Methods for isolating, recovering, and culturing coral polyps, and apparatus for carrying out these methods.

Abstract

To develop a method for efficiently isolating and culturing polyps from corals while minimizing damage to existing coral colonies. [Solution] A method for isolating coral polyps, comprising the steps of either immersing coral in an aqueous solution with a salinity of 30-40 ppt and increasing the salinity to a specific range at a specific rate, or decreasing it.

Description

Technical Field

[0005] ,

[0001] The present invention relates to a method for isolating, recovering, and culturing coral polyps, and an apparatus for implementing these methods.

Background Art

[0002] The world's coral ecosystems are declining due to overfishing and pollution, and in recent years, further decline has been progressing due to phenomena such as coral bleaching caused by rising seawater temperatures, predation by crown-of-thorns starfish, and runoff of topsoil. Since the recovery rate of coral is slow, there is a possibility of extinction if the current situation continues. Therefore, artificial coral regeneration and conservation methods are being studied.

[0003] As a method for regenerating coral, for example, there is a method in which a coral fragment collected from a coral colony is used as a seedling and attached to a rope or the like, suspended and cultured from a raft on the sea surface, and transplanted to a rocky reef on the seabed after sufficient growth (Patent Document 1). There is also a method in which the coral fragment is fixed to a substrate such as a rock or concrete on the seabed using an underwater bond or the like (Patent Documents 2, Non-Patent Document 1). Furthermore, there is also a method in which coral fertilized eggs are collected and coral larvae are cultured (Patent Documents 3, 4).

[0004] Furthermore, in Non-Patent Document 2, as an example of the change in coral genes due to environmental load, the relationship between the increase in salt concentration in seawater and the change in coral genes has been studied.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] [Non-Patent Document 1] Okinawa Prefecture Coral Transplantation Manual, 2008 Edition, Okinawa Department of Culture and Environment, Nature Conservation Division [Non-Patent Document 2] Po-Shun et al., Signaling pathways in the coral polyp bail-out response, Coral Reefs, Published online:31 July 2020. [Overview of the project] [Problems that the invention aims to solve]

[0007] However, coral regeneration methods using coral fragments, such as those described in Patent Documents 1 and 2 and Non-Patent Document 1, involve collecting fragments for each individual to be transplanted, resulting in significant damage to the existing coral colony. Furthermore, methods using fertilized coral eggs, as described in Patent Documents 3 and 4, are limited in their implementation period because opportunities to collect fertilized coral eggs only occur a few times a year.

[0008] Non-patent document 2 describes how polyps can be isolated from coral by increasing the salinity of seawater. The conditions for this are to increase the salinity of seawater from 35 ppt to 46 ppt over 24 hours. However, non-patent document 2 does not describe any technical concept for minimizing stress on the coral and the isolated polyps, and for efficiently isolating the polyps.

[0009] One aspect of the present invention aims to provide a method for efficiently isolating polyps from coral, regardless of the time of year, while minimizing damage to existing coral colonies and minimizing stress on the coral and isolated polyps. Another aspect of the present invention aims to realize a method for recovering the polyps, a method for culturing the polyps, and an apparatus for carrying out these methods. [Means for solving the problem]

[0010] The inventors of the present invention have discovered that the above problem can be solved by changing the salinity within a specific range at a specific rate in a coral rearing environment, and have completed the present invention. That is, the present invention includes the following configuration. <1> A method for isolating coral polyps, comprising the steps of: introducing coral into an aqueous solution with a salinity of 30-40 ppt; and either step A, increasing the salinity to 45-70 ppt at a rate of 1.5-13 ppt / h, or step B, decreasing the salinity to 10-26 ppt at a rate of 1.5-13 ppt / h. <2> In step A, the salt concentration is increased to 50-60 ppt. <1> The method for isolating coral polyps as described. <3> The rate of increase in the salt concentration in step A or the rate of decrease in the salt concentration in step B is 3 to 6 ppt / h. <1> or <2> The method for isolating coral polyps as described. <4> <1> ~ <3> A method for recovering coral polyps, comprising a recovery step of adhering the polyps isolated by any of the methods for isolating coral polyps described in any of the above to a substrate mainly composed of titanium and / or titanium oxide. <5> Furthermore, the process includes using a quartz crystal vibration microbalance to monitor the adhesion status of the polyps to the substrate and to confirm the plateau adhesion time. <4> The method for retrieving coral polyps as described. <6> <4> or <5> A method for culturing coral polyps, comprising a cultivation step of further culturing the coral polyps recovered by the method for recovering coral polyps described herein. <7> Coral polyp isolation apparatus comprising: a processing unit for containing an aqueous solution with a salinity of 30-40 ppt and coral; and a salinity adjustment unit capable of increasing the salinity to 45-70 ppt at a rate of 1.5-13 ppt / h, or decreasing the salinity to 10-26 ppt at a rate of 1.5-13 ppt / h. A polyp recovery device for corals, comprising a recovery unit for recovering polyps isolated by the polyp isolation device described in <8><7>, wherein the recovery unit comprises a substrate mainly composed of titanium and / or titanium oxide. A coral polyp culture device, comprising a culture unit for culturing polyps recovered by the coral polyp recovery device described in <9><8>.

Advantages of the Invention

[0011] According to one aspect of the present invention, it is possible to minimize damage to existing coral colonies, minimize stress on corals and isolated polyps, and efficiently isolate and culture polyps from corals regardless of the time.

Brief Description of the Drawings

[0012] [Figure 1] It is a schematic diagram showing an example of a coral polyp isolation and culture device according to an embodiment of the present invention. [Figure 2] It is an observation image of the state in which polyps are isolated from a coral fragment in an example. [Figure 3] It is an observation image of the state in which polyps are isolated from a coral fragment in an example. [Figure 4] It is a graph showing the relationship between the pre-incubation of a coral fragment and the start time of polyp bailout in an example. [Figure 5] It is a graph showing the relationship between the salt concentration after the end of dropping high-concentration artificial seawater and the time required for a coral fragment to bailout in an example, and a graph showing the relationship between the time the coral fragment is held in seawater with a salt concentration of 35 ppt and the above time. [Figure 6] It is an observation image showing the result of an adhesion test of polyps to a substrate in an example. [Figure 7] It is a graph showing the result of measuring the area where polyps adhere to a titanium oxide substrate using the crystal oscillation microbalance method for polyps adhered to a titanium oxide substrate in an example. [Figure 8]An observation image showing the measurement results of the adhesion test of polyps to a titanium substrate with a sandblasted surface in an embodiment. [Figure 9] A graph showing the results of the adhesion test of polyps to a titanium substrate with a sandblasted surface in an embodiment. [Figure 10] An observation image showing the results of the adhesion test of polyps to a titanium oxide substrate with a sandblasted surface in an embodiment. [Figure 11] A graph showing the results of the adhesion test of polyps to a titanium oxide substrate with a sandblasted surface in an embodiment. [Figure 12] An observation image showing the results of the adhesion test of polyps to a striped titanium substrate in an embodiment. [Figure 13] A graph showing the results of the adhesion test of polyps to a striped titanium substrate in an embodiment. [Figure 14] An observation image showing the results of the adhesion test of polyps with the substrate for seeding polyps changed in an embodiment.

Mode for Carrying Out the Invention

[0013] 〔1. Method for Isolating Coral Polyps〕 The method for isolating coral polyps according to an embodiment of the present invention includes a step of introducing coral into an aqueous solution having a salt concentration of 30 to 40 ppt, and either step A of increasing the salt concentration to 45 to 70 ppt at a rate of 1.5 to 13 ppt / h or step B of decreasing the salt concentration to 10 to 26 ppt at a rate of 1.5 to 13 ppt / h.

[0014] The inventors have discovered that by changing the salinity under the conditions described above, a stress-avoidance response occurs in corals, causing a large number of coral polyps to be released in a short time. Hereafter, the release of polyps due to the coral's stress-avoidance response will also be referred to as "bailout." This makes it possible to obtain a large number of coral polyps from a small amount of coral fragment. Conventional coral regeneration methods used coral fragments as seedlings, so only one coral colony could be obtained from one coral fragment. Therefore, when attempting to transplant corals on a large scale, there was a possibility of destroying existing coral colonies. However, with the isolation method of the present invention, a large number of polyps can be obtained from a single coral fragment, making it possible to grow a large number of corals without destroying existing coral colonies.

[0015] Furthermore, the isolation method described above can be carried out simply by changing the salt concentration within a specific range at a specific rate. Therefore, since it does not use chemicals such as enzymes or complex equipment, it has a low environmental impact and can be carried out without limiting the experimenter or location.

[0016] This configuration allows for the efficient and environmentally friendly propagation of corals, which are useful for carbon dioxide sequestration. This can contribute to achieving Sustainable Development Goal (SDG) 14, "Conserve and sustainably use the oceans, seas and marine resources," and other goals.

[0017] The type of coral that can be used in the isolation method described above is not particularly limited. Examples of such corals include cauliflower coral, thistle coral, ginger coral, staghorn coral, and Acropora. From the viewpoint of being able to isolate polyps more efficiently, cauliflower coral is preferred. In the isolation method described above, only one type of coral may be used, or multiple types of coral may be used.

[0018] The coral used in the isolation method may be, for example, a fragment of coral broken off from an existing coral reef, or coral obtained by cultivating polyps obtained by the isolation method. From the viewpoint of ease of handling, the size of the coral fragment is preferably about 1 to 5 cm in outer diameter.

[0019] The salinity of the aqueous solution at the start of the isolation method is 30 to 40 ppt, preferably 32 to 38 ppt, more preferably 34 to 36 ppt, and most preferably 35 ppt, the same as standard seawater. For corals, the salinity of seawater is most suitable. Therefore, if the salinity of the aqueous solution at the start of isolation is within the above range, the burden on the corals can be reduced.

[0020] The aqueous solution used in the isolation method described above is not particularly limited, but for example, filtered seawater may be used, or water in which salts such as NaCl have been dissolved may be used. From the viewpoint of reducing the burden on coral, seawater from the area where the coral fragments were collected may be used. In addition, additives such as amino acids, antibiotics, and strontium ions may be added to the aqueous solution as needed. Furthermore, commercially available artificial seawater mainly consists of sodium chloride and contains various inorganic salts and pH adjusters, and can be used as it has a composition similar to seawater by diluting it with tap water or distilled water.

[0021] The salts may include, in addition to sodium chloride, one or more salts selected from magnesium chloride, magnesium sulfate, calcium sulfate, potassium chloride, calcium chloride, etc. Preferably, the salts contain 75% by weight or more of sodium chloride.

[0022] The method for introducing coral into an aqueous solution with a salinity of 30-40 ppt is not particularly limited. For example, one method is to introduce the required amount of coral fragments, etc., into a processing unit (e.g., an aquarium) equipped with the aqueous solution. The amount of coral to be introduced into the aqueous solution is not particularly limited, but from the viewpoint of handling isolated polyps, it is preferable to use 1-50 g, and more preferably 5-30 g, per 1000-5000 ml of the aqueous solution. The coral fragments, etc., may be floating in the aqueous solution or may be attached to a substrate, etc.

[0023] The isolation method includes either step A, which increases the salinity of the aqueous solution in which the coral is introduced, or step B, which decreases the salinity.

[0024] The method for increasing the salinity in step A is not particularly limited; for example, the water in the aqueous solution may be allowed to evaporate naturally, or high-concentration artificial seawater with a high salinity may be added to the aqueous solution. Adding high-concentration artificial seawater to the aqueous solution is preferred because it makes it easier to control the rate of change in salinity. Similarly, the method for decreasing the salinity in step B is not particularly limited; for example, fresh water may be added to the aqueous solution, or low-concentration artificial seawater may be added. Adding low-concentration artificial seawater to the aqueous solution is preferred because it makes it easier to control the change in salinity.

[0025] Process A or Process B may be performed manually or automatically using equipment. As equipment for increasing or decreasing the salinity at the aforementioned rate, for example, equipment capable of quantitatively supplying high-concentration or low-concentration artificial seawater to the processing unit can be used. Salinity can be measured using, for example, an electrically conductive salinity meter or a refractive index salinity meter.

[0026] The isolation method may involve holding the coral in an aqueous solution with a salinity of 30-40 ppt before performing the steps of increasing or decreasing the salinity of the aqueous solution in which the coral is introduced. The holding time is not particularly limited, but may be, for example, 24-48 hours. Standard artificial seawater can be used as the aqueous solution with a salinity of 30-40 ppt.

[0027] By pre-treating the coral under conditions close to standard seawater salinity before changing the salinity of the aqueous solution, the time from when the salinity reaches 45-70 ppt until bailout occurs can be shortened compared to when this pre-treating is not performed. High or low salinity conditions are stressful for coral, so shortening the time until bailout occurs reduces stress on the coral while increasing the survival rate of the polyps.

[0028] The retention time may be determined based on the isolation status of the coral polyps. For example, if there are few isolated polyps, the retention time may be longer. Conversely, if a sufficient number of polyps have been isolated, the retention time may be shorter.

[0029] If the isolation method includes step A, the salt concentration of the aqueous solution is increased at a rate of 1.5 to 13 ppt / h, with an upper limit of 45 to 70 ppt, preferably 50 to 65 ppt, more preferably 50 to 60 ppt, even more preferably 55 to 60 ppt, and most preferably 55 ppt.

[0030] Corals are organisms sensitive to changes in the salinity of seawater. The inventors have found that when the salinity is changed rapidly, corals do not release their polyps. For example, if corals are directly introduced from seawater into an aqueous solution with a salinity of the aforementioned upper limit, the corals will not release their polyps, and the growth of the corals will deteriorate.

[0031] Non-patent document 2 describes a condition in which the salinity of an aqueous solution containing coral is increased from 35.0 ppt to 46.0 ppt over 24 hours, and states that this causes bailout.

[0032] However, if the salinity is increased to the upper limit (45-70 ppt) while maintaining the rate under the above conditions, the time required to increase from 35.0 ppt to the upper limit would be approximately 22-77 hours. During this time, the coral would be subjected to the stress of increasing salinity over a long period of time. Therefore, under the conditions described in Non-Patent Literature 2, it is difficult to efficiently isolate polyps while maintaining good growth conditions for the coral and polyps.

[0033] Thus, given that corals are organisms sensitive to environmental changes, it is necessary to find conditions that reduce stress on corals and allow for efficient isolation of polyps. However, these conditions are not easily conceivable based on the description in Non-Patent Document 2.

[0034] Step A is a condition uniquely discovered by the inventors, based on their consideration of the properties of coral, and the appropriate rate of increase in salinity and final concentration. The conditions shown in Step A are suitable for reducing stress on the coral and efficiently isolating polyps. Furthermore, by setting the upper limit of the salinity of the aqueous solution to 70 ppt or less, the survival rate of the coral and isolated polyps can be maintained at a high level.

[0035] If the isolation method includes step B, the salt concentration of the aqueous solution is reduced at a rate of 1.5 to 13 ppt / h, and the lower limit of the salt concentration is 10 to 26 ppt, preferably 15 to 24 ppt, and more preferably 18 to 22 ppt.

[0036] Step B involves considering the properties of coral and determining the appropriate rate of reduction in salinity and the final concentration, based on conditions uniquely discovered by the inventors. The conditions shown in Step B are also suitable for reducing stress on the coral and efficiently isolating polyps.

[0037] In step A or step B, the rate at which the salt concentration of the aqueous solution is increased or decreased is 1.5 to 13 ppt / h, preferably 2 to 12 ppt / h, more preferably 3 to 7 ppt / h, even more preferably 3 to 5 ppt / h, and particularly preferably 4 ppt / h.

[0038] In step A or B, the time for increasing the salinity to 45-70 ppt or decreasing it to 10-26 ppt is preferably 20 hours or less, more preferably 14 hours or less, and even more preferably 10 hours or less, from the viewpoint of reducing stress on the coral. The lower limit of the time for increasing or decreasing the salinity of the aqueous solution is not particularly limited, but from the viewpoint of reducing stress on the coral, it may be, for example, 1 hour or more, or 2 hours or more.

[0039] As mentioned above, a rapid increase or decrease in the salinity of the aqueous solution causes significant stress to the coral, leading to a decrease in the efficiency of polyp isolation. Furthermore, prolonged exposure to environments with fluctuating salinity also causes significant stress to the coral. If the rate of increase or decrease in salinity remains within the above-mentioned range, the salinity of the aqueous solution can be changed gradually and quickly, thereby reducing stress on the coral and polyps. As a result, polyps can be efficiently isolated from the coral, and the survival rate of both the coral and polyps can be maintained at a high level.

[0040] The method for adjusting the rate at which the salt concentration in the aqueous solution increases or decreases is not particularly limited, but it may be adjusted using, for example, a salt concentration adjustment unit provided in the apparatus described later. Furthermore, the rate at which the salt concentration increases or decreases may be constant within the aforementioned range, or the rate may be changed during the process.

[0041] In the isolation method described above, it is preferable to keep conditions other than the salt concentration in the aqueous solution, such as water temperature, irradiation light, concentration of components other than salt contained in the aqueous solution, dissolved oxygen amount, and water level, as constant as possible.

[0042] [2. Method for retrieving coral polyps] A method for recovering coral polyps according to one embodiment of the present invention includes a recovery step of adhering the polyps isolated by the isolation method to a substrate mainly composed of titanium and / or titanium oxide. Note that the matters described in [1. Method for Isolating Coral Polyps] are omitted in this section.

[0043] In this specification, "polyps adhering to the substrate" means, for example, that the polyps do not detach from the substrate even when the substrate is tapped in water. Immediately after isolation from the coral, polyps swim, and after a certain period of time, they sink towards the substrate and become stationary on the substrate. By tapping the substrate, polyps that are not adhering to the substrate will oscillate, while polyps that are adhering to the substrate will not oscillate, making it possible to determine whether or not the polyps are adhering to the substrate.

[0044] One method for performing the aforementioned tapping is to apply vibration to the substrate by hand or other means after the polyp has come to rest on the substrate.

[0045] By attaching the polyps obtained in the isolation step to the substrate in the recovery step, the polyps can be easily recovered and cultured in the culture step described later. Furthermore, since the polyps themselves adhere to the substrate, there is no need to fix each coral fragment with wire or the like, which reduces costs.

[0046] The substrate to which the polyps adhere may be concrete, resin, etc., but it is preferable that it be mainly composed of titanium and / or titanium oxide. In this specification, "mainly composed of titanium and / or titanium oxide" means that the weight percentage of titanium and / or titanium oxide contained in the substrate is more than 50% by weight. Furthermore, if the substrate is coated with titanium and / or titanium oxide, it means that 50% or more of the surface area of ​​the substrate is covered. Because titanium and titanium oxide have a high affinity for polyps, the above configuration allows polyps to grow stably. In particular, when the substrate is mainly composed of titanium, the adhesion force of the polyps to the substrate becomes stronger. Also, when the substrate is mainly composed of titanium oxide, the time it takes for the polyps to adhere to the substrate is shortened.

[0047] From the viewpoint of improving the adhesion of the polyps, the substrate is preferably made of titanium or titanium oxide, or a substrate on which a titanium oxide coating is formed on the surface of the titanium. Examples of substrates on which a titanium oxide coating is formed on the surface of the titanium include those on which a titanium oxide coating is formed by natural oxidation, and those on which a titanium oxide coating is formed on the surface of the titanium by anodic oxidation.

[0048] It is preferable that the substrate has an uneven surface. The uneven surface of the substrate increases the adhesion force of the polyps to the substrate and allows them to adhere to the substrate in a shorter time. Examples of methods for creating an uneven surface on the substrate include sandblasting using an abrasive, changing the shape of the substrate itself, scratching the surface with abrasive paper, and cutting.

[0049] When performing the sandblasting treatment, for example, an abrasive with a particle size of about 300 to 850 μm may be used. When changing the shape of the substrate itself, the substrate can be a plate with irregularities, a mesh, a wire, etc. From the viewpoint of how easily polyps can adhere to it, the substrate is preferably wire-shaped. For example, by bending a wire-shaped substrate into an arbitrary shape and intertwining the wires, many scaffolds can be provided that polyps can contact with using their pseudopods.

[0050] The recovery step can be carried out, for example, by transferring an aqueous solution containing the polyps isolated in the isolation step to a recovery unit having a substrate mainly composed of titanium and / or titanium oxide, and by making the polyps adhere closely to the substrate. The recovery unit can be, for example, a polyp recovery unit that constitutes a coral polyp recovery device described later.

[0051] The water temperature during the recovery process is preferably 20-30°C, more preferably 23-28°C, and even more preferably 24-26°C. When the water temperature during the recovery process is within this range, the polyps are more likely to adhere to the substrate.

[0052] The salinity of the aqueous solution used in the recovery process is preferably 30-40 ppt, more preferably 32-38 ppt, even more preferably 34-36 ppt, and most preferably 35 ppt, the same as standard seawater. If the salinity of the aqueous solution used in the recovery process is within the above range, the burden on the coral is small.

[0053] The salinity of the aqueous solution after step A is 45-70 ppt, and the salinity of the aqueous solution after step B is 10-26 ppt. Rapidly increasing the salinity of these aqueous solutions to 30-40 ppt is undesirable because it places a great deal of stress on the polyps. Therefore, it is preferable to increase the salinity of the aqueous solution in the recovery unit to 30-40 ppt by, for example, adding standard artificial seawater to a separate tank from the recovery unit, and then gradually adding the standard artificial seawater from that tank to the recovery unit.

[0054] The recovery method preferably includes a step of monitoring the adhesion of the polyps to the substrate using a quartz crystal microbalance (QCM) and further confirming the plateau adhesion time. In this specification, "plateau adhesion time" means the time during which the adhesion rate of the polyps to the substrate, as measured by the QCM, does not change significantly and remains almost constant. In other words, the time during which the adhesion of the polyps to the substrate plateaus is referred to as "plateau adhesion time".

[0055] In the aforementioned retrieval method, polyp adhesion stops once the plateau adhesion time is reached. By confirming the plateau adhesion time using QCM, it becomes possible to efficiently proceed to the culture process described later. As a device for performing QCM, for example, Seiko Easy & G Co., Ltd.'s QCM922A can be used.

[0056] [3. Method for culturing coral polyps] A method for culturing polyps according to one embodiment of the present invention includes a culturing step of culturing polyps recovered by the polyp recovery method. The method for the culturing step is not particularly limited and may be carried out by known methods used for culturing coral polyps.

[0057] The culture process is carried out, for example, by immersing polyps attached to a substrate in an aqueous solution with a salt concentration of 30-40 ppt and maintaining it at a temperature of 23-28°C for 24-200 hours. The culture process is not particularly limited, but may also be carried out under conditions of light irradiation using LED lighting (e.g., Blue Harbor SPECTRA SP200, etc.) and aeration using an air pump, etc.

[0058] The culture step may be performed simultaneously with the recovery step, or after the recovery step is completed. For example, by placing the substrate used in the recovery step into the culture tank, the recovery step and the culture step can be carried out simultaneously.

[0059] [4. Equipment] (4-1. Polyp isolation apparatus) An isolation apparatus for coral polyps according to one embodiment of the present invention comprises a processing unit for containing an aqueous solution with a salinity of 30 to 40 ppt and coral, and a salinity adjustment unit capable of increasing the salinity to 45 to 70 ppt at a rate of 1.5 to 13 ppt / h, or decreasing the salinity to 10 to 26 ppt at a rate of 1.5 to 13 ppt / h. Matters already explained in [1. Method for Isolating Coral Polyps] are omitted from this description.

[0060] In the aforementioned processing unit, coral polyps are isolated. The processing unit contains an aqueous solution with a salinity of 30-40 ppt, and corals are introduced into it. The processing unit may also include a coral placement section into which corals can be placed. The coral placement section may be, for example, a net or mesh that allows polyps to pass through but not corals. When corals are introduced into the processing unit, they release their polyps as the salinity of the aqueous solution contained within changes. A tank or the like capable of containing the aqueous solution can be used as the processing unit. Examples of materials for the processing unit include, but are not limited to, acrylic and glass.

[0061] In the polyp isolation apparatus, one or more processing units are sufficient, and there may be two, three, or more as needed. The more processing units there are, the more corals can be introduced, and thus more polyps can be obtained. If there are multiple processing units, each processing unit may be connected in series or in parallel.

[0062] The processing unit may further be equipped with sensors for measuring salinity, dissolved oxygen, water temperature, water level, etc. By equipping the processing unit with sensors, the salinity of the aqueous solution in the processing unit can be adjusted more accurately, making it possible to isolate polyps efficiently while minimizing damage to them.

[0063] The salinity adjustment unit adjusts the increase or decrease in the salinity of the aqueous solution in the treatment unit by changing the amount of high-concentration or low-concentration artificial seawater, etc., present in the tank of the polyp isolation device, added to the treatment unit. This adjusts the rate of increase or decrease in the salinity in the treatment unit to 1.5 to 13 ppt / h, and sets the salinity to 45 to 70 ppt or 10 to 26 ppt.

[0064] The salinity adjustment unit may be a device, such as a valve, that manually adjusts the amount of the high-concentration artificial seawater added, or it may be a device that can automatically adjust the amount added.

[0065] The tanks may consist of one or more, and may be two, three, or more as needed. Examples of liquids that can be stored in the tanks other than high-concentration or low-concentration artificial seawater include standard artificial seawater, aqueous solutions containing additives such as amino acids, and fresh water. In addition, each tank may be equipped with a concentration adjustment unit for NaCl aqueous solution, additives, etc., having a structure similar to that of the salinity adjustment unit.

[0066] The polyp isolation apparatus may further include a wastewater treatment section. The wastewater treatment section is not particularly limited as long as it can store or treat the wastewater from within the treatment section. By including a wastewater treatment section, it becomes possible to maintain the water quality within the treatment section. (4-2. Polyp retrieval device) A coral polyp recovery apparatus according to one embodiment of the present invention comprises a polyp recovery unit for recovering polyps isolated by the isolation apparatus, and the polyp recovery unit comprises a base mainly composed of titanium and / or titanium oxide. Matters already explained in [2. Method for recovering coral polyps] are omitted from this description.

[0067] For example, a tank can be used as the recovery unit. In the polyp recovery unit, isolated polyps are recovered. It is preferable that the recovery unit contains an aqueous solution with a salinity of 30 to 40 ppt, similar to the processing unit. The polyps isolated by the isolation device are sent from the processing unit to the recovery unit along with an aqueous solution whose salinity is the final concentration in process A or process B. In the recovery unit, the polyps are recovered by adhering to a substrate mainly composed of titanium and / or titanium oxide. The substrate can be placed, for example, at the bottom of the recovery unit.

[0068] Preferably, the recovery unit is connected to the processing unit by a pipe or the like. With this configuration, polyps isolated by the polyp isolation device can be sent directly to the recovery unit. The pipe connecting the processing unit and the recovery unit may also be equipped with a valve as needed. The recovery unit may also be further equipped with a switching valve that allows switching the destination to which the recovery unit is connected to either the processing unit or a tank described later.

[0069] When the polyps isolated by the isolation device are sent to the recovery unit, aqueous solutions with high or low salt concentrations contained in the processing unit are inevitably sent to the recovery unit along with the polyps. The salt concentration in the aqueous solution in the recovery unit is preferably 30 to 40 ppt in order to minimize stress on the polyps. However, rapidly changing the salt concentration of the aqueous solution with high or low salt concentrations to 30 to 40 ppt is undesirable because it will stress the polyps.

[0070] Therefore, it is preferable that the polyp recovery device further includes a salinity adjustment unit and a tank for adjusting the salinity of the aqueous solution in the recovery unit. The salinity adjustment unit and tank are as described above. For example, standard artificial seawater (salinity 30-40 ppt) contained in the tank is introduced into the recovery unit via the salinity adjustment unit. Next, the same amount of aqueous solution as the introduced standard artificial seawater is withdrawn from the recovery unit. By repeating this process, the salinity of the aqueous solution in the recovery unit can be adjusted to 30-40 ppt.

[0071] The recovery unit may also be equipped with sensors that the processing unit described above may have, as well as a waste liquid processing unit. By equipping the recovery unit with sensors, the range of the salinity and other parameters of the aqueous solution contained in the recovery unit can be maintained more accurately and appropriately. By equipping the recovery unit with a waste liquid processing unit, it becomes possible to maintain the water quality within the recovery unit. (4-3. Polyp culture apparatus) A coral polyp culture apparatus according to one embodiment of the present invention includes a culture section for culturing polyps recovered by the polyp recovery apparatus. The polyp culture apparatus may be a separate apparatus from the polyp recovery apparatus, or it may also function as the polyp recovery apparatus. That is, the culture section may be integrated with the recovery section described above.

[0072] For example, a separate tank from the polyp retrieval device can be prepared as the culture section, and an aqueous solution with a salinity of 30-40 ppt can be placed in this tank. A substrate with polyps attached can then be transferred to this tank, and the conditions such as water temperature can be adjusted to be suitable for polyp growth, allowing the polyps to grow into coral.

[0073] Furthermore, as mentioned above, the salinity of the aqueous solution in the recovery section is preferably 30 to 40 ppt. Since this salinity is a suitable condition for polyp growth, it is possible to cultivate the polyps and grow them into coral by setting the water temperature and other conditions in the recovery section to be suitable for polyp growth, without preparing a separate tank.

[0074] Therefore, the culture unit may be equipped with sensors, waste liquid processing units, etc., that can be provided in the recovery unit described above.

[0075] Furthermore, the culture section is not particularly limited, but may include, for example, an LED lighting device (e.g., Blue Harbor's SPECTRA SP200), an air pump or other aeration device, and the like.

[0076] Here, an embodiment of the polyp isolation apparatus, recovery apparatus, and culture apparatus will be described using Figure 1. Note that Figure 1 is merely an example, and the polyp isolation apparatus, recovery apparatus, and culture apparatus of the present invention are not limited to the embodiment shown in Figure 1.

[0077] Figure 1 is a schematic plan view showing the configuration of a polyp isolation device, recovery device, and culture device according to one embodiment of the present invention. For convenience, the device shown in Figure 1 will also be simply referred to as the "polyp isolation and culture device." As shown in Figure 1, the polyp isolation and culture device consists of a processing unit 1, a salinity adjustment unit 2, a recovery unit 3, and a tank 11. In the polyp isolation and culture device shown in Figure 1, the recovery unit 3 also serves as the culture unit. The processing unit 1 is equipped with a coral installation unit 21, and the recovery unit 3 is equipped with a base 22. Furthermore, standard artificial seawater 32 with a salinity of 30-40 ppt is present inside the processing unit 1. Inside the recovery unit 3, concentration-adjusted artificial seawater 33 is present, which has been adjusted to the same concentration (45-70 ppt) as the final salinity when the polyps were isolated in the processing unit 1, in order to avoid abrupt changes in salinity.

[0078] After the coral fragments 31 are introduced into the processing unit 1, high-concentration artificial seawater, for example, is added from the tank 11. The salinity adjustment unit 2 adjusts the amount of high-concentration artificial seawater added, increasing the salinity of the standard artificial seawater 32 to 45-70 ppt (final concentration) at a rate of 1.5-13 ppt / h. Subsequently, by maintaining the salinity at the final concentration, polyp release (i.e., bailout) occurs from the coral.

[0079] The polyps released by the bail-out are sent to the recovery unit 3 by switching the switching valve 23 to the processing unit 1 side. After all the polyps have been sent to the recovery unit 3, the switching valve 23 is switched again to add, for example, standard artificial seawater from the tank 11, thereby adjusting the salinity of the concentration-adjusted artificial seawater 33 in the recovery unit 3 to 30-40 ppt. The polyps sent to the recovery unit 3 are cultured after adhering to the substrate 22.

[0080] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Examples]

[0081] One embodiment of the present invention is described below.

[0082] [Obtaining Coral Fragments] Fragments of cauliflower coral, thorn coral, ginger coral, stony coral, and thistle coral, obtained from Blue Harbor Co., Ltd., were cut into small pieces of approximately 1-2 cm in size using wire cutters, and these were used as coral fragments for use in the examples.

[0083] [Preparation of standard artificial seawater] Approximately 3.5 grams of product name: RED SEA SALT Ideal for SPS Dominant Systems powder (manufactured by Red Sea) was gradually dissolved in 1 liter of distilled water while stirring. The salinity was measured using a salinity meter (MASTER handheld refractometer, manufactured by Atago Co., Ltd.) to prepare standard artificial seawater with a salinity of 35 ppt. In addition to NaCl, the salts contained were CaCl2 (approximately 440 mg / L), MgCl2 (approximately 1,300 mg / L), nitrates, and phosphates (totaling approximately 5 mg / L or less).

[0084] [Preparation of high-concentration artificial seawater] Approximately 8.0 grams of product name: RED SEA SALT Ideal for SPS Dominant Systems powder (manufactured by Red Sea) was gradually dissolved in 1 liter of distilled water while stirring. High-concentration artificial seawater was prepared to achieve a salinity of 80 ppt while measuring the salinity with a salinity meter. In addition to NaCl, the salts contained were CaCl2 (approximately 1,006 mg / L), MgCl2 (approximately 2,971 mg / L), nitrates, and phosphates (totaling approximately 11.4 mg / L or less).

[0085] [Preparation of low-concentration artificial seawater] Approximately 0.5 grams of product name: RED SEA SALT Ideal for SPS Dominant Systems powder (manufactured by Red Sea) was gradually dissolved in 1 liter of distilled water while stirring. The salinity was measured using a salinity meter, and low-concentration artificial seawater was prepared to a salinity of 5 ppt. In addition to NaCl, the salts contained were CaCl2 (approximately 63 mg / L), MgCl2 (approximately 186 mg / L), nitrates, and phosphates (totaling approximately 0.7 mg / L or less).

[0086] [Observation of active polyps] Isolated polyps were time-lapsed or video-recorded for approximately 30 minutes, and those moving horizontally or rotating in place were identified as active polyps.

[0087] [Evaluation of polyp adhesion to substrate using QCM] A quartz crystal oscillator with a fundamental frequency of 9 MHz and electrodes manufactured by IOT Corporation was used. Standard artificial seawater at 35 ppt was placed in the cell, and after the resonant frequency and resonant resistance stabilized, a small amount of the artificial seawater was removed, and polyps dispersed in seawater (not artificial seawater) from a tank were placed inside. The polyps were observed from the bottom of the cell using a digital stereomicroscope (THIRDWAVE UM-12). The contact area ratio with the substrate was calculated using image processing software (ImageJ).

[0088] [Experiment 1: Isolation of coral polyps by increasing salinity] 5g of cauliflower coral fragments were added to 3500ml of standard artificial seawater with a salinity of 35ppt, and high-concentration artificial seawater (salinity of 80ppt) was added dropwise. The salinity of the standard artificial seawater was increased to 55ppt over 5 hours (i.e., at a rate of 4.0ppt / h). The salinity was confirmed by measuring it with a handheld salinity meter. After the addition of the high-concentration artificial seawater was completed, the salinity of the artificial seawater was maintained at 55ppt, and observation of the coral fragments was continued. The results are shown in Figure 2.

[0089] Figure 2 shows that polyps rapidly isolated (bailed out) from the coral fragments 6 to 7 hours after the start of dripping the high-concentration artificial seawater (i.e., 1 to 2 hours after the end of dripping). A total of 40 polyps were isolated, of which 37 were active, meaning 93% of the obtained polyps were active. Therefore, it was found that a large number of active polyps can be obtained from coral fragments by increasing the salinity at an appropriate rate and reaching an appropriate final concentration.

[0090] [Experiment 2-1. Investigation of salinity concentration for polyp isolation 1] Four test plots were prepared, each containing 3500 ml of standard artificial seawater with a salinity of 35 ppt and 5 g of cauliflower coral fragments. High-concentration artificial seawater (salinity 80 ppt) was added dropwise to each plot over 5 hours. The salinity of the seawater was increased to 52, 55, 57, and 60 ppt, respectively, and these concentrations were maintained. Figure 3 shows the bailout process in this case.

[0091] The relationship between the final salinity and the rate of increase in salinity is as follows: For a final concentration of 52 ppt: rate of increase of 3.4 ppt / h; for a final concentration of 55 ppt: rate of increase of 4.0 ppt / h; for a final concentration of 57 ppt: rate of increase of 4.4 ppt / h; for a final concentration of 60 ppt: rate of increase of 5.0 ppt / h.

[0092] Figure 3 shows that the bail-out initiation time was earliest at a final salinity of 57 ppt, followed by 60 ppt, 55 ppt, and 52 ppt, in that order, and tended to be later. Of the isolated polyps, the proportion of active polyps was 50%, 87%, 76%, and 20% for final concentrations of 52, 55, 57, and 60 ppt, respectively.

[0093] [Experiment 2-2. Investigation of salinity concentration for polyp isolation 2] Six test plots were prepared, each containing 5g of cauliflower coral fragments in 3500ml of standard artificial seawater with a salinity of 35ppt. High-concentration artificial seawater (salinity of 80ppt) was then added to each plot, varying the drip rate.

[0094] High-concentration artificial seawater (salinity 80 ppt) was added dropwise to three test plots over two hours to achieve final concentrations of 52 ppt, 57 ppt, and 60 ppt. The relationship between the final salinity and the rate of increase in salinity was as follows: For a final concentration of 52 ppt: rate of increase 8.5 ppt / h; for a final concentration of 57 ppt: rate of increase 11.0 ppt / h; for a final concentration of 60 ppt: rate of increase 12.5 ppt / h. The proportion of isolated active polyps was 43%, 64%, and 11% for final concentrations of 52, 57, and 60 ppt, respectively.

[0095] In a separate test plot, high-concentration artificial seawater (salinity 80 ppt) was added dropwise over 7 hours until the final concentration reached 50 ppt. In this case, the rate of increase in salinity was 2.1 ppt / h. The proportion of isolated active polyps was 40%.

[0096] In addition to the above, high-concentration artificial seawater (salinity 80 ppt) was added dropwise over 10 hours to two separate test plots, resulting in final concentrations of 52 ppt and 55 ppt. The relationship between the final salinity and the rate of increase in salinity was as follows: For a final concentration of 52 ppt: increase rate 1.7 ppt / h; for a final concentration of 57 ppt: increase rate 2.0 ppt / h. The proportion of isolated active polyps was 42% and 76% for final concentrations of 52 and 57 ppt, respectively.

[0097] [Comparative Example] As a control group, a test group was created under the same conditions as in Experiment 2-2, and high-concentration artificial seawater (salinity 80 ppt) was added dropwise over 5 hours until the final concentration reached 40 ppt. In this case, the rate of increase in salinity was 1.0 ppt / h. The percentage of isolated active polyps was 0%.

[0098] As another control group, a test group was created under the same conditions as in Experiment 2-2, and high-concentration artificial seawater (salinity 80 ppt) was added dropwise over 2 hours until the final concentration reached 70 ppt. In this case, the rate of increase in salinity was 17.5 ppt / h. The percentage of isolated active polyps was 0%.

[0099] Thus, when the requirements of step A or step B in the coral polyp isolation method according to one embodiment of the present invention are met, it was possible to isolate active polyps while minimizing stress on the coral. On the other hand, in comparative examples that did not meet the above requirements, it was not possible to obtain active polyps. If active polyps can be obtained, they can be cultured to increase their numbers. Therefore, the results of tests 1, 2-1, and 2-2 can be said to be sufficiently useful regardless of the ratio of active polyps.

[0100] [Experiment 3. Examination of the effect of pre-incubation before increasing salt concentration] Three fragments (5g each) of cauliflower coral, freshly cut and different from those used in Experiment 2, were pre-incubated in 1000ml of standard artificial seawater at a concentration of 35ppt for 0, 24, or 48 hours, respectively. Subsequently, the high-concentration artificial seawater was added dropwise, increasing the salinity to 55ppt over 5 hours, and the concentration was maintained at that level. Observation of each coral fragment continued after the dropwise addition was complete. Figure 4 is a graph showing the relationship between the pre-incubation time and the time until bailout.

[0101] Figure 4 shows that, for fragments immediately after cutting, as the pre-incubation time until the salt concentration increased was extended to 24 hours and then 48 hours, the time until bail-out began decreased.

[0102] The graph on the left of Figure 5 shows the relationship between salinity after the drop-in of high-concentration artificial seawater has finished and the time required for coral fragments to bail out. This graph corresponds to Figure 3. From Figure 3 and the graph on the left of Figure 5, it can be seen that the time it took for bail-out to occur became faster as the salinity increased, but when the salinity exceeded 57 ppt, the time it took for bail-out to occur became about the same.

[0103] The graph on the right of Figure 5 shows the relationship between the time a cauliflower coral fragment held in standard artificial seawater with a salinity of 35 ppt immediately after cutting, and the time required for bailout. This graph corresponds to Figure 4. From Figure 4 and the graph on the right of Figure 5, it can be seen that by holding the fragment in standard artificial seawater for several days beforehand, rather than immediately increasing the salinity, bailout begins in about 5.5 hours or 6.5 hours, even when the final salinity is 55 ppt. In other words, it was found that by holding the coral in standard artificial seawater for several days beforehand, bailout can be induced in a shorter time than when the final salinity is 57-60 ppt.

[0104] Therefore, it was shown that polyp release can be achieved more efficiently by optimizing the salinity at the end of high-concentration artificial seawater dripping and the retention time in standard artificial seawater with a concentration of 35 ppt.

[0105] [Experiment 4. Isolation of coral polyps by reducing salinity] 5g of coral fragments were added to 3500ml of standard artificial seawater with a salinity of 35ppt, and low-concentration artificial seawater (salinity of 5ppt) was added dropwise. The salinity of the artificial seawater was reduced to 20ppt over 4 hours (i.e., at a rate of 3.8ppt / h). The salinity was confirmed by measuring it with a handheld salinity meter. After the addition of the low-concentration artificial seawater was complete, the salinity of the artificial seawater was maintained at 20ppt, and observation of the coral fragments was continued.

[0106] A total of 45 polyps were isolated, of which 41 were active, meaning 91% of the obtained polyps were active. Therefore, it was found that a large number of active polyps can be obtained from coral fragments by decreasing the salinity at an appropriate rate and achieving an appropriate final concentration.

[0107] [Test 5. Evaluation of the adhesion of coral polyps] In a separate container, 1 g of coral was placed in 1000 ml of standard artificial seawater with a salinity of 35 ppt. High-concentration artificial seawater (salinity of 80 ppt) was added dropwise, increasing the salinity of the artificial seawater at a rate of 4.4 ppt / h to 57 ppt. The polyps were then bailed out by holding the mixture at this final concentration for 2 hours. Subsequently, low-salinity artificial seawater was gradually added to return the salinity to 35 ppt. Next, the isolated coral polyps were aspirated with a pipette and seeded onto a titanium substrate or a titanium oxide substrate placed in 100 ml of standard artificial seawater. The titanium substrate is a substrate made of titanium. The titanium oxide substrate was obtained by anodizing the surface of the titanium substrate. Anodizing was performed in a 0.1 M citric acid aqueous solution at a voltage of 80 V. Subsequently, the substrate was tapped by hand over time, and the number of polyps that did not vibrate was measured as the number of polyps that adhered to the substrate. The results are shown in Figures 6 and 7.

[0108] The upper panel of Figure 6 shows the adhesion of polyps to the substrate when using a titanium substrate. The lower panel of Figure 6 shows the adhesion of polyps to the substrate when using a titanium oxide substrate. The time is the elapsed time after seeding, with 0h being the time when the polyps were seeded on the titanium substrate or the titanium oxide substrate. From Figure 6, it can be seen that the polyps showed excellent adhesion in both cases, with the use of titanium and titanium oxide substrates. From the results shown in the lower panel of Figure 6, it can be seen that the coral polyps adhered to the substrate more quickly, especially when using a titanium oxide substrate.

[0109] Figure 7 shows the results of measuring the area of ​​polyps in contact with a titanium oxide substrate using the quartz crystal vibration microbalance method. The measuring device used was the QCM922A from Seiko Easy & G Co., Ltd. Figure 7 shows that after 8 hours from the start of contact, the area has almost stopped changing. Furthermore, it can be seen that after 16 hours from the start of contact, the contact area has slightly decreased. Therefore, it was shown that the preferred contact time for coral polyps is 8 to 16 hours.

[0110] From these results, it was shown that the polyps obtained by the above method showed good adhesion to both titanium substrates and titanium oxide substrates, and in particular, the time required for adhesion to the titanium oxide substrate was short.

[0111] [Test 6. Evaluation of adhesion to surface-treated titanium substrate] Titanium substrates were prepared by sandblasting the surface using an abrasive. The surface roughness of the titanium substrates was varied by the average particle size of the abrasive. The average particle sizes of the abrasives were 600-850 μm (#24), 425-600 μm (#36), and 300-425 μm (#46), respectively. Note that the larger the average particle size of the abrasive, the rougher the surface of the titanium substrate. For comparison, a titanium substrate that had not been sandblasted was used. Coral polyps isolated using the same method as in Experiment 4 were seeded onto each titanium substrate. After seeding, the substrate was tapped every 15 minutes to check whether the polyps were adhering to the substrate. The results are shown in Figures 8 and 9.

[0112] Figure 8 shows the results of photographing a substrate on which polyps were seeded using a digital stereomicroscope from outside the tank. As shown in Figure 8, the time to initial adhesion was shorter on the sandblasted titanium substrate (Ti in the figure) than on the unsandblasted titanium substrate. Since the adhesion of the polyps to the substrate was observed in a relatively short time of 4 hours after seeding, this adhesion is referred to as "initial adhesion."

[0113] The graph in Figure 9 shows the relationship between the time elapsed since sowing and the adhesion rate of polyps to each titanium substrate. Figure 9 shows that the rougher the surface of the titanium substrate, the shorter the time it takes for the polyps to adhere to the substrate.

[0114] [Test 7. Evaluation of adhesion to surface-treated titanium oxide substrate] The titanium substrate to which the polyps were attached was sandblasted in the same manner as in Test 6, and then anodized in a 0.1 M citric acid aqueous solution at a voltage of 80 V. Isolated coral polyps were seeded onto the resulting titanium oxide (TiO2) substrate in the same manner as in Tests 5 and 6. After seeding, the substrate was tapped by hand every 15 minutes to check whether the polyps were adhering to the substrate.

[0115] Figure 10 shows the results of photographing the substrate on which polyps were seeded using a digital stereomicroscope from outside the tank. As shown in Figure 10, the time to initial adhesion was shorter on the sandblasted titanium oxide substrate (TiO2 in the figure) than on the unsandblasted titanium oxide substrate.

[0116] The graph in Figure 11 shows the relationship between the time elapsed since sowing and the adhesion rate of polyps to each titanium oxide substrate. Figure 11 shows that the rougher the surface of the titanium oxide substrate, the shorter the time it takes for the polyps to adhere. Note that the titanium oxide substrate that has not undergone sandblasting shows a high adhesion rate, but this is considered to be accidental.

[0117] [Test 8. Evaluation of polyp adhesion using a striped titanium substrate] To simultaneously test the adhesion of polyps to titanium and titanium oxide, striped titanium substrates were prepared. These striped substrates were created by masking a titanium substrate with cellophane tape at 2mm intervals, followed by the anodic oxidation treatment described above. Additionally, striped titanium substrates with scratched surfaces were also prepared by polishing with #80 emery paper. Polyps were seeded onto the striped substrates in the same manner as in tests 5-7. The results are shown in Figures 12 and 13.

[0118] Figure 12 shows the results of photographing a substrate on which polyps were seeded using a digital stereomicroscope from outside the aquarium. In the striped substrate shown in Figure 12, the lighter colored areas are titanium, and the darker colored areas are titanium oxide (anodic oxidation). From Figure 12, it can be seen that the polyps are mostly attached to the titanium oxide areas.

[0119] The graph in Figure 13 shows the relationship between the time elapsed since sowing and the degree of polyp adhesion to each striped substrate. Figure 13 shows that polyps adhered to the damaged striped substrate more quickly than to the undamaged substrate. It also shows that polyps adhered to the anodized titanium oxide section more quickly than to the titanium section. Therefore, polyps adhered to the damaged titanium oxide section the fastest.

[0120] [Experiment 9. Seeding polyps on various substrates] Polyps were seeded onto the substrate in the same manner as in experiments 5-8, except that the substrate was made of mesh (titanium), nonwoven fabric (titanium or titanium oxide), or wire (titanium). The results are shown in Figure 14.

[0121] Figure 14 shows the results of photographing substrates on which polyps were seeded using a digital stereomicroscope from outside the tank. When mesh was used as the substrate, it took 11 hours for initial adhesion to occur. Nonwoven fabric did not adhere even after 12 hours. On the other hand, with wire, the polyps were already attached to the wire at the time of seeding, indicating that adhesion occurred immediately. Therefore, wire was shown to be the most preferable substrate shape.

[0122] [Experiment 10. Isolation of polyps from thorn coral] A fragment of staghorn coral was used as the coral fragment, and polyps were isolated under the same conditions as in Experiment 1. A total of 38 polyps were isolated, of which 34 were active, meaning that 90% of the obtained polyps were active.

[0123] [Experiment 11. Isolation of polyps from ginger coral] Ginger coral fragments were used as the coral fragments, and polyps were isolated under the same conditions as in Experiment 1. A total of 36 polyps were isolated, of which 30 were active, meaning that 83% of the obtained polyps were active.

[0124] [Experiment 12. Isolation of polyps from Acropora corals] A fragment of Acropora was used as the coral fragment, and polyps were isolated under the same conditions as in Experiment 1. A total of 26 polyps were isolated, of which 18 were active, meaning that 70% of the obtained polyps were active.

[0125] [Experiment 13. Isolation of polyps from thistle coral] Thistle coral fragments were used as the coral fragments, and polyps were isolated under the same conditions as in Experiment 1. A total of 18 polyps were isolated, of which 7 were active, meaning that 40% of the obtained polyps were active. [Industrial applicability]

[0126] This invention can be used as a method for regenerating or cultivating coral. [Explanation of Symbols]

[0127] 1 Processing Unit 2. Salt concentration adjustment section 3. Recovery section 11 tanks 21 Coral installation area 22 Base 23. Switching valve 31 Coral Fragments 32 Standard artificial seawater 33 Concentration-adjusted artificial seawater

Claims

1. A method for isolating active coral polyps, comprising the steps of: introducing coral into an aqueous solution with a salinity of 30 to 40 ppt; increasing the salinity to 45 to 70 ppt at a rate of 1.5 to 13 ppt / h within 14 hours (Step A); or decreasing the salinity to 10 to 26 ppt at a rate of 1.5 to 13 ppt / h (Step B).

2. The method for isolating active coral polyps according to claim 1, wherein in step A, the salinity is increased to 50 to 60 ppt.

3. The method for isolating active coral polyps according to claim 1, wherein the rate of increase in salinity in step A or the rate of decrease in salinity in step B is 3 to 6 ppt / h.

4. A method for recovering active coral polyps, comprising a recovery step of adhering the polyps isolated by the method for isolating active coral polyps according to any one of claims 1 to 3 to a substrate mainly composed of titanium and / or titanium oxide.

5. The method for retrieving active coral polyps according to claim 4, further comprising the step of using a quartz crystal oscillator microbalance to monitor the adhesion status of the polyps to the substrate and confirming the plateau adhesion time.

6. A method for culturing active coral polyps, comprising a culturing step of further culturing the active coral polyps recovered by the method for recovering active coral polyps described in claim 4.

7. A processing unit containing an aqueous solution with a salinity of 30-40 ppt and coral, An isolation apparatus for active coral polyps, comprising: a salinity adjustment unit capable of increasing the salinity from 45 to 70 ppt at a rate of 1.5 to 13 ppt / h within 14 hours, or decreasing the salinity from 10 to 26 ppt at a rate of 1.5 to 13 ppt / h.

8. A coral polyp recovery apparatus comprising a recovery unit for recovering polyps isolated by the coral polyp isolation apparatus described in claim 7, wherein the recovery unit comprises a base mainly composed of titanium and / or titanium oxide.

9. A coral polyp culturing apparatus comprising a culturing section for culturing polyps recovered by the coral polyp recovery apparatus described in claim 8.

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