FOOD FOR PISCIVORO CULTIVATED FISH PROVIDING IT WITH A COLOR THAT ATTRACTS FISH FOR
INGER THE FOOD
TECHNICAL FIELD The present invention relates to a food for cultured piscivorous fish, the surface of which has been coated or the ingredients contained have been chosen to show a highly appetizing color to the fish, so that the food can stimulate a feeding cond ucta of the fish, and in this way ensure the food intake.
BACKGROUND OF THE INVENTION The food given to the cultured fish can be roughly divided into a raw food and a composite feed. A raw food generally consists of chilled or frozen small fish such as saurel, mackerel, sardines, young sand eel and squid, which are usually caught in large quantities. Feeding dependent on such raw food, however, is inevitably accompanied by the dumping of meat juices and small particles of dispersion of the raw food such as pieces of meat and scales to the contour of a fish culture. Such waste material scattered in the sea imposes a great weight on the environment around the fish culture so that the feed dependent on the raw food is very inadequate for the prolonged cultivation of fish. In addition, since small fish, it can serve with stable nutritive nutrition for one year; the size and nutritional content of such recently caught small fish vary from season to season; and the nutritional content of such small fish decreases and degrades during storage. In addition, there is always a risk that cultured fish will become infected as a result of consuming the raw food, and once the fish has become diseased, it would seriously interfere with the normal growth of the farmed fish. A compound food is a food obtained by mixing fish meal, which is a main ingredient, fish oil, vitamins, minerals and other ingredients with due consideration paying the nutritional requirements of the fish to be fed. Alternatively, the raw fish meat can be added to such a powder mix to be used as a compound feed. The resulting mixture is molded into pills that are of a suitable size and shape for the fish to be fed. In this way, the feed-dependent compound feed can minimize the dispersion of waste material around a fish culture during feeding in contrast to the feed dependent on the raw feed, and thus minimize the burden imposed on the environment by the feed. fish feeding. In addition, since the compound feed is obtained by appropriate choice of nutritious elements in accordance with the nutritional requirements of the fish to be fed, and by mixing and molding them, it can easily and reliably supply the fish with its required nutrients. In addition, food-based compound feed has the ability to remove infectious diseases from farmed fish, but it may also add a function to prevent fish from becoming infected. With the foregoing as background, it has recently been recommended that the fish culture industry should change from a raw food-based feed to a feed-based compound feed. Although the change to a diet based on computed food is particularly mandatory in the case of prolonged cultivation, there is an obstacle that such a change conceals: some kinds of fish naturally prey on other fish for their subsistence and thus have a high preference For raw fish food, acclimating them to a compound feed is far from easy. For example, bluefin tuna has a high preference towards raw fish feed and such low preference towards compound feed as compared to raw feed that changes from a raw feed to a compound feed has had serious delays for this kind of fish. The change has then proceeded slightly for greater amber and yellow tail, but raising them only by compound feed even now is not easy. To improve the avidity with which farmed fish consume compound feed, a conventionally adopted method consists in adding a substance that stimulates food intake such as a mollusk extract and fish to the compound feed. The substances that stimulate known food intake include peptides, amino acids, substances related to nucleic acid, lipids, a¾é ^ ^ s ^ -y-á ^ os-Ofo ^ icog (K Hararia (eg Japanese L
Fishers (superv.), "Substances stimulating the feed intake of fish", Fisheries Science Series 1 01, Koseisha Publishing, Co., 1 994). However, compound food supplemented with such a substance that stimulates the intake of food has rarely been consumed as eagerly as raw food. The visual warning is very important for the fish. Generally, marine fish possesses rhodopsin as a light sensitive substance, which absorbs maximum light having a wavelength of approximately 500 nm, although the wavelength at which maximum absorption occurs varies depending on the species of proven fish. For example, rhodopsin derived from gado shows a maximum absorption to light that has a wavelength in the range of 460-540 nm while that of blue mackerel shows a maximum absorption at 482-492 nm, both being in the bluish range -green (T. Arimoto ef al., (eds.) and Japanese Society for Fishermen (superv.), "Behavioristic physiology of fish, and their fishing", Fisheries Science Series 108, Koseisha Publishing, Co., 1 996). Since the visibility to a fish of an object in the sea is determined by the contrast between the object and the background, it does not mean that the object would be visible to the fish more if it is blue, even if the fish has a maximum sensitivity in the range bluish-green spectrum of visible light. In fact, when lures are tested on yellowfin tuna, kawakawa and tuna, the visibility of the lures does not correlate positively with the number of fish _ Fisheries Conventionally, the compound feed for cultured piscivorous fish has a color more or less resembling coffee on its surface, which in fact does not represent the color of food consumed by its wild counterparts, especially those that prey on other fish. For fish grown in a closed space, especially adapted such as an annex or tank, many studies have been published in the relationship between the chemical stimulants of a fish meat extract and its activity that stimulates the intake of food. However, the relationship between the color of the surface of a compound food and its activity that stimulates food intake has never been studied.
BRIEF DESCRIPTION OF THE INVENTION According to the foregoing, it is the object of the present invention to provide a compound feed for cultured piscivorous fish, particularly for a piscivorous fish, the compound feed having its activity that stimulates the intake of improved feed at an equal level or higher than aq ue of raw food. To achieve the above object, the present inventors have studied hard and found that a food composed with a color from the surface of indigo to blue or white markedly improves the intake of food by cultured fish, thus leading to the present invention. The characteristics of the inventive feed for cultured piscivorous fish are summarized as follows. (1) A food for cultured piscivorous fish that is provided with a fish capable of attracting a piscivorous fish to ingest the food, the color selected from a group consisting of a bluish hue and a whitish hue. A food for piscivorous fish cultured as described above (1), wherein 10% or more of the surface of the food has the color that is capable of attracting the fish to ingest the food or 1 0% by weight or more of the food is the food that has been provided with the color that is able to attract the fish to eat the food. A food for piscivorous fish cultured as described above (1) or (2), wherein the bluish hue is a color that reflects highly light with a wavelength corresponding to a range of indigo to blue and its coordinate b * is negative (-b *) when plotted in a color coordinate system L * a * b *. and the whitish hue is a color that shows a high luminosity and its L * coordinate is equal to or greater than 60 when plotted in the color coordinate system L * a * b *. A food for piscivorous fish cultivated as described above (1), (2) or (3), where a pigment has been added to the food or the surface of the food has been coated with a pigment to make 1 0% or more of the surface area have a color whose a system of color coordinates L * a * b *, or a color whose L * coordinate is equal to or greater than 60 when plotted in the color coordinate system L * a * b *. (5) A food for piscivorous fish cultivated as described above (4), which is produced by mixing a pigment with raw food materials where the main material is fish meal that has whitish color. (6) A food for piscivorous fish cultured as described above (5), where the main material is squid meal or white fish meal. (7) A food for piscivorous fish cultured as described above (5), which is a compound feed in a pill. (8) A food for piscivorous fish cultured as described above (4), which is produced by coating a pill formed for fish with white or blue ingredients. (9) A food for piscivorous fish cultured as described above (8), wherein the pill formed for fish is made of raw materials wherein the main material is fish meal that has whitish color. (10) A food for piscivorous fish grown as squid meal or white fish meal. (1 1) A food for piscivorous fish cultured as described above (1), (2) or (3) obtained by filling food materials in an edible housing that has a whitish or bluish color to make 10% or more of the surface area of the resulting filled food has a color whose coordinate b * is negative (-b *) when plotted in a color coordinate system L * a * b *, or a color whose coordinate L * is equal to or greater that 60 when plotted in the color coordinate system L * a * b *. (12) A food for piscivorous fish cultured as described above (11), wherein the edible housing is natural housing, artificial housing, gelatin capsules, or nets made of edible fibers, and food materials or pills made of materials of food are stuffed in the edible housing. (13) A food for piscivorous fish cultured as described above (1), (2) or (3), where its ingredients have been chosen to make 10% or more of the surface area have a color whose coordinate b * is negative (-b *) when plotted in a color coordinate system L * a * b *, or a color whose coordinate L * is equal to or greater than 60 when (14) A food for piscivorous fish grown as described above (13), which is produced with raw materials where the main material is fish meal that has whitish color and the materials that have a minor effect on the color, are selected as other materials. (1 5) A food for piscivorous fish cultivated as described above (14), where the main material is squid meal or white fish meal. (16) A food for piscivorous fish cultured as described in any of above (1) to (15), wherein the cultured piscivorous fish is classified as Perciformes or Salmon-lupus, and the food components are designed to meet the requirement of those fish. (1 7) A food for piscivorous fish cultured as described above (16), cultured piscivorous fish is Tuna (Perciformes Scombridae), Yellow Tails (Perciformes Carangidae) or Salmon (Salmoniformes Salmonidae), and the food components are designed to satisfy the requirement of those fish. (1 8) A method for culturing a piscivorous fish which comprises supplying the fish with an effective amount of the food as described in any of the above _ Wa4J-7). According to the present invention, it is possible to provide a compound feed for cultured piscivorous fish, particularly for fish such as blue tuna, greater amber and yellow tail, which have a strong natural predilection for fishmeal, the compound food having its activity that stimulates the intake of improved feed at a level equal to or greater than that of raw food .
DESCRIPTION OF THE PREFERRED MODALITIES The farmed fish to which the present invention specifically targets includes tuna such as bluefin tuna (Thunnus thynnus), southern blue (Thunnus maccoyi), yellowfin tuna (Thunnus albacore), large-eye tuba (Thunnus obesus). , etc.; yellow tails tale as yellow tail. { Seriota quinqueradiata), major amber (Serióla dumerili), yellow-tailed amber (Serióla lalandi), etc .; salmon such as trout (Salmo trutta), silver salmon (Oncorhynchus kisutch), Atlantic salmon (Salmo salar); etc.; and other fish including Japanese red sea bream (Pagrus major), flounder (Paralichthys olivaceus), puffer fish (Takifugu rubripes), jagged-edged perch (Epinephelus septemfasciatus), long-tailed grouper (Epinephelus moara), Japanese sea bass ( Lateolabrax japonicus), barramundi (Lates calcarifer), etc. The inventive food is particularly effective for growing fish that have a natural predilection for fish meat classified as Perciformes or Salmoniformes, such as tuna (Perciformes Scombridae), yellow tails (Perciformes Carangidae) and salmon (Salmoniformes Salmonidae).
One star gives inventive food that has a bluish colloid highly reflects light whose wavelength corresponds to a range of indigo to blue, and another kind of inventive food that has a whitish color has high luminosity. The previous food that shows a high light reflection whose wavelength corresponds to a range of indigo to blue has a negative b * coordinate (-b *) in a color coordinate system L * a * b *. The last food that shows a high luminosity has an L * coordinate equal to or greater than 60 in the color coordinate system L * a * b *. Suitable pigments used for coloration of the bluish composite food may include pigments derived from jasmine, pigments derived from spirulina, etc. , and can be used alone or in combination. Illustrative examples of such pigments may include "Kiriya EL blue" (iriya Chemical) obtained from the jasmine fruit layer, "Linablue LE" (Dainippon I nk &Chemicals) obtained from spilurine, etc. Illustrative methods for coloring the compound feed may include adding a pigment to the material used for the compound feed, immersing the compound feed in a pigment solution, spraying a pigment solution on the compound feed, and applying a pigment to the food surface. compound. The production of the whitish composite food whose surface has a color that gives a coordinate L * equal to or greater than 60 can be achieved by increasing the content of a specific ingredient such as fish meal that has whitish color, such as squid meal or harma_de white fish, or vegetable oil, which will improve the resultant shade - whitening - of the - food - compound ^ or by covering the food surface wholly or partially with sugar, starch or oil so that the surface has a desired whitish shade. As an illustrative method for covering the surface of the food compound with a whitening agent totally or partially, the coating used in the production of medicinal or sweet tablets can be used. To achieve the object of the invention, the surface area of the composite food having a desired color may be long enough to be visible to the fish to be fed and produce a feeding behavior of the fish, and a sufficiently large area is 1 0% or more than the total surface area. It is a feature of the present invention to provide a composite feed for cultured piscivorous fish that generally has a low predilection towards compound feed as compared to raw feed, where its activity that stimulates feed intake is improved by making the surface of the feed compound Totally or partially it has a whitish or bluish color. The inventive food can be wet pills or expansion pills, and is not limited to any specific form or production method. Having provided the food with the color that is capable of attracting the fish to ingest the food, it is preferably added in an amount of 10% or more by weight based on the amount of the food compounded in a pill. The inventive feed can be any size provided it can be easily eaten by the fish to be fed, and can be fed. Alternatively, the inventive feed can have a chosen size independently of the growth of the fish to be fed. The inventive food can be obtained by filling the food material in an edible housing whose surface is at least partially colored to show a whitish or bluish color. Suitable edible accommodations may include natural accommodations made from animal casings, animal-derived accommodations made from collagen obtained from fish or livestock, and plant-derived accommodations, and are not limited to any specific. For example, the inventive food can be obtained by filling the solid food in a colored housing as described in WO 2004/021800. Suitable accommodations made of a colored edible film can include, for example, those used for the production of ham and sausages, natural accommodations made of sheep intestines, artificial housings, nets made of edible fibers, and colored gelatin capsules obtained by lengthening those used for the production of medicinal capsules. The food material is filled in such a housing and sealed. Preferably, after the introduction of the material, the content is de-aerated, and the open end is hermetically sealed. To produce lodged composite feed which, when thrown into the sea, sinks on its own, it is preferable to prepare multiple pores on the surface of the housing, or to use a housing having a structure similar to a mesh. - When the water will penetrate the contents, the compound food will easily sink into the sea. In addition, a substance that stimulates the intake of food contained in the compound food will dissolve in water, and improve the intake of food by fish. Even when the compound food is covered with a perforated housing, it is possible to make it float in the sea by making the contents porous. The present invention will be specified below by means of examples. However, the present invention is not limited in any way by these examples. All percentages are by weight unless otherwise indicated. Example 1 The test fish consisted of approximately 1,500 blue tunas (Thunnus thynnus) weighing approximately 28 kg grown in an annex having an ellipsoidal cross section of 35 m x 50 m and a depth of 38 m. The test food samples are mainly made of thin mackerel meat that has been molded into Oregon wet pill. Three kinds of test food samples are prepared: a sample of brown food, a sample of blue food and a sample of white food. The brown food sample is obtained by using thin mackerel skin, red muscles and ordinary muscles as a raw material without the addition of any pigment. The blue food sample is obtained by adding a blue pigment, "Kiriya EL blue" (Kiriya Chemical) to the feed material. Specifically, the pigment is added to the feed material- (L-% T-qxie is molded -ejalojjjCje ^^ ej ^^ IldjitasL The sample of white food is obtained by using ordinary muscles of thin mackerel without skin and red muscles as a raw material, and mold the material into Oregon wet pill.Each of the food samples consists of pills that have a diameter of 2.4 cm and a length of 15 cm.The sample of brown food had the same color as that of pills commonly used (MP) or expansion pills (EP) The color of each food sample is measured with a colorimeter (CR-300), MINOLTA): the color is plotted in a color coordinate system L * a * b *. The data of the coordinates L * a * b * of each food sample are shown in Table 1. It is notable that the blue food sample has a negative b * and the white food sample has a high L * coordinate. Table 1
The determination of the percent of consumption of each food sample is made as follows. For each feeding session, 3 kg of a food sample are prepared. If the total amount of the food sample is given only once, large quantities of food pill will be disseminated in a timely manner to which the food is poured. .jcj¾nia- ^ e_ l ^ ca ntity of food currently consumed by fish. To avoid this, the food sample is supplied several times in small amounts. In addition to the food samples, raw food (frozen mackerel) is given as a sample of comparative improvement. For each food sample and comparative food sample, feeding sessions are repeated three times. For each feeding session, the initial amount of feed and the amount of residual feed are determined, and from them the amount of food actually consumed is calculated, and the average consumption percent is determined for each food sample and the sample of comparative food. Results: The percent of consumption of each food sample is shown in Table 2. The white and blue food samples are consumed more avidly than the brown food sample, and are consumed as avidly as the comparative food sample. (raw mackerel). Table 2
From the previous results it is confirmed that the samples of blue and white food used in the test had an activity that stimulates the food intake so. high as the raw food. Example 2 Materials and Methods: The test fish consisted of approximately 1,500 bluefin tunas (Thunnus thynnus) weighing approximately 31 kg grown in two annexes having an ellipsoidal cross section of 35 m x 50 m and a depth of 38 m. The test food samples are mainly made of thin blue grenadier meat (Hoki) that is molded in Oregon wet pill. Six kinds of test food samples are prepared, including samples of brown, blue, green, yellow, red and white food. Samples of brown, blue, green, yellow and red food are colored with pigments "Kiriya K-12 coffee", "Kiriya EL blue", "Kiriya green", "Kirisin L-1 00", and "red Carmine MK-40", respectively (all from Kiriya Chemical). The coloration of the food samples with the pigment is achieved by immersing the sample in a solution in which the pigment dissolves. Specifically, to obtain the coloring solution, "Kiriya K-1 2 coffee" is diluted 2 times, "Kiriya EL blue" is diluted 10 times, "Kiriya green" is used clean, "Kirisin L-100" is dilutes 1 00 times, and "carmín red MK-40" is diluted 50 times. The white food sample were clean wet pills without the addition of any pigment. Each of the food samples consists of pills that have a diameter of 3.0 cm and a length of 1 0 cm. The color of each food sample is measured with a colorimeter (CR-300, MI NOLTA): the color is plotted in a color coordinate system L * a * b *. The data of the coordinates L * a * b * of each food sample are shown in Table 3. It is notable that the target has a high L * coordinate. Table 3
For each feeding session, 1 0 kg of a food sample is prepared. To avoid feeding madness, each food sample is given several times in small amounts. For each food sample, feeding sessions are repeated three times. For each feeding session, the initial amount of feed and the amount of waste feed are determined, and from them the amount of food actually consumed is calculated, and the average consumption percent is determined for each food sample. The wavelength of reflected light of the pigment added to each food sample is determined as follows. Light that has different wavelengths is radiated to the food sample, and the intensity of reflected light is determined with a spectrophotometer (DU640, Beckman). For each test sample, the wavelength (nm) of reflected light giving the maximum intensity is determined and the result is shown in Table 4.
Coffee food Food blue Food Food Food red green yellow Long time of 735 481 51 8 61 7 798 wave (nm) of light reflected maximum
Result: The percent of consumption of each test sample is shown in Table 5. The samples of blue and white food are consumed more avidly. For the brown food sample whose color resembles that of common compound fish feed, a third or more of the initially prepared amount is left unconsumed after a feeding session. For green, yellow and red food samples, only about 30% of the amount initially prepared is consumed, that is, two thirds or more of the amount initially prepared is left unconsumed. Table 5
From the above results, it was shown that the blue and white food samples used in the test yielded ocoonndduuccttaa of aalliimmeennttaacciioonn dd-- pp-eessccaacckk * iinnddiiccaa qquuee llaass ddooss ccllaasseess ddee aalliimmeennttoo sseerránn mmuuyy úuttiilleess ccuuaannddoo ssee eemmpplleeaann ccoommoo aalliimmeennttoo ppaarraa ppeessccaaddoo ppiissccíívvoorroo ccuullttiivvaaddoo .. Cultivating in a closed environment, special such as annex or tank, the use of compound feed prepared according to the inventive method makes it easy to achieve the change of feed from raw food to food based on feed even for fish cultivated that has a strong predilection, natural to raw fish meat.