JPH10108581A - Pearl culture method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pearl culture method using culture facilities on land. SOLUTION: The sea water living bivalves or fresh water living bivalves transplanted with the mantle pieces and nuclei or mantle pieces of the shellfishes for nacre layer formation are cultured by feed essentially consisting of skim milk powder in the culture facilities on land having the sea water or the same compsn. as the compsn. of the sea water or in the fresh eater of the culture facilities on land. The sea water living bivalves are preferably pearl oysters, black lips, goldlips, or P. penguin. This breeding method is applicable to the breeding of the larva or spat of the sea water living or fresh water living bivalves and the breeding of the mother shells before the transplantation of the mantle pieces of the shellfishes for nacre layer formation. The skim milk powder is stable in supply and is higher in cost effectiveness that the conventional feed formed by culturing plankton. Since the bivalves are cultured in the culture facilities on land managed to an optimum environment, the growth of the mother shells and the nacre layers are much faster than in the natural sea and further, there are no possibilities of natural hazards, like typhoons and red tides.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of culturing pearls using an onshore cultivation facility, and more particularly, to a method for producing a pearl-based feed that is substantially the same composition as seawater or skim milk powder in freshwater. , Saltwater or freshwater 2
It is a method of breeding mussels and cultivating pearls in their tissues. The present invention can be applied to both a large-scale aquarium for aquaculture and fisheries and an aquarium for domestic appreciation fish.

[0002]

2. Description of the Related Art Conventionally, pearl oyster cultivation has been carried out on land and pearl cultivation has been carried out in the natural sea. In all cases, a method has been adopted in which plankton is artificially cultured and the plankton is used as feed to grow shellfish. ing. However, artificial cultivation of plankton is extremely difficult, and requires an expert and experienced technician.

[0003] Further, a culture room having special equipment and a large amount of chemicals used for culture are required. Therefore, large fixed assets such as land acquisition costs and facility costs required for these facilities are required. In addition, since plankton is cultured by photosynthesis, it is necessary to continuously irradiate light of about 6,000 to 10,000 lux day and night, which requires a considerably large-scale fluorescent lamp irradiation facility and a large amount of electricity required for it. .

Conventionally, in pearl cultivation, after the seedlings are harvested, young mussels are grown in the natural sea for a certain period of time, then floated on a raft or rope and fixedly laid with an anchor, and the shells are put into a pearl net. Cultivation, but earthquakes, tsunamis,
There was no effective defense against natural disasters such as heavy rain, intense heat, cold waves, and red tide. Occasionally catastrophic damage to aquaculture equipment and growing shells also occurred. When the seawater temperature drops below 15 ° C in the natural sea, plankton, which feeds on pearl oysters and the like, becomes seeds and penetrates into the mud on the seabed.

[0005] For this reason, plankton hardly exists in seawater, and feed such as pearl oysters disappears, so that the shellfish hibernates for about six months from November in the year to around April of the following year, during which time the shellfish hibernates. Growth and nacre growth stop. Due to changes in seawater conditions, mortality of shellfish during cultivation is several percent
It was difficult to lower it below.

[0006]

As described above, in the cultivation of pearls using the natural sea, shellfish hibernates for about half a year depending on the temperature of seawater, earthquakes, tsunamis, heavy rains, intense heat, and cold waves. There are no effective defenses against natural disasters such as red tides, and these problems also apply to rivers and lakes. Furthermore, the cultivation of plankton as the feed requires technical difficulties and high costs. In order to solve these problems, the water area for seafood cultivation, which is isolated from natural rivers, lakes and marshes and the ocean, is managed in an environment suitable for the growth of bivalves and other shellfish for pearl cultivation. The purpose of the present invention is to develop and provide a method for breeding pearls in shellfish tissues by breeding shellfishes with easily supplied feed.

[0007]

SUMMARY OF THE INVENTION The present inventor has taken into account the many problems of culturing pearls in the natural sea as described above, and has found a water tank on land for shellfish used for culturing pearls such as bivalves. Breeding was attempted. The biggest obstacle here is the cultivation of plankton as feed. Plankton cultivation is expensive both in terms of technical and cultivation costs, and plankton has the most serious problem that stable cultivation is difficult due to its sensitivity to subtle changes in culture conditions.

For this reason, various studies have been made on feeds of these shellfishes which can be used in place of plankton. As a result, when the skim milk powder is dispersed in water to form an emulsion, the fine particles of the milk powder or a part thereof is present in the water of Acinectobactor.
By the action of bacteria such as the genus and the genus Vibrio, Flavobacterium, and Pseudomonas, these bacteria are easily converted into substances that are easily digested partially as bait for these shellfish, and are also present inside the digestive organs of the shellfish. Were found to promote digestion. Furthermore, since the particles of skim milk powder dispersed in water were extremely small, it was found that they were suitable as bait for larvae and larvae of shellfish.

[0009] In addition to mother shells for pearl culture, larvae and juvenile shellfish were bred as feeds using an emulsion prepared by dispersing skim milk powder in water. As a result, it was confirmed that they grew smoothly for a long period of time. Furthermore, it has been found that the taste of the shellfish is further enhanced when a feed obtained by adding Moroheiya to skim milk powder is added, and the present invention has been achieved based on this finding.

[0010] That is, a marine aquatic bivalve transplanted with a mantle piece and a nucleus of a shell for forming a nacre, or a mantle piece is transplanted in a marine aquaculture facility on sea or on land having substantially the same composition as seawater. This is a pearl culture method characterized by culturing with a feed containing skim milk powder as a main component. Here, the genus Acinectobactor and Vibrio, Flavobacteri
The environment in which bacteria contained in the genus um and Pseudomonas are present is preferable, and the feed preferably contains moloheiya and calcium carbonate in addition to skim milk powder. Shellfish, white clams or mabe shells are preferred.

[0011] Further, it is desired that a freshwater bivalve, into which a mantle piece and a nucleus of a shell for nacre formation or a mantle piece are transplanted, be cultured in a land-based aquaculture facility using a feed containing skim milk powder as a main component. Characteristic pearl culture methods are also included in the present invention. Here, the feed preferably contains Moroheiya and calcium carbonate in addition to skim milk powder, and the freshwater bivalve is preferably a mussel or a giant mussel.

In addition, larvae, juveniles and mother clams of marine bivalves collected in the natural sea or hatched by artificial insemination are cultivated in a marine aquaculture facility on sea or on land having substantially the same composition as seawater. Raising freshwater bivalve larvae, larvae, and mother mussels collected from natural rivers and lakes or hatched by artificial fertilization in a terrestrial aquaculture facility on a diet based on skim milk powder In the method of breeding larvae or larvae of pearl culture shellfish, larvae and mother shellfish, and a pearl culture water tank installed on land, a filtration tank is provided in the piping for circulation of the liquid in the tank, and activated carbon as a filter material Alternatively, the present invention also includes a pearl aquaculture tank characterized by containing a carbon material.

[0013] Here, bivalves are bivalves having a habit of forming a pearl layer around them when foreign matter is mixed into the shell tissue, for example, for pearl culture like pearl oysters A shellfish that can be used for In addition, onshore aquaculture facilities refer to facilities that are artificially controlled in the environment in a water area for aquaculture, which is isolated from natural rivers, lakes, and the ocean. Seedling refers to collecting shellfish larvae hatched by natural or artificial fertilization in order to grow them into juveniles. Hereinafter, the present invention will be described in detail.

In the pearl culture method of the present invention, it is necessary to use a shell and a nucleus of a shell for forming a nacre, or a marine bivalve transplanted with a shell. The method of the present invention may be applied to a nucleated pearl in which a mantle piece and a nucleus are transplanted to form a nacre, or a non-nucleated pearl in which only a mantle piece is implanted without a nucleus and a nacre is formed around the nucleus. Can also be applied.

The shell and nucleus of the shell for the formation of nacre are implanted into the shell tissue from the outside and used to grow the nacre around the shell. Mantle strips are used, and the nuclei are generally cut into thick shells and implanted into the shell tissue together with the mantle pieces as spheres. The nucleus can be used after being processed into a spherical pear shape or other various shapes. The shell used as the core material includes, for example, shells such as the shells of the Mississippi River, which are processed from wax, plastic, and the like.

The bivalve of the present invention can be used in seawater or freshwater as long as it can be used for pearl culture.
As the aquatic bivalve, pearl oysters, red pearl oysters, taiwan pearl oysters, white pearl oysters, black pearl oysters, mabe oysters, etc. can be used. . In addition, as freshwater bivalves, ikechoi, kawashinju, hiraikecho (triangular mussel), crow shell, mussel, maldo mussel, etc. can be used. preferable.

For the cultivation of the bivalves of the present invention, it is necessary to use natural seawater or artificial seawater prepared to contain substantially the same components as seawater. Recently, since seawater and rivers are often contaminated, even if natural seawater or river water is used as it is, pearl mussels often contain germs and other components. In particular, pearl mussels after transplantation of mantle pieces or nuclei have reduced resistance to these environmental changes, and the mortality of the mussels may increase sharply. For this reason, it is preferable to artificially prepare a solution having the same components as seawater, or to collect clean natural seawater and purify it by filtration or other means before use. However, purification here means mainly to remove impurities such as fine dust and suspended matter, but does not mean to completely remove bacteria contained in seawater.

To artificially prepare a solution having the same components as seawater means that not only the composition of chemical components such as inorganic salts and pH is the same as seawater, but also that the solution is contained in seawater suitable for pearl cultivation. Is a solution that also contains bacteria. "Having substantially the same composition as seawater" means a solution thus artificially prepared. In order to prepare such a solution, for example, a solution prepared so as to contain inorganic salts having the same composition as seawater, or a sample of clean natural seawater, and after removing dust and dirt by filtration, It is obtained by partially mixing the solution in the aquarium where the pearl oysters have been cultured for a certain period of time.

A sample of seawater obtained by cultivating pearl mussels for a long time using skim milk powder as a feed was subjected to a bacterial culture test.
genus inectobactor and genus Vibrio, genus Flavobacterium, Pseu
It is recognized that the bacteria contained in the genus domonas are multiplying. When skim milk powder is used as a feed, even if a liquid prepared only with the same composition of chemical components such as inorganic salts and pH as seawater is used for cultivation of pearl mussels, seawater in which bacteria as described above have propagated can be used. The feed intake of the shellfish is lower and the growth rate is lower compared to the case of using. In particular, the mortality of pearl mussels after transplantation for pearl culture is increased.

These bacteria not only propagate in the seawater in the aquaculture tank, but are also swallowed with the food from the mouth of the shell and enter the inside of the digestive organs, and propagate in conjunction with the functions of the digestive organs, thereby ingesting nutrients. It is thought to play a role in promoting

In order to always keep these bacteria in a state of propagation in the seawater in the culture tank, a space filled with a porous substance, which is an environment in which bacteria can easily propagate, is provided in a liquid circulation system in the tank. Is preferred. The porous material filling space is preferably used in combination with a circulating liquid filtration system in view of the configuration of the aquaculture tank, and considering that it is necessary to also have a filtration and impurity adsorption function, the packing is preferably activated carbon, particularly powdered activated carbon. .

The cultivation of the pearls of the present invention must be carried out in onshore aquaculture facilities. As mentioned above, land-based aquaculture facilities are facilities that can artificially control the environment in the seafood aquaculture water area that is isolated from natural rivers, lakes, and the ocean. Here, large-scale facilities include a wide range of facilities from aquaculture ponds or pools and aquariums to small-scale facilities from tropical fish viewing aquariums used at home.

The water quality and temperature in the aquarium necessary for raising shellfish
Conditions such as the amount of light irradiation can be artificially controlled. In addition, there is an advantage that various conditions such as the amount of dissolved oxygen, the amount of feed, the amount of light irradiation, and the like can always be maintained in the most preferable state for the growth of shellfish. Furthermore, artificial cultivation as a closed system is possible by providing equipment that periodically removes excrement and other sediments, and circulation and filtration equipment that takes into account the growth of bacteria that promote shellfish growth in seawater. This is one of the major features of the present invention.

In the pearl culturing method of the present invention, it is necessary to cultivate shellfish with a feed containing skim milk powder as a main component. Skim milk powder is usually called skim milk, and is obtained by vacuum-drying the remaining liquid obtained by collecting butter from milk. It is produced worldwide in large quantities and is mainly used for livestock feed, and is cheap and has a stable supply.

In conventional pearl culture, the feed for shellfish is plankton, and plankton artificially cultured is generally used as feed. However, as described above, the cultivation of plankton is technically difficult, so that the supply is often insufficient. In addition, equipment costs and operation costs are high, and the cost is extremely high in terms of economy. The use of skim milk powder as feed is the most significant feature of the method of the present invention.

Bivalves such as pearl oysters feed on surviving plankton, the products of the plankton carcasses partially altered by the action of marine bacteria, and other small floating organic matter (detritus) in the sea. . Therefore, as a result of various attempts of bivalve diets that can replace plankton and detritus, it was found that skim milk powder was suitable.

The skim milk powder is easily dispersed in seawater to form an emulsion, and the fine particles of the dispersed skim milk powder or a part of the fine particles are composed of the genus Acinectobactor, the genus Vibrio, and the Flavobacterium.
Substances that have been partially altered by the action of bacteria or the like contained in the genus Pseudomonas have almost the same suitability as bait for pearl oysters as well as plankton. It is suitable for feeding not only grown shells, but also hatched larvae or juveniles. It can also be used as a feed for freshwater bivalves such as geese, like seawater bivalves.

As will be described later, a marine shell bivalve such as a pearl oyster transplanted with a mantle piece and a nucleus for forming a nacre, or a freshwater bivalve shell such as a ginkgo mussel transplanted with a mantle piece of another shell, As a result of feeding the skim milk powder as a feed in seawater or freshwater and cultivating the pearls for a long period of time, it was confirmed that both the mother mussel and the pearl layer in the tissue grew smoothly. This is because nutrients contained in skim milk powder are very similar to plankton, and they are easily dispersed in seawater or fresh water to form emulsified liquid particles. Plankton with a particle size of several μm and fine suspended organic matter ( The fact that the size of the particles is almost the same as that of the particles of (Detoritas) is also considered to be a factor that enhances the palatability of the shellfish.

Furthermore, skim milk powder is excellent in that its supply is more stable than plankton, which is difficult to culture, it is highly economical, and it does not require excessive cultivation equipment, electric power equipment and electric power cost. Furthermore, it has been found that when Moroheiya is added to skim milk powder as bait for seawater bivalves such as pearl oysters or freshwater bivalves such as pokeweeds, the preference of these shellfish for the skim milk powder is further enhanced. . In addition, when calcium carbonate is added, the effect of remarkably promoting the growth of nacre is recognized. It is considered that calcium carbonate is a main component of the nacre.

The ratio of Moroheiya to 100 parts by weight of skim milk powder is preferably 2 parts by weight or more as a lower limit, and 10 parts by weight or less as an upper limit. The lower limit of the calcium carbonate is preferably 15 parts by weight or more, and more preferably 40 parts by weight or less, as the upper limit relative to 100 parts by weight of the skim milk powder. Other nutrients or the like may be further added to the feed, and in some cases, plankton, which has been conventionally used as a feed for these shellfish, may be used in combination.

The method of the present invention further comprises collecting in the natural sea,
Or a breeding method characterized by using larvae or juveniles of marine bivalves hatched by artificial insemination, mother mussels in a land-based aquaculture facility, and using a feed containing skim milk powder as a main component, and a natural river, A breeding method characterized in that larvae, juveniles and mother mussels of freshwater bivalves collected in a lake or hatched by artificial insemination are used in a land-based aquaculture facility using a feed mainly composed of skim milk powder. Is also included.

In the pearl farming business, larvae or larvae of hatched shellfish are reared and grown, and the mother shellfish is further grown so that a shell piece and a nucleus of the shell for nacre formation can be transplanted. Raising mother mussels is a very important field. The feed comprising the skim milk powder of the present invention as a main component is also suitable for the growth of these shellfish, from the larva to the juvenile, and from the juvenile to the robust mother shell which can be transplanted for further nacre formation. It can be grown smoothly only with skim milk powder.

Of these, it is considered difficult to breed larvae or larvae. However, it is possible to grow satisfactorily only with skim milk powder in addition to the fact that nutritional components are similar to plankton, It is considered that when skim milk powder is dissolved in water, the fine particles in the resulting emulsion are several μm and almost the same size as plankton. Further, the addition of Moroheiya to skim milk powder further enhances the palatability of larvae and larvae as in the case of mother mussels. Furthermore, breeding of larvae and juvenile shellfish in onshore aquaculture facilities according to the method of the present invention is more excellent than that of mother mussel in terms of improvement in growth rate and reduction in mortality compared to the natural sea or lake.

The present invention further includes an invention relating to a basic structure of a pearl culture tank provided on land. The aquaculture tank is provided with a pipe for circulating the liquid in the tank, and the pipe must be provided with a filtration tank. The circulation pipe may be provided either inside or outside the tank, but is preferably installed outside the tank in consideration of periodic cleaning of the filtration tank provided in the pipe, replacement of the filter medium, and the like.
Bivalves for pearl culture are susceptible to water quality, and when contaminated, mortality may increase rapidly and growth rate may decrease. In particular, after transplantation for nacre formation, this effect is remarkable because the resistance decreases, and the growth rate of nacre is also significantly reduced. For this reason, the lower layer liquid in the tank is taken out and filtered to remove floating contaminants and then returned to the tank.

Further, the filter medium filled in the filter tank needs to contain activated carbon or carbon material. When carbon material is used as crushed particles, it has the effect of removing contaminants floating in water, but the proliferation of bacteria contained in the liquid in the tank due to the numerous fine pores on the surface Acin is effective as a medium for growth of pearl mussels
genus ectobactor and Vibrio, Flavobacterium, Pseudo
It has the effect of promoting the growth of bacteria contained in the genus monas.

Activated carbon generally has a large surface area of several hundred m ² or more per gram, and can be used in a wide range as long as it is a carbon material exhibiting high adsorptivity. As the raw material of the activated carbon, a carbide such as coconut shell or wood or coal is usually used, but any material may be used. The activation method may be one obtained by steam or carbon dioxide at a high temperature or by any of zinc chloride, phosphoric acid, concentrated sulfuric acid treatment and the like.

Activated carbon is a unique substance having extremely excellent adsorptivity as a nonpolar adsorbent, and exhibits high adsorptivity to almost all gaseous or liquid substances. For this reason, the action of adsorbing and removing other harmful components of pollutants in the liquid in the tank is high,
Furthermore, since the activated carbon itself is all composed of aggregates having a pore structure, it is more preferable as a culture medium for the aforementioned bacteria.

Sand or coral sand may be added to the filter medium in addition to the activated carbon or carbon material. Since coral sand is made of calcium carbonate, it not only functions as a filter medium, but also has a regulating action to elute and partially raise the pH when the pH of the liquid drops, and has many small pores on the surface. Therefore, it also has the function of a bacterial medium as described above. Further, other filter media can be used in combination.

Further, as the pearl culture water tank installed on land included in the present invention, (A) a culture tank and (B) a feed preparation tank,
(C) Filtration tank, (D) There is a water tank consisting of environmental control device.
(A) The feed solution is poured from the water surface into the culture tank, and the liquid extracted from the circulating fluid outlet provided at the lower part of the tank inner surface is filtered by a filtration tank, and then the upper part of the tank inner surface The liquid in the tank is ejected from a circulating liquid inlet provided in a horizontal direction and in a direction in which the liquid in the tank circulates along the inner wall surface of the tank, so that a circumferential water flow is generated in the tank. The bottom surface in the tank has a gentle inverted conical shape, and a drain port is provided at the bottom, and a drain port for removing sediment and lower layer liquid is provided at the bottom.

(B) The feed preparation tank is provided with a device for measuring and supplying skim milk powder and a stirring and dissolving device. The preparation of the feed solution and the supply of the feed solution to the culture tank are controlled by an environment control device so as to be performed at regular intervals. (C) The filter medium filled in the filter tank contains at least one selected from the group consisting of activated carbon and carbon materials, sand and coral sand. As described above, the filtration layer has an action as a medium for filtration and propagation of bacteria. (D) The environmental control device includes a fluorescent lamp lighting device, a temperature control device in the tank, an air blowing device, and an operation control device for other facilities related to the culture tank. With these devices, the inside of the tank is always maintained in an environment that is optimal for the growth of pearl mussels.Thus, the growth rate of nacres is faster than when cultured in a normal natural environment, so the layers are thicker and the quality is higher. Good.

The aquaculture is maintained in an aquarium on land at an optimum temperature, for example, pearl oysters are kept at 22 to 23 ° C., so they do not hibernate and maintain the environment most suitable for shellfish living all year round. It has always been growing. Because of this, the feed intake of the shellfish is large and the growth is fast, so that the generation rate of the nacre is two to three times that in the case of culturing in the natural sea, and a pearl having a large diameter is easily obtained. Furthermore, in the cultivation in natural seawater, the difficulty of plankton cultivation, unexpected damage due to natural disasters, etc. are quite large, so in view of these disadvantages, the present invention is considered to be a pearl culture method with great merit. I can say.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION When pearls are cultivated by a bivalve shell, for example, pearl oysters, into which a shell and a nucleus of a pearl shell are formed according to the method of the present invention, a skim milk dissolving tank is provided in an aquaculture tank. A liquid circulation pipe in the tank, a filtration tank filled with activated carbon and coral sand, and a seawater replenishment tank are attached. Further, a water temperature control device, an air blowing device, and a fluorescent lamp lighting device are attached to the aquaculture tank. The liquid in the tank always circulates
After being filtered, the seawater temperature, pH and dissolved oxygen amount are always maintained under constant conditions. After inserting the mantle pieces and nuclei of the shell for the formation of the nacre into the pearl oysters two years after the seedling collection, the oysters are cultured in an aquarium at a rate of 2 to 3 liters of exclusive seawater per shell.

The seawater used for the aquaculture tank can be used after filtering natural seawater through a filtration tank filled with activated carbon or coral sand, sand, and oyster shells to remove dust and dirt. Prepare artificial seawater containing inorganic salts with the same composition as above, and use a mixture of a part of the aquarium liquid where bacteria that breed pearls for a long time and promote the digestion of skim milk powder of shellfish are breeding. preferable.

For the feed, a mixture of 5 parts by weight of Moroheiya powder and 20 parts by weight of calcium carbonate fine powder with respect to 100 parts by weight of skim milk powder was sufficiently dispersed in seawater in a skim milk dissolution tank, and the valve was opened at regular intervals. Inject into aquaculture tanks. Table 1 shows the nutritional components contained in plankton, which is used as feed when skim milk powder and pearl oysters are cultured in the natural sea.
The nutritional components of Moroheiya are also shown.

[0045]

[Table 1]

As shown in the table, the nutritional components contained in skim milk powder are very similar to plankton. However, the palatability of shellfish such as pearl oysters to food cannot be determined only by the composition of the nutritional components. This may be due to the unique choice based on the habits of the organism. Bivalves such as pearl oysters feed on plankton as well as products that are partially altered by the action of marine bacteria in the plankton or microscopic organic matter (detritus) floating in the sea.

Fine particles of skim milk powder dispersed in seawater;
Some of the particles are from the genus Acinectobactor and Vibrio in seawater
Due to the action of bacteria such as the genus, it is thought that some of the components that have been altered can also be used as shellfish feed.However, even when bred solely with skim milk powder for a long time, pearl oysters grow smoothly and high quality pearls are obtained. The fact that the nutritional components contained in skim milk powder are similar to plankton is also considered to be a major factor.

As a meal for the pearl oysters, the addition of fine powder of Morohaya to skim milk powder increases the palatability of the shellfish with respect to the diet, and has the effect of improving the growth rate of the shellfish and the generation rate of the nacre. The nutrient component of Moroheiya is remarkably different from plankton, but its gel-like property is considered to promote the growth of bacteria that transform skim milk powder into a substance that can be eaten easily by shellfish, or play a role as a medium.
Further, calcium carbonate is added because it has an effect of remarkably promoting the growth of nacre.

When pearl oysters are cultured using skim milk powder as feed, the genus Acinectobactor, Vibrio, Flav
The culture test confirms that bacteria contained in the genus bacterium and the genus Pseudomonas are proliferating. These bacteria are considered to have the effect of altering part of the skim milk powder to change into a substance having high palatability of the shellfish and promoting digestion inside the digestive organ of the shellfish. A tank for aquaculture is provided with a filter tank filled with activated carbon and coral sand, and circulates and filters seawater in the tank. In the filtration tank, in addition to purifying seawater by removing dirt and garbage, the countless pores of activated carbon and coral sand that are the filtration layer,
It serves as a medium for these bacteria and promotes their propagation. The main component of the coral sand is calcium carbonate, and a part of the coral sand has a function of replenishing calcium carbonate ions in seawater which have been eluted and taken down by the shellfish and preventing a decrease in pH.

The bottom of the aquaculture tank is recessed in an inverted conical shape, so that impurities generated in the tank during the aquaculture, such as shellfish excreta, precipitate at the bottom of the aquarium. The valve opens the valve at regular intervals to take out the sediment and also functions to prevent the pH from dropping due to the accumulation of excrement. Further, the seawater in the aquaculture tank is appropriately replenished from a seawater replenishing tank, and a constant amount of seawater is always maintained. Other seawater temperatures are optimal for pearl oyster growth
The temperature is adjusted to 22-23 ° C, and the circulation of the liquid in the tank is stopped for a certain period after feeding the feed according to the habit of the shellfish. In addition, the environment such as the dissolved oxygen concentration is also controlled.

FIG. 1 shows the growth records of the nucleus-inserted pearl oysters bred in the above-mentioned aquarium for 6 months, showing the progress of the cultivation, the amount of the mussels when a feed consisting of skim milk powder, moloheiya and calcium carbonate was administered. Indicates weight. In addition, the weight of the shellfish was selected from 10 shellfish having an average growth degree at first, and thereafter, the average value was shown. Also, for comparison, the growth record when reared under the same conditions except that the conventionally used cultured plankton was used as feed was also shown.

[0052]

FIG.

From the results shown in the figure, the monthly average weight gains of pearl oysters cultivated on a diet containing skim milk powder as a main component and shellfish on plankton feed were 7.0% and 5.4%, respectively. It is noteworthy that the growth rate when using feed is rather higher than that when using plankton. In addition, the degree of growth of the nacres taken out after breeding for 6 months was better when skim milk powder was used as a result of visual observation.

In natural submerged aquaculture, the growth of pearl oysters and the growth of nacres are stopped during the winter months when the water temperature decreases, and the optimum water temperature is maintained in other seasons.
The growth rate of nacre decreases with increasing distance from ~ 25 ° C,
Shell mortality is high. According to the method of the present invention, since the optimum water temperature is always maintained at 23 ° C., the growth rate of the nacre is remarkably faster than that in the natural sea and reaches two to three times or more of the conventional method.
In addition, the mortality of shellfish is considerably low at 2-3%. In recent years, natural marine aquaculture often has mortality rates of 40-60%, probably due to ecological changes. In the method of the present invention, the obtained pearls are considerably large, and the nacres are uniform and good. Considering these points, the pearl culture method of the present invention is remarkably superior to the conventional method.

Further, larvae or larvae harvested in the natural sea or hatched by artificial insemination were bred with skim milk powder or a feed supplemented with sufficiently ground and ground Moroheiya as in the case of pearl culture. Both grew smoothly into mother mussels, and the mortality was much lower than when bred in the natural sea. When skim milk powder is sufficiently dispersed in seawater, it becomes ultrafine particles with a particle diameter of about 0.12 μm, which is one reason that small larvae and larvae are suitable for inhalation from sea mouths through small mouths together with seawater. it is conceivable that.

Next, the mantle pieces and nuclei of a shell for forming a nacre are transplanted to a white butterfly, and in a large land-based aquarium similar to the pearl culture by the pearl oysters described above, substantially the same as seawater. Culture in a liquid having a composition will be described. The structure of the aquaculture tank is the same as that for the pearl oysters, and the environmental management method is almost the same. After transplanting a mantle piece and a nucleus of a shell for forming a nacre to a white-headed mussel two years after the seedling was collected, the oyster was cultured in an aquarium with an exclusive seawater volume of 10 to 12 liters per shell. In addition, the seawater temperature is adjusted to 24 to 26 ° C, which is optimal for the growth of white clam.

FIG. 2 shows that the degree of shell growth was determined by the change in shell height when a mixture consisting of skim milk powder, moroheiya and calcium carbonate having the same composition as that of the pearl oysters was administered as feed and bred for two years. Indicated. In addition, at the beginning, 10 shellfish having an average degree of growth were selected, and the shell height of the shell was indicated by the average value thereafter. For comparison, a growth record in the case of rearing for one year under the same conditions except that cultured plankton conventionally used as a feed was also shown.

[0058]

FIG. 2

The mortality of shellfish is about 10 to 12% immediately after nuclear transplantation when bred on a diet containing skim milk as a main component in an environment in which such optimal conditions are selected. It has dropped to a few percent. Most of the shellfish grew smoothly, and the growth rate of the shellfish was about 3 to 4% higher than that of plankton, indicating that skim milk powder was also suitable for the feed of the white butterfly. After breeding for 2 years, the pearls were taken out and observed with the naked eye. As a result, the growth of the nacres was good and the quality was comparable to those collected in the natural sea.

[0061] White-butterfly oysters usually inhabit subtropical waters and have high temperatures suitable for survival. Therefore, it is difficult to cultivate in Japan except in a very small part of the waters, and the temperature of seawater decreases even when cultivated. In winter, shellfish and nacre growth also stops. In other seasons, the growth rate of nacre decreases rapidly as the temperature gets away from the optimal water temperature of 24-27 ° C.
The mortality of the shellfish was high and the pearl layer was thin and the quality was considerably inferior to those of South Sea pearls.

According to the method of the present invention, it is easy to always maintain the inside of the culture tank at the optimum water temperature, and the palatability of skim milk powder is equal to or higher than that of natural submarine plankton. The growth rate is also faster and much higher than conventional aquaculture methods. In addition, the mortality of shellfish was 12 immediately after transplantation.
-15%, but since then it has fallen to 4-5% per year, which is much better considering the recent pollution of natural seawater. In addition, the obtained pearls are considerably large and the pearl layer is thick and good, so that pearls of the same quality as in South Sea white pearl shell pearls can be cultured in Japan.

Next, also for the black mussel, a mantle piece and a nucleus of a pearl shell are transplanted and cultured for one year under the same conditions as the above-mentioned white mussel, and the mortality and the elongation of the shell height are increased. And the nacre growth was examined after one year. FIG. 4 shows the growth rate depending on the shell height of the shellfish. As a result of taking a liquid sample in the tank after cultivation and conducting a culture test,
Acinectobactor and Vibrio, Flavobacterium, Ps
Bacteria contained in the genus eudomonas were found to be proliferating.

[0063]

FIG. 3

As shown in the figure, when a mixture consisting of skim milk powder, moloheiya and calcium carbonate was administered as a feed, black butterflyfish also grew smoothly, indicating that skim milk powder was suitable as a feed. The mortality rate of shellfish is about 10% immediately after transplantation operation, and thereafter falls to 3-4% per year. The growth of the nacre was good and the quality was comparable to that collected in the natural sea. According to the method of the present invention, pearls having a quality comparable to that of Southsea black butterfly pearls can be cultured in Japan, and other advantages are almost the same as those of the aforementioned white butterfly.

Next, as an example of a freshwater bivalve, a mantle piece of shellfish for forming a nacre is transplanted to a mussel, and a small aquarium is prepared.
For example, a case of culturing in freshwater using a tropical fish viewing tank or the like will be described. The tropical fish viewing tank has a filter of coral sand containing small activated carbon particles, a water temperature controller,
An air blower and a fluorescent light for lighting are installed.
The fresh water in the aquarium may be circulated for a while with a coral sand filter containing activated carbon particles after dewatering the tap water, but bacteria that are suitable for shellfish growth will grow by culturing pearls. It is more preferable to use a part of the water in the water tank.

A shell of a shell for nacre formation was transplanted to a two-year-old ginkgo biloba two years after seedling, and placed in an aquarium at a rate such that the exclusive volume per water was 3 to 5 liters. . The water temperature, pH and dissolved oxygen amount in the tank are maintained at certain conditions.

As a feed, a mixture of 5 parts by weight of Moroheiya powder and 20 parts by weight of calcium carbonate fine powder with respect to 100 parts by weight of skim milk powder was poured directly into a water tank at regular intervals. The food of Ginkgo biloba is usually plankton, the product of the plankton carcass partially altered by the action of bacteria in the water, or microscopic organic matter (detritus) suspended in the water. It is thought that the fine particles of skim milk powder dispersed in water and the products partially altered by the action of bacteria can become bait for shellfish, but even if cultured for a long time only with skim milk powder, the ginkgo mussel grows smoothly. The high quality of pearls is also attributable to the fact that nutrients contained in skim milk powder are similar to plankton.

[0068] As in the case of pearl oysters,
The addition of fine powder of Moroheiya to skim milk powder as a feed increases the palatability of the shellfish to the feed, and has the effect of improving the growth rate and thus the formation rate of the nacre. Although the nutritional components of Moroheiya are significantly different from plankton as described above, they play a role in promoting the growth of bacteria that promote the action of shellfish to ingest skim milk powder, or as a medium. Further, calcium carbonate is added because it has the effect of remarkably promoting the growth of nacre, as in the case of pearl oysters.

The water in the water tank is circulated through a coral sand filter containing small activated carbon in order to keep the water in the water tank suitable for habitat. The activated carbon particles and the pores of the coral sand serving as the filtration layer are suitable for a culture medium of bacteria that acts to enhance the palatability of skim milk powder, and are also preferable for promoting their propagation. In addition, the main component of coral sand is calcium carbonate, a part of which is eluted and taken up by the shellfish to replenish the reduced calcium carbonate concentration in seawater and also to prevent the pH from lowering.

Since the excrement of shellfish and other suspended matter settle on the bottom of the water tank, the bottom is depressed so that the sediment accumulates there. At regular times, open the valve and take out or insert a pipe from the top. It is necessary to remove by suction. In addition, the water temperature is adjusted to 22 to 23 ° C, which is optimal for the growth of Ginkgo biloba, the circulation in the tank is stopped for a certain time after feeding the feed according to the habits of the shellfish, and the brightness is maintained for a predetermined time with a fluorescent lamp for a predetermined time. The lighting is made.

Sixteen ginkgo mussels transplanted with shell pieces of shellfish for nacre formation were bred for 6 months in a small aquarium for viewing tropical fish. As a result, only one dead shellfish grew steadily and the others grew satisfactorily.
８8 mm pearls were obtained in 2-3 shells per shell. The great feature of the method of the present invention is that the growth of nacre is much faster than when cultured in a natural lake, and the quality of nacre is also good. Such a small aquarium can be used not only for pearl culture but also for appreciation of tropical fish.
FIG. 4 shows an example of a growth curve when the geese are raised for a long time. In addition, Acinectobact
As a result of the culture test, it was confirmed that bacteria contained in the genus Or and the genus Vibrio, the genus Flavobacterium, and the genus Pseudomonas were proliferating.

Further, as in the case of pearl culture, larvae or larvae harvested from a natural lake or hatched by artificial insemination are fed with skim milk powder or a partially crushed and then ground Moroheiya diet. Bred. Both grew smoothly into mother mussels, and the mortality was much lower than when bred in natural lakes. When skim milk powder is sufficiently dispersed in water, it can be made into ultra-fine particles with a particle size of about 0.12 μm, which is one of the reasons that it is suitable for inhalation with water from small mouths of small larvae and larvae. Conceivable.

[0073]

The present invention is a method for cultivating pearls by breeding pearl oysters such as pearl oysters in an aquarium on land using a feed containing skim milk powder as a main component. Skim milk powder has a stable supply and is more economical than conventional plankton-fed feed, and can be cultivated in a large, industrialized land-based aquarium under optimal conditions for shellfish growth. For this reason, the growth of mother oysters and nacres is remarkably faster compared to natural submerged culture.
Pearls with a diameter of 10 to 12 mm are easily obtained, and the nacre is also homogeneous and of excellent quality. In addition, there is no danger of a natural disaster such as a decrease in mortality of the shellfish and typhoons and red tides. Further, there is a great advantage in comparison with the conventional method in which the shellfish hibernates for about six months in winter due to the temperature of seawater.

[Brief description of the drawings]

FIG. 1 shows an example of a growth curve when pearl oysters are cultured.

FIG. 2 shows an example of a growth curve in a case where a white butterfly is cultured.

FIG. 3 shows an example of a growth curve in a case where a black mussel is cultured.

FIG. 4 shows an example of a growth curve in a case where geese are cultured.

[Explanation of symbols]

 1 When pearl oysters are cultivated with skim milk powder 2 When pearl oysters are cultivated with plankton 3 When white pearl oysters are cultivated with non-fat dry milk 4 When white pearl oysters are cultivated with plankton 5 When black pearl oysters are cultivated with non-fat dry milk 6 Ikecho When shellfish are cultured with skim milk powder

Claims (10)

[Claims] 1. A marine aquatic bivalve transplanted with a mantle piece and a nucleus or a mantle piece of a shell for nacre formation, in a marine aquaculture facility on sea or on land having substantially the same composition as seawater, A method of culturing pearls, characterized by culturing with feed containing skim milk powder as a main component. 2. A marine aquatic bivalve transplanted with a mantle piece and a nucleus of a shell for nacre formation, or a mantle piece transplanted with a mantle piece, in a marine aquaculture facility on land or having a composition substantially identical to seawater, Ac
genus inectobactor and genus Vibrio, genus Flavobacterium, Pseu
A pearl culturing method comprising culturing with a feed containing skim milk powder as a main component in the presence of bacteria contained in the genus domonas. 3. A marine aquatic bivalve transplanted with a mantle piece and a nucleus of a shell for nacre formation, or a mantle piece transplanted therewith, is used in a marine aquaculture facility on land or having a composition substantially the same as seawater, A method of culturing pearls, comprising culturing with feed containing skim milk powder and moloheiya or / and calcium carbonate. 4. The seawater bivalve is a pearl oyster, a black mussel, a white mussel or a mabe mussel.
The pearl culture method described. 5. A method of culturing a mantle and a nucleus of a shell for nacre formation or a freshwater bivalve into which a mantle piece is transplanted with a feed containing skim milk as a main component at a land-based culture facility. Pearl culture method characterized. 6. A freshwater bivalve transplanted with a mantle and nucleus of a shell for nacre formation or a mantle piece transplanted with skim milk powder and moloheiya or / and calcium carbonate in fresh water of an onshore aquaculture facility. A pearl culture method characterized by culturing with a feed containing the pearl. 7. The method for culturing pearls according to claim 5, wherein the bivalve is a mussel or a finfish. 8. A larva or juvenile mussel of a marine bivalve collected in the natural sea or hatched by artificial insemination,
Larvae or larvae of freshwater bivalves, harvested in seawater or onshore farming facilities having substantially the same composition as seawater or in natural rivers, lakes or marshes, or hatched by artificial insemination;
A method of breeding larvae or juvenile shellfish for pearl culture, wherein the mother oyster is bred in a land-based cultivation facility using a feed mainly composed of skim milk powder. 9. A pearl culture tank, wherein a filtration tank is provided in a piping for circulating the liquid in the tank, and activated carbon or a carbon material is contained as a filter medium. . 10. The pearl aquaculture tank comprises: (A) a culture tank and (B)
Including feed preparation tank, (C) filtration tank, (D) environment control device,
(A) The feed solution is poured from the water surface into the culture tank, and the liquid extracted from the circulating fluid outlet provided at the lower part of the tank inner surface is filtered by a filtration tank, and then the upper part of the tank inner surface The liquid in the tank is ejected from the circulating liquid inlet provided in the horizontal direction and the direction in which the liquid in the tank circulates along the inner wall of the tank. (B) The feed preparation tank is equipped with a liquid and feed supply facility and a dissolution apparatus, and (C) The filter medium filled in the filter tank is activated carbon and carbon. At least one type selected from the group consisting of material, sand, and coral sand is included. (D) The environmental control device includes a fluorescent lamp lighting device, a temperature control device in a tank, an air blowing device, and operation control including the above-mentioned facilities. A pearl aquarium containing equipment.