, the light-transmitting member may be a polyolefin resin, vinyl acetate resin, polyester resin, polyvinyl chloride resin, acrylic resin, polyvinylidene chloride resin, polyethylene terephthalate resin, polycarbonate resin, methyl methacrylate resin. Examples thereof include a sheet-shaped member or a plate-shaped member selected from resins and polyamide resins.

The introduction portion may be formed such that the opening area decreases from the opening of the introduction portion toward the main body portion. Small fish that have entered the introduction part can be guided to the back side along the transparent wall surface.

Further, the main body portion may also be formed so that the opening area becomes smaller toward the connecting portion. By forming in this way, the introduction part and the main body part have a trumpet shape, a conical shape, a pyramid shape or the like, and the small fish can be supplied to the connection part more smoothly.

The small fish collecting device of the present invention comprises the small fish guiding member of the present invention, a conduit connected to the connecting portion of the small fish guiding member, and the suction means connected to the conduit. And

According to the small fish collecting device of the present invention, since the small fish guiding member of the present invention can reduce the caution of small fish, the small fish can be easily sucked into the conduit and collected without increasing the suction force of the pump or the like. can do.

A part of the conduit is formed of a transparent member, a light emitting part arranged on one side of the light transmitting part of the conduit, a light receiving part arranged on the other side opposite to the one side of the conduit, and the light receiving part. It may be provided with a counting unit that counts the number of times the light reception of the unit is blocked. The light from the light emitting portion enters the light transmitting portion of the conduit, transmits the water flowing through the conduit, and then exits from the transparent portion of the conduit opposite to the incident position and reaches the light receiving portion. When a small fish passes through the conduit, the light from the light emitting portion to the light receiving portion is blocked. Since the counting unit counts the number of times the light from the light emitting unit to the light receiving unit is blocked, the number of times small fish have passed, that is, the number of small fish that can be collected can be accurately counted.

According to the present invention, since the small fish can be allowed to enter the small fish guiding member by being less alert, the small fish can be efficiently sucked by the suction means without using a suction means having a large output. It can be collected safely.

It is a figure which shows the whole structure of the collection|recovery apparatus of the fry using the small fish induction member which concerns on embodiment of this invention. It is the perspective view which looked at the small fish guidance member shown in Drawing 1 from the side. It is the perspective view which looked at the small fish induction member shown in FIG. 1 from the front. It is the perspective view which looked at the small fish induction member shown in FIG. 1 from the back surface. It is a figure for demonstrating the counting device shown in FIG.

A small fish guide member according to an embodiment of the present invention and a small fish collecting device including the same will be described with reference to the drawings. In addition, in the present specification, the opening side into which a small fish, which is a farmed fish before recovery, enters will be described as a tip end and the opposite side will be a base end. In addition, the small fish guide member and the recovery device including the same according to the present embodiment assume fry as a small fish of 30 cm or less, and in particular, assume fry tuna, such as tie and yellowtail. It can also be used for fry and small fish other than tuna.

The fry collection device 10 of the present embodiment shown in FIG. 1 is used for collecting fry F from the aquaculture tank A and transferring it to the fry collection container B.
The small fish collecting device 10 includes a small fish guiding member 11, a conduit 12 connected to the base end of the small fish guiding member 11, a suction pump 13 as a suction means connected to the conduit 12, and a counting device 14. It has and.

As shown in FIG. 2 to FIG. 4, the small fish guiding member 11 has an opening through which the fry F enters, and an introducing portion 111 that guides the fry F to the back side, and a frame portion 112 that supports the introducing portion 111. A connection part 113 having an opening to which the suction pump 13 is connected, and a main body part 114 having a flow path connecting the introduction part 111 and the connection part 113 are provided.

The overall shape of the introduction portion 111 is a so-called prismatic shape formed so that the opening area decreases from the tip end portion 111b toward the base end portion 111a. In the present embodiment, the introduction portion 111 is formed of a transparent member which is an example of a light transmissive member. The transparent member is formed of, for example, a sheet member made of vinyl chloride (hereinafter referred to as “vinyl sheet”).

In the introduction portion 111 in the present embodiment, the bottom surface portion 111c extends horizontally and the top surface portion 111d extends obliquely upward toward the tip end in accordance with the shape of the frame portion 112 that extends in the tip end direction. ing.
The introduction portion 111 has a base end portion 111a fixed by being sandwiched by an opening edge portion of the main body portion 114 by a plate-shaped member 114m. Further, the introduction portion 111 is fixed by inserting a binding band rotated around the frame portion 112 into through holes formed at predetermined intervals in each corner portion 111e extending from the base end portion 111a to the tip end portion 111b. ..

The frame portion 112 supports the flexible introducing portion 111 and forms the contour shape of the introducing portion 111. The frame part 112 is assembled by connecting cylindrical pipes.
The frame portion 112 is located at the base end portion 112 a, is formed in a rectangular shape, and is located at the base end frame 1121 that surrounds the opening of the main body portion 114, and the distal end portion 112 b is formed in a rectangular shape, and the distal end of the introduction portion 111. A tip frame 1122 that supports the opening of the portion 111b, a support frame 1123 that connects the base end portion 112a and the tip portion 112b, and a reinforcing frame 1124 that is arranged so as to divide the opening of the tip frame 1122 into two parts are provided. ..

The support frame 1123 is formed by a plurality of frame members 1123a to 1123d.
The frame member 1123a is arranged so as to extend along the corner portion 111e of the introduction portion 111. Two frame members 1123b are arranged in the center of the upper surface portion 111d of the introduction portion 111 so as to extend toward the front end direction. Two frame members 1123c are arranged at the center of the bottom surface portion 111c of the introduction portion 111 so as to extend toward the tip direction.

In the connecting portion 113, the conduit 12 (see FIG. 1) is connected to the base end portion 113a. The connecting portion 113 is formed of a cylindrical metal cylinder.

The main body portion 114 is formed so as to expand from the base end portion 114a to which the connection portion 113 is integrally connected to the tip end portion 114b to which the introduction portion 111 is connected. In the main body 114 of the present embodiment, like the introduction part 111, the bottom face part 114c extends horizontally and the top face part 114d extends obliquely upward toward the tip direction. It is a cylinder.
As shown in FIG. 2, in the small fish guiding member 11 of the present embodiment, the length of the introducing portion 111 (the length of the transparent portion) is when the total length of the introducing portion 111 and the main body portion 114 is 100%. It is designed to be 70% or more.

As shown in FIG. 1, the conduit 12 is a pipe for transporting fry from the aquarium A to the fry collection container B. The conduit 12 can be made of metal, but a flexible resin hose such as a vinyl hose, a silicone rubber hose, a fluororesin hose, or an acrylic hose can be used. When the conduit 12 is a resin hose, it can be formed of a transparent hose. Further, when the conduit 12 is a resin hose, it can be a bellows-shaped hose. Stretchability can be provided by using the conduit 12 as a bellows-shaped hose.
When the conduit 12 having flexibility and elasticity is used, the hose can be easily bent or expanded and contracted, and the position and angle of the small fish guiding member 11 can be freely set. When the conduit 12 is a metal tube, a transparent member is used for the conduit 12 at the mounting position of the sensor unit of the counting device 14 described later.

The suction pump 13 suctions the water in the conduit 12 on one side and discharges it to the other side, thereby pumping the water in the conduit 12 in one direction and functioning as a suction unit. In the present embodiment, the suction pump 13 is a vacuum pump.

As shown in FIG. 5, the counting device 14 includes a sensor unit 141 attached to the conduit 12, and a counting unit 142 that counts the number of fry by the signal from the sensor unit 141. The sensor unit 141 includes a light emitting unit 1411 and a light receiving unit 1412.

The light emitting portion 1411 is arranged on one side of the transparent portion of the conduit 12. As the light emitting unit 1411, one that emits light when energized can be used. Although the light emitting diode is used in the present embodiment, it may be a light bulb or a fluorescent lamp.
The light receiving portion 1412 is arranged on the other side opposite to the one side of the conduit 12. The light receiving section 1412 receives the light from the light emitting section 1411 to be in a conducting state, or is in a high resistance state when the light is blocked. As the light receiving unit 1412, a photodiode or a phototransistor can be used.
The counting unit 142 counts the number of times the light receiving unit 1412 blocks light, and displays the count value on a display unit (not shown).

The operation and use state of the small fish collecting apparatus according to the embodiment of the present invention configured as described above will be described with reference to the drawings.
First, the small fish guiding member 11 is immersed in the aquarium A, and one end of the conduit 12 is connected to the connecting portion 113 of the small fish guiding member 11. Further, the other end of the conduit 12 is inserted into the fry collection container B. Next, the sensor unit 141 of the counting device 14 is attached to the conduit 12.
When the above preparation is completed, the user starts the suction pump 13.

By starting the suction pump 13, the water in the small fish guiding member 11 connected to the conduit 12 is sucked. The fry F located in front of the small fish guiding member 11 is attracted by the suction of the suction pump 13.
When the fry F approaches the small fish guiding member 11, the introducing portion 111 of the small fish guiding member 11 is transparent and has a light-transmitting property, so that the small fish guiding member 11 is located in the water. Also, since the outside light reaches the inside of the introduction section 111, the inside of the introduction section 111 becomes bright. As a result, the vigilance of the fry F can be diminished, so that the fry F can enter the small fish guiding member 11. Moreover, since the upper surface portion 111d, which is the water surface side of the introduction portion 111, is transparent, it is easier to take in outside light, and the fry that has entered the small fish guiding member 11 can be visually confirmed.

Since the introduction part 111 is formed so that the opening area decreases from the tip part 111b to the base part 111a, the flow velocity of the water flowing through the introduction part 111 gradually increases as it goes deeper. Therefore, the juvenile F that advances toward the back of the introduction section 111 is sucked from the introduction section 111 to the main body section 114 in accordance with the flow. Like the introduction part 111, the main body part 114 is formed so that the opening area decreases from the front end part 114b to the base end part 114a, so that the flow path becomes thinner than the introduction part 111. Therefore, the fry F sucked deep into the introduction portion 111 is easily sucked into the main body portion 114. Then, the fry F that has passed through the main body 114 is guided to the connecting portion 113.

The fry F that has passed through the small fish guide member 11 advances to the conduit 12. As shown in FIG. 1, a sensor unit 141 is arranged in the conduit 12. As shown in FIG. 5, the conduit 12a in the sensor unit 141 is formed of a transparent member. That is, when the conduit 12 is an opaque member such as a metal, the conduit 12a in the sensor unit 141 may be connected to a transparent member, and when the entire conduit 12 is a transparent member, it may be used as it is.

The light from the light emitting unit 1411 enters the conduit 12a formed by the transparent member in the sensor unit 141, transmits the water flowing through the conduit 12a, and then exits from the conduit 12a on the opposite side to the incident position and the light receiving unit. 1412 is reached. The fry F passes between the light emitting unit 1411 and the light receiving unit 1412 shown in FIG. At this time, since the fry F is located between the light emitting unit 1411 and the light receiving unit 1412, the light traveling from the light emitting unit 1411 to the light receiving unit 1412 is blocked by the fry F. Since the counting unit 142 counts the number of times the light from the light emitting unit 1411 to the light receiving unit 1412 is blocked, it can count the number of times the fry F have passed, that is, the number of the fry F that can be collected.

The transparent member of the conduit 12a in the sensor unit may be any transparent member that transmits light from the light emitting unit 1411 to the light receiving unit 1412, and the same transparent member as the fry guiding member described above can be used. Specifically, glass, polyolefin resin, vinyl acetate resin, polyester resin, polyvinyl chloride resin, acrylic resin, polyvinylidene chloride, polyethylene terephthalate resin, polycarbonate resin, methyl methacrylate resin and polyamide resin, etc. Examples include transparent resins.

If the conduit 12a in the sensor portion is placed in the air, the refractive index of air, the refractive index of the transparent member forming the conduit 12a, and the refractive index of water do not match, so depending on the position where the fry passes through the conduit 12a. May cause a miscount.
Here, the transparent member of the conduit 12a is made of an acrylic resin having a refractive index close to that of water, and the conduit 12a is placed in water so that the difference in refractive index between them is substantially eliminated, and the fish passes through the conduit 12a. Light from the light emitting unit 1411 can be linearly made to reach the light receiving unit 1412 regardless of the position. Therefore, the sensor unit 141 can accurately catch the fry F.

The fry F that has passed through the sensor unit 141 further moves inside the conduit 12 and is discharged to the fry collection container B. The juveniles released into the juvenile collection container B are moved to the intended growing cages or the like as they are, or after being subdivided with a tuna net or the like as necessary.

As described above, the small fish collecting device 10 according to the present embodiment can guide the fry F to the connection portion inside the small fish guiding member 11 by weakening the caution of the fry F on the small fish guiding member 11. Therefore, the fry F can be collected efficiently and safely without using a suction pump having a large output.

Further, since the introduction portion 111 is formed of a vinyl sheet, even if the vinyl sheet deteriorates due to use, the vinyl sheet is stretched on the frame portion 112 with a binding band. Therefore, the user can replace the existing vinyl sheet with a new one and easily reattach it to the frame portion 112.

The introduction unit 111 may use a transparent resin sheet member other than a transparent resin sheet member such as a vinyl sheet. Specifically, a transparent resin such as polyolefin resin, vinyl acetate resin, polyester resin, polyvinyl chloride resin, acrylic resin, polyvinylidene chloride, polyethylene terephthalate resin, polycarbonate resin, methylmethacrylate resin and polyamide resin can be used. The plate member may be formed in a quadrangular pyramid shape or a triangular pyramid shape. In this case, the metal main body 114 in the above-described embodiment can be integrated with the resin plate member that constitutes the introduction portion 111.
By integrating the introduction part 111 and the main body part 114, the entire structure can be formed of a light transmissive member. Further, by forming the introduction part 111 from a resin plate, the frame part 112 can be used also and can be omitted.

If the main body 114 is made of a light-transmissive member, the inside of the main body also becomes brighter, so that the existence of the main body 114 can be reduced with respect to the fry, and thus the caution of the fry can be further reduced.
Furthermore, if the connecting portion 113 is also made of a light-transmissive member such as a resin plate member, the entire small fish guiding member 11 becomes brighter and the alertness of the fry can be further reduced. Moreover, the stress when advancing the fry F to the narrowest flow path can be relieved.

By irradiating the connection portion 113 or the main body portion 114 with light or using indirect illumination such as a reflector, the inside of the connection portion 113 or the main body portion 114 may be brightly illuminated, and the caution of the small fish may be diminished.

Further, in the small fish guiding member 11 of the present embodiment, the length of the introducing portion 111 (the length of the transparent portion) is 70% or more when the total length of the introducing portion 111 and the main body portion 114 is 100%. However, it can be arbitrarily set in consideration of the type of fry and the output of the suction means, and may be set to 50% or more, for example.

Further, since the frame portion 112 is assembled by connecting the cylindrical pipes, it is possible to easily configure the frame portion 112 and reduce the weight of the frame portion 112.

Further, if the conduit 12 following the connecting portion 113 is made of a transparent member instead of being made of metal, the inside of the conduit 12 having a long moving distance can be made brighter, so that the stress on the fry F can be further reduced. be able to.

In addition, in the present embodiment, an example in which juvenile tuna is assumed as the juvenile has been described, but the small fish guide member and the small fish collecting device using the same according to the present invention, as described above, include ties and yellowtails. It can be used with other fry other than tuna. However, since juvenile migratory fish such as tuna have a strong swimming power, unless they can be guided into the fry guiding member, a suction means with a considerably large output is required. Therefore, the present invention is suitable for collecting juvenile tuna.

Further, in the present embodiment, the vacuum pump is described as an example of the suction means, but, for example, the water level of the aquaculture tank A is set higher than the water level of the aquaculture tank B, and the space between the aquaculture tank A and the aquaculture tank B is set. The structure connected by the conduit 12 may be used as the suction means. Since the water level in the aquaculture tank A is higher than that in the aquaculture tank B, the siphon principle works to suck the fry F together with the water from the aquaculture tank A into the small fish guide member 11 and to the aquaculture tank B via the conduit 12. Can be transferred.

According to the present invention, small fish can be collected efficiently and safely, and is thus promising as one of the fish culture techniques.

10 Recovery Device 11 Small Fish Induction Member 111 Introduction Part 111a Base End 111b Tip Part 111c Bottom Part 111d Top Part 111e Corner 112 Frame Part 112a Base End 112b Tip Part 1121 Base Frame 1122 Tip Frame 1123 Support Frame 1123a to 1123d Frame member 1124 Reinforcing frame 113 Connection portion 113a Base end portion 114 Main body portion 114a Base end portion 114b Tip portion 114c Bottom surface portion 114d Top surface portion 114m Plate member 12 Conduit 12a Sensor section conduit 13 Suction pump 14 Counting device 141 Sensor section 1411 Light emitting part 1412 Light receiving part 142 Counting part A, B Culture tank F Fry

Claims (7)

An introduction part that has an opening through which a small fish to be cultivated enters and that guides the small fish to the back side, a connection part that has an opening to which suction means is connected, and a flow path that connects the introduction part and the connection part. A small fish guide member, wherein at least the introduction portion is a light-transmissive member formed of a sheet-shaped member or a plate-shaped member. The small fish guide member according to claim 1, wherein the main body is also made of a light transmissive member. The small fish guide member according to claim 2, wherein the connecting portion is made of a light transmissive member. The light-transmissive member is selected from polyolefin resin, vinyl acetate resin, polyester resin, polyvinyl chloride resin, acrylic resin, polyvinylidene chloride, polyethylene terephthalate resin, polycarbonate resin, methyl methacrylate resin and polyamide resin. The small fish guide member according to any one of claims 1 to 3, which is a sheet-shaped member or a plate-shaped member. The small fish guide member according to any one of claims 1 to 4, wherein the introduction portion has an opening area that decreases from the opening of the introduction portion toward the main body portion. A small-sized apparatus comprising the small fish guiding member according to any one of claims 1 to 5, a conduit connected to the connecting portion of the small fish guiding member, and the suction means provided in the conduit. Fish recovery device. Part of the conduit is formed by a transparent member,
A light emitting unit arranged on one side of the light transmitting portion of the conduit, a light receiving unit arranged on the other side opposite to the one side of the conduit, and a counting unit for counting the number of times of interruption of light reception of the light receiving unit. The small fish collecting device according to claim 6, further comprising:

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