WO2014160450A1

WO2014160450A1 - System and method for handling and conditioning breeders of benthonic and demersal fishes and for their reproduction and obtaining of viable eggs

Info

Publication number: WO2014160450A1
Application number: PCT/US2014/026659
Authority: WO
Inventors: Juan Manuel ESTRADAS ARIAS; Pablo Andres FERNANDEZ TREVIGNO; Miguel Andres PRADENAS GONZALEZ; Diego Miguel RAMIREZ CARCAMO
Original assignee: Universidad Andres Bello
Priority date: 2013-03-13
Filing date: 2014-03-13
Publication date: 2014-10-02
Also published as: CL2015002607A1

Abstract

The present invention is related to a system for handling and conditioning marine and brackish benthonic and demersal breeding fishes, allowing their reproduction and production of viable eggs in captivity, the system comprising at least one tank or farm unit, at least one shelter or farm subunit, at least one label system, and at least one subsystem for measuring, weighing, treating, controlling, and transferring the breeders; and a method of fish farming for benthonic and demersal breeding fishes, the method comprising the steps of (a) farming of breeders; and (b) reproduction, which comprises spawning and fertilization.

Description

SYSTEM AND METHOD FOR HANDLING AND CONDITIONING BREEDERS OF BENTHONIC AND DEMERSAL FISHES AND FOR THEIR REPRODUCTION AND OBTAINING OF VIABLE EGGS

This application is being filed on 13 March 2014, as a PCT International patent application and claims priority to U.S. Provisional Application Serial Number 61/780,956, filed March 13, 2013, the subject matter of which is incorporated by reference in its entirety.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of aquaculture of benthonic and demersal fishes. The invention includes a tank comprising one or more shelters for these types of fishes, and a fish farming method to reproduce benthonic and demersal fishes in captivity.

BACKGROUND OF THE INVENTION

The reproduction of captive marine and brackish fishes is a complex process that is often interrupted by various stressors that prevent the normal release of gametes and subsequent fertilization. This problem is very serious considering that, in the field of marine and brackish fish farming, it is preferred to cultivate those eggs that are naturally obtained and fertilized, as they generally have better subsequent development than the eggs that are obtained by hormonal induction and/or massage. The causes of stress in marine and brackish fishes are varied but generally high levels of overcrowding, environments very different from the usual environment of the species and high levels of environmental noise, combined with the frequent emergence of people generate a chronic stress in fishes which prevents their normal reproduction. Farming of benthonic and demersal fishes represents an interesting development option in aquaculture or fish farming, given the high international price these species reach in international markets. Benthonic and demersal fishes with commercial value for example are cods, hakes, haddocks, seabass, groupers, monkfishes, orange roughies, red snappers, wreckfishes, conger eels, turbots, halibuts, flounders, and soles.

Conger eels (Actinopterygii: Ophidiidae) are an important fishing resource in Chile, where at least three species of conger eel preferentially live: red conger {Genypterus chilensis), black conger (Genypterus maculatus) and gold conger {Genypterus blacodes). Gold conger (G. blacodes) also lives and is an important fishing resource in Argentina, New Zealand and Australia. Other species of interest are Genypterus brasiliensis in Brazil and Genypterus capensis in South Africa. Chong et al. (2006) mention that even though conger eels are important resources in artisan fishing, the knowledge on their biology is scarce.

Together with the scarce knowledge on conger eel biology, and its capture during the last decades, the offer of conger eels has been reduced and its price increased.

Chilean aquaculture current trend is culture diversification, mainly in endemic species. Red conger Genypterus chilensis (Guichenot, 1848) is a highly demanded native species in gastronomy owing to its high quality meat. G. chilensis fishing has diminished producing shortage during the last years, from captures of 1,700 t in 1994 to 619 t in 2008 and in contrary sense its demand has been increasing (Sernapesca, 2008). In Chile the market is for 3,000 t at a price higher than US$ 7 kg^"1 of meat.

G. chilensis is a benthonic anguiliform seawater fish with red coloured abdomen, free from scales, which allows using its leather in handcraft (Kong & Castro, 2002). It is a fish distributed in the Chilean-Peruvian coastline, of cold tempered waters that lives in rocky habitats between 20 to 550 m deep. It has night habits and a gregarious behaviour in similar number size groups. It reaches a maximum size of

150 cm long (Tascheri et al., 2003). They are carnivore, cannibal, the larvae feeds on zooplankton and adults feed mainly on crustacean (Pleuroncodes monodon), fish and molluscs (Chong et al., 2006). The specie is separated by gender, with the first sexual maturity of the female as they reach 60 cm, their fertilization is external, spawning nearly all year (Chong & Gonzalez, 2009). It spawns at night a gelatinous mass floating in coastal waters, with up to 285,000 eggs of 0.13 cm diameter. Incubation lasts 4 days at 15°C, hatching 0.5 cm long pelagic larvae that undergoes metamorphosis after 30 to 45 days, turning benthic in order to start migrating to deeper waters. The literature related to the biology of G. chilensis is scarce, for this reason it is necessary the experience in captivity to complement their knowledge. As well as there exist information of other Genypterus species, mainly G. blacodes, G. maculatus and G. capensis that complement the knowledge of G. chilensis (Bahamonde & Savala, 1981; MacPherson, 1983; Japp, 1990; Balbontin et al, 2000; Ward et al, 2001; Nyegard et al, 2004; Paredes & Bravo, 2005)

Owing to over exploitation, farming technology development is considered a good solution (Centonzio, 2007, Estrada et al, 2009).

STATE OF THE ART

JP2007236291A describes a shelter for sea fishes comprising a floating device, an anchor, and a rope joining the floating device and the anchor, wherein the buoyancy is controlled by the speed of sea currents. KR2008020148A describes artificial shelters for conger eels. The document describes shelters in the farms, allowing each diving user to harvest a predetermined amount of conger eels.

The shelter is made of PVC pipes and concrete. The pipes are open at their ends, forming a set when joined. The set of pipes is fixed to a concrete tube, with open ends. The concrete tube comprises an upper orifice wherein the conger eel food is inserted. The concrete tube can have circular, rectangular, triangular, or diamond shapes.

CN201378999Y describes a box for aquaculture comprising a box with a discharge pipe, a positioning bar, reinforcement bars, a frame, supports, convex bars, a concave and a convex plate, a flange, a concave-convex fringe, a lower reverse water discharge channel, an air outlet, an orifice for temperature probes and a feeding hole.

CN2178993 Y describes a storage box for living fishes, comprising a sealed box, inlet and outlet pipes, an oxygenation valve and a discharge valve. CA2441002C describes an aquaculture process producing fishes at different densities with yields of up to 60 kg/ m³ of the tank, including fish spawning in short and long photo-periods. The process includes conditioning of breeders, reproduction, larvae growth, nursery and adult growth operations. The present invention discloses a new aquaculture method and system for reproduction of marine and brackish benthonic and demersal fishes, which is performed completely out of the sea, in specially conditioner tanks comprising one or more shelters where the fishes can develop their normal reproductive behavior. This method allows controlling all important parameters in the culture, optimizing the obtaining of eggs. This is the first time these kinds of fishes are obtained in completely captivity. There is no evidence of this kind of method in the state of the art, due to, up to now, benthonic and demersal fishes were cultured in the sea, without controlled conditions.

BRIEF DESCRIPTION OF FIGURES Figure 1 : A preferred embodiment of the tank or farm unit: perimeter tank shape: circular. Numbers indicate dimensions in cm. A: Upper view. B: Frontal view. C: Isometric projection.

Figure 2: A preferred embodiment of the tank or farm unit: perimeter tank shape: square with rounded corners. Numbers indicate dimensions in cm. A: Upper view. B: Frontal view. C: Isometric projection.

Figure 3: A preferred embodiment of the cover: perimeter cover shape: hexagonal. Numbers indicate dimensions in cm. A: Upper view with a detailed view of the cover top. B: Frontal view. C: Side view. D: Isometric projection.

Figure 4: A preferred embodiment of the cover: perimeter cover shape: square. Numbers indicate dimensions in cm. A: Upper view with a detailed view of the cover top. B: Frontal view. C: Side view. D: Isometric projection.

Figure 5: A preferred embodiment of the "flute shape" pipe for water entrance and circulation. Numbers indicate dimensions in cm. A: Frontal view. B: Side view. C: Isometric projection. Figure 6: A preferred embodiment of the outlet tube: the tube can also be used to support the cover.

Figure 7: A preferred embodiment of a circular tank or farm unit with a hexagonal cover and two shelters inside. Numbers indicate dimensions in cm. A: Upper view. B: Frontal view. C: Isometric projection.

Figure 8: Exploded view of a preferred embodiment of a square tank with rounded corners with two shelters and a square cover. 1 : Shelter. 2: Support tube. 3: Lid of support tube. 4: External cover support. 5: Tank or farm unit. 6, 7, 8, and 9: "Flute shape" pipe for water entrance and circulation. 10: Outlet tube acting also as central cover support. 11. Upper cover support. 12. Cover.

Figure 9: A preferred embodiment of a shelter including the support tubes. Numbers indicate dimensions in cm. A: Frontal view. B: Side view. C: Isometric projection.

Figure 10: A preferred embodiment of the label system. Numbers indicate dimensions in cm. A: Upper view. B: Side view. C: Frontal view. D: Isometric projection.

Figure 11 : A preferred embodiment of the subsystem for measuring, weighing, treating, controlling, and transferring the specimens: oval shape.

Figure 12: A preferred embodiment of the subsystem for measuring, weighing, treating, controlling, and transferring the specimens: square shape.

Figure 13: A preferred embodiment of the subsystem for measuring, weighing, treating, controlling, and transferring the specimens: rectangular shape.

Figure 14: A preferred embodiment of the subsystem for measuring, weighing, treating, controlling, and transferring the specimens: rectangular shape. Numbers indicate dimensions in cm. A: Upper view. B: Side view. C: Frontal view. D: Isometric projection.

Figure 15: Ratio between the weight and the length of 30 conditioned breeders in the second season. Figure 16: Monthly total volume of spawning during first, second and third season (26 months),

Figure 17: Monthly average volume of spawning during first, second and third season (26 months), Figure 18: Monthly ratio of average hatching during first, second and third season (26 months),

Figure 19: Monthly amount of spawning during first, second and third season (26 months),

SUMMARY OF THE INVENTION The present invention discloses a system and a method for handling and conditioning breeders of benthonic and demersal fishes and for their reproduction and obtaining of viable eggs.

The new fish farming method for benthonic and demersal fishes is performed in specially conditioned tanks comprising one or more shelters. The process allows controlling all important parameters in the culture, optimizing the obtaining of eggs. Shelters are also objects of the invention, and can be used in artificial facilities and not necessarily in the sea. Furthermore, the shelters do not need to be at a depth where benthonic and demersal fishes usually live, and can be installed in any artificial or natural facility, such as a shallow tank, out of the sea. The method and system of the present invention allows the reproduction of benthonic and demersal fishes for production of viable eggs.

DETAILED DESCRIPTION OF THE INVENTION

A compact system for handling and conditioning marine and brackish benthonic and demersal breeding fishes, allowing their reproduction and production of viable eggs in captivity has been developed. The system provides a proper environmental which prevents the causes of stress in captive reproduction of marine and brackish fishes. The system comprises at least one tank or farm unit, at least one shelter or farm subunit, at least one label system, and at least one subsystem for measuring, weighing, treating, controlling, and transferring the breeders.

The present invention also describes a fish farming method for marine and brackish benthonic and demersal breeding fishes, the method comprising the steps of (a) farming of breeders; and (b) reproduction, which comprises spawning and fertilization.

Compact system for reproduction of benthonic and demersal fishes. Tank: Farm unit.

The system comprises a tank of around 50 to around 200 cm in height. In a preferred embodiment, the tank height is around 110 cm. The volume of the tank can be between around 1.5 and around 50 m³. The tank perimeter can have any shape, for example, but not limited to, circular, oval, triangular, triangular with rounded corners, square, square with rounded corners, rectangular, rectangular with rounded corners, pentagonal, pentagonal with rounded corners, hexagonal, hexagonal with rounded corners, octogonal, octogonal with rounded corners, or any regular or irregular shape, with sharp or rounded corners or a combination thereof. In a preferred embodiment the tank perimeter has a circular shape (Figure 1). In another preferred embodiment the tank perimeter has a square shape with rounded corners (Figure 2) (5 in Figure 8). The tank can be manufactured in any material capable of resist external environmental conditions, such as wind, rain, light and sun, and salinity of the seawater or brackish water. The tank can be manufactured in, for example, but not limited to, reinforced fiberglass, stainless steel, galvanized steel, corrugated metal, or high density polyethylene (HDPE). In a preferred embodiment, the tank is manufactured in fiberglass. The walls and bottom of the tank can be covered with a dark liner. The inside of the tank is of any dark color, for example, but not limited to, matte black, dark blue or dark green. The tank is covered with a dark sunlight-proof cover, which prevents entry of visible and UV light, which damages the skin of the fish. The cover allows simulation of half-light natural conditions of deep sea environment and allows air entrance to keep temperature balance. The cover, as the tank, can be manufactured in any resistant material, such as reinforced black fiberglass or thick black cloth. In a preferred embodiment the cover is manufactured in PVC liner. The cover can have any shape that allows complete coverage of the tank surface. For example, the cover perimeter can be circular, oval, triangular, triangular with rounded corners, square, square with rounded corners, rectangular, rectangular with rounded corners, pentagonal, pentagonal with rounded corners, hexagonal, hexagonal with rounded corners, octogonal, octogonal with rounded corners, or any regular or irregular shape, with sharp or rounded corners or a combination thereof. In a preferred embodiment the cover perimeter has a hexagonal shape (Figure 3). In another preferred embodiment the cover perimeter has a square shape (Figure 4) (12 in Figure 8). In one embodiment, the cover can be supported on the walls of the tank. In another embodiment, the cover can be supported on supports located outside the tank (4 in Figure 8). The cover can also be supported on supports located inside the tank. A central support inside the tank can also be added (10 in Figure 8); in this case, an upper cover support could be needed (11 in Figure 8).

A vertical "flute shape" pipe with several holes allows slow entrance and circulation of water in the tank. The "flute shape" of the pipe allows circulation of the water at the different levels of the tank with homogenous flow and also allows removal of sediments. Figure 5 shows a preferred embodiment of the "flute type" pipe for water entrance and circulation. The water entering the tank could be seawater or brackish water. Rate of change of water is 0.25 to 2 per hour and provides enough aeration for these sedentary fishes. The tank can also have a supplementary oxygenation or aeration system.

The removal of food debris and feces is performed though a water outlet that is placed, for example but not limited to, in the central position of the tank. This outlet consists of a tube of around 10 to around 300 cm height perforated with several holes of around 1 to around 5 cm of diameter. In a preferred embodiment the central tube has a height of around 20 cm. In another preferred embodiment the diameter of the holes of the outlet tube is around 2.5 cm. The diameter of the outlet tube fluctuates according to the diameter of the tank around between around 11 and around 40 cm. The outlet tube can also have a lid to prevent fishes to leave the tank. The design of this tube prevents the gelatinous masses of eggs or the eggs to leave the tank. In a preferred embodiment, the outlet tube is around 240 cm and can also be used as central support for the cover (Figure 6) (10 in Figure 8). The used water of the tank can return to the sea or can recirculate in the system. Grazing sea snails can also be maintained in the tank, as they act as natural cleaners of the walls and bottom of the tank, without disturbing the fishes.

Optionally, each farm unit can have a lateral outlet for the collection of eggs, this lateral outlet corresponds to a gutter of any resistant material, for example, but not limited to, fiberglass, high density polyethylene (HDPE) or polyvinyl chloride (PVC), which is arranged horizontally on the water surface. This gutter leads the floating eggs to an optional lateral coated tank, inside which a removable mesh sieve of 400 microns to 800 microns is placed. The lateral tank can have any shape and any volume. In a preferred embodiment the lateral tank has a volume between around 1 and around 3 m³.

In another embodiment, there is no lateral outlet and the eggs are collected directly from the tank or farm unit using buckets.

Inside each unit, 1 to 10 farm subunits or shelters are arranged. The subunits or shelters are described below.

Figure 7 shows a preferred embodiment of a circular tank or farm unit with a hexagonal cover and two shelters inside. Figure 8 shows an exploded view of a preferred embodiment of a square tank (5) with rounded corners with two shelters (1) with support tubes (2) and lids (3), external cover supports (4), "flute shape" pipe for water entrance (6, 7, 8, and 9), outlet tube acting also as central cover support (10), upper cover support (11) and square cover (12). Besides the shelters, the system comprises the following elements: safe and inexpensive highly effective label system, and subsystem for measuring, weighing, treating, controlling, and transferring of breeders. Shelters or farm subunit.

Captured and captivity born breeders have a gregarious behaviour and need shelters to develop their normal behaviour, including their reproductive behaviour.

Shelter or farm subunit for conditioning marine and brackish benthonic and demersal breeding fishes, allowing their reproduction and production of viable eggs in captivity are also objects of the present invention.

The farm subunits correspond to tube shelters manufactured in any non-toxic and biologically inert material, for example, but not limited to, high density polyethylene (HDPE), poly(vinyl chloride) (PVC), or fiberglass, in dark color, for example, but not limited to black color. In a preferred embodiment the shelters are manufactured in HDPE. The shelters are arranged, for example, symmetrically within each tank or farm unit. The diameter and length of the shelters vary between around 20 and around 50 cm of diameter and around 50 to around 150 cm long. The final dimensions will depend on the size of the breeders that are being conditioning. In any case, the diameter of the shelter should allow the entry of at least two breeders.

The ratio of shelters in a tank to the number of breeders introduced in the tank is carefully controlled since this relationship has shown to be of utmost importance allowing up to 12 uninterrupted months spawning in captivity. The artificial shelter simulate the natural shelters where the fishes live, with similar light, silent and tranquility, thus, the fishes develop their normal behavior, including their reproductive behavior. The shelter is also the cause that there is not the need to have deep tanks.

Furthermore, low rugosity of the materials avoids fouling of small benthic invertebrates, facilitating cleaning and periodic disinfection. The shelters are prepared as follow: a tube of any non-toxic and biologically inert material, for example, but not limited to, high density polyethylene (HDPE), poly(vinyl chloride) (PVC), or fiberglass is cut in a specified length and the tube corners are beveled using different tools, removing any sharp corners that could damage the breeders. Then, two or four supports, acting as legs, are installed in each shelter (2 in Figure 8). The legs allow raising the shelter from the bottom of the tank at least around 5 cm, which avoid damage of the surface of the tank in which they are installed and allow free uninterrupted water circulation through the bottom of the tank, allowing self-cleaning.

These supports correspond, for example but not limited to, tubes of around 5 cm to around 6.3 cm in diameter and have a length of around 20 cm to around 40 cm (when four supports are used) or around 70 to around 140 cm (when two supports are used), in relation to the size of the shelters. The support tubes can also have lids on their ends (3 in Figure 8). Depending on the size of the shelter it may be necessary, to fill these supports with concrete, in order to prevent floating shelters. 1 to 10 shelters are arranged inside each farm unit or tank, depending on the size of the tank and the number of fishes. Under ideal operating conditions the system should have at least one shelter every two to six breeders.

In one embodiment, the shelters can be installed in any artificial or natural facility, such as a shallow tank. Figure 9 shows a preferred embodiment of a shelter including the support tubes and the lids.

Label system for the breeders

The label system should be any that allows the easy identification, recognition and tracking of the fishes. In a preferred embodiment, the label system corresponds to a modified electrical cable tie in which a numerical code is recorded by application of localized heat (Figure 10). Then this tie has been disinfected by immersion in a disinfectant solution, for example, but not limited to, iodine solution or quaternary ammonium solution, or a solution of any disinfectant acting through the oxidation of organic matter. Subsequently the numerical code on the plastic tie is painted using waterproof paint.

The insertion of this label is performed, for example, as follow. The fish is anesthetized by immersion in a solution of benzocaine and tricaine at a concentration between 20 and 40 ml of product per 100 liters of solution. The final concentration of anesthetic depends on the size of the fish and the fish larger, higher concentration to be used, always within the range specified above. Then, a small cut of around 0.5 cm in length in the fish's operculum is performed with a disinfected scalpel. In the meantime, the number of the label and characteristics of the specimen as height, weight and some morphological peculiarity worthy of note are recorded. Then, the label is going through the incision in the selected fish's operculum. The loop of the tie should have a length of 7 cm to 10 cm, allowing the eventual growth of the fish. The excess of the tie is cut. The label is finally disinfected with a disinfectant solution, for example, but not limited to, a solution of methylene blue or a solution of an iodophor. After being labeled, the fish is quickly returned to the tank. The whole label process takes no more than 1-2 minutes.

Subsystem for measuring, weighing, treating, controlling, and transferring of specimens

The subsystem for measuring, weighing, treating, controlling, and transferring the specimens minimizes the stress of the fishes, due to the reduction in the time they remain out of the water and the easy transfer of the breeders from one tank to another.

The subsystem basically comprises a device that acts like a container for the fishes. The subsystem is at least as long as the fishes. The subsystem is, for example, but not limited, around 100 to around 200 cm long. In a preferred embodiment the subsystem is around 150 cm long. The subsystem can have any shape, for example, but not limited to, oval (Figure 11), square (Figure 12), or rectangular shape (Figures 13 and 14). In a preferred embodiment the subsystem has rectangular shape (Figures 13 and 14). In a more preferred embodiment, the rectangular walls have a height of around 10 to around 20 cm and a width of around 20 to around 50 cm. One of the ends of the subsystem has a transversal cut and the other end is closed. In a preferred embodiment, the cut is made with an angle of around 30° to around 60°. The top of the subsystem is open and has one or two tape measures for measuring the long of the fishes. The subsystem can be manufactured in any resistant material, for example, but not limited to, fiberglass, high density polyethylene (HDPE) or polyvinyl chloride (PVC). In a preferred embodiment, the subsystem is manufactured in fiberglass.

This subsystem facilitates the handling of the fishes, particularly for big fishes, with 10 kg of weight or more, minimizing the stress allowing all handling routines to be developed at one single place.

The fish, previously anesthetized, is transferred to the subsystem where it is subjected to the following operations: measurement of the length (total and standard), measurement of the diameter of the maximum abdominal diameter, taking samples of tissue from the caudal region, taking blood samples from the caudal region, labeling of specimens, sampling of sex products (sperm and eggs), observing and recording label number, general observation of the specimens, weighing of the specimens, injection of vitamins.

After the aforementioned operations are performed, the design of this subsystem allows a fast move, with the specimen inside, toward the destination tank. Once there, the subsystem is gently tilted to allow the soft displacement of the specimen towards the water, similarly to what happens with the launching of a boat, which prevents damage to the specimens.

Method for fish farming of benthonic and demersal fishes (ground fishes)

The present invention also describes a fish farming method for marine and brackish benthonic and demersal fishes, using the system of the present invention, the method comprising the steps of (a) farming of breeders; and (b) reproduction, which comprise spawning and fertilization. a) Farming of breeders

The inside of the farm unit or tank, as the shelters should be washed carefully using swabs and soft bristle brushes and a detergent that does not generate foam. Then the tank and the shelters must be carefully rinsed to remove any detergent residues.

Later the tank and shelters should be disinfected using commercial disinfectants, such as for example, but not limited to, iodoform, or any disinfectant based on free iodine. It is very important to rinse the tanks several times. After being rinsed, tanks and shelters are allowed to dry for a couple of days before being filled with seawater or brackish water. Subsequently, the breeders are added in a rate of 1 : 1 or 1 :2 or 1 :3 (female: male). For big females (>15 kg) 2 or 3 males are needed for fertilizing the whole eggs. The gender of the fishes is determined by ultrasound and biopsies and also through abdominal massage for obtaining oocytes in the case of females and sperm in the case of males.

In one embodiment, individuals of size above 50 cm are captured, for example, but not limited to, with the adapted long-line fishing or by gillnetting. The time between the fish hitting the hook and when it is taken out of the water must not extend for long, the trawling process from the bottom to the surface must be very careful so as to avoid damaging the fish. At the time of taking them out to the surface the fish swim bladder is deflated with a syringe. Transportation from capture zones to the farm centre is made for example, inside plastic buckets.

In another embodiment, the breeders are obtained in captivity culture. The breeders are subjected to all the control operations periodically (measurement of the length (total and standard), measurement of the diameter of the maximum abdominal diameter, taking samples of tissue from the caudal region, taking blood samples from the caudal region, labeling of specimens, sampling of sex products (sperm and eggs), observing and recording label number, general observation of the specimens, weighing of the specimens, injection of vitamin) when they arrive to the breeders area.

The environmental conditions in which the breeders are kept, including basically physicochemical parameters, as temperature, dissolved oxygen concentration, and nitrogenous waste as ammonia and nitrite are daily recorded. The breeders are fed from one to seven times per week, depending on the water temperature (at higher temperature the fishes are more active and need more food), with humid and dry pellets (including extruded pellets) and fresh feed (oily fishes like scomber). Captivity born breeders are adapted to be fed only with pellets. They are fed with humid and dry pellets (including extruded pellets) rich in protein and low in fat. The breeders can be grown at densities ranging from about 1 to about 30 kg/m³, being the optimum densities between about 10 and about 15 kg/m³. They are kept at a light intensity of half dark of 50 to 100 luxes. b) Reproduction: spawning and fertilization Spawning in captivity with the present method is produced during the whole year. The fishes do not need spawning induction, but only careful handling. The gelatinous masses with eggs or the eggs are floating in the upper 20 cm from the water column and they are lead to a lateral coated tank through a lateral outlet of the tank or collected directly from the tank or farm unit using buckets as aforementioned. Mass eggs size is 0.13 cm in average each. The average volume of the mass is 2.5 L, with a range from 0.8 to 6.0 L. The spawning has an average fecundity of 82,000 eggs, ranging from 2,000 to 285,000 eggs per mass. Each female spawns in average one floating gelatinous egg mass per week, which is fertilized overnight by one or more males in the tank. Depending on the number of fishes living in the tank, it is possible diary obtaining viable fertilized egg mass.

The present invention, system for handling and conditioning marine and brackish benthonic and demersal breeding fishes, allowing their reproduction and production of viable eggs in captivity and method of fish farming for marine and brackish benthonic and demersal breeding fishes is applicable to benthonic and demersal fishes, both cylindrical or flat, for example but not limited to, cods, hakes, haddocks, seabass, groupers, monkfishes, orange roughies, red snappers, wreckfishes, conger eels, turbots, halibuts, flounders, and soles. In a preferred embodiment, the present invention is applicable to big benthonic and demersal fishes, weighing 10 kg or more. In another preferred embodiment, the present invention is applicable to cylindrical benthonic and demersal fishes.

INDUSTRIAL APPLICABILITY

The present invention, system for handling and conditioning marine and brackish benthonic and demersal breeding fishes, allowing their reproduction and production of viable eggs in captivity and method of fish farming for marine and brackish benthonic and demersal breeding fishes can be used in aquaculture or fish farming industry for producing fishes with high commercial value. The system and method of the present invention can be used in experimental or laboratory scale, in pilot scale, in commercial scale, and in industrial scale, and in small, medium, and large industries.

EXPERIMENTAL SECTION Example 1: Farming of the first breeders (red conger eel {Genypterus chilensis) and black conger eel {Genypterus maculatus)).

Specimens of red conger eel {Genypterus chilensis) and black conger eel {Genypterus maculatus) were captured from the roadstead of Quintay, Chile, by gillnetting, at a depth between 60 and 100 m. The captured specimens were taken to Quintay Marine Research Centre (CIMARQ) where they were transferred to 3 m³ receiving tanks. In the receiving tanks the specimens were individually examined to detect any serious injuries caused by gillnet or the extraction process. Additionally, the specimens that showed signs of barotrauma were treated through air bladder puncture, to remove excess gas therein and allow normal control of their buoyancy. The captured specimens stayed two weeks in the receiving tanks, in which health status was checked daily. During this period, the fishes were not fed and subjected to prophylactic baths with disinfectants for veterinary use.

80 specimens were captured, from which those that exhibited a better condition, without apparent injury were selected (n = 30). These 30 fishes were added to other specimens that CIMARQ had previously captured (n = 30). All specimens were doubly labeled, using both PIT tags inserted in the dorsal region and the label system for breeders of the present invention, which were placed in the right operculum of the fishes.

The gender of the fishes was determined by ultrasound and biopsies and also through abdominal massage for obtaining oocytes in the case of females and sperm in the case of males, and they were transferred to the tanks or farm units of the present invention. In this example the tanks were cylindrical with a diameter of 300 to 500 cm and a water column between 80 to 100 cm. Different designs of tanks, covers, water entrances and outlets, and shelters were assessed. The selected tank, as detailed in the present invention, had a gentle and uniform water circulation throughout the water column. This was achieved through a water entrance with a flute shape with 8 to 10 holes, for delivering a constant flow and promoting uniform flow, besides facilitating self-cleaning of the tank. Aeration was only used in case of interruption of the water supply, under emergency conditions. In this manner and under normal operating conditions, there was a low noise level inside the tank.

Furthermore, different covers were evaluated, including covers made of black shading nets with 80% and 90% shading ability, doubly and triply layered. These kinds of covers were not appropriate for the conditioning of the specimens; due to the UV light rays caused severe burns and depigmentation phenomena in fishes in less than a month. Therefore, solid covers made of PVC clothes or reinforced fiberglass were selected.

Due to the particular reproductive behavior of these specimens, in which females spawn a gelatinous mass of eggs which is subsequently fertilized by one or more males, it was necessary to design special water entrances and outlets systems for the tanks, in order to prevent these masses remain stuck or leave the tank. The water entrance, as mentioned, had a flute shape with 8 to 10 holes. The water outlet was designed as a central tube with several holes for avoiding floating eggs leaving while facilitating extracting of these daily using plastic buckets.

Special shelters or farm subunit, as detailed in the present invention, were arranged inside the tanks in order to provide in captivity the same conditions the fishes had in deep sea.

The specimens were arranged in a gender ratio of 1 : 1 in 5 tanks, considering 12 specimens per tank. The fishes were fed with chopped fatty fish on weekly rations equivalent to 5% of their biomass.

The total mass of eggs produced was considered as one of the clearest indicators of the success of the conditioning process, in addition to the average size of these masses (both measured in liters) and observed total fertility (number of eggs produced by season). The results of the conditioning process were reflected by comparing egg production between the first and second year, when the whole design was improve. While in the first season a production slightly exceeding 250 liters was achieved (equivalent to more than 8.6 million eggs). During the second season, the production exceeded 500 liters equivalent to more than 18.1 million eggs. Furthermore, it was possible to bring forward the start of spawning period in at least three months comparing with the period described in natural environment and also to extend it in at least three months. This was achieved through the diet and farming conditions. Summarizing, it was possible to obtain viable spawning throughout the whole year for black conger eel and during 9 months for red conger eel.

Notably, significant differences in the diameter of the eggs obtained during different spawning were not observed, corresponding to 0.13 cm average diameter. Similarly the average volume of spawning remained between 1.7 and 1.8 liters, often found spawning of 6 liters and more, produced by big females, weighing up to 15 kilograms.

This pattern of egg production, was held during the third season, when again more than 1000 liters of eggs, equivalent to more than 40 million eggs were produced.

The significant increase in length and weight of the breeders is another important aspect. The initial average weight was 3 kg, which was quadrupled in four years. Currently the average weight of the breeders is 12.5 kg and most specimens (80%) are larger than 120 cm in length.

The adaptation to farming and conditioning systems was also reflected in the low mortality recorded, which did not exceed more than one specimen per semester. In general, the fishes showed adequate adaptation to the conditions of farming. In this regard, it is remarkable the development of techniques, and systems for labeling and handling of breeders, which at all times sought to avoid the appearance of alarm signals in fishes.

In spite of this massive egg production, fertilization percentages varied between 0 and 100%, with an average of 15% fertilization. The fertilization rate was higher during the months when spawning occurs under natural conditions, i.e., during the spring. Most spawning occurred during early morning, after midnight, and the eggs were collected from Monday to Sunday at 07:30 in the morning.

Example 2: Features of the current breeding stock of congers (captured and conditioned).

• A total of 50 breeders of red conger {Genypterus chilensis) are currently farmed, whose average weight exceeds 12.5 kg with a biomass greater than 600 kg. Some of the specimens weighing over 16 kg.

• Additionally, a total of 26 breeders of black conger {Genypterus maculatus) are currently farmed, with an average weight of 6 kg and over 120 kg biomass.

• The farming density is kept between 15 and 20 kg/m³.

The 73 breeders are in their third breeding season in captivity. The production of viable eggs per season has exceeded 20 million eggs, and the total amount of eggs during the three seasons exceeded 50 million.

Figure 15 shows the ratio between the weight and the length of 30 conditioned breeders in the second season.

Example 3: First generation of breeders of red conger eel obtained in captivity (Fl).

CIMARQ has currently hundred specimens of breeders of 3 years of age (having a weight ranging between 1 and 2 kg), born in captivity from the breeders farmed with the systems and methods of the present invention. These specimens have already begun their spawning, are labeled and their gender was determined by ultrasound. They are arranged in 300 cm diameter cylindrical tanks or farm units according to the present invention, including one shelter per tank, and are adapted to be fed only with pellets. They are currently fed daily with humid and dry pellets (including extruded pellets) rich in protein and low in fat. F2 egg production is achieved from these specimens. Example 4: Productivity values during three seasons.

Table 1 shows productivity values for several parameters in the different stage of the farming of breeders during three seasons.

Table 1: Productivity values.

The systems and method of the present invention have successfully achieved a number of breeding stock, which given its high productivity in eggs and physiological condition, can support a commercial scale production.

Example 5: Production of eggs

The egg production of red conger has been successful from a quantitative and qualitative point of view. Figure 16, 17, 18, and 19 shows monthly total volume of spawning, monthly average volume of spawning, monthly ratio of average hatching, and monthly amount of spawning during first, second and third season, respectively.

The egg production was characterized by a significant increase in the percentage of fertilization and hatching from the first to the third season. In this sense, the achievements are outlined in adjusting the physicochemical parameters of the tank, labeling, gender determination, handling of gender ratio, sizes and collection techniques of eggs. Generally speaking, massive production of viable eggs was the result of a successful captivity handling protocol.

Claims

System for handling and conditioning marine and brackish benthonic and demersal breeding fishes, allowing their reproduction and production of viable eggs in captivity, wherein the system comprises at least one tank or farm unit, at least one shelter or farm subunit, at least one label system, and at least one subsystem for measuring, weighing, treating, controlling, and transferring the breeders.

System according to claim 1, wherein the tank or farm unit has a height between around 50 and around 200 cm, a volume between around 1.5 and around 50 m³, the inside of the tank is of a dark color, the tank is covered with a dark sunlight-proof cover which prevents entry of visible and UV light and allows air entrance, having a shape that allows complete coverage of the tank surface, the tank has a vertical flute shape pipe with several holes for water entrance and circulation, the tank has a water outlet for removal of food debris and feces consisting of a tube of around 10 to around 300 cm perforated with several holes, and has 1 to 10 farm subunits or shelters.

System according to claim 2, wherein the tank perimeter has circular, oval, triangular, triangular with rounded corners, square, square with rounded corners, rectangular, rectangular with rounded corners, pentagonal, pentagonal with rounded corners, hexagonal, hexagonal with rounded corners, octogonal, octogonal with rounded corners, or any regular or irregular shape, with sharp or rounded corners or a combination thereof.

System according to claim 2, wherein the tank or farm unit is manufacture in reinforced fiberglass, stainless steel, galvanized steel, corrugated metal, or high density polyethylene (HDPE).

System according to claim 2, wherein the walls and bottom of the tank or farm unit are covered with a dark liner.

System according to claim 2, wherein the cover of the tank or farm unit is manufactured in reinforced black fiberglass, thick black cloth or PVC liner.

7. System according to claim 2, wherein the cover of the tank or farm unit is supported on the walls of the tank.

8. System according to claim 2, wherein the cover of the tank or farm unit is supported on supports located inside or outside the tank and optionally on a central support.

9. System according to claim 2, wherein the water entering the tank is seawater or brackish water.

10. System according to claim 2, wherein the rate of change of water in the tank or farm unit is 0.25 to 2 per hour.

11. System according to claim 2, wherein the tank has a supplementary oxygenation or aeration system.

12. System according to claim 2, wherein the water outlet tube has a diameter between around 11 and around 40 cm.

13. System according to claim 2, wherein the water outlet has a lid.

14. System according to claim 2, wherein the water outlet is around 240 cm and is also used as central cover support.

15. System according to claim 2, wherein the used water of the tank returns to the sea or recirculates in the system.

16. System according to claim 2, wherein grazing sea snails are maintained in the tank for cleaning the walls and bottom.

17. System according to claim 2, wherein the tank or farm unit has a lateral outlet for the collection of the eggs, corresponding to a gutter of fiberglass, high density polyethylene (HDPE) or polyvinyl chloride (PVC), arranged horizontally on the water surface.

18. System according to claim 17, wherein the lateral outlet gutter leads the floating eggs to a lateral coated tank, inside which a removable mesh of 400 to 800 microns is placed.

19. System according to claim 2, wherein the eggs are collected directly from the tank or farm unit using buckets.

20. System according to claim 1, wherein the shelter or farm subunit corresponds to a tube in dark color, such as black color, of high density polyethylene (HDPE), poly(vinyl chloride) (PVC), or fiberglass, with a diameter between around 20 and around 50 cm cut in a length between around 50 and around 150 cm, with beveled corners, having two or four supports acting as legs.

21. System according to claim 20, wherein the dimension of the shelter or farm subunit depends on the size of the breeders and allows the entry of at least two breeders.

22. System according to claim 1, wherein the label system corresponds to a modified electrical cable tie in which a numerical code is recorded by application of localized heat, the numerical code on the plastic tie is painted using waterproof paint, and the label is disinfected and introduced through an incision in the selected fish's operculum.

23. System according to claim 1, wherein the subsystem for measuring, weighing, treating, controlling, and transferring the breeders comprises a device that acts like a container, is at least as long as the fishes or is around 100 to around 200 cm long, the subsystem has oval, square or rectangular shape, one of the ends of the subsystem has a transversal cut and the other end is closed, the top of the subsystem is open and has one or two tape measures, and the subsystem is manufactured in fiberglass, high density polyethylene (HDPE) or polyvinyl chloride (PVC).

24. System according to claim 23, wherein the walls of the subsystem have a height of around 10 to around 20 cm and a width of around 20 to around 50 cm.

25. System according to claim 23, wherein transversal cut of the subsystem is made with an angle of around 30° to around 60°.

26. System according to claim 1, wherein the fish breeders are cods, hakes, haddocks, seabass, groupers, monkfishes, orange roughies, red snappers, wreckfishes, conger eels, turbots, halibuts, flounders, and soles.

27. System according to claim 1, wherein the fish breeders are big benthonic and demersal fishes, weighing 10 kg or more.

28. System according to claim 1, wherein the fish breeders are flat benthonic and demersal fishes.

29. System according to claim 1, wherein the fish breeders are cylindrical benthonic and demersal fishes. 30. System according to claim 1, wherein the system is applicable in experimental or laboratory scale, in pilot scale, in commercial scale, and in industrial scale, and in small, medium, and large industries.

31. Shelter or farm subunit for conditioning marine and brackish benthonic and demersal breeding fishes, allowing their reproduction and production of viable eggs in captivity wherein the shelter or farm subunit corresponds to a tube in dark color, such as black color, of high density polyethylene (HDPE), poly( vinyl chloride) (PVC), or fiberglass, with a diameter between around 20 and around 50 cm cut in a length between around 50 and around 150 cm, with beveled corners, the shelter has two or four supports acting as legs. 32. Shelter according to claim 31, wherein the dimension of the shelter or farm subunit depends on the size of the breeders and allows the entry of at least two breeders.

33. Shelter according to claim 31, wherein the shelters are installed in any artificial or natural facility, such as a shallow tank.

34. Method of fish farming for marine and brackish benthonic and demersal breeding fishes, wherein the method comprises the steps of (a) farming of breeders; and (b) reproduction, which comprises spawning and fertilization.

35. Method of fish farming according to claim 34, wherein the step (a) of farming of breeders comprises washing the tank or farm unit and shelters or farm subunits, disinfecting the tank or farm unit and shelters or farm subunits, filling the tank of farm unit with seawater or brackish water, adding the breeders to the tank or farm unit in a rate of 1 :1 or 1 :2 or 1 :3 (female: male), subjecting the breeders to periodic control operation (measurement of the length (total and standard), measurement of the diameter of the maximum abdominal diameter, taking samples of tissue from the caudal region, taking blood samples from the caudal region, labeling of specimens, sampling of sex products (sperm and eggs), observing and recording label number, general observation of the specimens, weighing of the specimens, injection of vitamin), feeding the breeders from one to seven times per week.

36. Method of fish farming according to claim 35, wherein the breeders are individuals of size above 50 cm captured from the sea.

37. Method of fish farming according to claim 35, wherein the breeders are obtained in captivity.

38. Method of fish farming according to claim 35, wherein the breeders are fed with humid and dry pellets (including extruded pellets) and fresh feed (oily fishes like scomber).

39. Method of fish farming according to claim 37, wherein captivity born breeders are adapted to be fed only with humid and dry pellets (including extruded pellets) rich in protein and low in fat.

40. Method of fish farming according to claim 35, wherein the breeders are grown at densities ranging from about 1 to about 30 kg/m³.

41. Method of fish farming according to claim 34, wherein the spawning of the step (b) of reproduction, do not need spawning induction.

42. Method of fish farming according to claim 34, wherein the fish breeders are cods, hakes, haddocks, seabass, groupers, monkfishes, orange roughies, red snappers, wreckfishes, conger eels, turbots, halibuts, flounders, and soles.

43. Method of fish farming according to claim 34, wherein the fish breeders are big benthonic and demersal fishes, weighing 10 kg or more.

44. Method of fish farming according to claim 34, wherein the fish breeders are flat benthonic and demersal fishes. 45. Method of fish farming according to claim 34, wherein the fish breeders are cylindrical benthonic and demersal fishes.

46. Method of fish farming according to claim 34, wherein the method is applicable in experimental or laboratory scale, in pilot scale, in commercial scale, and in industrial scale, and in small, medium, and large industries.