EP4651708A1

EP4651708A1 - Method of culture of precious corals by fusion

Info

Publication number: EP4651708A1
Application number: EP24706195.5A
Authority: EP
Inventors: Giandomenico LUCCHINI
Original assignee: Red Coral Srl
Current assignee: Red Coral Srl
Priority date: 2023-01-20
Filing date: 2024-01-22
Publication date: 2025-11-26
Also published as: IT202300000810A1; JP2026504222A; WO2024154107A1

Abstract

The present invention generally relates to the field of cultivation and propagation of precious corals and in particular it relates to a method for the production or for culture of precious corals or colonies of precious corals, their recruits or their chimeras, starting from fragments, pre-existing colonies or recruits of precious corals belonging to the Corallidae family.

Description

"METHOD OF CULTURE OF PRECIOUS CORALS BY FUSION

FIELD OF THE INVENTION

The present invention generally relates the field of the cultivation and propagation of precious corals and in particular it relates to a method for the production or culture of precious corals or colonies of precious corals, their recruits or their chimeras, starting from fragments, colonies, preexisting recruits of precious corals belonging to the Corallidae family.

STATE OF ART

Because of the aesthetic qualities, the precious corals have been used as talismans, jewels or trading currency since the Neolithic Age and in many cultures they are considered magic or religious symbols, symbols of good luck or social status. Since Roman times, the precious corals have been much appreciated for their medical properties and still nowadays they are used in homeopathic medicine and traditional Chinese medicine.

According to The World Jewellery Confederation (CIBJO), among all species belonging to the class of Anthozoa of the Cnidaria phylum, commonly called corals (over 6.000 species), only eight species are defined as precious corals used in high jewellery. All these species belong to the Corallidae family, Scleraxonia suborder, Alcyoanacea order, Octocorallia subclass.

The precious corals have very different features from the common “reef’ corals, not only as to density and stiffness of the carbonate skeleton which makes them very attractive for jewellery, but especially for their biology. Contrary to common reef corals, the precious corals live at great sea depths (50-2000 m) in the mesophotic and aphotic band; in fact, these corals do not live in symbiosis with microalgae, the zooxanthellae, and then they do not require exposure to sunlight to carry out photosynthesis.

The precious corals are long-lived corals, but they are characterized by slow growth, low reproductive capability and low dispersion of larvae, factors which make them very vulnerable to overexploitation phenomena. Over the years, in fact, the resource overexploitation has determined dramatic changes in demographic structure of the precious corals. Particularly in less deep water, generally subjected to higher piscatory pressure, the colonies of precious corals having big sizes have almost disappeared and the coral “forests” have given way to “prairies” of young colonies having little developed three- dimensional structure, thus not constituting a functional habitat.

The temperate coralligenous constitutes a high-biodiversity ecosystem, then, its progressive disappearance has represented and still involves relevant critical issues from an ecological point of view. In order to face such critical issues, the collection of the precious corals is subject to several restrictions and 4 out of the 8 most precious species were inserted among the “endangered” species enlisted in the appendix III (species whose trade is regulated at local level) of the list prepared by the International Convention CITES (Convention on International Trade in Endangered Species of Flora and Fauna).

The progressive disappearance of colonies of precious corals has represented and still constitutes a relevant problem even from a socio-economical point of view, considering that the coral industry represents an important sector for many local communities, obliged to face the risk of economic extinction of the precious corals (95% less precious corals caught from 1974 to 2020 in the Mediterranean, FAO data).

In order to guarantee greater protection, two formal requests were made by China and USA to insert the 8 precious species of the Corallidae family in the appendix II of the CITES list (species whose trade is regulated at International level); however, such measure was strongly contrasted by the main producing Countries in the field due to the risk of a strong contraction of the precious coral industry, with important impacts on the local communities which commercially exploit such species.

In order to cope with the continuous decline of wild populations, over the last years many Marine Protected Areas (MPA) were established for the passive preservation of the precious corals. However, due to the long growth time of such species and then to the very slow recovery of the three-dimensional structure even in the same MPA, the passive preservation alone revealed to be insufficient to cope with increasingly frequent mass mortality events (MME). Therefore, there are numerous difficulties encountered in managing the available resources of precious coral; on one side, biologists are increasingly asking to adopt more stringent rules for the collection, together with MPA institution and insertion of the whole Corallidae family in the CITES list, appendix II (species whose trade is regulated at International level), with consequent contraction risks of the industry operating in the field; on the other side, within the coral industry, the authorization for the use of remote-controlled underwater vehicles (Remote Operating Vehicles, ROVs) is requested for searching for and exploiting currently not usable coral banks, with consequent risks of biological extinction of such species.

Currently, the long growth time and the particular biology of the corals of the Corallidae family have made impractical the development of effective large-scale strategies for cultivating such species. All culture attempts adopted up to now, in fact, have revealed to be ineffective or not advantageous from an economical point of view. Therefore, the collection of wild corals continues to represent the only source of supply in the field.

As already mentioned, the precious corals comprise very slow growth and take decades to reach 7 mm of diameter at the base (i.e. the minimum size of collection in the Mediterranean fixed by the convention “General Fisheries Commission forthe Mediterranean", GFCM); then, they require very long culture time, not economically sustainable.

All currently adopted active repopulation strategies of the precious corals provide direct transplants of colonies of coral collected in nature (Villechanoux et al. Water 2022, 14(7), 1071 ; Koido et al. Zoological Studies 2022, 61 :46). This type of repopulation strategy does not provide a preliminary step of culture of corals in propagation nursery, but it has already demonstrated - with common corals - to be not very effective in terms of increase in the total biomass of the corals. The first results obtained with species of the Corallidae family too showed a decrease in the total biomass, with homogeneous results among the various species of the family tested in nature (Villechanoux et al. Water 2022, 14(7), 1071 ; Koido et al. Zoological Studies 2022, 61 :46).

Among the techniques recently adopted in the development of coral repopulation projects, there is the technique of “micro-fragmentation” or “re-skinning", developed by D. Vaughan for a particular type of low-growth corals, the massive corals, which form balls or very big mounds such as, for example, the brain corals (“The culture of massive corals using “micro-fragmentation” for the “reskinning” of degraded coral reefs", Christopher Page and David Vaughan, Conference paper march 2014).

Such technique exploits the isogenic fusions between coral fragments to accelerate the growth rate (growth rate) of the corals, but however it has revealed to be applicable only with the common corals, since, even if it reduces drastically the long periods of time required to these corals to cover large areas with one thin layer, it has no effect on their three-dimensional structure and produces only thin encrustations rather than balls or mounds (Vaughan et al. 2014). Such technique then is ineffective to accelerate the three-dimensional growth of the arborescent corals such as those belonging to the Corallidae family.

For all above-illustrated reasons, the need is very felt for developing effective strategies which make the culture of precious corals possible and economically sustainable, so as to guarantee to the coral industry new sources for supplying raw material and to limit the exploitation of the wild populations of such species, very important from the environmental point of view and already strongly compromised by the economic overexploitation.

SUMMARY OF THE INVENTION

The technical problem underlying the present invention then is to provide a method for favouring and accelerating the production and/or the culture of precious corals or colonies of precious corals, as well as their recruits or their chimeras, starting from pre-existing fragments, colonies or recruits belonging to the Corallidae family, allowing to meet the above-mentioned needs with reference to the known art.

The present invention is based upon the finding that the fact of fixing fragments or recruits of precious coral of the Corallidae family to one support element according to a suitable geometry and, in particular, the positioning of the fragments or of the recruits to a suitable distance from one another, favours the fusion between adjacent fragments or recruits, by allowing in particular to reduce drastically the time for forming new colonies, recruits or chimeras of precious corals having the wished sizes, by avoiding to wait for the long growth time of such colonies, recruits or chimeras. The method, the present invention relates to, then exploits the capability of the fragments or of the recruits of precious coral to fuse together by isogenic fusion, allogenic fusion, interspecific fusion or chimerism when fixed to one support element on the base of a specific geometry devised by the author of the present invention.

In particular, the author of the invention found that the positioning of fragments of recruits of precious coral in strict contact or at a minimum distance between adjacent fragments or recruits, respectively, not higher than 2 cm, preferably equal or lower than 5 mm, still more preferably equal to 0, allows to obtain or accelerate the fusion between the above-mentioned fragments or recruits and then even to maximize the diameter at the basis of the precious coral or its resulting colony, with a consequent increase in its trade value. Surprisingly, the fusion between colonies of precious coral having an age comprised between 2 and 4 years, as well as of fragments of precious coral arranged according to the optimal geometry identified by the author of the present invention favours a significant acceleration in time for producing precious corals having the wished sizes - from decades to months - by making then possible and sustainable a cultivation thereof on industrial scale.

In an embodiment, the method of the invention then allows to obtain new raw precious corals having an important commercial value. In particular, the positioning of a number “x” of fragments of precious coral, with x = 2, 3, ... , n, each one having a weight rm, m2, up to m_n, in such a way that each one thereof results in strict contact with at least an adjacent fragment or at a distance not higher than 2 cm from the above-mentioned adjacent fragment, under culture conditions suitable to favour the growth thereof, is capable of inducing the fusion between adjacent fragments, by producing a coral having total weight m? ^a 011+012+....m_n but a total value VT »vi+V2+...v_n. As it is known, in fact, the value/kg of the raw precious corals increases rapidly as the sizes of the corals increase, especially as the diameter at the basis increases.

Differently from the known technique in the field for the culture of massive common corals which are not based upon the fusion of fragments, which require long waiting time - that is long culture time - in order to obtain corals with relevant sizes, the method, the present invention relates to, advantageously provides the possibility of using a high number of fragments of precious coral without this determining a lengthening of the time for forming the resulting coral. The author of the invention in fact found that the time of fusion between the fragments mostly depend upon the distance between the same and to a lesser extent even upon various biotic and abiotic factors (e.g. the used species, temperature, current, concentration of nutrients, salinity, ph, etc.), but they do not depend upon the number of the used fragments.

Therefore, the fact of increasing the number of the fragments in the method of the invention makes then possible to produce raw corals with important sizes, with diameters potentially even larger than the maximum ones obtainable in nature, without lengthening the production time.

The effectiveness of the geometry adopted by the method, the present invention relates to, in manipulating the diameter at the basis of the precious corals and in accelerating the formation and the three-dimensional growth thereof, represents a surprising novelty with respect to what observed with method of micro-fragmentation, which on the contrary results to be effective only at two-dimensional level and causes the formation of thin layers of coral.

The adopted technical solution is an innovative geometry for fixing the fragments of coral to the support with respect to the one adopted by the technique of micro-fragmentation and which allows to manipulate the diameter at the basis of the precious corals.

In fact, during implementation of micro-fragmentation it was observed that the positioning of fragments of massive common coral at distances lower than or equal to 2 cm did not result to be effective to favour a re-covering of huge areas in short time, since the growth rate of micro-fragments of massive common corals precipitates when the fusion takes place between the micro-fragments and if this takes place too early the technique is not effective (Vaughan et al. 2015).

The author of the invention, on the contrary, found that the fact of using geometries for fixing the fragments to one support element with distances between the fragments lower than 2 cm, preferably lower than 5 mm, still more preferably equal to 0 mm, instead favours the growth in the diameter of the trunk of the colonies of Corallidae in much shorter time than it would be necessary in nature.

Not only, the new geometry developed by the author of the present invention for the precious corals offers a great advantage with respect to the technique of micro-fragmentation of the massive corals. In fact, in a first qualitative experiment with the Corallium Rubrum, surprisingly it was observed that the growth rate of the fragments does not precipitate after reaching the fusions as in case of micro-fragmentation of the massive corals; on the contrary, the fused fragments showed a higher growth rate than the single fragments taken as reference and even a higher survival rate.

This unexpected effect makes that the colonies produced with the method, the invention relates to, have a greater resistance to transplants and grow quicker than the single fragments.

This is a very important aspect in the culture of corals and in particular for those belonging to the Corallidae family considering that it allows to overcome the main technical difficulties which make the culture of these corals extremely difficult, that is long time of culture in nursery and biomass loss with transplants.

Without wanting to be linked to theory, one hypnotizes that such phenomenon is due to the greater sizes of the fused coral fragments with respect to those of the single fragments and to the greater number of starting polyps. In fact, the age being equal, bigger corals generally have a greater growth and survival rate, a much greater number of oocytes and sperm sacs per polyp then higher reproductive capability, but even greater resilience and recovery capability and greater photosynthesis capability, moreover they reach a greater water volume and capture more preys, then they have more available energy.

Another important advantage is represented by the fact that, contrary to the technologies currently used in the field for the culture of slow-growing corals such as the massive corals, the method, the present invention relates to, is effective in determining an acceleration in time of culture of precious corals regardless of the fusion mechanism between the selected fragments or the recruits.

Currently, in fact, it is believed that the only fusion mechanism exploitable for practical purposes for the culture of corals is represented by the isogenic fusion and that it is necessary to use only corals coming from the same “mother” since the fusion between different genotypes (or between different species) necessarily leads to tissue rejection, to the prevalence of one genotype over the other ones and often even to the death of the recessive genotypes. On the contrary, the method, the invention relates to, offers the potential of using even genotypes or different species to create precious corals with huge contrasts of colour and shades which in nature would be very rare or even impossible to find.

The author of the present invention in particular has found that the positioning of single recruits of precious corals, such as for example recruits adhered or attached to a substrate suitable for their growth and being not older than six months, on one support element in strict contact or at a minimum distance between adjacent recruits not higher than 5 mm, still more preferably equal to 0, allows to obtain the formation of new chimeras of precious coral starting from the fusion of the selected adjacent recruits.

Advantageously, the positioning of single recruits of precious coral being not older than six months according to the distances and geometries provided by the method according to the invention can be used even to increase the sizes of the resulting colonies which then can be used in subsequent culture cycles according to the method, the invention relates to. Such procedure allows to increase the seedbed performances. In fact, the use of n individuals per colony instead of only one increases the biomineralization (growth rate) and the captured amount of food (energy) of the colony by a factor approximately equal to n.

The method, the present invention relates to, is particularly versatile and can be implemented easily by using a great variety of solutions and devices known in the art or suitable for the culture and propagation of corals in open marine areas or areas in controlled environment, for example in tank or aquarium.

By virtues of the capability of guaranteeing the production of colonies of precious coral of the wished sizes in short time with respect to the methods known in the field and, in particular, colonies more resistant to transplants and with a greater reproductive capability, the method, the invention relates to, has an enormous potential for the development of projects for the active repopulation of the colonies of precious corals of the Corallidae family, which are currently limited indeed due to the numerous technical difficulties found in the culture of such species.

For example, the method, the invention relates to, would allow to modify suitably the usual techniques of coral gardening which up to now have not yet been successfully applied to the Corallidae, by means of a preliminary step of culture of the fragments of precious coral in an ex-situ fusion nursery to implement the fusions between the fragments before the usual culture step in a nursery and of the subsequent transplant step in the repopulation site. The preliminary step in fusion nursery would reduce the long periods of time required to the fragments to reach the ideal size for the transplants, thus reducing the culture period in the propagation nursery and allowing the production of colonies more resistant to the transplants.

Moreover, thanks to the greater reproductive capability of the large colonies, the fused corals obtained through the method of the invention could act as reproductive hub and increase the natural recovery of the currently overexploited coral populations.

The method for cultivating the precious corals by fusion devised by the author of the invention can be also particularly helpful to a field such as that of jewellery, currently in crisis due to the shortage of raw material. Advantageously, the method of the invention, in fact, can be used for the production of corals or gems having shapes and sizes which could not be implemented with natural corals.

Another possible application of the method, the invention relates to, concerns the tourism field, particularly active for years in the development of projects of active repopulation of colonies of precious coral. An example provides to propose to the owners of resorts with access to the sea, in particular in the Mediterranean, the implementation of programs for the active restoration of the precious corals which are based upon the implementation of the method, the present invention relates to, for example through the positioning of electrified metal sculptures (nurseries in-situ) in front of the beach to improve the snorkeling experience, as well as the implementation of ex-situ propagation nurseries to show live corals even to non-swimmers.

The advantage of this type of partnership would be mutual, in fact on one side it would strengthen the efforts of the environmental associations involving private stakeholders in the preservation; on the other side it would involve an advantage for tourism operators not only from a point of view of an image return but also because, from various research, it has emerged that the operators of the field are aware of the economic return potentially deriving from the opportunity of having available reef or natural barriers, reef or artificial barriers or reef or barriers of electronic type near the beach or how this could increase the number of tourists.

Therefore, the invention relates to a method for the production or the culture of precious corals or their colonies, their recruits, or their chimeras, comprising the following steps: a) providing at least two fragments or at least two recruits of pre-existing precious corals belonging to the Corallidae family; b) fixing said fragments or said recruits to at least one support element, in such a way that each one of said fragments or said recruits is at a minimum distance from at least a different one of said fragments or said recruits, comprised between 0 and 2 cm, preferably between 0 and 5 mm, still more preferably equal to 0, 1 , 2, or 3 mm; c) subjecting the fragments or the recruits fixed in step b) to culture in sea water at a temperature ranging from 2 to 30°C.

Additional important features of the method according to the invention are defined in the depending claims. Other advantages and features of the present invention will result evident from the following detailed description.

DETAILED DESCRIPTION OF THE INVENTION

GLOSSARY

The terms used in the present description are as generally understood by the person skilled in the art, unless otherwise indicated.

As used within the scope of the present invention, the term “precious corals” relates to corals or colonies of corals belonging to the family of the Corallidae, not reef builders and not provided with zooxanthellae, then capable of living in relatively deep water, since they feed by capturing plankton or by osmosis. The skeletons of the precious corals are constituted by a complex of calcium carbonate and proteins. Generally, the precious corals show an arborescent shape, they are long- lived organisms with low growth rates and low reproduction rates. In any point of the present description and claims, the expression “of precious corals belonging to the Corallidae family” can be replaced by the expression “of colonies of precious corals belonging to the Corallidae family”.

Under the expression “family of the Corallidae”, in the context of the present invention, a family of corals of the sub-order Scleraxonia, order of Alcyonacea, sub-class of Octocorallia, class of Anthozoa, phylum of the Cnidaria, is meant.

The term “red coral” is used in the context of the present invention as synonym of the species of precious coral Corallium rubrum or colonies thereof. Corallium rubrum is an octocoral belonging to the Corallidae family (Corallium genus), widespread in the Mediterranean Sea and in the eastern Atlantic. Corallium rubrum is the only species of the Corallium genus living in the Mediterranean, from Greece to Tunisia as far as the Strait of Gibraltar, Corsica, Sardinia, Sicily and Balearics included, but it is widespread even in the eastern Atlantic in Portugal, Canaries, Morocco and Cape Verde Islands, usually as far as 200 meters deep in poorly lit places with little vegetation. It preferably lives in shady and sheltered places (semi-dark caves, overhangs, cracks in the rocks), starting from the depth of 20/30 meters as far as 200 meters. Colonies of Corallium rubrum were also traced at depth of 600-700 m in the Sicily channel, as far as a maximum of 1061 m in the marine area of the Maltese Islands (Knittweis L. et al. 2016, 41^stCIESM Congress), but the populations of red corals at high depths remain poorly characterized at the moment.

Corallium rubrum is a very slow growing species. Studies on the growth rates demonstrated that the colonies grow on the average between 0.25 and 0.66 mm in basal diameter within a year. The scientific literature reports a period of time of approximately 30/35 years so that Corallium rubrum reaches a diameter at the base of 7 mm and even 75/100 years to reach important diameters of great commercial value.

Corallium rubrum forms branched colonies, which can exceed 20-30 cm in height, having generally bright red colour, but sometimes pink. Completely white albino colonies are rarely observed. Corallium rubrum polyps are white and transparent, with tentacles edged with pinnate appendages, visible when these are everted to capture food.

In the context of the present invention the terms “coral nursery’, “coral breeding ground”, ‘fusion nursery’, “propagation nursery’ are to be meant as synonyms and designate any device known in the field which is suitable for the culture of corals in seawater, in the sea or in a controlled environment, such as natural or artificial reservoir, a tank or aquarium.

Under the term “thermocline”, in the context of the present invention, the transition band or layer between the surface remixed layer and the deep-water layer in deep water bodies such as oceans or seas is meant. In the thermocline layer, extending for few meters, the temperature decreases quickly, according to a gradient even equal to 10 degrees, from the value assumed in the surface mixing layer to the one corresponding to the temperature of the deep water, which is relatively constant and generally keeps below 20 degrees even in summer.

In the context of the present invention, under the expression “fragments of pre-existing colonies of precious corals” or “fragments of pre-existing precious corals” (i) fragments or portions of colonies of live precious corals, or (ii) colonies of live precious corals, in particular colonies of live precious corals aged between 6 months and 4 years, preferably aged between 2 and 4 years, are meant.

In any point of the present description and claims the expressions “fragments of colonies of precious corals” or “fragments of precious corals” then can be replaced by:

(i) portions of precious corals or portions of colonies of precious corals, in particular portions of precious corals or portions of colonies of adult precious corals, and still more in particular apexes obtained by ramifications of precious corals or colonies of precious corals; or

(ii) colonies of precious corals, in particular colonies of precious corals aged between 6 months and 4 years, preferably aged between 2 and 4 years.

In a particular aspect, as it will be explained more in details hereinafter, said colonies di precious corals (ii) usable in a method according to any one of the variants described in the present one, are colonies with small sizes, where under “small sizes” an average length or average diameter comprised between 0 and 50 mm and/or an average thickness comprised between 0 mm and 5 mm are meant.

In any point of the present description and claims the term “adults” can be replaced by the expression “aged over 4 years”.

In any point of the present description and claims, the plural expression “of precious corals” can be replaced by the singular expression: “of precious coral”.

In the context of the present invention, with reference to a fragment of precious coral or fragment of colonies of precious coral in form of a portion or apex of said precious coral or a colony thereof, the term “length” shows the extension of the fragment along its maximum size, in particular the extension of the fragment along the longitudinal growth of the same. In particular, under the term “length”, the distance between the oldest end and the youngest end of the considered fragment is meant.

In the context of the present invention, with reference to a colony, fragment, recruit or chimera of precious coral, under the term “width” the size of the section at the base of the corals according to any direction passing through the centre or axis is meant. In the context of this invention the terms “section”, “width” and “diameter” are synonyms.

With reference to colonies of precious corals in discoidal shape or substantially discoidal shape according to any one of the variants mentioned in the present description and claims, the term “thickness” can even be replaced by the term “height” and it preferably relates to the thickness or height or length of the considered colony determined in the centre and along the axis of biomineralization of the same. In the context of the present invention the terms “thickness”, “height” and “length” are synonyms.

In the context of the present invention, the expressions “recruits of precious corals”, “coral recruits" and “recruitments" are used interchangeably and they are meant as comprising one or more specimens or individuals of precious coral according to any one of the herein described species which have completed the adhesion (i.e. settlement) or attachment process on a suitable adhesion or growth substrate and which have not yet started, or are going to start or have already started, the metamorphosis process, as well as any colony resulting from such process of adhesion and/or metamorphosis adhered or attached to said substrate and which is aged between 0 and 6 months.

As a person skilled in the art knows, the process of adhesion of a larva or planula of precious coral on a suitable adhesion or growth substrate is defined in the field even as “coral recruitment’. In the first weeks subsequent to the settlement or attachment on an adhesion substrate, a larva of precious coral adhered on the substrate performs the metamorphosis in polyp, after which, it begins to spread tissue on the substrate in order to consolidate the attachment.

In the context of the present invention, under the term “chimera” a colony deriving from the fusion of two or more recruits of precious coral is meant, with different genomes, adhered or attached to a suitable adhesion or growth substrate according to any one of the herein described embodiments, preferably in contact to each other, in particular before these have developed a system of allocognition (immune system) capable of rejecting tissues with a different genome.

According to an aspect of the invention, when the fragments or the recruits of precious coral according to any one of the variants described in the present application are fixed to at least one support element through one end or portion thereof, as it will be better illustrated in details hereinafter, the expression “minimum distance” between fragments or recruits relates to the distance measured between resting or fixing bases of the above-mentioned fragments or recruits to the support element.

In the context of the present invention and of claims, the expressions “adhesion substrate”, “growth substrate” or “substrate suitable to growth” are used interchangeably to designate any substrate known to a person skilled in the art which is capable of favouring the adhesion (i.e. settlement) of single larvae of precious corals so as to promote the subsequent metamorphosis and growth process thereof to form recruits of precious coral, including any type of seabed suitable to the settlement and growth of the corals.

In any point of the present description and claims, the expression “comprising” can be replaced by “consisting of”.

DETAILED DESCRIPTION

As mentioned, the present invention firstly relates to a method for the production or for the culture of precious corals or their colonies, their recruits or their chimeras, comprising the following steps: a) providing at least two fragments or at least two recruits of pre-existing precious corals belonging to the Corallidae family; b) fixing said fragments or said recruits to at least one support element, in such a way that each one of said fragments or said recruits is at a minimum distance from at least a different one of said fragments or said recruits comprised between 0 and 2 cm, preferably between 0 and 5 mm, and still more preferably equal to 0, 1 , 2, or 3 mm; c) subjecting the fragments or the recruits fixed in step b) to culture in sea water at a temperature ranging from 2 to 30°C, preferably ranging from 16 to 22°C.

The method, the invention relates to, according to any one of the embodiments illustrated in the present description and claims then allows to obtain the production or the culture of new precious corals or their colonies, their recruits or their chimeras starting from fragments, pre-existing colonies or recruits of precious corals.

In an aspect, the method, the invention relates to, according to any one of the embodiments illustrated in the present description and claims allows to obtain the production or the culture of new precious corals or their colonies starting from at least two fragments of pre-existing precious corals belonging to the Corallidae family.

In an additional aspect, the method, the invention relates to, according to any one of the embodiments illustrated in the present description and claims allows to obtain the production or the culture of new colonies of precious corals starting from at least two recruits of pre-existing precious corals belonging to the Corallidae family.

In an additional aspect, the method, the invention relates to, according to any one of the embodiments illustrated in the present description and claims allows to obtain the production or the culture of new chimeras of precious corals starting from at least two recruits of pre-existing precious corals belonging to the Corallidae family.

In a particular aspect, the method, the invention relates to, according to any one of the embodiments illustrated in the present description and claims allows to obtain the production of new precious corals or their colonies having predetermined sizes starting from fragments, pre-existing colonies or recruits of precious corals belonging to the Corallidae family, in periods of time significantly shorter than the periods of time which would be required in nature to obtain precious corals, their colonies or their recruits or chimeras having the same sizes starting from the above- mentioned fragments, colonies or recruits belonging to the Corallidae family.

In fact, as previously mentioned, the fixing of each fragment or recruit of precious coral selected in strict contact or at a minimum distance not higher than 2 cm with respect to at least a different one of said fragments or recruits, allows to favour the fusion between adjacent fragments or recruits, respectively, and then the formation of precious corals or their colonies even with big sizes, in much shorter periods of time than the periods of time reported in literature as required to obtain a coral or a colony of the same sizes starting from one single fragment or single recruit of the considered species.

In particular, the method, the invention relates to, according to any one of the variants illustrated in the present description allows to obtain the production of new colonies of precious coral having a diameter at the base, that is a diameter of the trunk, much larger than that a colony in nature being of equal height, equal order of ramifications and equal age, would have.

According to a preferred aspect, the method, the invention relates to, according to any one of the embodiments illustrated in the present description and claims allows to obtain the production of new precious corals or their colonies having predefined sizes, in a period of time equal or lower than two years, still more preferably equal or lower than one year, still more preferably comprised between 12 and 24 months, between 8 and 12 months, or between 4 and 8 months. Such periods of time can vary within the ranges mentioned in the present description depending upon the mutual distance between the fragments fixed on the support element.

According to an additional aspect, the method, the invention relates to, allows to obtain the production of new colonies of precious coral starting from pre-existing recruits of precious corals belonging to the Corallidae family, in a period of time equal to or lower than four years or two years, still more preferably equal to or lower than one year, still more preferably comprised between 12 and 24 months. Such periods of time can vary within the ranges mentioned in the present description depending upon the mutual distance between the individuals fixed on the support element.

According to an aspect, the fragments or the recruits selected to be used in a method according to any one of the herein described embodiments belong to the same species or are obtained from the same species of precious coral, from the same colony of precious coral or from different colonies of the same species of pre-existing precious coral.

According to an additional aspect, the fragments or the recruits selected to be used in a method according to any one of the herein described embodiments belong to different species or are obtained from different species of precious corals or pre-existing different colonies of different species of precious coral.

According to an additional aspect of the invention, said at least two fragments or said at least two recruits belong to one or are obtained from one same species of precious coral belonging to the Corallium genus or Pleurocorallium, in particular red coral or pink coral of the Corallium genus.

In an additional aspect, said at least two fragments or said at least two recruits belong to or are obtained from different species of precious coral belonging to the Corallium or Pleurocorallium genus, in particular red coral or pink coral of Corallium genus.

In a preferred embodiment, said at least two fragments or said at least two recruits belong to one or more species or are obtained from one or more colonies of precious corals selected among Corallium rubrum, Corallium japonicum, Pleurocorallium elatius, Pleurocorallium konjoi, Pleurocorallium secundum, Hemicorallium regale, Hemicorallium laauense, and Hemicorallium sulcatum. According to a preferred embodiment of the method according to the present invention, said plurality of fragments or recruits belongs to one or more species and it is obtained from one or more colonies of corals selected among the species shown in the following table 1:

In a preferred embodiment according to the present invention, the at least two fragments or at least two recruits are fragments of recruits of Corallium rubrum or are obtained from one or more colonies of Corallium rubrum.

In a particular aspect, the method, the invention relates to, according to any one of the herein described embodiments allows to obtain the production of chimeras of precious coral starting from at least two recruits belonging to the same species or different species of precious coral belonging to the Corallidae family, still more in particular belonging to the Corallium or Pleurocorallium genus.

Additional features of the fragments and of the recruits of precious coral usable in a method according to any one of the herein described embodiments are illustrated hereinafter.

Fragments of precious coral or of colonies of precious coral

According to an aspect of the invention, fragments suitable to be used in the method, the present invention relates to, are apexes of precious coral obtained from the ramifications of colonies according to any one of the herein described embodiments, that is apical portions or “tips” of twigs of precious coral.

The use of this type of the fragments is particularly advantageous since the “tips” or apical portions of the precious corals generally are too thin to be processed as gems and then they are mostly considered waste material in the field due to the low commercial value. In fact, GFCM commission suggests - although this is not an obligation - to discard these portions from the boat directly on site during the fishing procedures. The use of this type of the fragments then allows to avoid to collect portions of precious corals in nature.

According to an aspect of the invention, the apexes di precious coral used in the method according to any one of the embodiments described in the present application, have a substantially cylindrical shape; however, apexes of precious coral with any shape can be also used in a method according to any one of the embodiments described in the present one.

According to an aspect of the invention, the fragments used in the method of the invention are collected from precious corals or donor colonies of precious coral, preferably adults. Alternatively, the fragments, in turn, can be obtained from fragments of the above-mentioned colonies previously propagated in a coral propagation nursery, in situ and/or ex situ. The fragments which can be used in a method according to any one of the herein described embodiments preferably have a length at least equal to 0 or 0.5 cm.

According to a preferred aspect of the method according to any one of the herein described embodiments, each fragment selected has a length comprised between 2.5 and 5 cm, preferably between 1.5 and 3.5 cm, preferably equal to 2.5 cm.

As previously mentioned, fragments of precious coral usable in the method according to any one of the herein described embodiments can be portions of precious corals having various shapes, preferably having a substantially cylindrical shape.

Fragments suitable to be used in a method according to any one of the herein described embodiments are in particular portions of precious coral having any shape or diameter. In a preferred embodiment of the method according to the invention, the above-mentioned fragments are apical fragments with length comprised between 2.5 cm and 5 cm, collected from Corallium rubrum, having a section or average diameter equal to 2 mm.

According to an aspect of the invention, the step a) of a method according to any one of the herein described embodiments provides to chop off or cut the above-mentioned fragments starting from one or more colonies of precious coral belonging to the Corallidae family selected according to any one of the variants described in the present application.

The fragments can be cut or chopped off from one or more of the selected starting colonies of by using any one of the techniques known to a person skilled in the art, for example they can be chopped off by using shears or any cutting pliers conventionally used to this purpose in the field (e.g. wire cutters), provided that it has a fine and sharp blade. In order to speed up the collection of the fragments in the sea, the selected colony can be fragmented by using a coral ice axe or hammer; the so obtained fragments can be collected and trimmed with shears or other cutting means known in the field once on dry land.

According to an additional aspect of the invention, fragments suitable to be used in the method, the present invention relates to, are colonies of precious corals, in particular colonies of precious corals aged between 6 months and 4 years, preferably aged between 2 and 4 years.

Colonies of precious corals suitable to be used in a method according to any one of the herein described embodiments are in particular colonies of precious corals aged between 6 months and 4 years having adequate sizes to allow a detachment thereof from the adhesion or growth substrate and then to allow a fixing thereof on one support element according to any one of the modes illustrated in the present description.

Based upon the considered species of precious coral, a person skilled in the art will be able to identify without difficulty, based upon age, colonies of precious corals having sizes so as to allow an easy and safe detachment from the adhesion or growth substrate so as not to compromise the vitality thereof and then the subsequent fixing to at least one support element according to any one of the modes illustrated in the present application. A person skilled in the art will also be able to perform the detachment of the colonies of selected age from the adhesion or growth substrates in a delicate and precise way that is so as not to damage the corals.

In a preferred aspect, said fragments in form of colonies of precious corals are aged between

2 and 4 years. As a person skilled in the art knows, colonies of precious coral aged between 2 and

4 years, in fact, generally have optimum sizes, so as to allow the detachment thereof from the adhesion or growth substrate and then to allow a fixing on one support element according to any one of the modes illustrated in the present description.

In an aspect of the invention, said fragments in form of colonies of precious corals have an average width or average diameter comprised between 0.5 cm and 5 cm and/or an average thickness or length comprised between 2 mm and 5 mm.

Colonies of the above-mentioned sizes can be for example fractioned asexually starting from colonies of coral having larger sizes. Alternatively, fragments in form of colonies of precious corals suitable to be used in a method according to the present invention can be produced starting from at least two recruits of precious corals by using a method according to any one of the herein described embodiments, in particular according to what described in Example 3.

In an aspect of the present invention, said fragments in form of colonies of precious corals are chimeras of precious corals obtained or produced starting from at least two recruits of precious corals by using a method according to any one of the embodiments described in the present application.

In a particularly preferred aspect, said colonies di precious coral according to any one of the variants described in the present one have a discoidal or substantially discoidal shape, in particular preferably they have an average height or thickness at least equal to 2 mm, at least equal to 3 mm or at least equal to 5 mm and an average diameter comprised between 5 mm and 15 mm.

In fact, a person skilled in the art knows that when recruits of precious coral grow until forming colonies having a discoidal or substantially discoidal shape having an average thickness comprised between approximately 2 and 5 mm, such colonies can be removed more easily from the adhesion substrate without causing significative damages and then be fixed to at least one support element according to any one of the variants exemplified in the present description.

Still in a particular embodiment, said colonies of precious coral are colonies of Corallium rubrum aged between 2 and 4 years, having a discoidal or substantially discoidal shape and having a diameter comprised between 10 and 15 mm and a height or thickness comprised between 2 and

5 mm.

Fragments in form of colonies aged between 6 months and 4 years according to any one of the variants described in the present one can be collected directly in a selected marine site or can be produced starting from single recruits of precious coral previously propagated in a coral propagation nursery, in situ and/or ex situ.

In an aspect, these colonies can be produced starting from single recruits of precious coral adhered or attached on a suitable adhesion or growth substrate by performing a method according to any one of the embodiments described in the present application. In particular, each one of said colonies can be obtained by fixing two or more recruits, each recruit being in particular adhered on a suitable adhesion or growth substrate, on a suitable support element in such a way that each one of said recruits is at a minimum distance from at least a different one of said recruits comprised between 0 and 5 mm, more preferably comprised between 0 and 3 mm, still more preferably comprised between 0 and 1 mm.

Alternatively, the colonies of precious coral usable in the method of the invention can be obtained starting from recruits of precious coral by using any one of the conventional methods known to a person skilled in the art, for example by recruiting one or more larvae of precious coral on a suitable adhesion or growth substrate and by subjecting to culture the so-obtained recruits for the required period of time, under the most suitable growth conditions.

As it will be illustrated more in details in the subsequent section, larvae of precious coral can be recruited directly in a marine site or in an artificial tank, by exposing the larvae to at least a substrate capable of favouring the adhesion (or settlement) of the larvae. Examples of adhesion or growth substrates suitable to be used for the capture of larvae of precious coral include polyvinyl chloride (PVC), steel, glass, marble or any other material allowing the adhesion or attachment of larvae and which, preferably, has not macro-porosity which could compromise the possible subsequent detachment of the colonies. By pure way of example, it is possible using marble tiles having sizes equal to 30x30 mm or any other size. The process of settlement of larvae to the substrate is a stochastic process and the number of captured larvae is proportional to the offered surface. For this reason, it is preferable that the supports have the maximum possible surface, without this making their fixing to the seabed too complicated.

In case of capture of larvae in a tank, it is preferable that the sizes of the used supports are a submultiple of the surface of the tank bottom in such a way that this is wholly coated. A person skilled in the art will be surely able to size the supports based upon the used method of anchoring to the seabed or based upon the sizes of the tank.

Recruits of precious corals

As mentioned previously, according to the invention, recruits of precious coral suitable to be used in a method according to any one of the herein described embodiments, comprise or are represented by one or more specimens or individuals of precious coral according to any one of the herein described species, which have completed the adhesion (i.e. settlement) process on a suitable adhesion or growth substrate and they have not yet started, are going to start or have already started the metamorphosis process, as well as any colony resulting from such process of adhesion and/or metamorphosis adhered or attached on said substrate and which is no older than 6 months, preferably no older than 3 months, still more preferably no older than 1 month.

In a particular aspect of the invention, said recruits comprise, each one, at least a larva of precious coral according to any one of the species described in the present application, which has just completed the process of adhesion or attachment on a suitable adhesion or growth substrate and has not yet started or completed the process of metamorphosis in polyp.

In an additional aspect, said recruits comprise, each one, at least a larva of precious coral according to any one of the species described in the present application which is adhered or attached on said substrate and which has just completed the process of metamorphosis in polyp.

In an additional aspect, said recruits comprise, each one, at least a colony resulting from the adhesion (or settlement) of one or more larvae of precious coral on a suitable adhesion or growth substrate, as well as their subsequent metamorphosis and growth on the above-mentioned substrate, which colony is less than 6 months old.

As mentioned previously, said recruits can be obtained starting from the settlement of larvae of the same species of precious coral or from different species of precious coral according to any one of the variants described in the present one.

In an aspect, said recruits can be obtained starting from the capture of at least two larvae of precious coral, which capture can be performed according to any one of the methods known to a person skilled in the art such as those previously mentioned in the present description.

For example, the recruitment of the larvae can be performed by fixing a suitable adhesion substrate on the seabed through a water-resistant glue, for example a two-component resin or any other glue which could be used underwater, near reproductive populations of the selected coral species, for example Corallium rubrum. Alternatively, the capture of larvae can be performed by fixing the selected adhesion substrate to the seabed by mechanical anchoring or to a dead body sufficiently heavy to sink. The typical weight of the dead body is about 5 kg but this can be selected by a person skilled in the art based upon the features of the selected site, for example based upon the current and the type of the seabed. It is important that the weight is concentrated downwards to lower the centre of gravity and avoid that the dead body overturns during sinking.

In an additional aspect, the capture of larvae can be performed by introducing at least an adhesion substrate inside a suitable tank or system used for the growth and/or maintenance of the selected precious corals in which there are larvae of precious corals, so as to allow the adhesion or settlement of larvae on the substrate. This procedure is particularly advantageous since it allows to avoid the dispersion of larvae and it allows a greater check of the larval genomes. Moreover, the high density of larvae in the tank increases the number of recruitments per offered surface unit. A person skilled in the art will be able to select the system more adequate to culture or maintenance of selected species of precious coral, as well as calibrating amount and frequency in the coral supply based upon the available system tanks. By pure way of example, reproductive colonies of Corallium rubrum can be collected before the reproductive season and put in culture in a tank suitable to the production of larvae and containing supports suitable to the settlement of larvae. The most used solution to maintain the Corallium rubrum is generally represented by a double-circuit system, which works in a closed circuit for the 90 days subsequent to the production (i.e. spawn) of larvae and in an open circuit afterwards. The colonies can be fed with brine shrimp nauplii, homogenized algae and homogenized fish or crustaceans, whereas the circuit can be fed with filtered sea water refrigerated at 12-16°C.

In an additional aspect, the capture of larvae can be performed in the sea by using one or more suitable nets during the step of production of wild larvae of precious coral. The so-captured larvae can be transferred in a suitable maintenance tank and herein exposed to an adhesion substrate according to any one of the variants exemplified in the present one.

Alternatively, it is possible to use any other method, tool and material already known in the art such as, for example, marble tiles with a hole in the centre. For anchoring, a hole is perforated in the seabed by using an oil drill or other suitable tool depending upon the type of seabed and subsequently the bar is inserted in the hole and one cements with two-component epoxy resin or other fixing method known in the field. The tile is fixed to the bar by inserting it in the hole and in case it is fixed with a parker bolt or two-component epoxy resin.

In a particular aspect, each one of the at least two recruits of precious corals used in the method according to the present invention is then adhered or immobilized or attached to an adhesion or growth substrate, that is a substrate suitable for the adhesion and growth of the above-mentioned recruits.

In other terms, in a particular aspect, the single recruits used in the method according to the invention are adhered or attached, each one, to a respective substrate suitable for their growth. In step b) of a method according to the invention, each substrate, on which at least a selected recruit is adhered, attached or immobilized, then can be fixed to the support element in such a way that at least a recruit adhered, attached or immobilized thereon is at a minimum distance from at least one of the recruits which is adhered or attached on a different substrate, lower than 2 cm, preferably lower than 5 mm.

An aspect of the present invention in particular relates to a method for the production or for the culture of precious corals or colonies of precious corals, their recruits or their chimeras, starting from pre-existing recruits of precious corals belonging to the Corallidae family according to any one of the variants described in the present one, which method comprises the following steps: a’) providing at least two recruits of pre-existing precious corals belonging to the Corallidae family according to any one of the variants described in the present one, each one of which recruits is adhered or attached to an adhesion or growth substrate; b’) fixing each one of said adhesion or growth substrates to at least one support element, in such a way that each one or at least one of the recruits adhered or attached on each one of said substrates is at a minimum distance from at least one recruit adhered onto a different substrate, comprised between 0 and 5 mm; c) subjecting the substrates fixed in step b’) to culture in sea water at a temperature ranging from 2 to 30°C, preferably ranging from 16 to 22°C.

Recruits according to any one of the variants described in the present application, each one thereof is adhered or attached to a suitable adhesion or growth substrate, can be obtained or produced by exposing one or more larvae of precious coral to a suitable adhesion or growth substrate according to any one of the herein described variants, in case by subjecting to culture the above-mentioned recruits for the wished time period and, at last, by cutting the selected adhesion or growth substrate in such a way as to obtain a plurality of separate substrates on each one of which at least a recruit, preferably one single recruit, is adhered or attached.

Preferably, the adhesion or growth substrate, on which the recruits usable in a method according to any one of the embodiments described in the present application and claims, are adhered or attached comprises or consists of a material capable of being able to be cut with millimetre or sub-millimetre precision.

In a particular aspect, said adhesion or growth substrate comprises or consists of a plastic material, in particular a polymeric material. In a particularly preferred aspect, said adhesion or growth substrate comprises or consists of a thermoplastic polymer, preferably comprises or consists of polyvinyl chloride (PVC).

An additional aspect of the present invention then relates to a method for the production or for the culture of precious corals or colonies of precious corals, their recruits or their chimeras, starting from pre-existing recruits of precious corals belonging to the Corallidae family according to any one of the variants described in the present one, which method comprises the following steps: a’) causing at least two larvae of said pre-existing precious corals belonging to the Corallidae family according to any one of the variants described in the present one to adhere or to attach to an adhesion or growth substrate according to any one of the variants described in the present one, in such a way as to obtain said at least two recruits; b’) cutting said adhesion or growth substrate in such a way as to obtain a plurality of separate substrates on each one of which one of said recruits, preferably a single one of said recruits, is adhered or attached; b”) fixing each one of said plurality of substrates to at least one support element, in such a way that at least one of the recruits adhered or attached on each one of said substrates, and preferably each one of the recruits adhered or attached on each one of said substrates, is at a minimum distance from at least one recruit adhered onto a different substrate preferably comprised between 0 and 5 mm; c) subjecting the substrates fixed in step b”) to culture in sea water at a temperature ranging from 2 to 30°C, preferably ranging from 16 to 22°C.

In a preferred aspect, said step b’) is carried out in such a way as to obtain a plurality of separate substrates on each one of which only one of said recruits is adhered or attached.

It is preferred that the cutting of the adhesion or growth substrate is performed in such a way as to obtain a plurality of separate substrates with equal or different shapes, thicknesses or sizes, provided that each one thereof includes at least one of said recruits, preferably a single one of said recruits.

In particular, it is preferable that the cutting of the adhesion substrate is performed in such a way as to obtain a plurality of separate substrates each one thereof includes at least one of said recruits at a suitable distance from at least one of the perimeter edges of the so-cut substrate. Under

“suitable distance from at least one of the edges”, in particular, a distance is meant so as to allow, when the substrates are fixed to one support element according to any one of the herein described variants, that the recruits adhered or attached on separate adjacent substrates fixed in contact to each other, are placed at a minimum distance the one with respect to the other one, preferably comprised between 0 and 5 mm.

In other terms, the suitable distance from the perimeter edge can be determined in such a way that, when the substrates are fixed to the support element, the edges of the substrates result to be in strict contact to each other and the recruits thereon are at the chosen distance from each other. This allows to avoid the presence of slits between the substrates after their fixing.

In order to avoid the formation of steps or differences in level between separate substrates, it is preferable that they all have the same thickness and are subsequently fixed to the support element in such a way that at least one of the edges is in contact with that of another substrate.

In a preferred aspect, said step b”) is then performed in such a way that at least a perimeter edge of each one of said substrates is in contact with a perimeter edge of at least a different one of said substrates.

Each one of said substrates preferably has sizes so as to guarantee that the recruits adhered or attached on each one of them have sufficient space to become larger as far as diameter sizes of 1.5 cm, without reaching the edges which are not in contact with other substrates.

A person skilled in the art will surely be able to size the substrates so that, once fixed to one support element, at least one of the recruits existing thereon results to be at the wished distance from at least another recruit and has sufficient space to grow without reaching the edges not in contact with other substrates, as it will be better explained hereinafter.

In case the edges of the substrates in contact with each other were not precise and slits remained due to the cutting irregularity, they can be possibly plastered by using the same glue used for fixing the substrates to the support element or other suitable material.

Before performing step b) of the method according to any one of the embodiments of the present invention, the fragments of precious coral, the recruits or the substrates on each one of which at least a recruit of precious coral according to any one of the herein described variants is adhered, attached or immobilized, are preferably kept in sea water at a temperature ranging from 16 to 22°C and they are not exposed to direct solar light.

In order to ease the subsequent manipulation thereof, the fragments or the recruits can be separated based upon the species and the provenance colony, for example they can be put in separate containers, which in turn can be grouped in a larger container, suitably filled in with refrigerated sea water.

It is preferred that all instruments used for the possible cutting, preparation or preservation of the fragments or the recruits of precious coral to be used in the method of the invention are suitably sterilized or disinfected, for example with 70% ethanol, as well as subjected to washing with fresh water, with the purpose of avoiding contamination of the fragments or of the selected recruits with unwished microorganisms. It is also advisable to use sterile gloves of surgical type to handle the fragments or the recruits of precious coral while performing any one of the steps of the method according to the invention.

According to an aspect of the present invention, the step a) of a method according to any one of the herein described embodiments plans to provide a plurality of fragments of recruits of colonies of precious corals belonging to the Corallidae family, or a plurality of adhesion substrates on each one of which at least a recruit of precious coral according to any one of the herein described variants is adhered, attached or immobilized.

In an additional aspect, the step a) of a method according to any one of the herein described embodiments provides to supply at least two fragments and at least two recruits of colonies of precious corals belonging to the Corallidae family according to any one of the previously described variants.

The fragments, the recruits or the substrates selected to be used in the method according to any one of the herein described embodiments, preferably comprise a number of fragments, recruits, or substrates comprised between 2 and 60, still more preferably at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 15, at least 20, at least 25, at least 30 fragments or recruits or substrates.

Based upon the wished sizes of the precious coral or its colony or its recruit resulting from the method, the invention relates to, that is based upon the sizes of the coral or its colony or its recruit resulting from the fusion of the fragments or recruits used in the method, the invention relates to, which one wishes to obtain, the person skilled in the art will be able to select a more suitable number of the fragments or recruits.

In case of fragments of substantially cylindrical shape, if one wants to obtain larger sizes than those obtainable in nature and then to use a very high number of fragments, the fusions can be performed many times to avoid excessive necrosis to the tissues of the central fragments and in order to minimize the possibility of anomalies in the density of the skeleton of the final colony. For example, firstly 4 fragments can be fixed to the vertices of a square; subsequently to fusions, additional 4 fragments can be added in the centre of the sides of the square to form an octagon, then additional 8 fragments can be added in the centre of the sides of the octagon, then additional 16 and so on.

Before being subjected to the fixing step b) provided by the method according to the present invention, the selected fragments or the recruits are preferably visually inspected, for example with the purpose of evaluating the presence of pathologies, possible necrosis of the tissues, as well as, if possible, to examine the vitality of polyps; then, such inspection is useful to discard not-vital fragments or recruits or those which do not have wished requirements.

As mentioned, in step b) of a method according to any one of the embodiments of the present invention, the fragments or the recruits provided in step a), or the adhesion substrates on each one of which at least one of the above-mentioned recruits is adhered, attached or immobilized, are fixed to at least one support element according to a precise geometry suitable to favour the fusion between adjacent fragments or recruits and then the formation of a resulting precious coral or its colony or recruit having the wished sizes.

Depending upon the selected type of fragments or recruits, the fusion between adjacent fragments or recruits placed at a minimum distance defined within any one of the limits specified in the present description and claims can take place according to different mechanisms, for example by isogenic, allogenic fusion, interspecies and/or chimerism.

In particular, the fusion between adjacent recruits placed at a minimum distance defined within any one of the limits specified in the present description and claims can take place by chimerism, leading to the formation of one or more chimeras of precious coral.

As previously mentioned, with the purpose of favouring the fusion between the fixed fragments or recruits it is important that each fragment or recruit, is fixed so as to be at a minimum distance from at least a different one of said fragments or recruits not higher than 2 cm, preferably not higher than 1 cm.

In a particularly preferred aspect, said minimum distance is comprised between 0 and 5 mm, for example is equal to 0, 1 mm, 2 mm, 3 mm o 5 mm.

In an aspect, the step b) of a method according to any one of the embodiments illustrated in the present description and claims comprises fixing a plurality of fragments or recruits provided in step a) to at least one support element, in such a way that each one of said fragments or recruits is at a minimum distance from at least a different one of said fragments or recruits, that is from at least a fragment or recruit adjacent thereto, comprised between 0 and 2 cm, between 0 and 1 cm, preferably between 0 and 5 mm, still more preferably equal to 0, 1 mm, 2 mm or 3 mm.

In a particular aspect, each substrate on which at least one recruit according to any one of the variants described in the present one results to be adhered, attached or immobilized, is fixed to the support element in such a way that each recruit is at a minimum distance from at least one recruit adhered or attached on a different one of said substrates not higher than 5 mm.

In a particular aspect, the step b) of a method according to any one of the embodiments illustrated in the present description and claims then comprises fixing a plurality of substrates provided in step a), on each one of which substrates at least one of said recruits of precious coral according to any one of the variants described in the present one is fixed, to at least one support element, in such a way that each one of the recruits adhered, immobilized or attached on each one of said substrates is at a minimum distance from at least one of the recruits adhered, immobilized or attached on a different substrate, comprised between 0 and 5 mm.

According to a preferred aspect of the invention, each fragment or recruit fixed to the support element has at least one point in contact with at least a fragment or recruit adjacent thereto and fixed to the support element. In other terms, according to a preferred aspect, each fragment or recruit fixed to the support element is positioned at a minimum distance equal to 0 mm from at least a fragment or recruit adjacent thereto.

According to an aspect of the invention, in step b) said fragments or recruits, in particular each one of said substrates on which said recruits are adhered, attached or immobilized, are fixed to a plurality of distinct support elements, provided that at least two fragments, recruits or substrates are fixed to each one support element.

One support element suitable to be used in a method according to any one of the embodiments, the present invention relates to, is any material known in the field which is suitable for the fixing or “attachment’ of corals or their recruits.

Support elements suitable to be used in step b) of a method according to any one of the herein described embodiments comprise supports made of a material selected from cement, ceramic, marble, travertine, plastics, in particular polyvinyl chloride (PVC), or any other material known in the field to allow fixing the fragments of precious coral or a combination of these materials.

According to a preferred embodiment, the support element or elements used in step b) of the method of the invention are implemented by mixing type 2 Portland cement with sand and fresh water, preferably in a ratio equal to about 1 :4:1. The obtained mixture is modelled in order to obtain the wished shape of the supports and the obtained shapes are left to air dry for least 24 hours.

According to an additional aspect of the invention, the support element or elements used in step b) of the method of the invention comprise or consist of one or more elements or surfaces of a sea bed suitable to fixing or settlement of corals such as, in particular, elements or surfaces selected among coralligenous rocks, carbonate rocks, skeletons of dead coral colonies or combination thereof. Elements or surfaces of a sea bed suitable to be used as support element according to the present invention, have abiotic conditions suitable to allow the growth of the precious corals.

The support element or elements used in step b) of the method according to the invention can have shapes and sizes variable depending upon the case needs, in particular depending upon the number of selected fragments or recruits and the type of nursery used for the culture step. A person skilled in the art will be able to select the shape and/or sizes of the support element or elements most suitable depending upon the number of the used fragments or the recruits, as well as based upon the wished final sizes of the resulting precious coral or colony or recruit and upon the used nursery type.

According to an aspect of the invention, the support element or elements used in step b) of the method according to any one of the herein described embodiments has a substantially discoidal shape. By pure way of example, the method according to the present invention can provide the use of one or more support elements in discoidal form having a diameter equal to 10 cm, also known in the field with the English term “cookies".

The fragments of recruits of precious coral, in particular the substrates on which the recruits according to any one of the herein described variants are adhered, attached or immobilized, can be fixed to the selected support element or elements by using suitable fixing means according to any one of the variants known to a person skilled in the art. Not limiting examples of fixing means suitable to be used in the method according to the present invention comprise glues or synthetic or natural glues, for example cyanoacrylate glue or epoxy resin, as well as any other adhesive or glue resistant in marine environment, threads, bands, suitable supports made of PVC or other material, or other fixing means of mechanical type. For fixing the fragments or the substrates to the support element it is preferable to use a two-component epoxy resin or a cyanoacrylate glue or other glue resistant in marine environment.

Alternatively, the fragments or the substrates on which said recruits according to any one of the herein described variants are adhered, attached or immobilized, can be fixed to the support element or elements by using the same support element or elements as fixing means.

In particular, according to an aspect of the method of the present invention, said at least one support element used in step b) consists of fishing thread or nylon thread or the same material used for fixing the fragments at the preferred mutual distance. In this case, the selected fragments can be bound to one another by using the same support element, i.e. the fishing thread, as fixing means, provided that each fragment results to be fixed at a minimum distance from at least a different one of said fragments comprised in any one of the ranges specified in the present description and in the claims. As it will also be illustrated in more details hereinafter, the fragments bound together with fishing thread can be hung on any device known in the field for the culture or propagation of corals in the sea, in tank or in aquarium (e.g. a tree-like propagation nursery), or fit between the meshes of one or more ropes commonly used in the field. Generally, the ropes have a braid-like structure; therefore, the fragments can be inserted between the meshes of the braid and locked in a predefined position due to the effect of the tension of the rope itself.

According to an aspect of the present invention, in step b) of a method according to any one of the herein described embodiments, each fragment is fixed to said at least one support element through an end thereof, preferably the end corresponding to the oldest portion of the fragment such as, for example, the end resulting from the cutting of the above-mentioned fragment starting from the tip or apex of a colony of precious corals; in such configuration, each fixed fragment then has a first end fixed to said at least one support element, that is a first end comprising a base for resting or fixing on the support element, and a second free end.

According to an aspect of the invention, in step b) of a method according to any one of the herein described embodiments, the selected fragments are fixed to said at least one support element in vertical position, in particular in such a way that the longitudinal development direction of the recruit or fragment is orthogonal to the surface of the support element. According to a preferred aspect, in step b) of a method according to any one of the herein described embodiments, the end of each fragment as it results from cutting or chopping off the fragment starting from said pre-existing colony of precious corals is fixed to said at least one support element in such a way that each fragment is in a vertical position.

In an additional aspect, when the method of the invention provides the use of fragments of precious coral in form of colonies having a discoidal shape, preferably colonies aged between 2 and 4 years, such as colonies having a diameter comprised between 5 and 15 mm and a thickness comprised between 2 and 5 mm, said colonies are fixed to said at least one support element in vertical position. In particular, said colonies are fixed in such a way that a portion of the perimeter edge of each colony is in contact with the support element. In such configuration, since the contact surface between the colony and the support element is very small, for fixing the colonies it is preferred to use a glue suitable to guarantee a suitable resistance of fixing on the support element, such as, for example, two-component resin or suitable supports made of PVC of other suitable material.

In an embodiment, the fragments or the recruits according to any one of the embodiments described in the present application are fixed to said at least one support element in such a way as to result in a substantially parallel position with respect to each other, in particular in such a way that the longitudinal development directions of each fragment result to be parallel to one another.

In an additional embodiment, the selected fragments can be fixed to said support element in such a way as to result to be stacked on top of each other, for example by using a fixing of mechanical type, such as sticks made of PVC fixed to the support element in vertical position.

According to an aspect of the invention, in step b) of a method according to any one of the herein described embodiments, the fragments or the selected recruits, in particular the substrates on which said recruits according to any one of the variants described in the present one are adhered, attached or immobilized, are fixed to said at least one support element so as to form a motif or pattern of the fragments or predefined recruits.

In other terms, the fragments or the recruits of precious coral, or the substrates on which said recruits according to any one of the herein described variants are adhered, attached or immobilized, can be fixed to the selected support element or elements so as to form a specific geometry. Such motif or geometry could be selected and predefined by the person skilled in the art depending upon the type of selected individuals, recruits, fragments or substrates as well as depending upon the final wished resulting shape of the precious coral or colony or recruit or chimera.

Preferably, the fixing pattern or geometry has a shape of line, stripe, beam, triangle, square or circle, in particular any shape suitable for the formation of plaques, such as plaques for cameos, or precious coral pellets, as well as other shapes of interest in the jewellery field.

By pure way of example, the recruits, the fragments or the substrates, on which said recruits are adhered or attached, can be fixed to each one support element in groups of 2 to form one line, in groups of 3 to form an equilateral triangle, or in groups of 4 to form a square.

According to a preferred aspect of the invention, the selected fragments are fixed so as to form one or more lines or one or more beams of the fragments; such arrangement is useful for the formation of plaques for cameos and/or precious coral pellets of interest for jewellery, whose final sizes could be varied based upon the number of the used fragments. By pure way of example, the fixing of 7 fragments of precious coral in line can allow to produce a cameo of approximately 4 cm along the major axis and 2.5 along the minor axis, whereas the fixing of 7 fragments in beams (6 like hexagon and a central one) can allow to produce 7/8 mm-wide pellets (distances between the fragments 1 mm). Still, the fixing of the fragments in form of colonies of precious coral having approximately 15 mm in diameter and 5 mm in height can allow to obtain small colonies of Corallium rubrum to implement 10-12 mm-wide pellets.

The fragments or the recruits can be fixed to the support element even so as to form shapes or patterns impossible to be found in corals present in nature, for example can be fixed so as to form corrugated plaques, letters, numbers and other fantasy shapes.

As previously mentioned, each pattern or specific geometry of the fragments or recruits fixed to the support element can be implemented by using fragments or recruits coming from the same colony (isogenic fusion) or fragments or recruits coming from the same species but different colonies (allogenic fusion) or from fragments or recruits belonging to different species (interspecific fusion), or from recruits aged less than 6 months coming from the same species but from different colonies

(chimerism).

The step c) of a method according to any one of the herein described embodiments provides that the fragments or the recruits, in particular the substrates on which said recruits according to any one of the herein described variants are adhered, attached or immobilized, suitably fixed to the element or several support elements according to the specific geometry devised by the author of the present invention, are transferred in sea water and here subjected to culture for a period of time sufficient to favour the fusion between adjacent fragments or recruits and then the formation of a resulting precious coral or colony or recruit or chimera having the wished shape and sizes, in particular the wished diameter.

Optionally, with the purpose of allowing to immobilize or to hook the support element or elements used in step b) to a device suitable for culture/propagation of the fragments in a marine area and/or in controlled environment, as it will be illustrated hereinafter, such support element or elements can be suitably perforated or can be provided with hooking means of mechanical type.

Alternatively, any fixing support or method known in the field can be used. By way of example, the fragments or the recruits can be even directly fit in a small tube made of PVC, subsequently fitted between the meshes of a plastic net, or the fragments or the recruits can even be glued to gardening stakes, which can be fit in a plastic net.

The use of mechanical hooks is particularly convenient in case of excessive fouling and massive presence of microalgae such as, for example, in a fish farming system during the summer months. In fact, the supports hooked to the nursery in mechanical way, usually, can be removed easily from the nursery, shaken in order to clean up the colonies from fouling and then placed again on the nursery. Alternatively, it is possible to move water with hands or one can use a lance which uses compressed air of the cylinders to produce a water flow.

Preferably, in order to allow to identify the samples subjected to culture, to keep tract of the selected fixing geometry, of the fusion type and/or of the culture start date, as well as any other piece of information of potential interest relating the coral species used in the method of the invention, a numbered tag, for example a metal tag, can be applied to each support element used in step b).

According to an aspect of the invention, before performing step c) of the method according to any one of the herein described embodiments, the fragments or the recruits suitably fixed in step b) are transferred in sea water, preferably in a “quarantine” or “accumulation” tank and herein kept under controlled conditions, preferably at a temperature ranging from 2°C to 30°C, preferably ranging from 16°C to 20°C and for a period of time comprised between 7 and 30 days, preferably at least 30 days. Such period is sufficient to reduce drastically the possibility of subsequent epidemics in the nurseries. Such procedure is useful to allow to better evaluate the conditions and vitality of the selected fragments or recruits and to accumulate a suitable number of the fragments or recruits before positioning the same in a suitable culture environment, for example in an open marine area, so as to reduce, in the last case, even the number of dives required for the correct positioning of the fragments or of recruits in the selected culture area. Where necessary, it is possible even to perform

targeted therapies or to use disinfectants of the type used for the ornamental aquariums with the modes and concentrations shown by the manufacturer.

The sea water used in step c) for the culture of the fragments or the recruits of colonies of precious coral according to any one of the herein described embodiments can be artificial sea water or natural sea water, preferably it is natural sea water.

According to an aspect of the invention, the step c) of a method according to any one of the herein described embodiments comprises the transfer of said plurality of fragments or recruits fixed to said at least one support element in a host environment selected from: an open marine area; and/or a controlled marine environment chosen from a natural or artificial basin, for example a fish farming system or a protected marine area, a tank, for example an on-shore tank, or an aquarium.

According to a preferred aspect of the invention, the step c) of a method according to any one of the herein described embodiments comprises at least the following steps: c’) subjecting the fragments or recruits fixed in step b) to culture in sea water in a controlled marine environment chosen from a natural or artificial basin, a tank or an aquarium, at a temperature ranging from 2°C to 30°C, preferably from 16°C to 22°C, until obtaining the fusion of the fragments or of the recruits; and c”) transferring the above-mentioned fused fragments or recruits in an open marine area.

According to an aspect of the invention, in case of transfer of the fragments or of the recruits in open marine area, said at least one support element and then the fragments or recruits fixed thereto, optionally by the help of a suitable culture device, as it will be illustrated hereinafter, these are positioned at a marine depth located below the summer thermocline layer of the selected area.

Preferably, in open marine area the fragments or recruits are positioned at a depth ranging from 15 to 100 m. This is important in order to guarantee that the fragments of recruits of precious coral are exposed to an almost constant temperature comprised in a range between 2°C and 30°C, during the whole culture or propagation step. Depending upon the provenance precious coral species of the selected fragments or recruits, the person skilled in the art will be able to identify the most suitable temperature range thereto the fragments or recruits are to be subjected during the step di culture c) and, in case of culture in the sea, determining the sea depth thereat the fragments or recruits fixed are to be fixed so that they could be subjected to the wished temperature. By pure way of example, fragments of Corallium rubrum will be preferably subjected to a temperature comprised in the range between 16°C and 22°C, whereas fragments of hemicorallium laauense, which typically lives at huge depths, will be preferably subjected to temperature ranging from 5°C to 12°C.

In order to make that the fragments of recruits of corals subjected to the culture step c) in the sea are exposed to a suitable temperature within the range as specified in the present description and claims, the position, that is the depth thereat said at least one support element and then the fragments or recruits fixed thereto are positioned, can be modified during the year based upon the variations in the seasonal thermocline in the selected marine area.

By pure way of example, for the Corallium rubrum the fragments or recruits fixed to said at least one support element can be positioned at a depth equal to 18 metres in the winter period and subsequently positioned at 40 metres in the summer period in the selected marine area.

The depth of 40 m further represents the safety limit for the non-professional air diving and then it is a depth quite safe for professional divers, which can be reached without using mix of gases nor decompression stages.

Alternatively, and in particular in case of precious coral species which live exclusively at huge depth (aphotic band), it is possible to position the nurseries at a depth comprised in the bathymetric band populated by the used species and to recover them at culture end. In this case, the corals should be preferably assembled on the nurseries before their diving according to the already- described modes and moreover the nurseries should be preferably provided with a device which could be hooked for the recovery of the same such as, for example, a metal ring or any other device known in the field.

The depth buoys used to guarantee to the nurseries a positive attitude should be so as not to implode at the selected depth. On the market there are several materials, volumes and resistance and a person skilled in the art will be able to choose based upon the technical specifications of the manufacturer and the operating depth of the nursery.

Since the Corallidae feed on suspension (suspension feeders) carried by the sea current, this parameter represents an important factor for the culture of such species.

In case of transfer/culture in open marine area, it is then preferred that the fragments or recruits fixed to said at least one support element are placed in an area exposed to a sufficiently strong current, that is suitable to guarantee a sufficient supply of nutrients, aspect which a person skilled in the art will be able to evaluate based upon the species and the selected marine area.

In case of transfer/culture of the fragments or recruits in a controlled marine environment, for example an artificial or natural basin, in tank or in aquarium, it is preferred that a flow of sea water is made to flow, in such environment, in such a way that said flow laps the support element or elements thereto the fragments or recruits and/or the fragments or the recruits themselves are fixed.

According to an aspect of the invention, food substances for the growth can be added to said flow, for example small planktonic living organisms, not-living particulate, dissolved organic substances or a combination thereof.

The sea water used in step c) for the culture of the fragments or the recruits of precious coral according to any one of the herein described embodiments preferably has a constant salinity, in particular comprised between 28%o and 40%o, variable in relation to the considered precious coral species. Based upon the selected different species of precious corals, the person skilled in the art will be able to identify the most suitable salinity ranges.

As mentioned previously, in an aspect of the invention, the step c) of a method according to any one of the herein described embodiments comprises the transfer of said plurality of fragments or recruits fixed to said at least one support element in a controlled marine environment represented by a fish farming system. The positioning of a fish farming system is particularly advantageous since it allows to exploit the nutrient enrichment produced by the organic residues of the farming to increase the speed in biomineralization of the colonies.

According to an aspect of the invention, in step c) of a method according to any one of the herein described embodiments said at least one support element is fixed to or is positioned in a device suitable for the culture of corals in the sea and/or in sea water.

According to an additional aspect, the support element or elements used in step c) of the method according to the invention can be fixed inside one or more containers (known in the art under the term “trays”), suitable to be fixed to or positioned in the selected culture device.

For fixing the support elements to a tray or directly to the selected culture device, as well as for the possible fixing of the same tray to the selected device, conventional fixing means known in the field, such as fishing threads, plastic bands or mechanical fixing means, can be used, by paying attention, in case of sea culture, to remove the possible exceeding portions of such fixing means to avoid the accumulation of algae.

The devices usable in step c) of a method according to any one of the herein described embodiments for the culture of the fragments or recruits fixed in the sea and/or in water sea can include any device suitable to the culture or propagation of corals.

Devices particularly suitable for the culture of corals in the sea and/or sea water include devices known in the field as “coral nurseries" or nurseries of corals. Not limiting examples of such devices include different types of nurseries, such as floating nurseries, fixed nurseries, electric or electrified nurseries, string nurseries and/or anti-predator nurseries.

Depending upon the host environment selected for the culture of the fragments or recruits, as well as upon the specific needs, funds and available equipment, the person skilled in the art will be able to identify the type of device or nursery most suitable to be used for the culture in sea water of the specific type of coral fragments used in the method of the invention.

According to a preferred aspect of the invention, in step c) of a method according to any one of the herein described embodiments, said at least one support element is fixed to a floating mininursery and the culture of the coral fragments or recruits is performed in an open marine area. Said floating mini-nursery represents a very cheap and practical device, which can be assembled on the ground, requiring a little maintenance and it allows to reduce considerably the problem of accumulation of algae and debris. This type of nursery can even be easily raised at a more comfortable working depth and then brought back to the selected culture depth. This simplifies considerably the work to be performed in water and makes it particularly suitable to be installed at high depths, where the dives have a short useful time and are more dangerous.

Preferably, the floating mini-nursery is anchored to the seabed and comprises a pallet with substantially rectangular shape, in particular made of plastic and having sizes equal to 120x100 cm, at which angles buoyancy buoys are fixed, suitable to keep it suspended at a predefined distance from the bed. When in use, the pallet of the fusion mini-nursery has an upper face directed towards the surface of the water body and an inferior face directed towards the bed.

The support element or elements are preferably fixed to the upper surface and/or to the lower surface of the nursery pallet. The configuration which provides the fixing of the support element or elements to the lower face of the pallet, provides that the fragments fixed thereto result to be positioned “upside down”, in this way allowing to simulate the preferred growth conditions of the precious corals, such as Corallium rubrum, which grow on cave ceilings and under rock cornices where sedimentation is absent.

According to an aspect of the invention, the method according to any one of the herein described embodiments further comprises at least a step of inspecting the fragments or the recruits fixed to said at least one support element subjected to culture in step c).

The inspection is preferably performed at regular time intervals, for example weekly or monthly. This is useful in order to monitor the culture progress but also in order to perform cleaning of the fragments or of the recruits, of the support elements or of the possibly used devices.

The visual inspections, in fact, allow to evaluate the state of the corals, the progress of fusions and the structural seal of the possibly used devices. This allows to remove possible corals which have signs of necrosis or lesions of tissues, pathologies, etc. with the purpose of avoiding the spreading thereof.

The inspections are further useful to perform procedures of cleaning from algae and sediments, the removal of encrustations and possible predatory sponges or their larvae, for the extraordinary maintenance in case of structural failures of the used culture devices as well as to correct the asset of the above-mentioned devices. As the corals and the accumulation of algae and debris grow, the floating of a nursery can change and for long culture periods this makes necessary to correct the asset thereof.

By way of example, for cleaning algae and debris a soft bristle brush or a toothbrush can be used, whereas in order to remove sponges and encrustations a knife or alternatively any other tool known in the art can be used.

In order to ease the procedures of inspection and/or cleaning in the cases wherein the culture step c) is performed in the sea at a relevant depth, e.g. at 40 m, it is generally advisable to transport the fragments or the recruits fixed to said at least one support element, or the possibly used culture device, at a lower working depth, e.g. 9 m.

The step c) of a method according to any one of the embodiments as described in the present description or claims ha preferably a duration not higher than 4 years, preferably not higher than 2 years, still preferably comprised between 1 and 2 years, still more preferably comprised between 4 and 8 months.

An additional aspect of the present invention is represented by precious corals or their colonies or their recruits or their chimeras which can be obtained by means of a method according to any one of the herein described embodiments.

Examples are reported herebelow, having the purpose of better illustrating the methods illustrated in the present description, such examples in no way have to be considered as a limitation of the preceding description and of the subsequent claims.

EXAMPLES

Example 1 - Culture of fragments of Corallium rubrum by fusion

A method was devised, for the culture of fragments of Corallium rubrum in the sea comprising the materials and the steps shown hereinafter.

1) Preparation of the coral fragments As starting material fragments of Corallium rubrum of 2.5-5 cm were used.

The fragments were found by licensed professional fishermen. Fishermen usually “clean” the fished corals of the “tips”, that is the apical portions of the twigs which are too thin to be worked as gems. This because the tips have a very low commercial value, but affect the daily/annual quota of catch. It is waste material which currently GFCM recommends, but does not oblige, to throw from the boat on site.

They are then “fragments of opportunity’ which avoid the collection of fragments directly in nature.

The selected fragments were kept in sea water at the temperature of 16-22 Celsius degrees and they were separated based upon the provenience colony in order to not confuse them. In order to keep them separated, containers made of perforated plastics were used (i.e. moulds) commonly used for the cheese processing. The moulds were immersed in a bigger container filled up with refrigerated sea water through instant ice packs, by paying attention to not expose the container to direct solar light.

For the cutting of the fragments bonsai shears were used.

All used material was at first disinfected with 70% ethanol and rinsed abundantly with fresh water. In order to handle the fragments, sterile gloves of surgical type were used.

2) Fixing of the fragments to support elements

The selected fragments of Corallium rubrum were fixed on disks having diameter of 10 cm (cookies) provided with 4 holes for the subsequent fixing of the same to a fusion nursery.

The cookies were made of type II Portland cement, river sand and fresh water (1 :4:1 approximately) and made to dry up for more than 24 hours.

A numbered metal tag was applied to the supports, in order to keep track of the fixing geometry, of the fusion type and of the culture start date.

In order to perform the fixing to the support, each “cutting” of the fragment was suitably dried up with a clean cotton cloth and then glued to the support with cyanoacrylate glue.

Even in this step the fragments were handled with sterile gloves. The fragments were inspected visually carefully to evaluate the presence of pathologies, necrosis of the tissues and possibly the vitality of the polyps. In case they were discarded.

The fragments were fixed on each support in groups of 2 (line), 3 (equilateral triangle) and 4 (square), spaced apart by 0 mm, 1 mm, or 2 mm, with 3 repetitions for each configuration.

Also groups of 7 fragments in line (0 and 1 mm) and 7 beam fragments (0 and 1 mm) to implement cameos and pellets having big sizes, with 3 repetitions for each configuration, were implemented.

Each configuration was implemented both by using fragments coming from the same colony (isogenic fusion) and fragments coming from different colonies (allogenic fusion).

At last, 30 single fragments were used as reference (10 for each one of the used nurseries). The 3 repetitions of each configuration were fixed on 3 different nurseries.

Once the fragments are fixed to the cookies, they are kept in refrigerated sea water at 16-22 degrees until positioning on the fusion nursery.

In order to simplify the procedures in the sea, the single cookies were fixed in the boat on trays of 4x4 (30x50 cm) plasticized electro-welded net trays and these then were fixed to the fusion nurseries. Alternatively, for the trays plasticized nets with different meshes (not too small, otherwise the accumulation of algae is excessive) can be used and made of different materials or the cookies can even be fixed directly to the nursery.

For the fixing, 2.5 mm plastic bands were used, by paying attention to remove the exceeding portions in order to avoid accumulation of algae. Alternatively, bands having different sizes, fishing threads, mechanical fixing, etc. can be used.

3) Culture in the sea of the fragments by means of floating fusion nursery

The culture by fusion of the selected fragments was performed in the sea by means of three mini-nurseries floating for the cultivation in the sea. It is a very cheap solution (100 euro of material), practical, which can be assembled on the ground, requiring a little maintenance and which reduced considerably the problem of the predators, of epidemics and of the accumulation of algae and debris. In case, it can be even easily raised at a more comfortable working depth and then brought back to the culture depth. This reduces considerably the work to be performed in water and makes it particularly suitable to be installed at high depths, where dives have a short useful time and are more dangerous.

Each nursery consists of a plastic pallet (120x100 cm) at whose angles are fixed 4 1 -liter buoyancy buoy are fixed and it is anchored to the bottom with a cement weight of 50 kg.

Usually, the cookies are positioned on the upper surface of the nursery but the corallium rubrum tends to grow upside-down on cave ceilings and under rock cornices where sedimentation is absent. Then, one of the three nurseries used in the study was implemented by using a box pallet assembled backwards to simulate a cave. The coral fragments were hung upside-down considering that this position gave good results in a test on the direct transplants. Such configuration, apart from simulating the “preferred” position of the corallium rubrum, further avoids the deposition of sediments and the perforated edges of the box protect the corals while allowing the water flowing.

Alternatively, different sizes, different materials, different anchoring to the bottom and all types of nursery, known or suitable for the propagation of the corals (floating, fixed, electric, anti- predatory, etc.) can be used, depending upon the site and the contingent needs of the project.

In the marine area selected for the experiment (Mediterranean Sea) the temperature of the surface layer in summer can exceed 26 degrees.

However, the corallium rubrum under experiment does not tolerate prolonged periods of temperatures higher than 22 degrees.

The nurseries were then positioned below the summer thermocline of the area (a band of few meters with a strong temperature gradient, even 10 degrees) below which the temperature is more constant and keeps under 20 degrees even in summer.

In past, this area was known as having a high summer thermocline (around 12 m) and in fact here the corallium thrived already as from 18/20 m.

However, over the last years, both fishermen and biologists report a deeper (35 m) or even absent thermocline which caused mass mortality events (MME) of gorgonia (close relatives of corals) and of corallium rubrum from 35 m upwards.

One nursery was kept at 40 m, one followed the seasonal thermocline and the fake cave was fixed at 18m and lowered at 40 m in summer. In fact, the coral in this area colonizes even the band above 35m but only in dimly lit caves or ravines.

Moreover, the depth of 40 m is the safety limit for non-professional air diving and then a quite safe depth for professional divers, which can be reached without using mix of gases nor decompression.

Moreover, Corallidae feed on nutrients under suspension (suspension feeders) brought by the sea current. This means that for them the current is more important than the concentration of the nutrients (phytoplankton and nanoplankton).

In order to be sure of having the right biotic conditions a point was selected in which coral experts had documented the presence of colonies at the depth selected for the nurseries.

4) Preliminary results

The fixing of coral fragments at the selected distances favoured the fusion between adjacent fragments. With the first performed qualitative experiment, it was possible to observe a higher survival rate of the fused fragments than the single fragments used as reference.

Without wanting to be linked to the theory, this can be explained by considering that the growth speed and the survival rate of the corals seem to depend upon their sizes and upon the number of polyps rather than their age; then, the higher number of polyps and the larger sizes of the fused fragments with respect to the single fragments could explain this effect.

For the corals, as well as for other modular organisms, the sizes seem to be more important than age in many of their biological processes and often the sizes describe their dynamics better than age.

At the same age, the bigger corals have greater growth and probability of survival, greater reproductive capability (the corals reach sexual maturity at a determined size, not at a determined age), but even greater resilience and recovery capability and greater photosynthesis capability, moreover, they reach a greater water volume and capture more preys, then have more available energy.

Example 2 - Culture of colonies of Corallium rubrum by fusion A method for the culture by isogenic and allogenic fusion of fragments of Corallium rubrum consisting of recruits of 2/4 years with random genomes (random mothers) was devised, comprising the materials and steps shown hereinafter.

1) Recruitment of larvae and their culture in seedbed

By way of example, new colonies of Corallium rubrum were produced by fusion according to the method, the present patent application relates to, starting from recruits of 2/4-year old Corallium rubrum with almost random genomes.

The fact of using this type of recruits offer great advantages from the ecological point of view and in our opinion the recruitment of wild larvae on adhesion substrates is the most sustainable method of collecting and supplying the fragments to be used according to the method of our invention.

By way of example, alternatively, the recruits directly in wild marine environment can be collected, provided with natural substrate or generally they can be produced according to any method known to a person skilled in the art.

As already mentioned, the preferred method is to collect adult wild colonies in order to make them to reproduce in a tank suitable to the purpose and wherein supports are immersed which allow the settlement of larvae. In this way all produced larvae have the same donor mother and then compatible genetic heritages for isogenic fusions which, as it is known, are more stable than the allogenic ones. Unfortunately, this technique requires a suitable system.

In the herein described case, by way of example, the larvae were captured in wild marine environment near surface populations of Corallium rubrum at the depth of 35/55 m and then they have a substantially random genetic heritage with sporadic isogenic pairs. Then, in the herein described case, the production di colonies by isogenic fusion is only sporadic.

By pure way of example, the recruitment of larvae was performed with 30x30 cm marble tiles, having 1cm of thickness, perforated in the centre. The tiles were anchored near reproductive patches of Corallium rubrum at a depth comprised between 35 and 55 mt through a 1-cm galvanized threaded rod with two-component resin. Alternatively, for the recruitment of larvae all methods known in the art can be used. The tiles were positioned in May/June and were removed in October/November, the recruits adhered to the capture substrates then are aged approximately between 0 and 6 months.

The substrates of recruitment with the adhered recruits were assembled on floating mininurseries of the type already described previously positioned near a farm fishing system at the operating depth of 25 mt on a seabed comprised between 35 and 40 m.

When the recruits reach the thickness sufficient for their detachment, they are removed from the recruitment substrate and they are ready to be cultivated by fusion. In the herein described example the culture in the seedbed lasted 2/4 years.

The productive cycle of the seedbed herein described by way of example lasts 2/4 years but this influences only the starting time of the seedbed since the larvae are collected on an annual basis and, by collecting larvae all years, after 4 years an annual production is obtained, which depends for the most part upon the total surface offered for the settlement of larvae.

2) Culture by fusion of the fragments of Corallium rubrum produced in seedbed according to the method, the present invention relates to.

2.1) Selection and fixing of the recruits to one support element

As starting fragments of culture by fusion according to our method used colonies of Corallium rubrum of discoidal shape were used, aged between 2 and 4 years, having approximately 5-15 mm of diameter and 2-5 mm of height or thickness (determined at the centre of the base). Alternatively, fragments of precious coral of younger age can be used, provided that they have the sizes sufficient to be able to be detached from the used growth substrate. Fragments of older age can also be used, but this lengthens the duration of the culture in the seedbed.

By pure way of example, the colonies were fixed on squared travertine supports with sizes equal to 10 x 10 cm and thickness equal to 0.5 cm. Shape and sizes of the support elements were selected to optimize the space on the nurseries. The selected colonies were fixed on each support element in vertical position, in rows of 4 with parallel bases, at a mutual distance lower than one millimetre and more preferably equal to 0. In particular, the edge of each fragment with discoidal shape was fixed to the support element by using two-component resin. Even one single recruit was fixed to each support as reference.

Alternatively, other geometries can be used provided that the distance between adjacent fragments is lower than 5 mm and preferably lower than 1 mm, still more preferably equal to 0. For example, it is possible to stack the fragments of discoidal shape on top of each other (like voltaic pile) by using a mechanical fixing consisting of 4 sticks made of pvc fixed to the support vertically to form a square whose diagonal is slightly smaller than the diameter of the colonies.

2.2) Culture by allogenic fusion in floating nurseries

The so-fixed colonies are subjected to culture in sea water assembled on the same nurseries previously used for the seedbed according to the modes already described previously. The resulting colony has the shape of a cylinder with the irregular lateral surface. For colonies fixed in strict contact, the expected duration of the culture period is 18/24 months, that is sufficient so that the minimum diameter of the cylinder reaches the wished size. The final product is represented by small colonies of Corallium rubrum, which allow to implement one single pellet with sizes comprised between 8 mm and 15 mm. 15 mm represents the maximum limit obtainable by pellets produced according to this particular embodiment.

Example 3: Production of chimeras or recruits of big sizes to be used for the production di precious corals according to the method the present invention relates to.

A method was devised for the culture of chimeras or recruits of precious coral with big sizes produced by chimerism or by isogenic fusion starting from recruits of corallium rubrum with less than 6 months of age, more preferably less than 3 months of age and still more preferably less than 1 month of age.

The fact of replacing the supports with monthly, quarterly or semi-annually frequency guarantees that the captured recruitments are all quite young to be able to chimerize.

The sizes of such recruits are near zero and the recruit is little more than a punctiform encrustation.

1) Recruitment of larvae Recruits of precious coral being aged less than 6 months are too thin to be detached from the adhesion substrate and then for the recruitment of larvae it is necessary to use a substrate which could be then cut with millimetric or sub-millimetric precision so as to use in the devised method the recruits adhered to their recruitment substrate.

For example, a sheet of PVC having 1 mm of thickness and sizes 30x30 cm can be used. Alternatively, different sizes, different thickness or different material can be used provided that the used material is useful for the attachment or the settlement of the corals and that then it can be cut with millimetric or sub-millimetric precision, for example glass, steel, marble, etc.

The sheet made of PVC is glued to a stiff support perforated in the centre by applying a glue resistant in marine environment; it is preferred that the glue is applied only near the edge of the sheet and of the hole in such a way that this could be then removed more easily from the stiff support with a cutter or other suitable tool.

As support it is preferred to use 30x30 marble tiles, perforated at the centre. The recruitment substrate is fixed to the marble support through glue resistant in marine environment applied near the edge and the support hole.

The stiff support is not required, but it is practical and alternatively only PVC can be used, but with thickness greater than 1 mm or any other type of support allowing the recruitment of corals and which can be cut with millimetric precision.

The recruitment of larvae was performed in natural marine environment near surface patches of corallium rubrum at a depth of approximately 35-55 m. The collected larvae then have a substantially random genome. Alternatively, in order to recruit the larvae, the spawn in tank is to be preferred since it allows to produce recruits with one single mother of provenance, but all the techniques known in the field are good to favour the settlement of the larvae.

2) Production of recruits or chimeras

Once collected the stiff support on which the adhesion substrate is constrained, whereon the larvae are adhered or attached, the substrate made of PVC is removed from the stiff support and it is cut into smaller portions, each one comprising at least one recruit, in particular at least one recruit at the right distance from one of the perimeter edges of the substrate. Under right distance from the edges, a distance is meant so that when the substrates containing one recruit are fixed on a support for the culture in nursery, each recruit is at a distance from at least another recruit less than 10 mm, more preferably less than 3 mm, still more preferably less than 1 mm or equal to 0.

By pure way of example, for the production di chimeras, the sheet made of PVC was cut so as to obtain 2x2 cm square portions with one recruit positioned less than 1mm from one of the edges and approximately 1cm from the adjacent edges; for the production of recruits having big sizes to be used in a method according to the Example 2, the sheet made of PVC was cut so as to obtain 2x2 cm square portions with one recruit positioned approximately 1.2 and 3 mm from one of the edges and approximately 1 cm from the adjacent edges.

The portions of PVC obtained as described previously were fixed on a suitable support in pairs of 2 or 4 per square by putting in strict contact the edges of the single substrates near the recruit present on the single portion, by making attention that no steps or slits remain between the portions of PVC; the latter are in case plastered with the same glue used for fixing the substrates to the support or with other suitable material.

The shape, sizes and the material used as support for fixing the portions made of PVC are not relevant in this Example. By way of example, we used 10x10 cm travertine tiles with 4 holes for fixing to the fusion nursery through plastic bands. Alternatively, all variants already described previously or those already known in the field can be used.

The supports were then put in culture on fusion nurseries.

As fusion nursery, floating mini-nurseries as those already described previously were used, positioned in a fish farming system with the modes already described previously. Alternatively, all variants known in the art and those already described previously can be used.

Since our recruits have an almost random genotype, our pairs are almost all allogenic (different mother colonies) with sporadic isogenic pairs (equal mother colonies).

The isogenic fusions produce new recruits of corallium rubrum, but with greater sizes and number of polyps, whereas the allogenic fusions produce chimeras of corallium rubrum. The duration of the culture in fusion nursery preceding the use of the recruits for the culture with the method of our invention is 4 years, preferably comprised between 2 and 3 years.

Alternatively, by taking into account that the isogenic fusions and chimerism lead to stable colonies, the recruits produced according to the method by fusion described herein can be kept in culture for much longer periods, even more than 10 years to be then transplanted or used as starting fragments for our method or for commercial purposes.

The fragments and the chimeras produced in this way are constituted by 2 recruits or 4 recruits fused to each other and they will have then greater sizes of the fragments produced in the seedbed described in Example 2 which, on the contrary, are constituted by one single recruit, as well as greater biomass and number of polyps. This allows to exceed the maximum limit of 1.5 cm of diameter in the seedbed described previously and generally increases the performances.

From what already known for the chimeras, this particular Example perhaps could be used to force the horizontal evolution of the precious and common corals through chimerism and, in its variants with known genotypes, perhaps even to guide it. In fact, it was then hypothesized that by chimerizing therebetween corals of any species selected for their particular resistance to the climatic changes (for example the corals survivors of mass mortality events or mass bleaching events) it is possible to further increase the resistance thereof. For the first time, a method is provided to force chimerism between recruits of precious coral starting from random genomes or genomes selected with great advantage for the project of repopulation of the corals.

Moreover, considering the presence in nature of hybrid species or interspecific hybrids of coral, it is possible to hypothesize the possibility of using this particular Example of the invention to force the interspecific chimerism that is to force the fusion between young recruits of different species through chimerism and then to produce interspecific hybrids of corals, in particular of precious corals.

Claims

1. A method for the production of precious corals or colonies of precious corals, their recruits or their chimeras, comprising the following steps: a) providing at least two fragments or at least two recruits of pre-existing precious corals belonging to the Corallidae family; b) fixing said fragments or said recruits to at least one support element, in such a way that each one of said fragments or said recruits is at a minimum distance from at least a different one of said fragments or said recruits comprised between 0 and 2 cm, preferably between 0 and 5 mm; c) subjecting the fragments or the recruits, fixed in step b) to culture in sea water at a temperature ranging from 2 to 30°C, preferably ranging from 16 to 22°C.

2. The method according to claim 1 , wherein said at least two fragments or said at least two recruits belong to one or more species of precious corals selected from Corallium rubrum, Corallium japonicum, Pleurocorallium elatius, Pleurocorallium konjoi, Pleurocorallium secundum, Hemicorallium regale, Hemicorallium laauense, and Hemicorallium sulcatum.

3. The method according to claim 1 or 2, wherein said at least two fragments or said at least two recruits belong to the same species or to different species of said precious corals belonging to the Corallidae family.

4. The method according to any one of claims 1 to 3, wherein said at least two fragments or said at least two recruits are fragments or recruits of Corallium rubrum.

5. The method according to any one of claims 1 a 4, wherein said at least two fragments are apexes of precious coral obtained from the ramifications of colonies of said precious corals.

6. The method according to the preceding claim, wherein each fragment has a length comprised between 0 and 10 cm, more preferably between 2.5 and 5 cm.

7. The method according to any one of claims 1 to 4, wherein said at least two fragments are colonies of precious corals belonging to the Corallidae family and have an age comprised between 0 and 10 years, more preferably between 6 months and 4 years, still more preferably an age comprised between 2 and 4 years.

8. The method according to any one of the preceding claims, wherein said at least two fragments are colonies of precious corals belonging to the Corallidae family and have a substantially discoidal shape.

9. The method according to the preceding claim, wherein said colonies have an average thickness comprised between 0 mm and 20 mm, more preferably between 2 and 5 mm and/or have an average diameter comprised between 0 and 20 mm and more preferably between 5 and 15 mm.

10. The method according to any one of claims 1 to 9, wherein said at least two fragments or said at least two recruits are fixed to said at least one support element in such a way as to result in a substantially parallel position with respect to each other.

11. The method according to any one of claims 1 to 10, wherein said at least two fragments are fixed to said at least one support element in such a way as to result to be stacked on top of each other.

12. The method according to any one of claims 1 to 11 , wherein said at least two recruits of precious corals belonging to the Corallidae family are less than 6 months old.

13. The method according to any one of claims 1 to 12, wherein each one of said at least two recruits of precious corals belonging to the Corallidae family is adhered or attached to an adhesion or growth substrate.

14. The method according to any one of claims 1 to 13, wherein said method comprises the following steps: a’) providing at least two recruits of pre-existing precious corals belonging to the Corallidae family, each one of which recruits is adhered or attached to an adhesion or growth substrate; b’) fixing each one of said adhesion or growth substrates to at least one support element, in such a way that at least one of the recruits adhered or attached onto each one of said substrates is at a minimum distance from at least one recruit adhered onto a different substrate, comprised between 0 and 5 mm; c) subjecting the substrates fixed in step b’) to culture in sea water at a temperature ranging from 2 to 30°C, preferably ranging from 16 to 22°C.

15. The method according to any one of claims 1 to 13, wherein said method comprises the following steps: a’) causing at least two larvae of said pre-existing precious corals belonging to the Corallidae family to adhere or attach to an adhesion or growth substrate in such a way as to obtain said at least two recruits; b’) cutting said adhesion or growth substrate in such a way as to obtain a plurality of separate substrates on each one of which at least one of said recruits is adhered or attached; b”) fixing each one of said plurality of substrates to at least one support element, in such a way that each one of the recruits adhered or attached on each one of said substrates is at a minimum distance from at least one recruit adhered onto a different substrate comprised between 0 and 5 mm; c) subjecting the substrates fixed in step b”) to culture in sea water at a temperature ranging from 2 to 30°C, preferably ranging from 16 to 22°C.

16. The method according to the preceding claim, wherein said step b”) is carried out in such a way that a perimeter edge of each one of said substrates is in contact with a perimeter edge of at least a different one of said substrates.

17. The method according to any one of claims 13 to 16, wherein said adhesion or growth substrate comprises or consists of a polymeric material, preferably polyvinyl chloride (PVC), still more preferably is a sheet comprising or consisting of PVC.

18. The method according to any one of claims 1 to 17, wherein said at least one support element is made of a material selected from concrete, ceramic, marble, plastic, or a combination thereof, or wherein said at least one support element consists of nylon thread, preferably wherein said at least one support element is made from type 2 Portland cement mixed with sand and water.

19. The method according to any one of claims 1 to 18, wherein said at least one support element comprises or consists of an element of a seabed, preferably selected from carbonate rocks, coralligenous rocks, skeletons of dead precious coral colonies or a combination thereof.

20. The method according to any one of claims 1 to 19, wherein said fragments or said recruits are fixed to said at least one support element so as to form a predefined pattern of fragments or recruits, in particular wherein said pattern has the shape of line, stripe, beam, triangle, square or circle.

21 . The method according to any one of claims 1 a 20, wherein said step a) comprises at least one step of chopping off pre-existing colonies of precious corals in order to obtain said at least two fragments.

22. The method according to any one of claims 1 to 21 , wherein said step c) comprises transferring said plurality of fragments or recruits fixed to said at least one support element in a host environment selected from: an open marine area; a controlled marine environment chosen from a natural or artificial basin, a tank or an aquarium.

23. The method according to the preceding claim, wherein, said at least one support element is positioned in said open marine area at a marine depth located below the summer thermocline layer of said area, preferably at a depth ranging from 15 to 2000 m, more preferably from 15 to 60 m.

24. The method according to any one of claims 1 to 23, wherein said at least one support element is fixed to a device suitable for the culture of corals in the sea or coral nursery.

25. The method according to any one of the preceding claims, wherein said at least two fragments are chimeras of precious corals belonging to the Corallidae family, which chimeras are produced from at least two recruits of precious corals by using a method as defined in any one of claims 1 to 24.

26. A method for the culture of precious corals or colonies of precious corals, their recruits or their chimeras, comprising the following steps: a) providing at least two fragments or at least two recruits of pre-existing precious corals belonging to the Corallidae family; b) fixing said fragments or said recruits to at least one support element, in such a way that each one of said fragments or said recruits, is at a minimum distance from at least a different one of said fragments or said recruits, comprised between 0 and 2 cm, preferably between 0 and 5 mm; c) subjecting the fragments or the recruits fixed in step b) to culture in sea water at a temperature ranging from 2 to 30°C, preferably comprised from 16 to 22°C.

27. The method according to the preceding claim, wherein said fragments or said recruits are as defined in a method according to any one of claims 1 to 25.

28. The method according to claims 26 or 27, comprising the steps of a method as defined in any one of claims 1 to 25.