JP2006061107A - Parasitic disease inhibitor, feed for marine cultured fishes and method for preventing parasitic disease of marine cultured fishes - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a parasitic disease inhibitor that is used without being limited by kinds of fishes and parasites being extermination targets, reduces labor and cost of an aquaculturist and does not excessively stress cultured fishes. <P>SOLUTION: The parasitic disease inhibitor controls parasitic diseases caused by ectoparasites such as Benedenia seriolae, Heteraxine heterocerca, living within marine cultured fishes such as yellow tail, amberjack, Seriola aureovittata, red sea bream, sea bass, flatfish, Sphoeroides rubripes, hardtail, Oplegnathus punctatus, Rachycentron canadum, horse mackerel. The parasitic disease inhibitor comprises a cacao bean composition obtained from cacao bean, namely cocoa powder formed from cacao bean or beanstalk of cacao bean as an active ingredient. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a parasitic disease inhibitor, and more particularly to a parasitic disease inhibitor that suppresses parasitic diseases caused by ectoparasites parasitic on marine cultured fish. Moreover, this invention relates to the method for preventing the parasitic disease of marine cultured fish by administering the feed for marine cultured fish containing such a parasitic disease inhibitor and a parasitic disease inhibitor.

  There are various types of parasites that infest and damage marine fish that are widely cultivated in Japan, depending on the species of fish used as the host and the part of the infestation, but yellowtail, amberjack, red sea bream, sea bass, flounder, Commonly known as an aphid that parasitizes ectoparasites, commonly called Hadamushi, which parasitize the body surface of marine aquaculture fish such as troughfish, striped eagle, Japanese cypress, Japanese cedar, bluefin tuna, etc., and common worms that parasitize cormorants such as yellowtail, amberjack, Japanese cypress, red sea bream, tiger pufferfish, Japanese flounder, etc. There are known ectoparasites called.

  The damage of marine cultured fish due to such ectoparasites is not a big problem at the stage where the number of parasites is small. However, in May to July, which is the appropriate water temperature season (22 ° C to 26 ° C), the parasites The life cycle of the larvae hatching to become adults and laying eggs is relatively short (2 to 3 weeks), resulting in a large amount of infestation and a major problem. This parasitic stimulation stress causes a decrease in food intake, growth stagnation, and loss of vitality of cultured fish. Furthermore, secondary infection of pathogenic microorganisms is induced from the damaged part of the body surface due to external parasitism, resulting in increased damage. Such a situation is particularly problematic during the juvenile and juvenile stages when resistance to parasites is weak.

  As a method for detoxifying ectoparasites in such marine cultured fish, methods such as a fresh water bath and a concentrated salt water bath are conventionally known. The principle of these methods is that the fish body is immersed in fresh water or concentrated salt water having a different osmotic pressure from seawater for 3 to 5 minutes, the ectoparasites are killed by the difference in osmotic pressure, and the transparent insect body is whitened and the fish body Based on peeling off from the table. For example, in a common freshwater bath, freshwater is filled in a special water tank installed around a sea surface aquaculture ginger or on a ship, and the special water tank is aerated by aeration. The cultured fish taken up from the cultured ginger is immersed in this special aquarium and left for 3 to 5 minutes to kill and peel off the parasite.

  However, in this method of deworming using a fresh water bath, it is necessary to carry a large amount of fresh water and pump it into a special aquarium. In addition, a huge number of cultured fish are taken from the ginger and placed in the special aquarium, and then the fresh water bath is completed. Later, it is necessary to take it out of the special tank and return it to the farmed ginger. Thus, the anthelmintic method using a fresh water bath has to repeat complicated and harsh work, and requires excessive labor and time.

  Moreover, the picking up of the cultured fish in these work processes and the handling in the fresh water bath give great stress to these cultured fish. In particular, the life cycle of ectoparasites is shortened to 2-3 weeks during the optimal water temperature period for breeding, and as a result, frequent fresh water bathing is required, so stress is accumulated in the farmed fish and the health of the farmed fish is improved. It will also have an adverse effect.

As described above, freshwater baths have generally been used as a method for detoxifying ectoparasites (spotted beetles and aphids) that parasitize various types of marine cultured fish. Recently, some fish have been treated with anthelmintic drugs. The method of bathing is shown by the Ministry of Agriculture, Forestry and Fisheries (see Non-Patent Document 1). For example, 1 kg of approved hydrogen peroxide is mixed and dissolved in 1 m ^{3 of} on-site sea water for 3 minutes for the anthracnose deworming in perch such as yellowtail, amberjack, red sea bream, Japanese horse mackerel, bluefin tuna, etc. Method, a method for mixing 1 kg of hydrogen peroxide approved in 1 m ^{3 of} on-site sea water and bathing the fish for 20 minutes for the aphid in a puffer fish such as tiger puffer or kingfish, For this reason, a method has been proposed in which 1 kg of approved hydrogen peroxide is mixed and dissolved in 1 m ^{3 of} on-site seawater and the fish body is bathed for 20 to 30 minutes. In the chemical bath method using hydrogen peroxide, industrial hydrogen peroxide and hydrogen peroxide for food additives are not approved. Can not be used.

  According to the method of mixing and dissolving hydrogen peroxide in the field seawater as a medicinal bath anthelmintic agent and using it for the medicinal bath, a large amount of fresh water is transported to a special aquarium around aquaculture ginger or on a ship like a fresh water bath. There is an advantage that the labor and cost to pump are not necessary. However, this medicinal bathing work is no different from a freshwater bath in that it requires a lot of effort over a long period of time, and the stress associated with medicinal bathing reduces the vitality of cultured fish, which is the target of anthelmintic, and causes pathogenic microorganisms. There remains a concern that the secondary infection of this cause of fish disease will be induced.

  In order to solve these problems, a method of orally administering an anthelmintic agent has been proposed as a method that does not depend on a fresh water bath or a chemical bath (see Patent Document 1, Patent Document 2, and Non-Patent Document 1). For example, for perch fish such as yellowtail, amberjack, red sea bream, cedar, bluefin tuna, etc., a method of orally administering 150 mg of praziquantel (isoquinoline / pyrazine derivative) per day as fish weight is proposed as a beetle anthelmintic. According to such a method, in an everyday feeding operation, an anthelmintic agent may be mixed with the feed and fed to the cultured fish, so that no great effort is required. Further, since the anthelmintic agent is taken orally together with the feed, there is a great advantage in that the anthelmintic treatment can be surely performed without giving stress to the cultured fish.

  However, for example, the Hadamushi anthelmintic agent mentioned in the above-mentioned example is an expensive drug approved as a marine product. Since the amount of medicine to be fed to farmed fish increases as the weight of the farmed fish increases, the use of such expensive anthelmintics is limited to the fry or juvenile stage when the weight of the fish is small because of the cost of medicine. Will be. Therefore, it is necessary to use the above-described fresh water bath or medicinal bath for fish weighing more than 1 kg.

  In addition, the above-mentioned anthelmintic agents are approved as oral anthelmintic agents that can be used only for the periwinkle fishes, and are suitable for the puffer fishes such as tiger pufferfish and kingfisher, and for the beetles and aphids of flounderfishes such as flounder and flounder. It is not approved for use. Therefore, there is no method other than responding to freshwater baths and medicinal baths for the aphids of the perch fishes, the Hadamushi and the aphids of the puffer fishes and the flatfishes. As described above, although an anthelmintic agent as a pharmaceutical product is convenient, it has many restrictions on use and is difficult to use.

JP-A-7-213234 JP 2000-281568 A Ministry of Agriculture, Forestry and Fisheries, Consumer Affairs and Safety Bureau, Sanitation Management Section, “About the use of pharmaceuticals for fisheries”, 17th report, July 18, 2003, p. 9,12

  The present invention has been made in view of such problems of the prior art, and can be used without being limited to the types of fish and parasites to be anthelmintic, thus reducing the labor and cost of the fishermen. A first object is to provide a parasitic disease inhibitor that does not give excessive stress to cultured fish.

  In addition, the present invention can be used without being limited to the type of fish and parasites that are the target of anthelmintic, and it is also possible to insulate marine aquaculture fish at low cost and with little labor without giving excessive stress to the aquaculture fish. A second object is to provide a feed for marine cultured fish that can suppress worm disease.

  Furthermore, the present invention can be used at low cost without being limited to the species of fish and parasites that are the targets of anthelmintic, reducing labor burden and cost of the fishermen, and giving excessive stress to the fish It is a third object of the present invention to provide a method for preventing parasitic diseases in sea surface cultured fish that do not have water.

  For example, the susceptibility to beetles in cultured yellowtails such as yellowtail, amberjack, and Japanese whitefish vary among individuals even in the same fish species. Individuals with a low initial number of parasites tend to reduce the number of parasites again after anthelmintic treatment in a fresh water bath, and conversely, individuals with a high number of initial parasites tend to increase the number of reparasitises after anthelmintic treatment. is there. These tendencies are similar to the tendency for individuals with high biodefense activity to have low onset frequency and individuals with low biodefense activity to have high onset frequency in bacterial / viral infections of cultured fish. From these facts, the present inventors considered that it is effective to increase the biological defense activity of farmed fish as a method for suppressing parasitic diseases caused by the beetle.

  In addition, it is said that in the farmed trough puffer, if an individual with aphids on the cocoon survives mortality, the frequency of subsequent aphid infestation is low. This is in common with bacterial and viral infections of cultured fish that individuals who have survived moribund gain antibody immunity, improve their bioprotective activity, and then suppress the onset of infection. From these facts, the present inventors considered that it is effective to increase the biological defense activity of cultured fish as a method for suppressing parasitic diseases caused by aphids.

  Examples of substances that enhance the bioprotective activity of cultured fish include peptidoglycan derived from bacterial cells, yeasts, mushrooms, seaweed-derived β-1,3-glucan, or shrimp / crab shell chitin / chitosan (“ Aquaculture ", Midori Shobo, November 2001, p. 61) has been developed and used. Recently, polyphenolic compounds represented by flavonoids, anthocyans, catechins and the like contained in various plants Has come to be noticed.

  Polyphenol is a group of water-soluble phenols and is a general term for compounds having a plurality of hydroxyl groups (—OH groups) directly connected to a benzol nucleus (carbon six-membered ring) in the same molecule. In the natural plant kingdom, this polyphenol is usually widely distributed as a glycoside bonded to sugar, and constitutes a plant pigment, a bitter component, and the like. Such polyphenols are antioxidant and anti-stress effects that suppress the harmful effects of in vivo active oxygen and lipid peroxides that cause various diseases, or vitamin P effects (strengthening capillaries, normal permeability) It is known to show medicinal effects such as maintenance of allergy, allergic anti-hypersensitivity, vitamin C oxidation inhibition, etc. (“Food Science”, Sankyo Publishing, 1994, p. 117-122; Iwanami Shoten, 1986, p. 1030, 1130).

  While the present inventors are conducting various studies on substances that enhance the bioprotective activity of marine cultured fish, they have not been used at all in the field of fish feed, and the physiological role for cultured fish has not been studied. Focused on cocoa beans. Cocoa beans are known to be rich in cocoa polyphenols, such as flavonoids quercetin and its glycosides, rutin that exhibits vitamin P action, tannin, epicatechin and the like. As a result of experiments by the present inventors, it was found that ectoparasite disease can be extremely effectively suppressed by orally administering this cocoa bean as a bioprotective active substance to marine cultured fish, leading to the completion of the present invention. It was.

  That is, according to the 1st aspect of this invention, the parasitic disease inhibitor which suppresses the parasitic disease by the ectoparasite which parasitizes marine cultured fish is provided. This parasitic disease inhibitor contains, as an active ingredient, at least one of a cocoa bean composition obtained from cocoa beans, that is, cocoa powder produced from cocoa beans and cocoa bean shells.

  According to the 2nd aspect of this invention, the feed for marine cultured fish containing the said parasitic disease inhibitor is provided. For example, the above-mentioned parasitic disease inhibitor is mixed with a mixed feed powder and granulated into a solid feed, or the parasitic disease inhibitor is mixed with a feed powder and a raw feed for raw feed moist The granulated product can be used as a feed for marine cultured fish.

  According to the 3rd aspect of this invention, the prevention method of the parasitic disease of marine cultured fish is provided. That is, by orally administering the above-mentioned feed for marine aquaculture fish to aquaculture such as yellowtail, amberjack, flounder, etc. and marine aquaculture fish including red sea bream, sea bass, flounder, tiger puffer, striped horse mackerel, sea bream, cedar, bluefin tuna, etc. Can prevent parasitic diseases in marine aquaculture fish.

  Here, the term “cocoa beans” refers to seeds contained in the fruit of a cacao tree that is a plant belonging to the genus Caenoraceae cultivated in the tropical region. The cocoa powder refers to a product obtained by fermenting and roasting the cocoa beans by a usual processing method, removing the skin, crushing and processing into a powder, and is also called pure cocoa. The cocoa bean husk (hereinafter referred to as cocoa bean husk) refers to a bean husk (cocoa husk) obtained as a processing byproduct when cocoa powder is processed. In general, cocoa powder is called cocoa when used for drinking, and is called chocolate when used for confectionery (“Ingredients”, Shogakukan, 1995, p.351). Therefore, it goes without saying that these cocoa and chocolate are included in the cocoa powder of the present invention.

  In order to examine the approximate component composition of cocoa powder and cacao bean hulls, the present inventors applied these to solvent fractionation and compared fraction ratios. As a result, the cocoa powder has a moisture content of 4.0%, a fat-soluble component of 19.1%, a water-soluble extract component of 38.2%, and an insoluble component of fiber of 38.2%. They were 0%, fat-soluble component 8.9%, water-soluble extract component 11.2%, and insoluble component fiber 73.0%. As described above, it was confirmed that the cacao bean husk, which is a by-product of processing of cocoa powder, contains a considerable amount of fat-soluble components and water-soluble extract components that are components of cocoa powder. From these results, the present inventors considered that cocoa bean husks could be handled in the same manner as cocoa powder as an active ingredient of a parasitic disease inhibitor. It is exemplified that the cocoa bean husk is used only very slightly as a fiber source in livestock feed for dairy cattle (“Feed Raw Material Encyclopedia”, Shiba Kogyo, 1997, p. 39). ).

  According to the present invention, it can be used without being limited to the species of fish and parasites to be anthelmintic, and without causing excessive stress to the cultured fish, the parasitic disease of the marine cultured fish is inexpensive and requires little effort. Can be suppressed.

  The parasitic disease inhibitor according to the present invention contains as an active ingredient at least one of a cocoa bean composition obtained from cocoa beans, that is, cocoa powder produced from cocoa beans and cocoa bean shells. When this anti-parasitic agent is administered to marine aquaculture fish, it may be administered to the aquaculture fish as it is, but in order to ensure that the marine aquaculture fish can be ingested orally, it is necessary to use a mixed feed powder for marine fish. After adding a certain amount of cocoa bean composition and mixing it uniformly, it is preferable to feed what is granulated and formed into an appropriately sized blended solid feed. In this case, prepare a premix (mixed feed premix), usually called mixed feed, mixed with feed excipients so that the content of the cocoa bean composition is a constant concentration. The feed premix may be added to and mixed with the mixed feed powder for marine cultured fish and granulated. Alternatively, after adding a predetermined amount of cocoa bean composition directly to the feed powder for raw feed moist and mixing it uniformly, feed the raw feed moist feed with an appropriate size together with the raw feed. Also good. In this case, a predetermined amount of the above mixed feed premix may be added to and mixed with the raw feed moist feed powder, and then granulated and formed into an appropriate size raw feed moist feed together with the raw feed.

  Here, as the feed excipient used for the preparation of the mixed feed premix, for example, calcium carbonate, calcium phosphate, silica gel, lactose, feed yeast, wheat flour, starch, dextrin, cereal flour, potatoes, etc. Can be mentioned. Further, if necessary, nutritional supplements such as vitamin mixtures and mineral mixtures can be added to enhance the nutrition of marine cultured fish. Further, a binder such as sodium alginate or guar gum may be added at the same time in order to facilitate granulation molding of the raw feed moist feed.

  In addition, when a solid feed or a live feed moist feed containing the above parasitic disease inhibitor is fed to marine cultured fish, the concentration of cocoa powder in the feed when the feed moisture is 10% is 500 to 5000 ppm, preferably 1000 It is preferable that the concentration of cacao bean husk is 3000 to 10000 ppm, preferably 5000 to 10000 ppm, so as to be ˜3000 ppm.

  The weight of the cocoa composition to be fed varies depending on the type and size of the target fish, but is usually 10 to 100 mg, preferably 20 to 60 mg of cocoa powder per kg of fish weight per day, or 60 It is preferable to feed ~ 200 mg, preferably 100-200 mg of cocoa bean husk. In addition, these values are converted from the feed intake (average feed rate of 2%) of the feed containing the cocoa bean composition that the target fish is satiety ingested.

  For example, Benedenia seriolae (Benedenia seriolae), Benedenia sekii (Bedenia seriolae), Benedenia sekiolae (Benedenia seriolae), Benedenia sekiola (Bedenia seriolae), Benedenia sekiolae (Benedenia seriolae) Benedenia sekii, Benedenia hoshinai, Benedenia epinepheli, Benedenia girellae, Anoplodiscus tai. Sp. Nov., Anoprodiscus spa (Anoplodiscus spari), Caligus lalandei, Caligus longipedis, Pseudocaligus fugu and others have been reported.

  In addition, for example, heteraxine heterocerca, Zeuxapta japonica, Bivagina tai, and heterobots are included as aphids that parasitize moths such as yellowtail, amberjack, flounder, red sea bream, and flounder. Reported examples include Heterobothrium okamotoi, Heterobothrium tetrodonis, Neoheterobothrium hirame, Caligus spinosus.

  The feed for marine cultured fish containing the above-mentioned parasitic disease control agent is effective for these beetles and aphids, and can be administered before these ectoparasites infest the marine cultured fish. In the culture of yellowtail and amberjack, the administration from 1 to 3 times a day may be performed every day for the period from juveniles to juveniles (body weight 600 to 800 g) that are greatly damaged by ectoparasites. In addition, red sea bream and tiger puffer may be administered 1 to 3 times a day from the juvenile stage to the juvenile stage. Furthermore, in order to effectively suppress ectoparasitic diseases, cultured fish once suffered from parasitic diseases may be anthelmintically treated in a fresh water bath or the like, and then the parasitic disease inhibitor may be administered.

  Hereinafter, although the specific Example of the feed for marine cultured fish mentioned above is described, this invention is not limited to these Examples.

  First, we investigated the parasitism suppression effect of marine aquaculture fish feed on amberjack, the fish species most likely to be damaged by the ectoparasite Hadamushi (Benedenia seriolae). As the test feed, cacao bean husk is added to the mixed feed powder for marine fish and mixed uniformly so that the concentration of the cocoa bean shell becomes 1000 ppm, 3000 ppm and 5000 ppm, respectively, and then suitable for the size of the test fish. Pellet-shaped dry solid feed granulated to size and cocoa powder are added and mixed uniformly so that the concentration of cocoa powder is 500 ppm and 1000 ppm, respectively, and then made into an appropriate size according to the size of the test fish The pellet-shaped dry solid feed formed into granules was used. Moreover, the solid feed which does not contain these cocoa bean compositions was used as a control feed.

  In this Example 1, a campip larvae having an average weight of about 130 g at the start of the test was subjected to a fresh water bath for 3 minutes prior to the experiment, and after completely deworming the above-mentioned beetle, 25 fish were placed in a 1 ton FRP circular tank For 4 weeks after housed, each feed was bred by feeding the test fish twice a day with a satiety feed (average feeding rate of 2%). During this period, body weight is measured every 2 weeks, and 5 fish are randomly extracted from each test area and placed in a fresh water bath. Naturally parasitic beetles are removed from the body surface during each period. The total number of infestations was counted. Thereby, the suppression effect of the parasitic disease by the density | concentration according to the density | concentration of a cocoa bean composition was compared based on the number of infestations. The average weight of the amberjack after the test was about 220 g. The results are shown in Table 1.

  In Example 2, the same experiment as in Example 1 was conducted on amberjack fry having an average body weight of about 35 g at the start of the test. In this experiment, test feeds having a cocoa bean shell concentration of 5000 ppm and 10,000 ppm, respectively, and cocoa powder concentrations of 1000 ppm, 3000 ppm, and 5000 ppm were used. Thirty amberjack larvae that were completely dewormed by a freshwater bath were housed in a 1-ton FRP circular aquarium and fed with each feed for 6 weeks. During this period, every 2 weeks, 5 fish were randomly extracted from each test section and placed in a fresh water bath to count the total number of parasitoids. The average weight of the amberjack after the test was about 140 g. The results at this time are shown in Table 2.

  In Example 3, the same experiment as in Example 1 was conducted on amberjack fry having an average body weight of about 45 g at the start of the test. In this experiment, test feeds having a cacao bean hull concentration of 5000 ppm and 10,000 ppm, respectively, were used. Seventeen amberjack larvae that were completely dewormed by a freshwater bath were housed in a 1-ton FRP circular aquarium and fed with each feed for 6 weeks. During this period, every 2 weeks, 3 fish were randomly extracted from each test area and placed in a fresh water bath, and the total number of parasitoids was counted. The average weight of the amberjack after the test was about 130 g. The results at this time are shown in Table 3.

  From the results shown in Tables 1 to 3 above, for the larvae or juvenile size amberjack, the number of parasitoids of Hadamushi was clearly reduced in all test diets compared to the control diet during the 4 to 6 week breeding period. I understand that. Moreover, it was confirmed that the feed having a cocoa powder concentration of 1000 ppm and the feed having a cocoa bean shell concentration of 5000 ppm to 10000 ppm have a high effect of increasing the weight of the test fish.

  In Example 4, the same experiment as in Example 1 was performed on amberjack in the growing stage where the average body weight at the start of the test was about 500 g. In this experiment, a test feed having a cocoa bean shell concentration of 5000 ppm was used. Twenty-four amberjacks that were completely dewormed by a freshwater bath were housed in a 1 ton FRP circular water tank and fed with feed for 8 weeks. In the meantime, every 2 weeks, 4 fish were randomly extracted from each test area and placed in a fresh water bath, and the total number of parasitoids of the beetle was counted. The average weight of the amberjack after the test was about 750 g. The results at this time are shown in Table 4.

  In Example 5, the same experiment as in Example 1 was performed on amberjack in the growing stage where the average body weight at the start of the test was about 650 g. In this experiment, a test feed having a cocoa bean shell concentration of 5000 ppm was used. Sixteen amberjacks that were completely dewormed by a freshwater bath were housed in a 1 ton FRP circular water tank and fed with feed for 8 weeks. In the meantime, every 2 weeks, 4 fish were randomly extracted from each test area and placed in a fresh water bath, and the total number of parasitoids of the beetle was counted. The average weight of the amberjack after the test was about 850 g. The results at this time are shown in Table 5.

  From the results shown in Tables 4 and 5 above, with regard to the growth-size amberjack, all the test feeds had fewer parasitoids than the control feed throughout the 8-week rearing period, Inhibition of parasitic diseases caused by. Further, the test feeds used in Examples 4 and 5 were also found to have a high effect of increasing the weight of the test fish, similarly to the test feeds used in Examples 1 to 3 described above.

  Conventionally, organic selenium-containing cells (see, for example, JP-A-7-213234) and capsaicin (see, for example, JP-A-2000-281568), which is a pungent component of chili, suppress parasitic diseases. It is known to be effective. In Examples 6 to 9 to be described below, the effect of suppressing parasitic diseases on the amberjack of the test feed having a cocoa bean shell concentration of 5000 ppm tested in Examples 4 and 5 described above, containing selenium-containing feed and capsaicin Compared to feed.

  In Example 6, the inhibitory effect of parasitic diseases was compared on juvenile amberjack having an average weight of about 40 g at the start of the test. As feeds to be compared, selenium is added to the blended feed powder and mixed uniformly so that the selenium concentration becomes 1 ppm, and then the feed prepared as pelleted dry solid feed and capsaicin is added to obtain a capsaicin concentration of 15 ppm. After uniformly mixing as such, the feed prepared as pelletized dry solid feed was used. Thirty amberjacks that were completely dewormed by a freshwater bath were housed in a 1 ton FRP circular water tank and fed with feed for 4 weeks. During this period, every 2 weeks, 5 fish were randomly extracted from each test section and placed in a fresh water bath to count the total number of parasitoids. The average weight of the amberjack after the test was about 100 g. The results at this time are shown in Table 6.

  The same experiment as in Example 6 was performed on amberjack in the growing stage where the average body weight at the start of the test was about 330 g. As a feed for comparison, a pellet-shaped dry solid feed having a selenium concentration of 1 ppm was used. 15 amberjacks that were completely dewormed by a freshwater bath were housed in a 1 ton FRP circular water tank and fed with feed for 6 weeks. In the meantime, every 2 weeks, 2 fish were randomly extracted from each test area and subjected to a fresh water bath, and the total number of parasitoids was counted. The average weight of the amberjack after the test was about 450 g. The results at this time are shown in Table 7.

  An experiment similar to Example 6 was performed on amberjack in the growing stage where the average body weight at the start of the test was about 580 g. As a feed to be compared, a pellet-shaped dry solid feed having a selenium concentration of 0.5 ppm and 1 ppm, respectively, was used. 15 amberjacks that were completely dewormed by a freshwater bath were housed in a 1 ton FRP circular water tank and fed with feed for 6 weeks. In the meantime, every 2 weeks, 2 fish were randomly extracted from each test area and subjected to a fresh water bath, and the total number of parasitoids was counted. The average weight of the amberjack after the test was about 650 g. The results at this time are shown in Table 8.

  An experiment similar to Example 6 was performed on adult amberjack having an average body weight of about 1.07 g at the start of the test. As a feed to be compared, a pellet-shaped dry solid feed having a selenium concentration of 1 ppm and a pellet-shaped dry solid feed having a capsaicin concentration of 35 ppm were used. Eight amberjacks that were completely dewormed by a freshwater bath were housed in a 2-ton FRP circular water tank and fed with feed for 4 weeks. In the meantime, every 2 weeks, 4 fish were randomly extracted from each test area and placed in a fresh water bath, and the total number of parasitoids of the beetle was counted. The average weight of the amberjack after the test was about 1.6 kg. The results at this time are shown in Table 9.

  As is clear from the results shown in Tables 6 to 9, the cocoa bean shell feed having a concentration of 5000 ppm according to the present invention has an effect superior to that of the conventional parasitic disease inhibitor as an inhibitory effect on the cabbage parasitism. showed that. Moreover, it was found that the feed for marine cultured fish according to the present invention has a comparatively stable parasitic disease control effect at any stage from amberjack fry to adult fish.

  Next, the parasitism inhibitory effect of Hadamushi (Benedenia seriolae) on the hamachi of the feed for marine cultured fish according to the present invention was examined. As test feed, add cacao bean husk to blended feed powder for marine fish and mix evenly so that the concentration of cacao bean hull is 5000 ppm, then granulate and shape to suitable size according to the size of test fish The pelleted dried solid feed and cocoa powder were added and mixed uniformly so that the concentration of cocoa powder was 1000 ppm, 3000 ppm, and 5000 ppm, respectively, and then granulated to an appropriate size according to the size of the test fish A pellet-shaped dry solid feed was used. In Example 10, 50 Hamachi fry with an average weight of about 45 g at the start of the test were housed in a water tank and bred for 4 weeks. During this period, the total number of parasitoids in each test area that naturally parasitized was counted. The average weight of hamachi after the test was about 135 g. The results at this time are shown in Table 10.

  From the results shown in Table 10 above, it can be seen that for the larvae-sized hamachi, the number of Hadamushi parasites is clearly reduced in all the test feeds compared to the control feed throughout the breeding period. Moreover, about the test feed used in Example 10, it was confirmed that the effect which increases the body weight of a test fish is high.

  Next, the parasitic suppression effect of the aphid (Bibagina, Thailand) on red sea bream of the marine cultured fish feed according to the present invention was examined. As test feed, cacao bean husk is added to the mixed feed powder for marine fish and mixed uniformly so that the concentration of cocoa bean shell becomes 5000 ppm and 10000 ppm, respectively, and then adjusted to the appropriate size according to the size of the test fish. A granulated and molded pellet-shaped dry solid feed was used. In this Example 11, 20 fish of red sea bream with an average weight of about 160 g at the start of the test were housed in an aquarium and bred for 8 weeks. During this period, 5 fish were randomly extracted from each test group every 2 weeks. The body weight was measured and the sputum was excised and the state of the aphid infestation was observed with a microscope to count the total number of aphid infestations. The average weight of red sea bream after the test was about 270 g. The results at this time are shown in Table 11.

  From the results shown in Table 11 above, it can be seen that for the red sea bream-sized red sea bream, the number of aphid parasites is clearly reduced in all the test feeds compared to the control feed throughout the breeding period. Moreover, about the test feed used in Example 11, it was confirmed that the effect which increases the body weight of a test fish is high.

  Next, the parasitic suppression effect of the sand beetle (Neobenedenia guillere) on the flounder of the feed for marine cultured fish according to the present invention was examined. As test feed, add cacao bean husk to blended feed powder for marine fish and mix evenly so that the concentration of cacao bean hull is 5000 ppm, then granulate and shape to suitable size according to the size of test fish The pelleted dried solid feed and cocoa powder were added and mixed uniformly so that the concentration of cocoa powder was 1000 ppm, 3000 ppm, and 5000 ppm, respectively, and then granulated to an appropriate size according to the size of the test fish A pellet-shaped dry solid feed was used. In Example 12, 50 flounder larvae having an average weight of about 85 g at the start of the test were housed in an aquarium and bred for 6 weeks. During this period, body weights were measured every 2 weeks, and 5 fish from each test group. Were randomly extracted and placed in a fresh water bath, and the natural parasitism was removed from the body surface during each period, and the total number of parasitism was counted. The average weight of the flounder after the test was about 180 g. The results at this time are shown in Table 12.

  From the results shown in Table 12 above, it can be seen that for the larvae of juvenile size, the number of parasitoids of the beetle is clearly reduced in all the test feeds compared to the control feed throughout the breeding period. In the experiment on Japanese flounder in Example 12, it was recognized that the effect of increasing the body weight of the test fish was lower than that of the control feed, unlike amberjack and hamachi.

  In the sea surface farm, the parasitic inhibitory effect of Hadamushi (Benedenia seriolae) on the amberjack of the feed for marine cultured fish according to the present invention was tested. An 8 m × 8 m × 8 m square wire netting ginger contained 4580 amberjack having an average weight of about 1.55 kg at the start of the test as a test group, and a similar ginger was accommodated as a control group. As test feed, add cacao bean husk to blended feed powder for marine fish and mix evenly so that the concentration of cacao bean hull is 5000 ppm, then granulate and shape to suitable size according to the size of test fish Cylindrical semi-dry solid feed (diameter 1.2 cm, length 1.1 cm) was used. In addition, as a control feed, a raw feed moist feed (a feed obtained by granulating and forming a mixture of frozen fish and feed powder for moist) containing no cacao bean composition was used.

  The above feed was fed to the test group and control group amberjack once a day for 6 days a week for 2 months. At the start of the test, all fish are placed in a medicinal bath to completely deworm the beetle. In the first month of the breeding, 10 fish are taken from the test group and the control group and weighed. Was measured. At this time, all the test fish in the test group and the control group were subjected to a medicinal bath to completely destroy the beetle, and then the test was continued. In the second month of breeding, the same work was performed to measure body weight and the number of parasitoids. The average weight of the amberjack after the test was about 2.1 kg. The results at this time are shown in Table 13.

  In Table 13 above, the number of Hadamushi parasitism in the first month of breeding in the amberjack of the sea surface farm is 300 in the control plot and 170 in the test plot, and in the second month of breeding. The number of Hadamushi parasitism is 670 in the control group while it is 380 in the test group. That is, from the results shown in Table 13 above, it was found that the number of parasitics in the test group was suppressed to about ½ of the number of parasitics in the control group in any measurement. This result suggests that, when the control group requires two drug baths, the test group requires only one drug bath.

  Thus, according to the present Example in the scale of a farm, it became clear that a cocoa bean composition has the advantage that the frequency | count of a medicine bath can be reduced while being effective in suppression of a parasitic disease. In addition, about the increase in the body weight of the test fish in a present Example, since a feed form differs with a solid feed (test feed) and a raw feed moist feed (control feed), it cannot compare in general, but it is 1 of test. It is inferred that, since the number of parasites increased in the control group after a lapse of months, the food intake decreased and the body weight gain significantly decreased.

  Next, the cacao bean composition was mixed with the raw food frequently fed at the sea surface farm and fed to the cultured amberjack, and the parasitic suppression effect of Hadamushi (Benedenia seriolae) was tested. An 8 m × 8 m × 8 m square wire netting ginger accommodated 17500 amberjack larvae having an average weight of about 280 g at the start of the test to serve as a test group, and a similar ginger accommodated 16000 fishes as a control group. As the test feed, a raw feed pellet feed obtained by granulating a frozen fish as it was by crushing it with a pulverizer and adding the cocoa bean shell to a cocoa bean shell concentration of 1000 ppm was used. Moreover, the raw feed pellet feed which does not contain a cocoa bean composition was used as a control feed.

  The above feed was fed sativaly once a day for 6 days a week to the test group and control group. At the start of the test, all fish are placed in a medicinal bath to completely deworm the beetle. In the first month of the breeding, 10 fish are taken from the test group and the control group and weighed. Was measured. The average weight of the amberjack after the test was about 400 g. The results at this time are shown in Table 14.

  From the results shown in Table 14 above, the number of infestations in the control group in the first month was 470, whereas the number of infestations in the test group was 280, and the number of infestations in the test group was 1 in the control group. It turns out that it was suppressed to about / 2. Since this result is similar to the result of the above-mentioned Example 13 tested using the cylindrical semi-dry solid feed, the parasitic suppression effect on the cabbage of the marine cultured fish feed according to the present invention is fed. The possibility of being affected by the form of feed is considered to be small. In this example, the increase in the body weight of the amberjack in the test group was larger than the increase in the body weight in the control group, but drowning that seemed to be a natural depletion was observed in both the test group and the control group.

  Next, in the sea surface farm, the parasitic inhibitory effect of the aphid (heterobotulinum okamotoi) and the bark beetle (body surface calligus: pseudocarigus pufferfish) on the trough puffer of the feed for marine cultured fish according to the present invention was tested. A square net ginger measuring 10 m × 10 m × 5 m accommodated 3800 trough puffers having an average weight of about 390 g at the start of the test as a test group, and 4500 fish were housed in a similar ginger as a control group. As the test feed, raw feed moist feed (raw feed and moist feed powder) prepared by adding cacao bean husk to the mixed feed powder for marine fish and uniformly mixing and shaping the cacao bean shell to a concentration of 1000 ppm. The ratio of 9: 1) was used. Moreover, as a control feed, a moist feed containing no cocoa bean composition was used.

  The above feed was fed to trough puffer in the test group and the control group twice a day, 6 days a week, and fed for 8 weeks. At the start of the test, all fish are placed in a medicinal bath to completely deter the aphids and bark beetles (Karigusu), and only the control fish are taken into the medicinal bath every time the intermediate weight is measured in the third and fifth weeks. It was attached. In the body weight measurement, 10 fish were taken from the test group and the control group, 4 of which were subjected to a fresh water bath, the beetle (Karigusu) was measured, the sputum was excised, and the aphid was measured with a microscope. The average weight of trough puffer after the test was about 500 g. The results at this time are shown in Table 15.

  From the results shown in Table 15 above, it can be seen that the number of aphid infestations in the control group is 29-67 throughout 8 weeks, whereas it is clearly reduced to 3-7 in the test group. In addition, the number of parasitoids (Karigusu body surface) in the control group showed 8 at the 8th week, but in the test group, no infestation was observed throughout the breeding period. Thus, according to the present example, it was revealed that the cacao bean composition has an effect of suppressing the parasitism of tiger pufferfish and scallops (Karigusu). In this example, the increase in the body weight of trough puffer in the test group was larger than the increase in the body weight in the control group, but moribundity that seemed to be spontaneously depleted was observed in both the test group and the control group.

  Although the embodiments of the present invention have been described so far, it is needless to say that the present invention is not limited to the above-described embodiments and may be implemented in various forms within the scope of the technical idea.

Claims (15)

A parasitic disease inhibitor that suppresses parasitic diseases caused by ectoparasites parasitic on marine cultured fish,
A parasitic disease inhibitor comprising at least one of cocoa powder produced from cocoa beans and cocoa bean shells.   2. The parasitic disease according to claim 1, wherein the marine cultured fish is at least one of a yellowtail, amberjack, Japanese cypress, red sea bream, Japanese perch, Japanese flounder, trough puffer, Japanese horse mackerel, Japanese red sea bream, Japanese cedar, and bluefin tuna. Inhibitor.   The parasitic disease suppressant according to claim 1 or 2, wherein the ectoparasite is a beetle.   The beetles are Benedenia seriolae, Benedenia sekii, Benedenia hoshinai, Benedenia epinepheli, Benedenia girre (Benedia) (Anoplodiscus tai. Sp. Nov.), Anoplodiscus spari, Caligus lalandei, Caligus longipedis, and Pseudocaligus fugu The parasitic disease inhibitor according to claim 3, wherein the number is at least one.   The parasitic disease inhibitor according to claim 1 or 2, wherein the ectoparasite is aphid.   The aphids are Heteraxine heterocerca, Zeuxapta japonica, Bivagina tai, Heterobothrium okamotoi, Heterobothium tetrodonium, The parasitic disease inhibitor according to claim 5, which is at least one of Botulinum flounder (Neoheterobothriuum hirame) and Caligus spinosus (Caligus spinosus).   A feed for marine cultured fish, comprising the parasitic disease inhibitor according to any one of claims 1 to 6.   The feed for marine cultured fish according to claim 7, wherein the parasitic disease inhibitor is mixed with a mixed feed powder and granulated into a solid feed.   The feed for marine cultured fish according to claim 7, wherein the parasitic disease inhibitor is mixed with feed powder for live feed moist and live feed and granulated into a live feed moist feed.   The feed for marine cultured fish according to claim 8 or 9, wherein a mixed feed premix obtained by mixing the parasitic disease inhibitor and a feed excipient is mixed with the feed powder.   11. The marine cultured fish feed according to claim 7, wherein the cocoa powder contains 500 ppm to 5000 ppm in terms of a feed moisture equivalent value of 10%.   The feed for marine cultured fish according to any one of claims 7 to 10, wherein the cocoa powder is contained in a concentration of 1000 ppm to 3000 ppm in terms of a feed moisture equivalent value of 10%.   The feed for marine cultured fish according to any one of claims 7 to 10, wherein the bean husk is contained in a concentration of 3000 ppm to 10000 ppm in terms of a value equivalent to 10% of feed moisture.   The feed for marine cultured fish according to any one of claims 7 to 10, wherein the bean husk is contained in a concentration of 5000 ppm to 10000 ppm in terms of a feed moisture equivalent value of 10%.   A method for preventing parasitic diseases in marine cultured fish, comprising administering the marine cultured fish feed according to any one of claims 7 to 14 to the marine cultured fish.