JP6749966B2 - Therapeutic agent for diseases caused by microspores and myxospores parasitic on marine fish - Google Patents

Description

The present invention relates to a parasite control agent for marine fish and a parasite control method. More specifically, the present invention relates to a drug and a method for exterminating the mildew or myxosporidiosis caused by microsporidia parasitic on marine fish by oral administration.

The causal parasite of yellowtail mildew is Microsporidium seriolae. In microspores, if it is clear that it is a new species and it is difficult to identify the taxonomic position above the genus level, they can be placed in the collective genus Microsporidium, which is the causative parasite of yellowtail blight. This is also the case. Parasitism of yellowtail by this insect was reported in 1982, and since then, parasitism has also been observed in amberjack and amberjack. This disease is characterized by the formation of white irregularly-shaped small cyst aggregates of parasites of several mm to 1 cm in the lateral muscles of diseased fish. When spore formation is completed in the cysts and the cysts collapse, the surrounding muscles melt and the body surface at that site appears to be depressed. For this reason, the appearance of irregularities on the body surface is called mildew. The parasite spreads over a wide area of the trunk, and sometimes the fish become extremely thin and die. If the affected area is localized and there is no secondary infection such as bacteria, the cyst will thaw and the wound will heal naturally after the microspores escape. However, not all cysts melt and the worms escape to the outside of the body, and it is known that cysts exist in the trunk even after a long period before shipment, which is one of the causes of reducing the commercial value. ing. The current situation is that no therapeutic drug for this disease has been developed, and the damage is continuing.

Also in fish species other than yellowtail, downy mildew caused by microsporidia is known in red sea bream, bluefin tuna, and the like.

The causative parasite of yellowtail myxosporosis is Kudoa yasunagai. In 1980, the worm was found in the brains of diseased fish with abnormal swimming in cultured sea bass and cultured rockfish in Nagasaki Prefecture. Since spores usually have 7 spore shells and polar sac, it was described as a new species, Septemcapsula yasunagai. However, in the subsequent phylogenetic analysis, the family Septemcapsulidae and the genus Septemcapsula were deleted, and this species was transferred to the genus Kudoa. Diseased fish show a characteristic swimming that bends and turns. In the case of yellowtail, the body may be curved. Small spherical white cysts are seen around the brain. There are no effective measures to control this disease.

In fish species other than yellowtail, tuna, flounder, etc. are known to have myxosporidiosis, which is also called kudoasis due to myxosporean insects of the genus Kudo, and in puffer fish it is caused by myxospores of the genus Enteromixum or Leptotheca. Intestinal myxosporosis (also called puffer skin thinning disease) is known.

Benzimidazoles are known as antiparasitic drugs, and in Japan, mebendazole is a therapeutic agent for pinworm disease, albendazole is a therapeutic agent for hydatid disease, and flubendazole is an animal for roundworm and roundworm nematodes. As drugs, fevantel and fenbendazole are approved as veterinary drugs against nematodes and tapeworms. For fisheries, Fevantel is approved for blowfish.

There is a report that tests the effect of albendazole on Loma salmonae, which is a microspore insect parasitizing rainbow trout (Non-patent document 1). There is a report that tests the effects of Flubendazole, Mebendazole, Oxibendazole, Parbendazole, and Triclabendazole on the monoparasite Gyrodactylus sp. parasitic on rainbow trout (Non-patent Document 2). There is a report of in vitro test of the effects of Flubendazole, Mebendazole, Oxibendazole, Parbendazole, and Triclabendazole on Philasterides dicentrarchi, which is a ciliate parasitic on turbot and sea bass (Non-patent Document 3). There is a report that tests the effects of Albendazole, Mebendazole, and Fenbendazole on Glugea anomala, which is a microspore insect parasitic on Itoyo (Non-patent document 4). There is a report that a benzimidazole-based drug is effective against Heterobothurium okamotoi, which is a monoparasite parasitic on troughfish (Patent Document 1).

WO02/005649

D.J.Speare, et al., J.Comp.Path.121, 241-248, 1999. “A Preliminary Investigation of Alternatives to Fumagillin for the Treatment of Loma salmonae Infection in Rainbow Trout”. J. L. Tojo, M. T. Santamarina, Disease of Aquatic Organisms, 33, 187-193, 1998. “Oral pharmacological treatments for parasitic diseases of rainbow trout Oncorhynchus mykiss. II: Gyrodactylus sp.”. R. Iglesias, et al., Disease of Aquatic Organisms, 49, 191-197, 2002. “Antiprotozoals effective in vitro against the scuticociliate fish pathogen Philasterides dicentrarchi”. Schmahl G., Benini J., Parasitol Res., 84(1), 41-49, 1998. “Treatment of fish parasites. 11. Effects of different benzimidazole derivatives (albendazole, mebendazole, fenbendazole) on Glugea anomala, Monies, 1887. (Microsporidia): ltrastructural aspects and efficacy studies.”.

An object of the present invention is to provide an orally administered drug for downy mildew or myxosporidiosis in marine fish (particularly, farmed fish), a method for exterminating the drug with the drug, and the like.

The inventors searched for existing anti-parasitic drugs for animals, substances derived from natural products, and the like in search of an orally administered drug effective against downy mildew, which is an important problem in the cultivation of yellowtails. As a result, they found that some of the benzimidazole drugs sold as antiparasitic drugs for animals are effective, and completed the present invention.

The gist of the present invention is the following (1) to (24) therapeutic agents for diseases caused by microspores or myxospores parasitic on fish.
(1) A therapeutic agent for downy mildew or myxosporosis of marine fish, comprising any of albendazole, fevantel, fenbendazole, oxfendazole, mebendazole, and flubendazole as an active ingredient.
(2) The therapeutic agent for downy mildew of (1), wherein the causative parasite of downy mildew is a microsporidium belonging to the genus Microsporidium or the genus Spraguera.
(3) Myxospore of (1), wherein the causal parasite of myxosporidiosis is a myxosporeworm belonging to any one of the genus Kudoa, the genus Enteromyxum, and the genus Leptotheca. A remedy for insect diseases.
(4) The therapeutic agent according to (1) to (3), wherein the marine fish is a sea bass, flatfish or puffer fish.
(5) Fishes of the order Perciformes belong to the genus Yellowtail, Thai family or genus Tuna, fishes of the order Flatfish belong to the flounder family, and fishes belonging to the order blowfish belong to the family pufferfish, ( 4) The therapeutic agent.
(6) The fishes belonging to the genus Yellowtail are yellowtail (Seriola quinqueradiata), amberjack (Seriola dumerili), flatfish (Seriola lalandi), spinach (Seriola rivoliana), Seriola carpenteri, Seriola fasciata, southern amberjack (Seriola hipposu), Seriola perpos. And Seriola zonata, and the fishes belonging to the family of the Thai family are Mina microdye (Acanthopagrus sivicolus), Taiwandai (Argyrops bleekeri Oshima), Red sea bream (Dentex tumifrons), Red sea bream (Evynnis tumifrons), Red sea bream (Pagrus major), Black sea bream (Acanthopagrus schlegelii) and sea bream (Rhabdosargus sarba, Sparus sarba), and fish belonging to the genus Tuna include bluefin tuna (Thunnus orientalis), Atlantic bluefin tuna (Thunnus thynnus), southern bluefin tuna (Thunnus maccoyii), and bigeye tuna (Thunnus tuna). obesus), albacore tuna (Thunnus alalunga), yellowfin tuna (Thunnus albacares), tuna tuna (Thunnus tonggol), and Atlantic tuna (Thunnus atlanticus). Fish belonging to the flounder family are flounder (Paralichthys olivaceus) and California. (Paralichthys californicus), juvenile flounder (Paralichthys dentatus), buffalo sole (Pseudorhombus pentophthalmus), elephant flounder (Pseudorhombus cinnamoneus), megalois (Pseudorhombus dupliciocellatus) or porpoises (Pseudorhombus dupliciocellatus) The fish belonging to the pufferfish family is Takifugu rubripes or Takifugu. porphyreus), the therapeutic agent of (5).
(7) The therapeutic agent according to any one of (1) to (6), for oral administration of the active ingredient in an amount of 5 to 100 mg/kg of fish body weight per day.
(8) A therapeutic agent for downy mildew of marine fish, comprising any of albendazole, fevantel, fenbendazole, oxfendazole, and mebendazole as an active ingredient.
(9) A therapeutic agent for downy mildew or myxosporosis of marine fish, which comprises albendazole as an active ingredient.
(10) A therapeutic agent for myxosporosis, which comprises albendazole or flubendazole as an active ingredient.
(11) A method for treating downy mildew or myxosporosis of marine fish, which comprises orally administering to a marine fish an effective amount of any of albendazole, fevantel, fenbendazole, oxfendazole, mebendazole, and flubendazole. Said method characterized by administering.
(12) The method for treating downy mildew according to (11), wherein the causative parasite of downy mildew is a microsporidium belonging to the genus Microsporidium or the genus Spraguera.
(13) Myxospores of (11), wherein the causal parasite of myxosporidiosis is a myxospore worm belonging to any of the genus Kudoa, the genus Enteromyxum, and the genus Leptotheca. How to treat worm disease.
(14) The method according to (11) to (13), wherein the marine fish is a sea bass, flatfish or puffer fish.
(15) Fishes of the order Perch are fishes belonging to the genus Yellowtail, Thai family or Tuna genus, fishes of the order Flatfish are fishes belonging to the family Flounder, and fishes belonging to the order Bluffer are fishes belonging to the family Fugu. The method of (14).
(16) The fishes belonging to the genus Yellowtail are yellowtail (Seriola quinqueradiata), amberjack (Seriola dumerili), amberjack (Seriola lalandi), spinach (Seriola rivoliana), Seriola carpenteri, Seriola fasciata, southern amberjack (Seriola hipposu), Seriola peru. And Seriola zonata, and the fishes belonging to the family of the Thai family are Mina microdye (Acanthopagrus sivicolus), Taiwandai (Argyrops bleekeri Oshima), Red sea bream (Dentex tumifrons), Red sea bream (Evynnis tumifrons), Red sea bream (Pagrus major), Black sea bream (Acanthopagrus schlegelii) and sea bream (Rhabdosargus sarba, Sparus sarba), and fish belonging to the genus Tuna include bluefin tuna (Thunnus orientalis), Atlantic bluefin tuna (Thunnus thynnus), southern bluefin tuna (Thunnus maccoyii), and bigeye tuna (Thunnus tuna). obesus), albacore tuna (Thunnus alalunga), yellowfin tuna (Thunnus albacares), bluefin tuna (Thunnus tonggol), and Atlantic tuna (Thunnus atlanticus). Fish belonging to the flounder family are flounder (Paralichthys olivaceus) and California. (Paralichthys californicus), juvenile flounder (Paralichthys dentatus), buffalo sole (Pseudorhombus pentophthalmus), elephant flounder (Pseudorhombus cinnamoneus), megalois (Pseudorhombus dupliciocellatus) or porpoises (Pseudorhombus dupliciocellatus) The fish belonging to the pufferfish family is Takifugu rubripes or Takifug. u porphyreus), the method of (15).
(17) The method according to any one of (11) to (16), wherein any of albendazole, fevantel, fenbendazole, oxfendazole, mebendazole, and flubendazole is orally administered at 5 to 100 mg/kg of fish body weight per day.
(18) Use of any of albendazole, fevantel, fenbendazole, oxfendazole, mebendazole, and flubendazole in the manufacture of a medicament for the treatment of downy mildew or myxosporosis of marine fish.
(19) The use according to (18), wherein the causative parasite of downy mildew is a microsporidium belonging to the genus Microsporidium or the genus Spraguera.
(20) Use of (18), wherein the causative parasite of myxosporidiosis is a myxosporeworm belonging to any one of the genus Kudoa, the genus Enteromyxum, and the genus Leptotheca.
(21) Use of (18) to (20), wherein the marine fish is a sea bass, flatfish or puffer fish.
(22) Fishes of the order Perch are fishes belonging to the genus Yellowtail, Thai family or Tuna genus, fishes of the order Flatfish are fishes belonging to the flounder family, and fishes belonging to the order blowfish are fishes belonging to the family pufferfish, Use of (21).
(23) Yellowtail (Seriola quinqueradiata), amberjack (Seriola dumerili), amberjack (Seriola lalandi), spinach (Seriola rivoliana), Seriola carpenteri, Seriola fasciata, southern amberjack (Seriola hipposu), Seriola perpos And Seriola zonata, and the fishes belonging to the family of the Thai family are Mina microdye (Acanthopagrus sivicolus), Taiwandai (Argyrops bleekeri Oshima), Red sea bream (Dentex tumifrons), Red sea bream (Evynnis tumifrons), Red sea bream (Pagrus major), Black sea bream (Acanthopagrus schlegelii) and sea bream (Rhabdosargus sarba, Sparus sarba), and fish belonging to the genus Tuna include bluefin tuna (Thunnus orientalis), Atlantic bluefin tuna (Thunnus thynnus), southern bluefin tuna (Thunnus maccoyii), and bigeye tuna (Thunnus tuna). obesus), albacore tuna (Thunnus alalunga), yellowfin tuna (Thunnus albacares), tuna tuna (Thunnus tonggol), and Atlantic tuna (Thunnus atlanticus). Fish belonging to the flounder family are flounder (Paralichthys olivaceus) and California. (Paralichthys californicus), juvenile flounder (Paralichthys dentatus), buffalo sole (Pseudorhombus pentophthalmus), elephant flounder (Pseudorhombus cinnamoneus), megalois (Pseudorhombus dupliciocellatus) or porpoises (Pseudorhombus dupliciocellatus) The fish belonging to the pufferfish family is Takifugu rubripes or Takifug. u porphyreus), use of (22).
(24) The medicament is used for oral administration of any one of albendazole, fevantel, fenbendazole, oxfendazole, mebendazole, and flubendazole at 5 to 100 mg/kg fish body weight per day, (18) to (23) Either use.

Further, the gist of the present invention is the following (A1) to (A5) pesticides for microspores or myxospores parasitizing fish of the genus Seriola.
(A1) A repellent for microspores or myxospores parasitic on fish of the genus Seriola, which contains a benzimidazole-based drug as an active ingredient.
(A2) Microspores or myxospores are Microsporidium seriolae, Microsporidium belonging to the genus Spraguera, Kudoa yasunagai, Myxobolus acanthogobii, Kudoor. An exterminating agent for (A1), which is any one of Kudoa shiomitsui, Kudoa pericardialis, and Kudoa amamiensis.
(A3) The pesticide of (A1) or (A2), wherein the benzimidazole drug is any of albendazole, fevantel, flubendazole, triclabendazole, fenbendazole, oxfendazole, and thiabendazole.
(A4) Yellowtail fishes are yellowtail (Seriola quinqueradiata), amberjack (Seriola dumerili), amberjack (Seriola lalandi), spinach (Seriola rivoliana), Seriola carpenteri, Seriola fasciata, southern amberjack (Seriola hipposu), Seriola perpos. (A1) to (A3) which is any of zonata.
(A5) The pesticide of any one of (A1) to (A4) for orally administering 0.5 to 500 mg/kg of fish weight per day of a benzimidazole drug.

Further, the gist of the present invention is the method for controlling parasites of (A6) to (A10).
(A6) A method for exterminating microspores or myxospores parasitic on fish of the genus Seriola, which comprises administering a benzimidazole drug.
(A7) Microsporidium seriolae, Microsporidium seriolae, Spraguera microspore worm, Kudoa yasunagai, Myxobolus acanthogobii, Kudoa shiomitsui Kudoa shiomitsui), Kudoa pericardialis, or Kudoa amamiensis (A6).
(A8) The method according to (A6) or (A7), wherein the benzimidazole drug is any of albendazole, fevantel, flubendazole, triclabendazole, fenbendazole, oxfendazole, and thiabendazole.
(A9) Yellowtail fishes are yellowtail (Seriola quinqueradiata), amberjack (Seriola dumerili), amberjack (Seriola lalandi), spinach (Seriola rivoliana), Seriola carpenteri, Seriola fasciata, southern amberjack (Seriola hipposu), Seriola peru. The method according to any one of (A6) to (A8), which is any of zonata.
(A10) The method according to any one of (A6) to (A9), wherein the benzimidazole drug is orally administered at 0.5 to 500 mg/kg of fish body weight per day.

According to the present invention, a widely-raised marine fish, particularly a parasitosis that is an important problem parasitizing fish belonging to the genus Yellowtail, Thai, tuna, flounder, or pufferfish The disease or myxosporidiosis can be effectively treated by oral administration.

FIG. 9 is a diagram showing a test schedule in Example 7 in which the test feed administration during the breeding period was set to 2 cycles.

The active ingredient of the therapeutic agent or parasite control agent of the present invention is one that is effective against downy mildew or myxosporosis among the agents classified as benzimidazole-based agents. The benzimidazole-based drug is a drug having benzimidazole as a basic skeleton, and is a drug known as a parasiticidal agent or a bactericide. Albendazole (methyl N-(5-propylsulfanyl-1H-benzimidazol-2-yl)carbamate) and febantel (methyl (NE)-N-[[[ 2-[(2-methoxyacetyl)amino]-4-phenylsulfanylanilino]-(methoxycarbonylamino)methylidene]carbamate), Fenbendazole; methyl N-(5-phenylsulfanyl-1H-benzimidazol-2-yl)carbamate), ox Examples include phenfazole (Oxfendazole; methyl N-[5-(benzenesulfinyl)-1H-benzimidazol-2-yl]carbamate) and mebendazole (Mebendazole; methyl [5-(Benzoyl)benzimidazol-2-yl]carbamate). Fevantel is known to be a prodrug and its active ingredients are fenbendazole and oxfendazole. Examples of the benzimidazole drugs effective for myxospore disease include albendazole and flubendazole (Flubendazole; methyl N-[5-(4-fluorobenzoyl)-1H-benzimidazol-2-yl]carbamate).

In one aspect, the therapeutic agent or parasite control agent of the present invention comprises any one of albendazole, fevantel, fenbendazole, oxfendazole, and mebendazole as an active ingredient, and treats mildew of marine fish as a treatment target. .. In a preferred embodiment, the therapeutic agent or parasite control agent of the present invention contains albendazole as an active ingredient, and is intended for the treatment of downy mildew of marine fish.

In yet another embodiment, the therapeutic agent or parasite control agent of the present invention contains albendazole or flubendazole as an active ingredient and treats myxosporidiosis as a treatment target.

A benzimidazole drug effective against mildew, especially albendazole, exterminates the parasites that cause mildew before cyst formation, not only has an effect of inhibiting cyst formation, but also treats diseased fish that have formed cysts. Have an effect.

Parasites for which the anti-parasitic effect of the therapeutic agent or the parasite control agent of the present invention is recognized are microsporidians that cause Botrytis that parasitize fishes belonging to marine fish, or cause myxosporosis. It is a myxosporean. Examples of the microsporidian causing causal disease include microsporidia belonging to the genus Microsporidium sp. or the genus Spraguera. Specific examples include Microsporidium seriolae, which is parasitic on yellowtail, and Microsporia of the genus Spraguera, which causes microsporian encephalomyelitis. As the myxosporeworm that causes myxosporosis, there are myxospores belonging to the Kudoa genus that causes kudoa, and enteromyxum that causes intestinal myxospore disease (Enteromyxum) or Myxosporeans belonging to the genus Leptotheca are mentioned. Specifically, Kudoa yasunagai, which causes brain myxosporosis, Myxobolus buri, which causes scoliosis, and Kudoa shiomitsui, which causes cardiac kudos. (Kudoa shiomitsui) and Kudoa pericardialis, Kudoa amamiensis, the cause of Amami kudoa, and Kudoa hexapunctata known to be parasitic on tuna , Kudoa septempunctata known to infest flounder, Enteromyxum leei, Enteromyxum fugu known to infect puffer fish , Leptotheca fugu.

The marine fish that is the subject of the present invention is a fish that is parasitized by the above-mentioned parasites. Examples of such marine fish include fishes belonging to the order Perciformes, and examples thereof include fishes belonging to the genus Periformes of the family Perciformes, the family Perciformes of the family Perciformes, or the family Tuna of the family Perciformes Mackerel.

The fish species belonging to the genus Yellowtail include yellowtail (Seriola quinqueradiata), amberjack (Seriola dumerili), amberjack (Seriola lalandi), spinach (Seriola rivoliana), Seriola carpenteri, Seriola fasciata, southern amberjack (Seriola hippos), Seriola perpos. An example is Seriola zonata. In a preferred embodiment, the therapeutic agent or parasite control agent of the present invention is used for farmed fish such as yellowtail, amberjack, amberjack, and spinach amberjack, which are particularly abundantly cultured.

The fish species belonging to the Thai family include Mina microdye (Acanthopagrus sivicolus), Taiwandai (Argyrops bleekeri Oshima), red sea bream (Dentex tumifrons), red sea bream (Evynnis tumifrons), red sea bream (Pagrus major), black sea bream (Acanthopagrus schlegelii), and red sea bream. (Rhabdosargus sarba, Sparus sarba) are exemplified.

Fish species belonging to the genus Tuna include bluefin tuna (Thunnus orientalis), Atlantic bluefin tuna (Thunnus thynnus), southern bluefin tuna (Thunnus maccoyii), bigeye tuna (Thunnus obesus), albacore tuna (Thunnus alalunga), yellowfin tuna (Thunnus albacares, Thunnus albacares). tonggol) and Atlantic tuna (Thunnus atlanticus) are exemplified.

Fishes belonging to the flounder family are flounder (Paralichthys olivaceus), California Halibut (Paralichthys californicus), juvenile flounder (Paralichthys dentatus), lentil sole (Pseudorhombustus pengulathom) (Pseudorhomus pentophthalmus) Pseudorhombus arsius) and Alamegalei (Tarphops oligolepis) are exemplified.

Examples of the fishes belonging to the pufferfish family are Takifugu rubripes and Takifugu porphyreus.

The therapeutic agent or parasite control agent of the present invention can exert its effect by oral administration. Further, it is also possible to administer the drug in a liquid bath in which the drug is dissolved and administer it by injection.

The dose of the therapeutic agent or parasite control agent of the present invention is, for example, 5 mg to 100 mg, preferably 10 to 50 mg, or 10 to 40 mg per day for 1 kg of fish weight in any fish. To do. The administration period is 1 to 20 days, preferably 3 to 10 days.

The therapeutic agent or parasite control agent of the present invention uses the above-mentioned compound as an active ingredient alone, and if necessary, supplements other substances such as carriers, stabilizers, solvents, excipients, diluents, etc. It can be used in combination with the components. Further, the form may be any of the forms usually used for these compounds, such as powder, granules, tablets and capsules. In the case of fish that is sensitive to the taste and smell of the compound, a method such as coating can prevent a decrease in the palatability of the feed and prevent the compound from leaking.

In the case of fish, the orally administered drug is usually used by adding it to the feed. When the therapeutic agent or parasite control agent of the present invention is added to the feed, it is preferable to use a feed that takes into consideration the nutritional components and physical properties required for each fish species. Usually, it is made by mixing fish meal, rice bran, starch, minerals, vitamins, fish oil, etc. into pellets, or by mixing frozen fish such as sardines with powdered feed (mash) in which vitamins are added to fish meal. Pelletized materials are used. Since the daily food intake is almost determined depending on the type and size of fish, the therapeutic agent or the parasite control agent of the present invention is added to the feed in an amount converted so as to be the above-mentioned dosage. The therapeutic agent or parasite control agent of the present invention may be administered in a single daily dose or in several divided doses. Since the therapeutic agent of the present invention is used by adding it to the feed of fish, it is preferable to prepare a formulation suitable for adding an appropriate concentration to the feed that the fish ingests per day. Specifically, it is preferable to formulate and use the active ingredient in an amount of 1 to 50% by weight, preferably 5 to 30% by weight, and more preferably 10 to 20% by weight.

Examples of the present invention will be described below, but the present invention is not limited thereto.

<Anthelmintic effect of albendazole against mildew>
Fry was produced from yellow-tailed fertilized eggs using sand filtration and UV sterilized seawater at a land-based breeding facility. The produced juveniles were taken offshore to a cage, raised for a few days, and then re-loaded into the onshore facility. By the rearing of the sea cages, juvenile yellowtail were naturally infected with the parasite causing causal disease. The young juvenile yellowtails that were transported to the onshore facility again were divided into two groups, a control group and an albendazole oral administration group, and each group was stored in a 200-liter aquarium. Sand filtration and UV sterilization Seawater was poured into the aquarium of each ward under the condition of 2.4 liters/minute. The fish weight was measured on the last day of acclimatization. After acclimatization, the test feed was fed for 10 consecutive days. The albendazole administration condition was 40 mg/kg fish body weight/day, and the administration was once a day. To prepare albendazole-added feed, put a certain amount of commercially available feed and albendazole in a polyethylene bag, and spread the spreading agent S-E30 (low saccharified and reduced starch syrup, Bussan Food Science Co., Ltd.) into the bag 4 times the feed weight. % Amount was added and the mixture was stirred. The feed for the control group was prepared by adding only diluted S30 to the mixture at 4% of the feed weight and stirring. After administration of the test feed for 10 days, a commercial feed was fed, and the feed amount was 2% of the fish body weight. The test was conducted 4 times, and the number of days to keep the sea cages, the temperature of the water when the cages were kept, the acclimatization period after the facility was brought in, the weight of the test fish at the start of the test, the feeding rate at the time of oral administration of the drug, the period of the breeding test, and the test Table 1 shows the water temperature and the number of samples tested. Only the fourth control section was housed in a 500-liter water tank, and sand-filtered and UV-sterilized seawater was poured under the condition of 4.8 liters/minute for breeding.

At the end of the breeding test, all the fish were picked up from both areas, and the presence or absence of cysts in the body muscle was observed by autopsy, and the fish in which the cysts were observed was taken as the onset fish. The evaluation was carried out by comparing the incidence rates (number of onset fish tails/number of test tails×100) between the control group and the albendazole oral administration group.

Results and discussion In the control group, diseased fish were observed in all four tests. On the other hand, in the albendazole oral administration group, no cyst-forming fish was observed in all the tests, and the downy mildew incidence was 0% (Table 2). Therefore, it was confirmed that oral administration of albendazole exterminates the worms invading the fish body and inhibits the cyst formation of the worms.

<Anthelmintic effect of benzimidazole drugs on mildew-1>
In Example 1, it was found that albendazole is effective for controlling an anthelmintic causative agent of downy mildew. Therefore, the anthelmintic effect of benzimidazole drugs on the causative agent of mildew was investigated. The juveniles produced in the same manner as in Example 1 were taken out to the sea surface cage, bred for 10 days, and again carried into the onshore facility. By the rearing of the sea cages, juvenile yellowtail were naturally infected with the parasite causing causal disease. The 40 juvenile yellow fry brought back to the onshore facility were divided into 10 groups with 40 fish each (control group 2 groups, albendazole administration group 2 groups, fevantel administration group 2 groups, triclabendazole group 2 groups, flubendazole group 2 groups), Each was housed in a 200 liter aquarium. Water was poured into the water tank under the same conditions as in Example 1. The fish weight was measured on the last day of acclimatization, and the fish weight of the test fish was about 10 g. After acclimatization, the test feed was fed for 10 consecutive days. The administration condition of the benzimidazole drug was 40 mg/kg fish body weight/day, and the administration was once a day. The benzimidazole drug-added feed and the control feed were prepared in the same manner as in Example 1. After administration of the test feed for 10 days, a commercial feed was fed, and the feed amount was 2% of the fish body weight. The test was performed twice. The breeding period was 37 days for the first test and 40 days for the second test. The water temperature during the rearing was about 20.5°C.

At the end of the breeding test, all fish were picked up from all plots, and the presence or absence of cysts in the lateral muscles was observed by autopsy, and the fish in which cysts were observed was taken as the onset fish. The evaluation was carried out by comparing the incidence (number of onset fish/number of test fish×100), number of cysts of onset fish, and cyst length between the control group and the benzimidazole drug administration group.

Results and Discussion In the albendazole administration group and the fevantel administration group, no cyst-forming fish was observed in both tests, and the downy mildew incidence was 0% (Tables 3 and 4). Therefore, it was revealed that albendazole repels the worm and inhibits the cyst formation of the worm, and it is also revealed that fevantel also has the worm action against the worm. On the other hand, in the triclabendazole-treated group and the flubendazole group, onset fish were observed in both tests, and the incidence was slightly higher than that of the control group. Furthermore, the number of cysts and the length of cysts of the affected fish were similar to those in the control group. From these results, it was considered that these two agents did not exterminate the worms, but rather promoted the onset. It was found that not all benzimidazole drugs exert an anthelmintic effect on the worm.

<Anthelmintic effect of benzimidazole drugs on mildew-2>
Subsequent to Example 2, the anthelmintic effect of the benzimidazole-based drug mebendazole against the causative agent of mildew disease was examined. The juveniles produced in the same manner as in Example 1 were taken out of the sea cages, bred for 11 days, and then re-loaded into the onshore facility. By the rearing of the sea cages, juvenile yellowtail were naturally infected with the parasite causing causal disease. The 40 juvenile yellow fry that were again transported to the onshore facility were divided into 6 groups (40 control groups, 2 albendazole administration groups, 2 mebendazole administration groups), and each was stored in a 200-liter aquarium. Water was poured into the water tank under the same conditions as in Example 1. The fish weight was measured on the last day of acclimatization, and the fish weight of the test fish was about 10 g. After acclimatization, the test feed was fed for 10 consecutive days. The administration condition of the benzimidazole drug was 40 mg/kg fish body weight/day, and the administration was once a day. The benzimidazole drug-added feed and the control feed were prepared in the same manner as in Example 1. After administration of the test feed for 10 days, a commercial feed was fed, and the feed amount was 2% of the fish body weight. The breeding period was 40 days. The water temperature during the rearing was about 20.1°C.

At the end of the breeding test, all fish were picked up from all plots, and the presence or absence of cysts in the lateral muscles was observed by autopsy, and the fish in which cysts were observed was taken as the onset fish. The evaluation was performed in the same manner as in Example 2.

Results and Discussion No cyst-forming fish was observed in the albendazole-treated group, and the downy mildew incidence was 0% (Table 5). Therefore, it was reproduced that albendazole repels the worm and inhibits the cyst formation of the worm. The incidence of mebendazole administration, the number of fish cysts, and the length of cysts were all lower than those of the control group, and the anthelmintic effect against this insect was exhibited. However, its effect was considered to be lower than that of albendazole.

It has been found that the benzimidazole-based drugs have different anthelmintic effects depending on the drug.

<Effect of albendazole and fevantel on feeding of yellowtail>
From the results of Examples 1 to 4, it was revealed that the benzimidazole drugs albendazole and fevantel exert a high anthelmintic effect against Microsporidium seriole, which causes downy mildew of yellowtail. It was For use in yellowtail aquaculture, it is desired that these drug administrations have no or low side effects that adversely affect feeding. In the previous tests, water temperatures above 20°C were used, and no adverse effects on food intake were observed. Therefore, it was investigated whether albendazole and fevantel administration adversely affect feeding at a water temperature of about 18°C. Ten yellowtail larvae were divided into 6 groups with 10 fish each (control group 2 groups, albendazole administration group 2 groups, fevantel administration group 2 groups), and each was stored in a 200-liter aquarium. Water was poured into the water tank under the same conditions as in Example 1. The fish weight was measured on the last day of acclimatization, and the fish weight of the test fish was about 73 g. After acclimatization, the drug-added feed was fed for 10 consecutive days, then continued to be fed with the commercially available feed for 20 days, further fed with the drug-added feed for 10 consecutive days, and then again fed with the commercially available feed for 29 days. The administration conditions of albendazole and fevantel were 40 mg/kg fish body weight/day, and the administration was once a day. Preparation of the drug-added feed and the control feed was carried out in accordance with Example 1. The feeding amount was 1.5% of the fish weight. The water temperature during the rearing was about 18.3°C.

At the end of the breeding test, all fish were picked up from all plots and the fish weight and body length were measured.

Results and discussion In the albendazole-treated group, feeding activity was slightly reduced during the first drug administration, and it took longer to feed than in the control group. However, no decrease in feeding activity was observed during the subsequent feeding or drug administration, and the fish weight and body length at the end of the test were comparable to those in the control group (Table 6). On the other hand, in the fevantel administration group, at the time of the first administration of the drug, about 20% of the remaining food came out without eating all the prescribed amount of the drug-added feed. Approximately 20% of the remaining feed was observed during 10 days even after switching to commercial feed after drug administration. No decrease in feeding activity was observed at the time of the second administration of the drug-added feed, but a decrease in feeding activity was observed for 10 days after switching to the commercially available feed after drug administration, and all the prescribed amount of feed was eaten. I gave it twice a day to let me know. At the end of the test, the fish weight and body length of this group were clearly lower than those of the control group and the albendazole administration group. Therefore, it was revealed that fevantel reduces the feeding activity of yellowtail at low water temperature. From these results, it was inferred that side effects on fish were higher in fevantel than in albendazole.

<Examination of albendazole dose for powdery mildew>
The juveniles produced in the same manner as in Example 1 were taken out of the sea cages, bred for 11 days, and then re-loaded into the onshore facility. By the rearing of the sea cages, juvenile yellowtail were naturally infected with the parasite causing causal disease. The 40 juvenile yellow fry that were brought into the onshore facility again were divided into 12 groups with 40 fish each (control group 0 mg/kg fish body weight 2 groups, 5 mg/kg fish body weight administration group 2 groups, 10 mg/kg fish body weight administration group 2 groups, 20 mg/ kg fish body weight administration group 2 group, 30 mg/kg fish body weight administration group 2 group, 40 mg/kg fish body weight administration group 2 group), each was stored in a 200 liter aquarium. Water was poured into the water tank under the same conditions as in Example 1. The fish weight was measured on the last day of acclimatization, and the fish weight of the test fish was about 10 g. After acclimatization, the test feed was fed for 10 consecutive days. The administration was once a day. The albendazole-added feed and the control feed were prepared in the same manner as in Example 1. After administration of the test feed for 10 days, a commercial feed was fed, and the feed amount was 2% of the fish body weight. The breeding period was 40 days. The water temperature during the rearing was about 20.1°C.

At the end of the breeding test, all fish were picked up from all plots, and the presence or absence of cysts in the lateral muscles was observed by autopsy, and the fish in which cysts were observed was taken as the onset fish. The evaluation was performed in the same manner as in Example 2.

Results and Discussion In the albendazole 5 mg/kg fish body weight administration group, cysts of downy mildew were observed, although less than in the control group (Table 7). On the other hand, in the administration group of 10 mg/kg or more of fish body weight, no fish forming cysts of downy mildew was observed. Therefore, it was considered that the minimum effective dose for Botrytis worm is about 10 mg/kg fish body weight.

<Study on the number of days of administration of albendazole for powdery mildew disease>
Naturally caught fry were introduced into fish cages and raised for 21 days. By the rearing of the sea cages, juvenile yellowtail were naturally infected with the parasite causing causal disease. The juvenile yellow fry carried into the onshore facility were divided into 4 groups (control group: 0 mg/kg fish weight: 10 days, 90 fish, 40 mg/kg fish weight: 3 days administration group: 70 fish, 40 mg/kg fish weight: 6 days administration group) 70 fish, 40 mg/kg fish weight, 10-day administration group 70 fish). Each group was housed in a 200 liter aquarium. Water was poured into the water tank under the same conditions as in Example 1. The test feed was fed after 2 days of acclimatization. The administration was once a day. The fish weight of the test fish at the start was about 8 g. The albendazole-added feed and the control feed were prepared in the same manner as in Example 1. After administration of the test feed, a commercially available feed was fed, and the feed amount was 3% of the fish body weight. The breeding period was 22 days. During the breeding period, the water temperature was 20°C for the first 10 days and then 22°C until the breeding was completed.

At the end of the breeding test, all fish were picked up from all plots, and the presence or absence of cysts in the lateral muscles was observed by autopsy, and the fish in which cysts were observed was taken as the onset fish. The evaluation was performed in the same manner as in Example 2.

Results and discussion In the albendazole 40 mg/kg, 10-day administration group, no onset fish was observed. Occurrence of fish was observed in the 3 and 6-day treatment groups, although the number was small, but the incidence rate, the number of cysts in the diseased fish, and the cyst length were clearly lower than those in the control group, and the administration period was 3 or 6 days. However, it showed anthelmintic effect against the main insect. In addition, albendazole died due to thinning due to feeding away from each one in the administration groups for 3 days and 10 days. These fish did not eat any food from the time of grouping. It is speculated that transportation and environmental changes had an impact.

<Therapeutic effect of albendazole on mildew-bearing fish>
Naturally caught fry were introduced into the cage of the fishing ground and bred for 50 days. By the rearing of the sea cages, juvenile yellowtail were naturally infected with the parasite causing causal disease. Frying yellowtail fry carried into the onshore facility were divided into 10 groups with 28 fish each (control group 0 mg/kg fish weight, 10 days 2 groups, 10 mg/kg fish body weight, 3 days administration group 2, 10 mg/kg fish body weight) 10-day administration group 2 groups, 40 mg/kg fish body weight/3-day administration group 2 groups, 40 mg/kg fish body weight/10-day administration group 2 groups). Each group was housed in a 200 liter aquarium. Water was poured into the water tank under the same conditions as in Example 1. In addition, in order to understand the onset status of downy mildew at the start of the test, 29 autopsies were performed and the number of cysts and cyst length of the lateral muscles were examined. The test feed was fed after 3 days of acclimatization. The administration was once a day. The fish weight of the test fish at the start of the test was about 21 g. The albendazole-added feed and the control feed were prepared in the same manner as in Example 1. After administration of the test feed, a commercially available feed was fed, and the feed amount was 2% of the fish body weight. In this test, the administration of the test feed during the breeding period was 2 cycles, and the test schedule is shown in FIG. The water temperature during the rearing period was 22°C.

At the end of the breeding test, all fish were picked up from all plots, and the presence or absence of cysts in the lateral muscles was observed by autopsy, and the fish in which cysts were observed was taken as the onset fish. The evaluation was performed in the same manner as in Example 2.

Results and discussion In all albendazole administration groups, the incidence rate, the number of cysts and cyst length of the sick fish decreased compared to the start of the test, and it was revealed that the worms also exert an anthelmintic effect even in the sick fish that has already been observed. did. The increase in the number of onset fish in the control group at the end of the test was considered to be due to the formation of cysts by the main stage insects that had not yet formed cysts, and the effect of albendazole on cyst formation was again recognized. In addition, it was found that the therapeutic effect and the cyst formation inhibitory effect were exhibited even by administering albendazole 10 mg/kg fish body weight for 3 days. In addition, several dead fish were observed in each test plot. The dead fish was thin and, as in Example 6, it was speculated that the fish died due to anorexia.

<Anthelmintic effect of benzimidazole-based drugs against myxospore insect Kudo and Mussel>
We investigated the anthelmintic effect of benzimidazole drugs against Kudo and L. snails. The juveniles produced in the same manner as in Example 1 were taken out to the sea surface cage, bred for 10 days, and again carried into the onshore facility. By this breeding in the sea cage, juvenile yellowtail was naturally infected with Kudo/Morning snail. The 40 juvenile yellow fry brought into the onshore facility again were divided into 10 groups with 40 fish each (control group 2, albendazole administration group 2, fevantel administration group 2 group, triclabendazole group 2 group, flubendazole group 2 group), Each was housed in a 200 liter aquarium. Water was poured into the water tank under the same conditions as in Example 1. The fish weight was measured on the last day of acclimatization, and the fish weight of the test fish was about 10 g. After acclimatization, the test feed was fed for 10 consecutive days. The administration condition of the benzimidazole drug was 40 mg/kg fish body weight/day, and the administration was once a day. The benzimidazole drug-added feed and the control feed were prepared in the same manner as in Example 1. After administration of the test feed for 10 days, a commercial feed was fed, and the feed amount was 2% of the fish body weight. The breeding period was 40 days. The water temperature during the rearing was about 20.5°C.

At the end of the breeding test, all fish were picked up from all plots, brain smears were prepared, and stained with Diffquick. 40 fields of view were observed with an optical microscope at 400 times to examine the presence or absence of spores and the number of spores. The evaluation was performed by comparing the detection rate (the number of detected fish/the number of test fish×100) and the number of spores of the detected fish between the control group and the benzimidazole drug administration group.

Results and Discussion The detection rate and spore count were significantly lower in the albendazole-treated group and the flubendazole-treated group than in the control group. On the other hand, the number of spores in the fevantel-treated group was higher than that in the control group. Therefore, it was revealed that albendazole and flubendazole exert an anthelmintic effect on the worm, and fevantel promotes the growth of the worm.

It was found that not all benzimidazole drugs have anthelmintic effects on the worm, and that even if they have anthelmintic effects on downy mildew, they do not necessarily have an effect on Kudoa/Mussel. ..

Incidentally, 7 dead fish were observed in the control group and 1 dead fish in the albendazole group. The dead fish were thin and it was speculated that the fish died from the same cause as in Example 6.

INDUSTRIAL APPLICABILITY The present invention can provide an antiparasitic drug capable of combating downy mildew or myxosporidiosis caused by microsporidia parasitic on marine fish by oral administration.

Claims (19)

The febantel as an active ingredient, per day, wherein the active ingredient is administered 10 to 40 mg / kg fish body weight orally, a anthelmintic cause parasites downy this disease marine fishes, causes downy this disease The above-mentioned anthelmintic agent, wherein the parasite is a microsporidium belonging to the genus Microsporidium. Fluparabendol is an active ingredient, and the active ingredient is orally administered per day in an amount of 10 to 40 mg/kg of fish body weight, which is an anthelmintic agent for parasites causing myxosporosis of marine fish. The anthelmintic agent, wherein the causative parasite of the disease is myxosporeworm belonging to the genus Kudoa. The anthelmintic agent according to claim 1 or 2 , wherein the marine fish is a sea bass, flatfish or puffer fish. Suzuki eyes of fish, yellowtail genus, is a fish belonging to the sparidae or tuna species, Flatfish of fish is a fish belonging to the flounder family, fish belonging to the tetraodontiformes is a fish belonging to the puffer family, according to claim 3 The anthelmintic agent described in. The fish belonging to the genus Buri includes yellowtail (Seriola quinqueradiata), amberjack (Seriola dumerili), amberjack (Seriola lalandi), amberjack (Seriola rivoliana), Seriola carpenteri, Seriola fasciata, southern amberjack (Seriola hipposola), Seriola peru Any of the zonata, and the fishes belonging to the family of the Thai family are Minamicrodai (Acanthopagrus sivicolus), Taiwandai (Argyrops bleekeri Oshima), Red sea bream (Dentex tumifrons), Red sea bream (Evynnis tumifrons), Red sea bream (Pagrus major), Black sea bream (Acanthopagrus) schlegelii) and sea bream (Rhabdosargus sarba, Sparus sarba), and fish belonging to the genus Tuna include bluefin tuna (Thunnus orientalis), Atlantic bluefin tuna (Thunnus thynnus), southern bluefin tuna (Thunnus maccoyii), and bigeye tuna (Thunnus obesus). , Albacore (Thunnus alalunga), yellowfin tuna (Thunnus albacares), bluefin tuna (Thunnus tonggol), and Atlantic tuna (Thunnus atlanticus). Fish belonging to the flounder family are flounder (Paralichthys olivaceus) and California ichalibut (Paralichthys olivaceus). californicus), juvenile flounder (Paralichthys dentatus), elephant's sole (Pseudorhombus pentophthalmus), elephant flounder (Pseudorhombus cinnamoneus), megalois (Pseudorhombus dupliciocellatus), pearl oyster flounder (Pseudorhombus dupliciocellatus) (Pseudorhomar phospora) (Pseudorhomar phophorus). The fish belonging to is Takifugu (Takifugu rubripes) or Mafugu (Takifugu p orphyreus), the anthelmintic agent according to claim 4 . The anthelmintic agent according to any one of claims 1 to 5 , wherein the administration period of the active ingredient is 1 to 20 days. The anthelmintic agent according to any one of claims 1 to 6 , wherein the administration period of the active ingredient is 3 to 10 days. The anthelmintic agent according to any one of claims 1 to 7 , wherein a non-administration period of 10 to 17 days is provided after administration of the active ingredient. The anthelmintic agent according to any one of claims 1 to 8 for starting the administration on the 9th to 23rd days after the introduction of the fry into the cage. A method for repelling parasites causing downy mildew of marine fish, which comprises treating marine fish by orally administering 10 to 40 mg/kg of fish body weight per day of active ingredient fevantel. The anthelmintic method as described above, wherein the causative parasite of the disease is a microsporidium belonging to the genus Microsporidium. A method for repelling parasites causing myxosporosis of marine fish, comprising treating marine fish by orally administering 10-40 mg/kg of fish weight of the active ingredient, flubendazole, The anthelmintic method as described above, wherein the causative parasite of myxosporidiosis is a myxosporeworm belonging to the genus Kudoa. 12. The anthelmintic method according to claim 11, wherein the marine fish include marine fish infested with microspores and marine fish infested with myxospores. The anthelmintic method according to any one of claims 10 to 12 , wherein the marine fish is a sea bass, flatfish or puffer fish. Perciformes fish is seriola, a fish belonging to sparidae or tuna genus Flatfish fish are fish belonging to the flounder family, fish belonging to tetraodontiformes is fish belonging to the puffer family, claim 13 Deworming method. The fish belonging to the genus Buri includes yellowtail (Seriola quinqueradiata), amberjack (Seriola dumerili), amberjack (Seriola lalandi), amberjack (Seriola rivoliana), Seriola carpenteri, Seriola fasciata, southern amberjack (Seriola hipposola), Seriola peru Any of the zonata, and the fishes belonging to the family of the Thai family are Minamicrodai (Acanthopagrus sivicolus), Taiwandai (Argyrops bleekeri Oshima), Red sea bream (Dentex tumifrons), Red sea bream (Evynnis tumifrons), Red sea bream (Pagrus major), Black sea bream (Acanthopagrus) schlegelii) and sea bream (Rhabdosargus sarba, Sparus sarba), and fish belonging to the genus Tuna include bluefin tuna (Thunnus orientalis), Atlantic bluefin tuna (Thunnus thynnus), southern bluefin tuna (Thunnus maccoyii), and bigeye tuna (Thunnus obesus). , Albacore (Thunnus alalunga), yellowfin tuna (Thunnus albacares), bluefin tuna (Thunnus tonggol), and Atlantic tuna (Thunnus atlanticus). Fish belonging to the flounder family are flounder (Paralichthys olivaceus) and California ichalibut (Paralichthys olivaceus). californicus), juvenile flounder (Paralichthys dentatus), elephant's sole (Pseudorhombus pentophthalmus), elephant flounder (Pseudorhombus cinnamoneus), megalois (Pseudorhombus dupliciocellatus), pearl oyster flounder (Pseudorhombus dupliciocellatus) (Pseudorhomar phospora) (Pseudorhomar phophorus). The fish belonging to is Takifugu (Takifugu rubripes) or Mafugu (Takifugu p a orphyreus), anthelmintic method of claim 14. The anthelmintic method according to any one of claims 10 to 15 , wherein the administration period of the active ingredient is 1 to 20 days. The anthelmintic method according to any one of claims 10 to 16 , wherein the administration period of the active ingredient is 3 to 10 days. The anthelmintic method according to any one of claims 10 to 17 , wherein a period of no administration for 10 to 17 days is provided after administration of the active ingredient. The anthelmintic method according to any one of claims 10 to 18 , wherein the administration is started on the 9th to 23rd day after the introduction of the fish cage into the cage.

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