Method for manufacturing true round nucleated cultured pearls using abalone shell

Abstract

Due to the unique body structure of abalone, which differs from that of bivalves, and the pressure generated by the powerful movement of its foot muscles, the production of spherical, nucleated, perfectly round cultured pearls using abalone oysters was previously considered impossible. However, in abalone-based pearl cultivation, the nucleus implantation site is selected at the anterior leaf of the mantle, where the nucleus can be stably maintained. Furthermore, the size of the inserted nucleus is appropriately suited to accommodate this location, ensuring stable retention and preventing detachment. This allows for the production of previously unproducible spherical, nucleated, perfectly round pearls. Moreover, by employing a method of multiple nucleation and cultivation, spherical, nucleated, perfectly round pearls with excellent sphericity and smoothness can be produced in subsequent stages. Even further, during this process of multiple nucleation and cultivation, semi-shaped pearls can be simultaneously produced from the same abalone, achieving the co-production of spherical and semi-shaped pearls.

Description

Technical Field

[0001] This invention relates to the field of pearl farming technology, specifically to a method for producing perfectly round, nucleated cultured pearls using abalone shells as the mother oyster. Background Technology

[0002] The method of pearl cultivation using the Pinctada martensii (Akoya oyster) was first developed in Japan over a century ago. Since then, the technology has continued to evolve, and the types of mother-of-pearl used for pearl cultivation are no longer limited to Pinctada martensii but have expanded to include other species such as the white-lipped oyster, which inhabits overseas areas. Furthermore, in addition to the production of saltwater pearls, freshwater pearls are also cultivated using freshwater oysters, and these pearls are widely supplied to the global jewelry market.

[0003] Currently, pearl farming production countries include not only Japan, but also Australia, the Philippines, Indonesia, Myanmar, Tahiti, Vietnam, and China.

[0004] The basic principle behind the cultivation of nucleated, perfectly spherical cultured pearls from bivalve oysters such as the Pinctada martensii and the white-lipped oyster is as follows: A perfectly spherical nucleus, processed from the shell of a freshwater bivalve, is implanted into the reproductive cavity of the oyster. A sheet of mantle epithelial cells (also called a "mantle sheet"), obtained from the mantle of the same species of mother oyster, is then attached to this nucleus. During cultivation, the attached mantle epithelial cells divide and proliferate, gradually enveloping the entire nucleus, thus forming a pearl sac. Further, the inner wall of the pearl sac secretes nacre, covering the entire surface of the nucleus, thereby forming a pearl.

[0005] The above process is the basic method for manufacturing nucleated round pearls established in Pinctada martensii, and it has been extended to pearl farming of other bivalve oysters.

[0006] Abalone oysters, as a type of snail, have a unique inner shell color that differs from that of Pinctada martensii, possessing a metallic sheen of green, blue, and other colors that changes hue depending on the viewing angle, exhibiting a highly attractive luster. Here, we will first explain abalone pearls (also known as "abalone beads," or simply "abalone pearls" in English). Occasionally, irregularly shaped natural abalone pearls are found within abalone oysters. Natural abalone pearls are formed by chance, making them extremely rare and precious. Although these abalone baroque pearls with their beautiful luster are not spherical, their scarcity and unique shape often lead to their use in precious metal decoration, making them high-value jewelry. However, to date, there have been no reports of finding perfectly spherical pearls within natural abalone pearls.

[0007] Based on the above, several attempts have been made to produce perfectly round pearls using abalone oysters, similar to the Pinctada martensii oyster. However, to date, products sold under the name "Abalone Pearl" are limited to irregularly shaped baroque pearls and hemispherical semi-circular pearls. In other words, the technology for cultivating perfectly spherical nucleated pearls is not yet mature, and therefore cannot be purchased on the market. It should be noted that in the pearl farming industry, spherical pearls are generally referred to as "perfectly round pearls," and hemispherical pearls as "semi-circular pearls." In this invention, the term "semi-circular pearl" does not refer to a semi-circular shape, but rather to a semi-circular pearl with a hemispherical surface.

[0008] The purpose of this invention is to provide a culture technology that enables the successful production of previously unattainable "true spherical" nucleated, perfectly round cultured pearls from abalone shells.

[0009] Here, it is necessary to explain the definition of "nucleated, perfectly round pearl".

[0010] Non-patent document 2, "Pearl Pointer 2020," states on page 19: "A truly round pearl is a pearl whose entire surface is covered with nacre." In other words, "a truly round pearl" does not necessarily mean that its shape is truly spherical. Therefore, in this invention, in order to emphasize that its shape is truly spherical, the expression "a truly spherical nucleated round pearl" is specifically used.

[0011] Furthermore, on page 74 of the same document, it is stated that "the nucleus material used for nucleated pearl culture is limited to the nacreous layer of freshwater bivalve shells, and other materials are not recognized." The reasons for this are also explained.

[0012] Although the "method for obtaining true spherical nucleated round pearls" described in this invention does not limit the material of the pearl nucleus, from the perspective of the strength and quality of the obtained pearl, it should follow the "Pearl Guidelines" and use a pearl nucleus derived from a freshwater bivalve oyster.

[0013] Pearl cultivation involves implanting a pearl nucleus into a pearl oyster, causing nacre to form on its surface (commonly known in the industry as "shell-rolling pearl"). However, simply implanting the nucleus is not enough to achieve this. A section of epithelial cells from the mantle of the same species of oyster, capable of secreting nacre (i.e., a "mantle sheet"), must adhere to the surface of the implanted nucleus. During cultivation, this mantle sheet gradually grows and covers the surface of the nucleus, forming a sac-like tissue that envelops it—the pearl sac. Further, nacre is secreted from the inner wall of the pearl sac, thus covering the entire surface of the nucleus and forming a perfectly round pearl. Therefore, pearl formation requires the following conditions: implantation of the nucleus, attachment of the mantle sheet, stable bonding between the nucleus and mantle sheet, and the subsequent cultivation process.

[0014] Bivalves such as the Pinctada martensii and the white-lipped oyster feed on plankton floating in seawater, obtaining their food through filter feeding. Therefore, they do not need to actively move to hunt for food. In the cultivation of Pinctada martensii, after the nucleus implantation surgery, they are usually housed in cultivation cages and suspended in seawater for a period of time. During this process, a pearl sac forms inside their bodies, and a nacreous layer forms on its inner side (i.e., the surface layer of the implanted nucleus).

[0015] In contrast, gastropod mollusks such as abalone and whelks feed on seaweed, such as wakame and kelp. To ingest this seaweed, the mollusks must actively move to find food. Furthermore, when abalone sense danger, they strongly adhere to surfaces such as rocks for protection. Therefore, abalone have highly developed foot muscles and rely on these muscles for crawling. This characteristic is significantly different from that of bivalves.

[0016] When attempting to transplant nucleus grafts from the Pinctada martensii oyster to the abalone oyster, the procedure is severely hampered by the vigorous movement of the foot tendons. Therefore, anesthesia is necessary to inhibit foot tendon movement. Available anesthetics include benzocaine, clove oil, phenoxyethanol, phenoxypropanol, and carbon dioxide gas. Magnesium chloride (i.e., brine), a component of seawater, also has an anesthetic effect and is harmless. In the examples described below, magnesium chloride aqueous solution will be used as the anesthetic.

[0017] Although the complexity of the implantation procedure is significantly reduced by using the above-mentioned anesthesia method, there are still technical problems that need to be further solved in practical applications.

[0018] In pearl farming of bivalve oysters such as Pinctada martensii, the genital cave is used for nucleus implantation and pearl formation. Within the internal structure of these bivalve oysters, the genital cave is separate from the liver and other internal organs, and has ample space. Therefore, during nucleus implantation surgery, damage to the liver or other internal organs is relatively easy to avoid, and larger nuclei can be implanted more readily, thus achieving the production of large-diameter pearls.

[0019] In contrast, the internal structure of the abalone oyster differs significantly from that of the Pinctada martensii. Its genital nest is located close to internal organs (such as the liver), making it extremely difficult to implant the nucleus without damaging these organs. In oysters that successfully implant the nucleus without denucleation during cultivation, a pearl sac forms within the genital nest. However, this pearl sac itself can deform under pressure from foot muscle movements. Consequently, even with a perfectly spherical nucleus, the pearl formed within this deformed sac will deviate from a spherical shape, resulting in a baroque pearl.

[0020] In this context, to prevent the implanted pearl nucleus from detaching due to foot tendon movement and pressure, various techniques have been attempted in Japan, as shown in Patent Documents 1-3: creating holes in the shell or using steel wire, nylon thread, etc., to fix the pearl nucleus. These methods prevent the pearl nucleus from detaching and inhibit its movement within the shell. However, even if pearls are successfully cultured using these methods, the resulting pearls are still deformed baroque pearls.

[0021] Patent document 3 describes a method for obtaining a semi-circular pearl.

[0022] Although Patent Document 4 has been published, no substantive examination was requested, and it is considered withdrawn. According to the information disclosed in this patent, it claims to be able to obtain true spherical pearls, but it still involves the problem of "silk marks used to prevent the outer membrane from separating from the pearl nucleus." In other words, to date, a true spherical nucleated pearl without deformation or scratches has not yet been obtained.

[0023] Patent document 5 points out that since the genital cave has atrophied during the implantation of the nucleus, there is a gap between the mantle and the genital cave, and the nucleus can be implanted into this gap, but the obtained pearl is still a baroque pearl.

[0024] Patent document 6 describes a Chilean pearl cultivation method where the nucleus is implanted in the reproductive fossa, and the survival rate is improved by suturing the cut portion with absorbable sutures. However, even when a true spherical nucleus is inserted using this method, the resulting pearl is still a baroque pearl.

[0025] Furthermore, Non-Patent Document 3 describes a method where a flat disc with one spherical side is pressed between the mantle and the shell using a special tool. After approximately 1.5 to 2.5 years of cultivation, the pearl portion is cut from the shell to obtain a semi-circular pearl. Currently, semi-circular abalone cultured pearls obtained using this technology are processed into pendants, earrings, and other products, and sold under the brand "Arapawa Pearls".

[0026] (See: https: / / arapawabluepearls.co.nz)

[0027] In summary, to date, various technologies have been developed to obtain nucleated, perfectly round pearls from abalone oysters, but the successfully obtained pearls have all been baroque pearls, semi-circular pearls, or flawed pearls. A technology for obtaining flawless, perfectly round, perfectly spherical nucleated pearls with excellent sphericity and surface smoothness has not yet been established.

[0028] [Preliminary Technology Documents]

[0029] [Patent Documents]

[0030] Patent Document 1: Japanese Patent Application Publication No. 1974-107888 discloses a method for using abalone as the mother oyster, which involves making a hole of appropriate size above the reproductive cavity on the back of the mother oyster and using steel wire or the like to fix the pearl nucleus inside the oyster for pearl cultivation.

[0031] Patent document 2: Japanese Patent Application Publication No. 1981-154936 discloses a method in which a pearl nucleus and a mantle sheet are inserted into contact with each other on the inside of the abalone mantle, and then the abalone is placed in a cylinder and cultured in seawater to form a pearl.

[0032] Patent document 3: Japanese Patent Application Publication No. 2018-110553 discloses a method for forming a semi-circular pearl by inserting a pearl nucleus between the shell and the mantle from the head side of the abalone using a straw-like tube.

[0033] Patent document 4: Japanese Patent Application Publication No. 1986-15636 discloses a method in which a hole is made at the point where the abalone mantle attaches to the edge of the shell, and through holes are made in the nucleus and the mantle to prevent them from separating. A nylon thread is passed through the through hole and then fixed to the nucleus and the mantle from the outside through the hole in the shell to form a pearl. However, this patent has been withdrawn, and there have been no reports of obtaining a true spherical pearl to date.

[0034] Patent Document 5: Japanese Patent No. 7418626 (2024) describes a method for implanting a nucleus in the abalone genital nest, but implantation within the genital nest is extremely difficult. This patent proposes a method for implantation when the genital nest contracts after sperm or egg release, creating a gap between the nucleus and the mantle. However, the resulting pearl shape is not a true sphere, but rather a deformed Baroque shape.

[0035] Patent document 6: International patent application WO2016183695 discloses a method for abalone pearl cultivation developed in Chile, which involves inserting a pearl nucleus after making an incision inside the abalone's genital nest. However, due to foot muscle movement, the implanted nucleus is prone to dislodgement. This method uses absorbable sutures to suture the incision site to prevent dislodgement. Even so, the resulting pearls are still deformed baroque pearls. Pearls produced using this technology are sold under the brand "Atacama Pearls".

[0036] (See: https: / / atacamapearls.com / )

[0037] [Non-patent literature]

[0038] In Non-Patent Literature 1, "Pearl Cultivation" (1987, pp. 185–188), Hiroshi Uno mentions methods for cultivating abalone semi-circular pearls and true round pearls. For semi-circular pearls, a hole is made on the outside of the shell to insert a semi-circular nucleus. After implantation, a fixative is used to fix the nucleus, thus forming a semi-circular pearl.

[0039] Non-patent document 2: The definition of pearl, cultured pearl and nucleated round pearl is recorded on page 59 of the Pearl Promotion Association's "Pearl Guide 2020".

[0040] (See: https: / / pearlexperts.net / wp-content / uploads / 2021 / 04 / pearl_guidelines_2020.pdf)

[0041] Non-patent literature 3: The autumn 1998 issue of the Gemological Institute of America (GIA) journal *GEMS & GEMOLOGY* describes a method for cultivating New Zealand abalone pearls. According to this literature, a flat, spherical disc with one side is used as the pearl nucleus and inserted between the abalone's mantle and shell for cultivation. This creates a nacreous layer on the surface of the inserted nucleus, identical to the inner layer of the shell. The resulting pearl is integrated with the shell, and then a round pearl portion is cut from the shell and shaped through cutting and processing to form a semi-circular pearl. Summary of the Invention

[0042] [The problem this invention aims to solve]

[0043] The problem that this invention aims to solve is that, despite long-awaited development, no technology has yet been successfully developed that can produce "true spherical nucleated round pearls" with rich hues (such as green and blue) not found in other pearl oysters, excellent sphericity and surface smoothness, and high commercial value using abalone as the mother oyster.

[0044] [The means adopted to solve the above problems]

[0045] This invention is proposed to solve the above-mentioned problems.

[0046] First, regarding the issue of suppressing vigorous foot muscle movement in abalone shells during the procedure, this invention employs an anesthesia method used in abalone pearl farming. As mentioned earlier, various anesthetics can be used, and all are suitable; however, in this embodiment, a magnesium chloride aqueous solution method is employed. This anesthesia method suppresses foot muscle movement, thereby facilitating the implantation procedure.

[0047] In this invention, the selected implantation site is a part of the mantle tissue, specifically the anterior mantle lobe, which has been completely ignored until now. Figure 1 and Figure 2 (As shown in number 1).

[0048] This area is located at the vent ( Figure 1 and Figure 2 The narrow area between the center (number 5) and the edge of the shell. For example... Figure 2 As shown, the flat mantle bends towards the shell at this point in order to form a breathing pore.

[0049] The reason why this part of the abalone shell has not been considered as a nucleation site until now is that the area is extremely narrow.

[0050] Specifically, for abalone shells with a shell length of 70-80 mm, the size of the pearl nucleus that the anterior lobe can accommodate is only about 3 mm in size in order to avoid the nucleus falling off as much as possible under the pressure of the foot muscles.

[0051] If the implanted pearl nucleus is only 3mm, even if it can form a true spherical pearl, its commercial value will be very low due to its small size.

[0052] In other words, even if this part is specifically chosen as the implantation site for cultured pearls, if the value of the obtained pearls is low, the economic benefits of implanting nuclei in this part cannot be realized. This is also considered one of the reasons why nuclei have not been implanted in this part so far.

[0053] However, the shape of the front leaf is as follows Figure 2 As shown, it is slender, and this part of the shell is slightly concave along the edge of the shell, so that it can accommodate a smaller than usual bead nucleus that is easier to hold stably.

[0054] In other words, by using a smaller pearl nucleus that can be housed in the anterior leaf, the pressure exerted by the foot muscles can be reduced, making it less likely for the pearl nucleus to fall out. This means that although the obtained pearls are smaller, the "survival rate" will be improved.

[0055] In pearl culture, the ideal is to implant the largest possible nucleus, but if the nucleus protrudes, it's pointless. Furthermore, even if the pearl is small, its low commercial value negates its significance.

[0056] Furthermore, after the small nucleus is implanted and allowed to form a pearl, it takes approximately one month for a pearl sac to form from the mantle membrane. During this period, each movement of the foot muscles applies pressure, which may cause deformation or wrinkles in the formed pearl sac. These deformations or wrinkles may also be reflected on the surface of the pearl that forms within the sac. Therefore, pearls obtained from the initial nucleus implantation are not only smaller in size, but also have significantly reduced sphericity and surface smoothness, classifying them as low-quality pearls.

[0057] Although spherical pearls can be formed, their value is low, presenting a dilemma. This invention overcomes this dilemma through a cyclical method of multiple implantation, cultivation, and pearl harvesting (at sea), as described below.

[0058] In other words, the present invention provides a method for producing (cultured) true spherical abalone pearls with high commercial value in abalone pearl farming, where only deformed baroque pearls or semi-circular pearls can be obtained to date.

[0059] For abalone, being a single-shelled mollusc, the pearl nucleus can be implanted without breaking the shell, and the pearl can be extracted during pearl harvesting without breaking the shell. Therefore, after the first pearl harvesting process following cultivation, the pearl sac can be carefully cut open to remove the pearl, and a pearl nucleus can be implanted back into the empty pearl sac for cultivation, thus obtaining pearls again.

[0060] Incidentally, for the second and subsequent implantation, since the pearl sac has already formed, there is no need to attach a cover film.

[0061] After the pearl nucleus is implanted into the pearl sac, the pearl sac will try to fit as closely as possible to the implanted pearl nucleus. Therefore, the deformation or wrinkles that occur when the pearl sac is first formed will be naturally corrected, thus forming a pearl with excellent sphericity and surface smoothness.

[0062] In addition, when a nucleus slightly larger than the removed pearl is inserted, the pearl sac is subjected to moderate tension after the nucleus is implanted. This can also correct wrinkles and looseness in the pearl sac, thereby obtaining a larger, more spherical, and smoother nucleated round pearl than the previous one.

[0063] Therefore, the size of the pearl nucleus used for the second and subsequent implantation should be similar to or slightly larger than the size of the pearl extracted the first time, taking into account that the anterior lobe increases in size as the oyster grows.

[0064] Even if a pearl nucleus of the same size as the previously extracted pearl is implanted, the size of the resulting pearl will still be slightly larger due to the thickness of the pearl layer formed inside the pearl sac.

[0065] In other words, in the multiple cycles of implantation, culture, and harvesting, the pearls obtained in the second and subsequent cycles gradually increase in size with the increase in the number of implantation and culture cycles, and have excellent sphericity and surface smoothness, thus obtaining pearls with high commercial value.

[0066] However, although the pearls obtained in the first culture are true spherical, they are small in size and have poor sphericity and surface smoothness, resulting in low commercial value.

[0067] Therefore, in this invention, the primary goal of the first pearl farming of abalone is to form pearl sacs for the second and subsequent uses, rather than directly obtaining pearls with high commercial value, so as to obtain pearls with high commercial value in the second and subsequent uses.

[0068] Of course, during the first pearl harvest, pearls with better sphericity or unique shape and higher commercial value can be selected for commercialization.

[0069] A concern might arise when implanting a larger nucleus for the second or subsequent implantations. However, the anterior lobe has grown with the oyster and can accommodate larger nuclei. Unlike the first implantation, the formed pearl sac is integrated with the anterior lobe tissue, providing a more secure hold for the implanted nucleus. In reality, the survival rate of pearls implanted a second or subsequent time is extremely high, though this also depends on the implantation technique; it can easily exceed 90%.

[0070] Of course, the multiple (nucleus implantation, cultivation, pearl harvesting) cycle method described in this invention is not limited to a second cycle; a third, fourth, or other multiple pearl cultivation cycles can also be performed. In this case, as mentioned above, the size of the pearl obtained in each cycle is larger than the size of the pearl obtained in the previous cycle. This is also one of the important features of this invention.

[0071] First, the selection of the implantation site in the anterior leaf is an important feature of this invention. Second, although multiple implantation, cultivation, and pearl harvesting are carried out, a pearl sac is formed in the first cultivation, and this pearl sac is used in the second and subsequent cultivation to obtain a true spherical nucleated round pearl, which is also a feature of this invention.

[0072] The features of the method of the present invention are summarized in Table 1 below.

[0073] Table 1

[0074]

[0075] In this invention, to obtain true spherical pearls during the cultivation period, multiple cycles (nucleus implantation, cultivation, and pearl harvesting) can be performed every six months to one year. By simultaneously implanting a pearl nucleus in the anterior lobe and simultaneously implanting a flat hemispherical pearl nucleus in parallel between the mantle and the shell, multiple true spherical nucleated pearls can be obtained during the cultivation period, and finally the hemispherical pearls are removed from the shell.

[0076] That is, the method of the present invention can achieve the simultaneous production of true spherical nucleated round pearls and semi-circular pearls.

[0077] [Invention Effects]

[0078] 1. The implantation site is changed from the reproductive nest commonly used in Pinctada martensii pearl oyster technology to the anterior leaf of the mantle. The implanted nucleus size is set to be large enough for the anterior leaf to accommodate, difficult to remove from the nucleus, and stable to maintain, thus forming a pearl sac for obtaining pearls with excellent sphericity and smoothness in secondary and subsequent culture. By removing the pearl from this pearl sac and re-implanting the nucleus into the empty pearl sac, it is possible to obtain "abalone nucleated round pearls with excellent sphericity and smoothness" comparable to Pinctada martensii pearls, which was previously impossible to achieve.

[0079] 2. By using nuclei of the same or slightly larger size as the previous one in the second and subsequent cultivation, larger nucleated round pearls with excellent sphericity and smoothness can be obtained as the number of nuclei implantation and cultivation increases.

[0080] 3. Although the skill level of the implantation process may have some impact, in the second and subsequent cultivation, due to the low denucleation rate, it is possible to obtain perfectly spherical nucleated pearls with excellent sphericity and smoothness with a high yield of at least 90%.

[0081] 4. By combining the implantation of a nucleus in the anterior lobe with the parallel implantation of a flat, hemispherical nucleus in the gap between the mantle and the shell, multiple perfectly round, nucleated pearls can be obtained during the cultivation period. Finally, the hemispherical pearls that have grown attached to the shell are removed. In other words, perfectly round pearls and hemispherical pearls can be obtained simultaneously within the same cultivation cycle, achieving concurrent production.

[0082] 5. Furthermore, after the final pearl harvest, abalone can be consumed as a high-grade food ingredient. In other words, meat can be produced concurrently with pearl production. This is also significant, enhancing the overall value of abalone and pearl farming. Attached Figure Description

[0083] Figure 1 This is a dorsal view of an abalone shell, viewed from the direction of the foot muscle 7, but with the foot muscle removed.

[0084] Figure 2 An oblique view illustrating the positional relationship between the anterior leaf of the mantle and the phreatic pores on its side inside the abalone shell. Detailed Implementation

[0085] Taking the cultivation of bivalve oysters such as the Pinctada martensii as an example, the main method involves placing the implanted oysters into a cultivation basket and then suspending them in the sea for cultivation. However, as mentioned earlier, the pearl production cultivation method using abalone oysters described in this invention is completely different from that of the Pinctada martensii due to the different diet of abalone.

[0086] Abalone farming requires feeding abalone with seaweed; therefore, edible abalone is currently mainly farmed in land-based tanks. Similarly, abalone farming for pearl production can also be conducted using land-based methods. In fact, from a breeding and management perspective, land-based farming is more suitable and feasible.

[0087]

Example

[0088] Purchase commercially available artificially hatched abalone juveniles (shell length approximately 50-60mm), cultivate them on land for about six months until they grow to approximately 70mm in size before use.

[0089] The implantation technique basically uses the conventional methods used for Pinctada martensii pearl oysters.

[0090] In this embodiment, a 3mm diameter nucleus is inserted into the anterior lobe of the abalone shell. The nucleus is the right size to be contained by the anterior lobe and can be stably held without falling off. At the same time, a tissue piece taken from the mantle of the same species of abalone is attached to the nucleus. Then, the abalone shell is returned to the normal terrestrial aquaculture environment.

[0091] The specific operating steps are as follows:

[0092] First, to facilitate the implantation procedure, the abalone shells need to be anesthetized. In this embodiment, an aqueous solution of magnesium chloride dissolved in fresh water is used as the anesthetic. The specific gravity of the magnesium chloride aqueous solution is adjusted to be the same as that of seawater. After immersing the abalone shells in this solution for several tens of minutes, the anesthetic effect is achieved, temporarily immobilizing the abalone shells.

[0093] The tissue slices used for adhesion are selected from the green part of the shell inside the mollusc, and the mantle is cut off with scissors to make square tissue slices with a side length of about 1 to 1.5 mm. 5 to 10 slices can be prepared from each mollusc.

[0094] Since the purpose of the first implantation is to form a pearl sac, a small nucleus with a diameter of 3 mm is used to ensure that a spherical pearl sac can be formed even under the vigorous movement of the abalone shell. This is to accommodate the anterior lobe, maintain stability, and prevent the nucleus from falling off.

[0095] Incidentally, since the nacreous layer is formed from secretions of mantle epithelial lamellae attached to the nucleus, the color and hue of a pearl necessarily depend on the color and hue of the mantle from which the lamellae originated. Therefore, to obtain a pearl with the desired color and hue, one should naturally observe the color and hue of the mantle and cut lamellae from the mantle tissue that best approximates the desired color and hue.

[0096] Therefore, mother-of-pearls with desired mantle colors and hues are selected and crossbred. By repeatedly performing this selection and crossbreding process across successive generations, it is believed that pearls with desired colors and hues can be obtained with a high probability. In recent years, this method has been used to produce high-quality Akoya pearls.

[0097] In this invention, where a perfectly round pearl is obtained from abalone, it can naturally be assumed that using a similar method can more effectively increase the probability of obtaining abalone pearls with the desired color and hue.

[0098] This method is expected to improve the production efficiency of pearls, which have higher added value and are suitable for jewelry use.

[0099] The specific implantation procedure is as follows:

[0100] During the first implantation, the procedure was performed under anesthesia. Figure 1 The central region, number 4, is slightly incised with a sharp scalpel, and a nuclear passage is formed by extending along the anterior lobe (number 1) from this incision (number 4).

[0101] Next, a 3mm diameter nucleus was inserted into the incision (number 4) and advanced to position 3. Then, the tissue slide was pushed along the surface of the nucleus (number 2) to ensure close contact with the nucleus.

[0102] After the implantation process is completed, the abalone shells are returned to their conventional aquaculture environment. The aquaculture cycle depends on environmental conditions such as seawater temperature, and the first pearl harvest usually takes about six months to a year.

[0103] In early embodiments, due to lower operational skill levels and a lower yield, approximately 10 nucleated, perfectly round cultured pearls could still be obtained from approximately 100 abalone, according to the definition in Non-Patent Document 2, "Pearl Pointer." This confirms that, even with lower pearl quality, previously unsuccessful attempts can be made to obtain perfectly round abalone pearls through nucleation of the anterior leaf portion.

[0104] However, most of these pearls are deformed or wrinkled, failing to meet product evaluation standards. Even those that are truly spherical need improvement in their sphericity and surface smoothness.

[0105] Therefore, the purpose of the first culture is not to directly obtain marketable pearls, but to form pearl sacs for use in the second and subsequent cultures. In the second and subsequent cultures, there is a high probability of obtaining pearls with excellent sphericity and smoothness.

[0106] In other words, only through the newly developed "multiple implantation, cultivation, and pearl harvesting cycle method" can "nucleated, perfectly round pearls with excellent sphericity and smoothness" be obtained with a high probability.

[0107] The purpose of the second and subsequent pearl culture is to produce high-value, true spherical, nucleated, round pearls. Therefore, the size of the nucleus used must be suitable for inserting into the empty pearl sac formed in the first culture. A nucleus of the same size as or slightly larger than the pearl that was removed can be used.

[0108] In the specific operation, the first pearl extraction and the second nucleus implantation process require carefully cutting one end of the pearl sac to avoid damaging the pearl inside. Then, the pearl is gently removed using tweezers, ensuring no damage to the abalone shell. Subsequently, a nucleus of the same size or slightly larger than the extracted pearl is inserted into the empty pearl sac.

[0109] After implantation, the abalone shells are returned to their normal aquaculture environment and cultured for about six months to a year before harvesting the pearls, resulting in a second set of nucleated, perfectly round pearls. During this process, denucleation after implantation occurs almost non-existently.

[0110] As expected, the pearls obtained from the second and subsequent harvests were of excellent sphericity and surface smoothness, becoming highly valuable abalone-shaped, nucleated, round pearls.

[0111] By repeating this process, each culture yields larger, more spherical, and smoother high-quality nucleated round pearls with a high success rate.

[0112] Of course, if the quality is found to be poor during the second pearl harvesting and an ideal pearl cannot be obtained in the third pearl harvesting, the cultivation of the oyster can be stopped at this stage.

[0113] The evaluation results of the pearls were obtained.

[0114] The nucleus implantation process was repeated up to the third time. Table 2 shows a comparison of the nucleus size and the final pearl size obtained in this embodiment. Although the pearl diameter varies depending on the cultivation cycle, it is typically 1.2 to 1.7 times the diameter of the nucleus at the time of implantation when harvesting the pearl.

[0115] Table 2

[0116]

[0117] The method for assessing the sphericity of a pearl is as follows: measure the diameter of the pearl along three axes (X, Y, and Z) and calculate the relative deviation from the average diameter.

[0118] Relative error = {(measured value - average diameter) / average diameter}

[0119] True sphericity is expressed as the standard deviation of these relative deviations.

[0120] The average standard deviation of the 15 pearls harvested from the second and subsequent harvests was 1.60%. After further excluding two pearls with lower sphericity, the average standard deviation of the remaining 13 pearls was 1.06%.

[0121] The standard deviation of a perfect sphere is 0.

[0122] Simultaneously, the sphericity of Akoya pearls was measured, and the standard deviation averaged approximately 0.5% to 2.0%, depending on the quality. This confirms that the sphericity of abalone pearls obtained by this method is comparable to that of Akoya pearls.

[0123] In addition, the surface smoothness was assessed visually, and the pearls showed no scratches or wrinkles on the second and subsequent tests, with a smooth surface.

[0124] Thus, the method of the present invention successfully verified the feasibility of using abalone shells to cultivate true spherical nucleated round pearls.

[0125] Industrial availability

[0126] Baroque pearls or semi-circular pearls (i.e., Avalon pearls) cultivated using abalone oysters have secured a place in the pearl market as high-end pearls due to their unique color. This invention makes it possible to produce "true spherical" nucleated, perfectly round pearls (true spherical Avalon pearls) from abalone oysters, which were previously impossible to produce.

[0127] Compared to baroque or semi-circular pearls, these true spherical pearls are more upscale and are expected to be widely accepted by the market, thus potentially further expanding the pearl market.

[0128] Symbol Explanation

[0129] 1. Anterior lobe of the mantle in abalone shell

[0130] 2. Mantle epithelial cell sections (pearl sac tissue, Piece) taken from other mollusks of the same species.

[0131] 3 cores

[0132] 4. Incision

[0133] 5. Exhalation Hole

[0134] 6. Outer membrane

[0135] 7. Shell muscle (foot tendon)

[0136] 8. Liver (The gonads surround the liver and their abundance or scarcity changes with the reproductive season)

[0137] 9 seashells

Claims

1. A method for producing pearls using abalone shells, characterized in that: The nucleus is inserted into the abalone shell and cultured. After cultivation, the pearl is harvested. The implanted nucleus is part of the mantle, but a previously unused area, selected as a narrow, groove-shaped region—the anterior leaf of the mantle. A shallow incision is made in the anterior leaf of the mantle using a sharp scalpel to form an incision. A long, sharp scalpel is then inserted deep into the anterior leaf of the mantle through the incision to form a channel for inserting the nucleus. The inserted nucleus is contained within the channel of this narrow, groove-shaped region, its size adapted to the channel, and it remains stably in place without detaching from the nucleus. This yields a perfectly round, spherical nucleated pearl with minimal deformation.

2. The method for producing spherical, nucleated, round pearls from abalone according to claim 1, wherein, The primary purpose of the first culture is to form a pearl sac for use in the second and subsequent cultures. By utilizing the formed pearl sac in the second and subsequent cultures, the sphericity and smoothness of the obtained pearls are improved. In addition, the nucleus size used in the second and subsequent cultures is the same as or slightly larger than that of the pearls obtained in the previous culture. This method is used to obtain spherical nucleated pearls with excellent sphericity and smoothness, which become larger with each subsequent culture.

3. The method for producing pearls using abalone shells according to claim 2, characterized in that: During the process of multiple nucleation, cultivation, and pearl harvesting, a flat, hemispherical nucleus is inserted between the mantle and shell of the same abalone oyster, either simultaneously or at different times. This allows for the multiple production of true spherical nucleated round pearls. Furthermore, after the final production of a nucleated round pearl, by cutting the hemisphere attached to the shell, multiple true spherical nucleated round pearls can be obtained from the same abalone oyster, ultimately yielding a hemisphere pearl.

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