JP2008193928A - Method for culturing infaunal bivalve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for culturing infaunal bivalves by a relatively simple equipment, especially those living in a brackish water area and fresh water area with efficiency. <P>SOLUTION: This culturing method is provided by housing the young shellfishes of the infaunal bivalves in a container having water-permeability, and hanging and holding it at the underwater of a culturing place, and it is possible to perform the culture efficiently. Further, in culturing, by giving stress treatments to the infaunal bivalves, it is possible to improve the growth of the shellfishes markedly. As the stress treatments, at least ≥1 treatment selected from an ultraviolet light-irradiation treatment, a surface tension-changing treatment, a water pressure-changing treatment, a fine radiation-irradiating treatment and a vibration treatment, can be cited. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for culturing buried bivalves, and more particularly, to a method for efficiently cultivating buried bivalves that live in brackish and fresh water areas.

  In Japan, there are three types of rainbow trout: Yamato Shijimi, Setashijimi and Masjimi. For example, Yamato Shijimi is a bivalve that lives in brackish water, and its growth pattern is settled after a short period of floating life after fertilization, buried in the sediment, and organic suspension in water. It keeps growing with food.

  In Lake Shinji, the representative production area for Yamato Shijimi, the shell length grows to about 7 mm in one year after fertilization, grows to about 15 mm in two years, and then grows when the shell length reaches about 20 mm or more. It has been reported that it will become moderate, and it is generally said that it takes 3 to 4 years to grow to a size that can be shipped as a product.

  Due to pollution in the lake water, sludge sludge, overfishing, etc., the yield of such rainbow trout has been declining year by year, and measures to maintain and increase resources quickly are desired.

  For example, as a method of culturing, it is conceivable to divide the aquaculture area into several areas and perform ground-based aquaculture. However, as described above, in order to grow to a size that can be shipped as a product, it takes 3 to 4 years. Since it takes years, it is necessary to divide the water area into at least four areas, which requires a large area of water, and its management becomes difficult.

  In addition, due to the recent inflow of domestic wastewater, agricultural wastewater, industrial wastewater, etc., the eutrophication of the aquaculture area has progressed, and an anoxic water mass is generated near the bottom, threatening the habitat of shellfish. The effect was not expected very much by the simple ground farming.

  By the way, as a method for cultivating so-called superficial bivalves such as oysters, scallops, and pearl oysters that inhabit seawater and grow on the base, seedlings seedlings that have been put into net cages or attached to shells There is a widespread use of aquaculture methods in which water is suspended in water without being covered with a net or the like.

  However, as for buried bivalves, it is considered that a sand bed into which shellfish should infiltrate is generally necessary because it is buried in sand mud, and such a culture method that hangs in water is applied. Not.

  As a method for culturing buried bivalves that live in seawater, Patent Document 1 describes a method in which sand or mud is placed in a small container, seeds of the buried bivalve are buried in the sand or mud, and suspended in the sea. Is disclosed.

  However, in this method, it is necessary to embed seedlings in sand or mud in a small container, so efficient production of cultivating a large number of shellfish cannot be performed, especially as a method for culturing small shellfish. It is not very suitable. It is also proposed as a method for culturing buried bivalves that live in seawater, and it is unclear whether it can be applied immediately as a method for culturing buried bivalves that live in brackish and freshwater areas. It was.

  In Patent Document 2, a production center that produces microalgae and seedlings of young shellfish, a plurality of beach cultivation sites for releasing and growing the young shellfish produced at the production center, and the production center A bivalve production system has been proposed that combines several district centers for short-term cultivation in order to feed the microalgae produced in Japan and clean the adult shellfish grown at the beach cultivation site. This system has been put to practical use as a clam culture method.

This method raises the survival rate of adult shellfish by raising juvenile shellfish using artificially produced microalgae, and raises the yield of aquaculture, and finally the adult shellfish are short-term in an artificial storage tank. Although it is a system that removes sand by interbreeding, basically, the growth from juvenile shellfish to adult clams is no different from the conventional land-culture method, and the juveniles are released to the beach area. It includes a process of collecting the sample after a predetermined time, and it is affected by eutrophication of the aquaculture area, contamination of the bottom sediment, and the like, as in the case of the ground culture method. In addition, this method has three locations: a production center that produces microalgae and seedling production of juveniles, a beach cultivation site that releases and grows juveniles, and a district center that cleans adult clams. However, although the production efficiency is increased, cost, labor, and the like are required for conveying goods between them. In addition, this system is also proposed as a method for culturing buried bivalves that live in seawater, and it is unclear whether it can be applied immediately as a method for culturing buried bivalves that live in brackish and freshwater areas. It was where.
Japanese Patent Laid-Open No. 9-266736 JP 2002-125507 A

  Therefore, an object of the present invention is to provide a method for efficiently cultivating buried bivalves, particularly buried bivalves that live in brackish waters and freshwater bodies, with relatively simple equipment.

  The method for cultivating buried bivalves according to the present invention that solves the above-mentioned problem is that the larvae of buried bivalves are accommodated in a water-permeable container, and this is suspended and maintained in the water of the farm. Features.

  In the method for culturing embedded bivalves according to the present invention, it is preferable to apply stress treatment to the embedded bivalves.

  In the method for culturing buried bivalves according to the present invention, the stress treatment is at least one treatment selected from an ultraviolet irradiation treatment, a surface tension fluctuation treatment, a water pressure fluctuation treatment, a trace radiation irradiation treatment, and a vibration treatment. Is preferred.

  Further, in the method for culturing buried bivalves according to the present invention, the buried bivalves are buried bivalves that inhabit brackish water and fresh water, and the breeding ground is a brackish or fresh water lake, pond, swamp, artificial It is preferably a pool, artificial water tank, or river area.

  According to the method for cultivating buried bivalves according to the present invention, surprisingly, in a very short period of time, the brackish water and the fresh water are It was found that the inhabiting buried bivalve can grow and the degree of growth is very excellent. Specifically, for example, when cultivated Yamatoshijimi grows to a size that can be shipped as a product, it took about 3 to 4 years to grow in about 2 years, and the size also increased. To do. In particular, after growing to a certain size or more, the tendency to slow growth is not seen so much, and the size is increased.

  Hereinafter, the present invention will be specifically described based on specific embodiments. In the method for cultivating the buried bivalve according to the present invention, the larvae of the buried bivalve are accommodated in a water-permeable container, and are cultured while being suspended in the water of brackish water or freshwater breeding grounds. Features.

  The target shellfish is not particularly limited as long as it is a buried bivalve and can be applied to various shellfish, but a buried bivalve that inhabits brackish water and freshwater is particularly preferred. Become.

  Specific examples of the buried bivalve inhabiting brackish water and fresh water include, for example, Yamatoshijimi, Setashijimi and Masjimi.

  In addition to these edible bivalves that are edible, the number of individuals increases from the standpoint of protecting the natural environment, for example, they become spawning shellfish for fish such as sea lions, and the number of inhabitants has decreased due to environmental destruction. Other shells that are required, for example, mussel, mussels, shellfish, crow shellfish, mussel shellfish, oyster shellfish, pine shellfish, scallop shellfish, scallop shellfish, Yokohama clam shellfish, scallop shellfish, shellfish shellfish, Shellfish, Sasanoha and Tongarisa Sanoha can also be used.

  Of course, it is not limited to those exemplified above. For example, in addition to the shells exemplified above in Japan, the target is buried bivalve shellfish inhabiting brackish water and freshwater in other countries. You can also.

  In addition, as seawater bivalves, for example, clams such as clams, ginseng clams, oyster clams, clams such as clams, peacock clams, clams, funnels such as scallops, sugar mussels, clams, mussels, mussels, lobster mussels, etc. It is also possible to use mussels such as mussels, mussels, snails, milk mussels, and mussels.

  In the present invention, such buried bivalve larvae are prepared by sampling or separately cultured. Although it differs depending on the type of shellfish, for example, as for swordfish, juvenile shellfish of about 3 to 7 months of age or about 2 to 5 mm in diameter can be used. In addition, it is also possible to cultivate shellfish grown more than that for further growth.

  Moreover, as a farm where the farming method of the present invention is carried out, a natural place such as a lake, a swamp, a river, or a sea area where the shellfish originally live can be used. In addition, it is also possible to use an artificially made outdoor pond or pool, or a smaller outdoor or indoor water tank. In general, it is preferable to use natural lakes, swamps, rivers, or sea areas from an economic point of view, but if you manage feeding, water temperature, water quality, water flow, etc., use artificial farms. It is also desirable from the viewpoint of effective use of land.

Next, the water-permeable container for accommodating such buried bivalve larvae is not particularly limited as long as it has sufficient water permeability and can stably hold shellfish in water at the farm. Although not intended, for example, various nets and moss can be used. Although it does not specifically limit even if it is the magnitude | size, For example, the thing whose internal volume becomes about 1-2 m < ³ > can be illustrated as a preferable thing from the workability | operativity at the time of culture being easy.

  As a method for arranging the buried bivalve in a water-permeable container, it is possible to place it flat in a container where the shell does not overlap too much, or to arrange it in a lump with considerable overlap, In any case, it is desirable to hold the shellfish in a state where it can move freely to some extent.

  In addition, when using a natural place such as a lake, pond, swamp, river, or sea area as a farm, the water-permeable container may be damaged by obstacles such as driftwood and garbage floating in the water area. For example, a fence having a relatively strong strength, for example, an enclosure having at least a rigid material such as metal, plastic, or wood as a frame is used as a protective exterior body. It is desirable to have a double or multiple structure, such as arranging a plurality of nets, shells and other breathable inner containers.

  In addition, when an exterior body is provided in this way, this exterior body can be used as a support body for the vibration equipment when a vibration equipment as described later is provided. Further, a stress substance such as a photocatalyst or a low-level radioactive substance can be put in a container or the like, and the container or the like can be attached to the exterior body.

  A method for holding such a water-permeable container in the water of the farm is not particularly limited. For example, as schematically shown in FIG. 1, several floats 11 are floated on the water surface 10 of the farm, The float 11 is placed on the bottom wall 13 of the farm by being anchored or locked from the quay 14, and the breathable container 16 is suspended from the support rope 15 stretched between the floats. Can be done.

  In the embodiment shown in FIG. 1, the breathable container 16 has a double structure having the breathable inner container 16A for shellfish accommodation and the protective outer package 16B surrounding the outside as described above. ing.

  Moreover, when culture | cultivating by an artificial pool, a water tank, etc. in which a mud sand floor does not exist in a bottom part, it is also possible to take the aspect of simply submerging a breathable container in water.

  The underwater position for holding the water-permeable container is not particularly limited as long as plankton or organic suspension is sufficiently deep to serve as food for shellfish contained in the water-permeable container. For example, the position of the shell contained in the water-permeable container can be held in a water area having a depth of about 10 cm to 250 cm, although it depends to some extent on the topography, its type, and the type of shellfish.

  The method for culturing buried bivalves according to the present invention can be carried out by storing juvenile bivalve molluscs in a water-permeable container as described above and holding them in water for a predetermined period, for example, about 1 to 2 years. However, it is preferable to apply stress treatment to the shellfish from the viewpoint of further increasing the degree of shellfish growth.

  Examples of the stress treatment include at least one treatment selected from an ultraviolet irradiation treatment, a surface tension fluctuation treatment, a water pressure fluctuation treatment, a trace radiation irradiation treatment, and a vibration treatment. In the culture method of the present invention, the degree of growth of the buried bivalve can be rapidly accelerated by applying one or more stress treatments to the shellfish. In addition, when giving several stress processing, the combination is free. The plurality of stress treatments may be performed simultaneously or alternately.

  The ultraviolet irradiation treatment can be performed by holding the position of the buried bivalve accommodated in the water-permeable container in a water area having a depth of about 10 cm to 250 cm that is not so deep from the water surface. By holding in this position, the shellfish can be exposed to more ultraviolet rays.

  Surface tension fluctuation treatment is a treatment that changes the surface tension of water around the shell. Specifically, a photocatalyst or low-level radioactive compound is provided around the shell, and the action of the photocatalyst or low-level radioactive compound. The surface tension of the water around the shell can be changed by the hydroxy radical (OH radical) generated by.

  As the photocatalyst, a known photocatalyst represented by, for example, titanium oxide or a composite compound thereof, for example, Japanese Patent Application Laid-Open No. 10-34143 or Japanese Patent Application Laid-Open No. 2003-335523 can be applied. Moreover, as a low level radioactive compound, the processing material etc. which generate | occur | produce the radiation of the grade which does not have a bad influence on a living organism, for example, natural uranium (for example, extract | collected with a Japanese puppet bowl), etc. can be used. This processed material acts as a radon-generating ceramic. Specifically, it changes from uranium (U) to radium (Ra), and from this radium, it comes out as radon (Rn) gas. Also, various low-level radioactive compounds other than radon can be preferably applied.

  The low-level radioactive compound acts to change the surface tension of water by generating hydroxy radicals as described above. However, even if the effect of changing the surface tension is small, only the generated hydroxy radicals can cause shells. Can give stress. Therefore, the stress treatment using the low level radioactive compound can also be referred to as a trace radiation irradiation treatment.

  These photocatalysts and low-level radioactive compounds are put in a container or the like, and the shell can be subjected to surface tension variation treatment or trace radiation irradiation treatment by attaching the container to a water-based container or attaching to the exterior body. .

  The water pressure fluctuation treatment is performed by stressing the shellfish by, for example, periodically changing the position of the shell in the water-permeable container up and down to change the water pressure or artificially changing the water pressure in an artificial water tank. Can be given.

  Examples of the vibration treatment include a method of applying vibration to the shell by performing aeration from the vicinity of the water-permeable container to the inside of the container. For example, in the embodiment shown in FIG. 1 described above, a bubbling device 17 is installed in the vicinity of the bottom surface portion of the protective exterior body 16B. The bubbling device 17 has an air supply pump installed on the quay wall 14. The air supply line 19 extended from 18 is connected, and aeration can be performed on the breathable inner container 16A by the pressure-fed air. Of course, the device mechanism for the aeration is not limited to the one illustrated in FIG. 1 and can take various forms.

  A specific method of aeration, which is an example of vibration processing, is not particularly limited, but it is desirable that fine microbubbles can be generated. Of course, aeration can be performed continuously, but intermittently, for example, repeats operation and pause every 30 minutes to 1 hour, or operates only during a certain time of day or night, and rests for the remaining time. It is also possible to take a form such as.

  As an apparatus for performing aeration, for example, a gas-liquid using a porous body such as a sponge, air stone, or porous ceramic attached to the tip of an air supply line, an ultrasonic vibrator, a venturi tube, or the like is used. Although the thing of the structure etc. which make a two-phase flow hydrodynamically shear can be illustrated, the method using an ultrasonic transducer is desirable from the viewpoint that a finer bubble can be generated.

  When performing aeration, for example, an ozone generator using an ultraviolet lamp or the like may be attached in the middle of an air supply line sent to a bubbling device, and ozone may be included in the gas to be aerated. By containing ozone having a bactericidal action, the shellfish can be stressed, and as a result, the growth of the shellfish can be remarkably enhanced.

  By applying stress to the shells as described above, the shells grow significantly faster to resist the stress, the shells become thicker and larger in size.

  The aquaculture period by the method for culturing buried bivalves according to the present invention is not particularly limited, and may be carried out until the cultivated shellfish grow to a sufficient size, for example, embedded in sand mud. In the conventional aquaculture method of growing up, it takes about 3 to 4 years to grow to a size that can be shipped as a product. Even in the period, it is possible to grow to a sufficiently large one over 3-4 years in the conventional method. In addition, in the conventional method, the growth rate becomes slow when the shell length is grown to a certain value or more. However, in the method of the present invention, the growth rate is substantially reduced even after such a size is reached. However, by continuing the cultivation, larger shellfish can be obtained.

  In addition, in the conventional aquaculture method, since it takes many years to cultivate, it is necessary to divide the water area of the aquaculture farm into multiple sections, for example, four sections or more, even if it is partitioned every year. In the aquaculture method of the present invention, since the aquaculture can be performed in a short period of time, even if it is divided every year, a large water area is not required, and its management and the like are facilitated.

  Hereinafter, the present invention will be specifically described by way of examples.

(Example 1)
2kg Koda, 2576 Koda, Inashiki-shi, Ibaraki Prefecture, 1 kg of Yamato Shijimi larvae collected in an aquaculture pond owned by Daiko Pearl Co., Ltd. is placed in a container made of wire mesh with a mesh of 1 mm mesh. In an aquaculture farm of about 2.5 m, it was kept under water at a depth of 0.1 to 1 m below the surface of the water, cultured, and regularly observed for shellfish growth. The farm was the Shintone River, 2576 Koda, Inashiki City, Ibaraki Prefecture, and the start of the aquaculture was April 2006. As a result, the average diameter of the shellfish was about 15 mm in 10 months from the start of the cultivation, and the total weight was about 5 kg. In addition, no particular illnesses or deaths were observed during the cultivation period.

(Comparative Example 1)
2576 Koda, Inadaki-shi, Ibaraki Prefecture, 1 kg of Yamatojimi larvae with a diameter of about 5 mm collected in a culture pond owned by Oko Pearl Co., Ltd. is cultured in an artificial pool of 40 cm depth owned by Oko Pearl Co., Ltd. went. The start of aquaculture was April 2006. In this artificial pool, sand and mud were laid 15 cm thick, and larvae were buried in the sand and mud for cultivation. As a result, the average diameter of the shellfish was about 7 mm within 10 months from the start of the cultivation, and the total weight was about 1.5 kg.

It is drawing which shows typically the aquaculture equipment used in one Embodiment of the culture method of the buried bivalve according to the present invention.

Explanation of symbols

10 Water surface of aquaculture 11 Float
DESCRIPTION OF SYMBOLS 13 Bottom wall of aquaculture site 14 Quayside of aquaculture site 15 Support rope 16 Breathable container 16A Breathable inner container for shellfish storage 16B Protective outer body 17 Bubbling device 18 Air supply pump 19 Air supply line

Claims (4)

  A method for cultivating buried bivalve, characterized in that juvenile bivalve molluscs are housed in a water-permeable container and are suspended and cultured in the water of a farm.   2. The method for cultivating an embedded bivalve according to claim 1, wherein stress treatment is applied to the embedded bivalve.   The embedding according to claim 1 or 2, wherein the stress treatment is at least one treatment selected from an ultraviolet irradiation treatment, a surface tension fluctuation treatment, a water pressure fluctuation treatment, a trace radiation irradiation treatment, and a vibration treatment. How to cultivate bivalve molluscs.   The buried bivalve is a buried bivalve that lives in brackish and freshwater areas, and the farm is a brackish or freshwater lake, pond, swamp, artificial pool, artificial water tank, or river area The method for culturing buried bivalves according to any one of claims 1 to 3.

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