JP2020096599A - Fish ectoparasite disinfestation method using low density hydrogen peroxide water - Google Patents

Abstract

To provide a safe and effective disinfestation method of ectoparasites which live on body surfaces of fishes.SOLUTION: There is provided a method of disinfestation of ectoparasites living on marine fishes by using low density hydrogen peroxide water characterized in that immersion in hydrogen peroxide water of 30 ppm to 150 ppm for 15 minutes or more is executed. In the method of disinfestation of ectoparasites living on marine fishes by low density hydrogen peroxide water, a side surface of a fish live-box is covered with a sheet and sea water inside is held, and in the state, the hydrogen peroxide water is administered to the sea water in the fish live-box by an amount at which an average density of the hydrogen peroxide water in calculation is 30 ppm-150 ppm, and after passage of 15 minutes or more, the sheet is removed.SELECTED DRAWING: Figure 1

Description

The present invention relates to an ectoparasite control agent and a parasite control method for marine fish (especially farmed fish). More specifically, the present invention relates to a drug and a method for exterminating parasites of monoparasites parasitizing the body surface of fish such as hadhid beetles and aphids.

Parasitic diseases have become a very serious problem in fish farming because they interfere with stable production. Among parasitosis, monoparasites belonging to the genus Monophyllia of the genus Flatmophyta and caligus of the phylum Crustacea of the arthropod occur in many cultured fish and are one of the most serious infectious diseases. Among the monotonous insects, there are ones generally called hadem and some aphids. The parasites called Hadamushi are, for example, Neobenedenia girellae and Benedenia seriolae , which are single-sucker suckers Capsalaidae, such as amberjack , yellowtail, amberjack , yellowtail amberjack, striped horse mackerel , sea bass, red sea bream It is known to parasitize many fish species such as, yellow-bellied, pheasant grouper, queer, flounder, tiger puffer, and cedar. On-site diagnostic methods include dying with symptoms such as redness of the epidermis on the abdomen, threads on the fins, and cloudiness of the eyeball.In fish with a large amount of parasitism, the body surface becomes cloudy due to a large amount of mucus secreted. You can see things. In addition, abnormal swimming, such as rubbing the body on the cage net, may be frequently seen. Rubbing the body against the nets, etc. worsens the symptoms and increases the chances of infection by pathogenic bacteria from the parasitic site, which may spread the damage. When the parasites of the worm are confirmed, they are exterminated by taking a fresh water bath or a high-concentration hydrogen peroxide bath for about 3 minutes while paying attention to the water temperature.

The monoworms known as aphids are Heterotaxine heterocerca , which is a flatterinary phylum of the yellowtail parasitoid , Heteraxine heterocerca, Zeuxapta japonica , and Vivagina tai , which are parasitic on red sea bream. Microcotyle sebastis , which parasitizes black soy , Microcotyle sebastisci , which parasitizes scorpionfish, Heterobothrium okamotoi , which is parasitized by trufflefish, Neoheterobotulium , which parasitizes flounder ( Neoheterobothrium hirame ), and so on. On-site diagnostic methods include gill fading, fish anemia, and reduced obesity. In addition, abnormal swimming, such as rubbing the body on the cage net, may be frequently seen. Since the body is rubbed against a cage net, etc., the chances of infection with pathogenic bacteria increase from the thread surface of the body surface, and the damage may spread. When the parasite of the worm is confirmed, it is exterminated by performing a high-concentration hydrogen peroxide water bath for about 3 minutes while paying attention to the water temperature.
In either case, the labor required for processing such as transfer of fish and the stress applied to the fish are large, so that a simpler treatment method is strongly desired.
Further, recently, a large number of Lamellodiscus spp. parasites may be found in the gills of cultured red sea bream, and their influence on the host is concerned. This insect is also called aphid, but it is classified into the genus Lamelodiscus of the single post-sucker diplectanidae (Diplectanidae). Anthelmintic methods for this insect have not been established.

Parasites known as arthropod crustacean caligus are Caligus longipedis that parasitizes striped horse mackerel, Pseudodocaligus fugu that parasitize tiger puffers, salmonids and mullets, Examples include Caligus orientalis, which is parasitic on tilapia. The on-site diagnostic method, the effect on the infested fish, and the anthelmintic method are the same as for the beetle. However, it takes about 20 minutes to treat freshwater baths and hydrogen peroxide baths for deworming, which is longer than that of beetles.

The beetles that occur in yellowtail are Benedenia ceriole and Neobenedenia gillere. In addition, Neovenedia gillere has been reported to be parasitic on many marine fish other than yellowtail. The on-site anthelmintic method is mainly a medicinal bath or a fresh water bath using a hydrogen peroxide solution (Katayama Chemical Industry Co., Ltd., trade name Marin Sour and Hodogaya Chemical Co., Ltd., trade name Sakura Guard). In Japan, hydrogen peroxide is approved as a veterinary drug for the perch fish Benedenia seriole and red sea bream Vivagina tai (aphid). The dosage and administration of these parasites is 3 minutes at a hydrogen peroxide concentration of 300 ppm. In amberjack aquaculture, the damage caused by Neo-Benedenia gillere is more serious than that of Benedenia ceriole, and the hydrogen peroxide is also used for the aphid Neo-benedenia gillerea. However, this dose/dosage has a low anthelmintic effect against Neobenedonia gillere, and a medicinal bath of 300 to 5 minutes at 300 ppm is used in the field. Moreover, this drug is highly toxic to amberjack at high water temperature, which may cause fatal accidents that are considered to be caused by oxygen deficiency.
Recently, the hydrogen peroxide agent has been approved as an animal drug for the puffer fishes Neobenedonia girelle and Pseudocaligus puffer, and its dosage and usage is 300 ppm for 20 minutes.

Patent Document 1 describes, as an ectoparasite control method for seawater-cultured fish, a method in which a hydrogen peroxide solution having a concentration of 200 to 3000 ppm is used for a chemical bath for 1 to 20 minutes. Patent Document 2 describes a method of eradicating gyrodactylus of freshwater fish by subjecting a hydrogen peroxide solution having a concentration of 10 to 100 ppm to a chemical bath for 30 to 120 minutes. Patent Document 3 describes a method for preventing the heterobothurosis of troughfish by bathing with hydrogen peroxide solution having a concentration of 400 to 2000 ppm for 20 to 120 minutes.

Japanese Patent Publication No. 7-51028 Patent No. 2575240 Patent 2817753

An object of the present invention is to provide a safer and highly effective method for exterminating ectoparasites that parasitize the body surface and gills of fish.

The inventors have been studying a chemical bath using hydrogen peroxide solution, and by using a low concentration hydrogen peroxide solution of 150 ppm or less, compared with the conventional case of using a high concentration hydrogen peroxide of 300 ppm or more. Also, they found that the parasites can be greatly damaged and can be completely exterminated, and the present invention was completed. In addition, by combining low-concentration hydrogen peroxide solution with the spray method (method of directly spraying chemicals on cages, etc.), an oxygen deficiency accident caused by bathing with a small amount of seawater, which is the existing method so far, will occur. Moreover, the present inventors have found a superior and simpler and safer anthelmintic method as compared with the existing methods, which can significantly reduce the enormous work of collecting and picking up fish.
The gist of the present invention is the method for controlling ectoparasites of marine fish according to (1) to (5).
(1) A method for exterminating ectoparasites of marine fish with low-concentration hydrogen peroxide water, which comprises immersing in hydrogen peroxide water having a concentration of 30 ppm to 150 ppm for 15 minutes or more.
(2) At least the side surface of the cage net is covered with a sheet so that the internal seawater is retained, and hydrogen peroxide water is added to the seawater in the cage to calculate the average concentration of 30 ppm to 150 ppm, The method according to (1), wherein the sheet is removed after 15 minutes or more have elapsed.
(3) The method according to (1) or (2), wherein the ectoparasite is a parasite belonging to the genus Monophyta of the phylum Monophyta or Crustacea of arthropods.
(4) The method according to (1) or (2), wherein the ectoparasite is a monophyletic single-posterior sucker, a multi-posterior sucker, or a parasite of the arthropod Crustacea Caligaceae.
(5) The ectoparasites are Monophylla, Capsularidae, which is a single post-sucker, or Diplextanidae, Heteraxineaceae, which is a multi-poster sucker, Micrococcidiaceae, Dicridophora or Neoheterobothurium, or arthropod Crustacea. The method according to (1) or (2), which is a parasite belonging to the family Caligaceae. (6) Ectoparasites are Benedenia seriole, Benedenia epinepheri, Benedenia Hoshinai, Benedenia Sekii, Neobenedenian gillere, Neobenediania congeri, Lamerodiscus, Zeuxapta japonica, Vivagina tai, Heteraxinechiraceco, heterocerco, heterocerca, -The method of (1) or (2), which is Sebastiski, Heterobothurium okamotoi, or Neoheterobothurium flounder, Caligus longipedis, Pseudocalligues puffer, and Caligus orientalis.
(7) The method according to any one of (1) to (6), wherein the fish belongs to the order Perciformes.
(8) The method according to (7), wherein the fish is a yellowtail or Thai fish.
(9) The method of (1) or (2), wherein the immersion time is 15 minutes to 6 hours.
(10) The method according to (1) or (2), wherein the immersion time is 15 minutes to 2 hours.

By using the extermination method of the present invention, it is possible to exterminate ectoparasites more reliably and without adversely affecting the fish. In particular, it is possible to effectively control ectoparasites such as Benedenia seriole, Neobenedonia girere, Zeuxapta japonica, Vivagina Thailand, and Lamelogiscus that have a great influence on the aquaculture business.

FIG. 3 is a graph showing the anti-Neobenedenia girellae action of hydrogen peroxide solution in Example 1. 3 is a photograph showing the anti-Neobenedenia girellae action of hydrogen peroxide solution (300 ppm, 3 minutes treatment) in Example 1. A: Control area, B: Immediately after returning to seawater after treatment, C: Returning to seawater after treatment for 3 minutes, D: Returning to seawater after treatment for 15 minutes. 3 is a photograph showing the anti-Neobenedenia girellae action of hydrogen peroxide solution (300 ppm, 6 minutes treatment) in Example 1. A: Immediately after returning to seawater after treatment, B: 30 minutes after returning to seawater after treatment, C: 60 minutes after returning to seawater after treatment. 3 is a photograph showing the anti-Neobenedenia girellae action of hydrogen peroxide solution (75 ppm, 30 minutes/60 minutes treatment) in Example 1. A: Immediately after returning to seawater after treatment for 30 minutes, B: Immediately after returning to seawater after treatment for 60 minutes, C: Returning to seawater after treatment for 60 minutes, 60 minutes later, D: After treatment to seawater for 60 minutes 10 hours after returning (D-1: peeled solid, D-2: fixed solid). FIG. 7 is a graph showing the anti-Neobenedenia girellae action of hydrogen peroxide water of 300 ppm and 75 ppm in Example 2. 8 is a photograph showing Neobenedenia girellae affected by each section in Example 2. A: After treated with 300ppm hydrogen peroxide for 60 minutes, returned to seawater for 30 minutes, B: After treated with 300ppm hydrogen peroxide for 60 minutes, returned to seawater for 30 minutes, C: After treated with 75ppm hydrogen peroxide for 60 minutes, seawater 30 minutes after returning to. It is a figure in Example 6 which shows the influence which 300 ppm and 75 ppm hydrogen peroxide water treatment gives to Neobenedenia girellae reinfection of a fish. FIG. 8 is a graph showing the anti-Benedenia seriolae action of hydrogen peroxide solution in Example 7. 9 is a photograph showing Benedenia seriolae affected by hydrogen peroxide treatment in Example 7. In the figure, arrows indicate atrophy of the fixation disc and detached individuals. A: Immediately after treatment with 300ppm hydrogen peroxide for 3 minutes, B: Treatment with 300ppm hydrogen peroxide for 3 minutes, then returning to seawater for 2 hours, C: Immediately after treatment with 75ppm hydrogen peroxide for 30 minutes, D: 75ppm hydrogen peroxide After treatment for 30 minutes, return to seawater for 2 hours. 9 is a photograph showing the anti-Zeuxapta japonica action in hydrogen peroxide solutions of 300 ppm and 75 ppm in Example 9. In the figure, marks indicate atrophy of the fixation disc. A: Immediately after 6 minutes treatment with 300ppm hydrogen peroxide, B: 10 minutes after 75ppm hydrogen peroxide treatment. FIG. 9 is a graph showing the anti-Zeuxapta japonica action of hydrogen peroxide solutions of 300 ppm, 75 ppm and 50 ppm in Example 9.

Examples of the parasites to which the present invention is applied include monoparasites (generally referred to as wasps and aphids) belonging to the monophytes of the flatworms of the fishes, caligus belonging to the crustaceans of the arthropods. Examples of parasites called hadhid insects include those that parasitize marine fish such as the monophylet Benedenia subfamily. The Benedenia subfamily, e.g. Benedenia-Seriore (Benedenia seriolae), Benedenia-Epineferi (Benedenia epinepheli), Benedenia-Hoshinai (Benedenia hoshinai), Benedenia-Sekii (Benedenia sekii) such Benedenia (Benedenia) and Neobenedenia-Jirere (Neobenedeniagirellae ), and Neobenedenia-Kongeri (Neobenedenia congeri) such Neobenedenia (Neobenedenia) is. Solitary insects are called Eramushi is, Heterakishine Department Heterakishine-Heteroseruka (Heteraxine heterocerca) belonging to the multi-after sucker class, Zeukusaputa Japonica (Zeuxapta japonica), Mikurokochire family Bibagina, Thailand (Bivagina tai), Mikurokochire-Sebasuchisu (Microcotyle sebastis) , Microcotyle sebastisci ( Microcotyle sebastisci ), Diclidophoridae, Heterobothrium okamotoi ( Heterobothrium okamotoi ), Neoheterobothrium hirame ( Neoheterobothrium hirame ). In addition, some parasites called aphids are classified into single post-suckers, and include the genus Lamelodiscus ( Lamellodiscus spp.). Examples of calligraphy include Caligus longipedis , Pseudocaligus fugu , Caligus orientalis , and the like belonging to the family whitefly. In particular, it is effective for Neo-Benedenia, Benedenia, Zeuxapta japonica, Vivagina-Thailand and Lamelogiscus.

In the present invention, the marine fish is a marine fish species that is treated as aquaculture fish or ornamental fish that requires the control of parasites. Among them, farmed fish are of particular industrial importance, and for example, parasitoids of fish parasites such as beetles and aphids are known, such as the puffer fish of the pufferfish pufferfish, the grouper of the perciform grouper, the tilapia of the perch family Cichlid family. The agents of the present invention can be used prophylactically or therapeutically in existing fish species, or in fish species that may be infested with fish parasites.
Fish species covered by the present invention include aquaculture fish of all ages, aquarium and commercial ornamental fish that survive in seawater. Particularly, in the aquacultured fish, the fishes are Perciformes, Flatfishes, Pufferidae, Herringidae and eels, such as yellowtails, groupers, Thais, flounders, puffers, salmon and eels. Specifically, amberjack, amberjack, yellowtail, yellowtail, kingfish, horse mackerel, striped horse mackerel, chub mackerel, perch, red sea bream, stone bream, stone bream, tilapia, cedar, pheasant grouper, queer, mahata, chilomaruhata, yaitohata, sarasahata, sujiara, tamaira , Scorpionfish, flounder, matsukawa, hoshigarei, turbot, halibut, tiger pufferfish, riverfish, yellowfish, horsetail, rainbow trout, Atlantic salmon, coho salmon, sockeye salmon, and the like. In particular, aphid, yellowtail, grouper, covia, snapper, barramundi, tilapia, and Suzuki have been reported to be the major victims of beetles.

The hydrogen peroxide solution used in the present invention is not special, and may be a commercially available one. Since a 35% solution is sold, dilute it to the specified concentration and use it as a medicated bath agent. For marine fish, it has been conventionally considered that a medicinal bath should be carried out at a concentration of 300 ppm or more, and such practice has been carried out. However, in the present invention, the chemical bath is carried out at a low concentration of 30 ppm to 150 ppm, preferably 30 to 100 ppm, more preferably 30 to 90 ppm, 30 to 80 ppm, 37.5 to 75 ppm. The medicinal bath time is preferably 15 minutes or more. Although it depends on the fish species, if the concentration is low, no adverse effect is seen on the fish body even after long-term drug bathing, so there is no particular upper limit. As shown in Example 5, at 150 ppm for 6 hours, there were symptoms such as poor feeding, but there was no death like at 300 ppm, and no abnormality was observed at 75 ppm. However, it is not necessary to apply an unnecessary burden to the fish body, and from the viewpoint of work efficiency, it is 15 to 120 minutes, preferably 15 to 90 minutes, more preferably 30 to 60 minutes. Therefore, 30 minutes to 150 ppm is preferable for 15 minutes to 6 hours, and further 15 minutes to 2 hours is preferable. Alternatively, 30 minutes to 100 ppm is preferable for 15 minutes to 6 hours, and further 15 minutes to 2 hours is preferable.
For example, 37.5 to 75 ppm is most preferable for parasites of single-posterior suckers and multi-posterior suckers excluding vivagina, and 75 to 100 ppm is preferable for vivagina.
If you suspect a parasite infection, take this medicine bath immediately. You only have to take the medicine bath once. After that, if parasite infection is suspected during breeding, it may be carried out once once. In the present specification, ppm represents the amount of hydrogen peroxide in water by weight/volume.

The reason why the effect of controlling the parasites of the chemical bath of the present invention at a low concentration is higher than that of the conventional chemical bath of a high concentration can be explained as follows from the results of Examples.
Treatment of Neobenediania gillere with a hydrogen peroxide concentration of 300 ppm for 6 minutes at a water temperature of 25° C. apparently causes the worms to atrophy, but the sucker (fixation disc) for fixing to the host does not atrophy or deform. Therefore, the worm remains adsorbed on the wall surface of the petri dish, and the worm gradually recovers after the treatment (Example 1). It is thought that the same thing is happening on the surface of the host body, which causes the anthelmintic effect to be unstable. In fact, when the amberjack infected with Neobenedenia gillere was subjected to a medicated bath with a hydrogen peroxide concentration of 300 ppm for 6 minutes, the anthelmintic rate was 59.1%, and the anthelmintic effect was limited (Example 3).
On the other hand, it was found that, when Neobenediania gillere was treated at a low concentration of 75 ppm or 50 ppm for 30 to 60 minutes, the atrophy of the worms was weak, but the sucker also atrophied and deformed to separate from the wall surface of the petri dish. Further, the atrophy of Neovenedia gillerea after the treatment was continued (Example 1).
Even when Neovenedian gillere was treated with a high concentration of hydrogen peroxide (300 ppm) for 60 minutes, the atrophy/deformation (sticking disc) of the suction cup remained at 30%. Therefore, it was revealed that a low concentration of 75 ppm or 50 ppm was more effective than a high concentration in atrophing and deforming the suction cup of Neobenediania gillere (Example 2).
Amberjack infected with Neobenedenia gillere was subjected to a chemical bath at a water temperature of 25° C. and a hydrogen peroxide concentration of 75 ppm for 30 minutes. The anthelmintic rate was 94.3%. The anthelmintic rate after treatment at 50 ppm for 30 minutes was 86.6%. Therefore, it was clarified that it is important for the anthelmintic worm of Neobenedenia gillere to atrophy and deform the fixation disc, so that a high anthelmintic effect can be stably obtained (Example 3). Furthermore, in Example 4, it was confirmed that a high anthelmintic effect was obtained even under the condition of hydrogen peroxide concentration of 37.5 ppm for 30 minutes or 60 minutes. When the concentration is low, the fixed disc of Neobenediania gillere atrophies/deforms and detaches from the host, so there is no factor for the main insect to recover after the treatment, and a stable anthelmintic effect can be expected.

The chemical bath with a hydrogen peroxide agent at the aquaculture site is carried out by preparing a pool-shaped sheet of about 200 tons with a hydrogen peroxide concentration of 300 ppm and storing the fish there. When the amberjack was subjected to a medicinal bath with a hydrogen peroxide concentration of 150 ppm or more, the fish vigorously swam up and down 1 to 3 minutes after the stimulation (Example 5). A fatal accident that may be caused by oxygen deficiency may occur at high water temperature in summer, and one of the causes was considered to be the intense swimming observed in this test. On the other hand, when amberjack was soaked in a hydrogen peroxide concentration of 75 ppm for 6 hours, it did not adversely affect swimming and feeding behavior on the next day (Example 5). From these results, it was clarified that a hydrogen peroxide concentration of less than 150 ppm, particularly 75 ppm or less, can reliably perform a chemical bath without adversely affecting amberjack. It was also clarified that high-concentration drug bath treatment damages the amberjack surface and makes it susceptible to reinfection with Neobenedenia gillerii, and low-concentration treatment does not damage the body surface. (Example 6).

The Norwegian salmon aquaculture method uses a skirt method in which the sides of the cage are surrounded by a sheet. This method does not require the fish to be transferred to a narrow drug bath, which ensures dissolved oxygen in the breeding environment. It is also possible to maintain dissolved oxygen in the environmental water by aeration of oxygen or air. By combining the present invention with such a method, a relatively long drug bath of 30 to 60 minutes is possible.
For the drug injection, a dedicated device with many holes in a cylindrical tube has been devised, and the drug can be sprayed simultaneously from the top layer to the bottom layer of the cage. Further, the swimming of the fish allows the drug to be diffused and made uniform.
Specifically, cover the side of the net of the cage with a sheet to keep the seawater inside, and add hydrogen peroxide solution to the seawater in the cage to the average concentration of 30 ppm to 150 ppm. After 15 minutes or more, preferably 15 minutes to 6 hours, or 15 minutes to 2 hours, more preferably 30 to 60 minutes, the sheet can be removed to carry out the medicinal bath of the present invention. By this method, it is possible to take a medicinal bath without stressing the fish.

It was confirmed that similar results were obtained not only with Neo-Benedenia gillere but also with Benedenia-seriole (Examples 7, 11, 12). Furthermore, it was revealed in an in vivo test that it exerts a clear anthelmintic effect also on Lamelogiscus (Example 8). Benedenia ceriole is classified into the genus Benedenia of the monophyletic single post-sucker, Neobenedenia gillere is classified into the same genus Neobenedonia, and Lamelogiscus is classified into the same genus Lamelogiscus. Since the low-concentration hydrogen peroxide solution baths exhibited a high anthelmintic effect in common with these parasites, it was considered to have an effect on the parasites of the monophyletic single post sucker.
In addition, the deformation and persistence of the parasites at the time of low-concentration treatment were also observed in the sticking plate where the graspers of Zeuxapta japonica were arranged (Example 9). When examined by an in vivo test, it was revealed that a clear antiparasitic effect was exerted also on the worm (Examples 11 and 12). Furthermore, a clear antiparasitic effect was exhibited against Vivagina tai (Example 10). Zeuxapta japonica is classified into the genus Zeuxapta of the monophyletic polyhedron, and Vivagina Thailand is classified into the same genus Vivagina. Since the low-concentration hydrogen peroxide solution bath exhibited a high anthelmintic effect in common with these parasites, it was considered that it also has an effect on the parasites of the monophyletic multi-sucker discs.
Examples of the present invention will be described below, but the present invention is not limited thereto.

<In vitro anthelmintic effect of treatment with low-concentration hydrogen peroxide solution against Neobenedonia gillere in vitro-1>
Test method: About 100 g of four yellowtails were housed in one 100-liter aquarium, and 2000 neo-Benedenia gillerei hatching larvae were placed in the aquarium for attack. On the 14th day after the attack, the fish were sampled, and the adult parasites on the body surface were collected with tweezers and used for the test. The water temperature during the rearing period was 25±0.5°C. The seawater was filtered seawater that had been UV-sterilized, and the supply rate was 1.2 liters/minute. Commercially available EP feed was used as the feed, the feed was once a day, and the feed amount was 2% of the fish body weight.
Ten adult worms were housed and fixed in seven 90 mm tissue culture dishes containing 20 ml of seawater. After fixing, it was washed with seawater three times. The seawater was removed with a decanter, and the remaining seawater was wiped off with a Kimwipe. 20 ml of each test solution was added thereto and cultured at room temperature of 25°C. After the treatment, the plate was washed 4 times with seawater, 20 ml of seawater was added, and the mixture was cultured for 10 hours. Immediately after returning to seawater after treatment, every 30 minutes after returning to seawater for 2 hours, and 10 hours after treatment, the number of atrophic individuals and adults detached from the wall of the petri dish were counted and recorded. In addition, in order to understand the size of the tested Neobenedenia gillere, the body length of 30 worms was measured.
Test plots: The test plots are shown in Table 1.

Results and discussion The body length of the worms used in the test was 4.17 ± 0.25 mm.
Hydrogen peroxide solution is an anthelmintic agent of Venegian seriole which parasitizes the body surface of yellowtail and Vivagina Thai which parasitizes gills of red sea bream, and its dosage regimen is 3 minutes at a hydrogen peroxide concentration of 300 ppm.
Regarding Neobenedenia gillere in Test Area 1, all the individuals showed moderate atrophy immediately after being treated and returned to seawater (Fig. 1, Fig. 2B), and the atrophy increased within about 10 minutes after being transferred to seawater. , 3 out of 10 had severe atrophy (Fig. 2C). However, the atrophied individuals gradually recovered (Fig. 2D), and all the individuals recovered from atrophy within 30 minutes after returning to seawater (Fig. 1).
In Test Area 2, Neobenedenia gillere, all of the individuals were severely atrophied immediately after being treated and returned to seawater (Fig. 3A). All the individuals were atrophied 30 minutes after returning to seawater after the treatment (Fig. 1), but the atrophy was restored to a moderate degree (Fig. 3B). 90 minutes after returning to seawater, 90% of the individuals recovered from atrophy (Fig. 1, Fig. 3C).
In test section 1 and test section 2, Neobenedenia gillere sticking discs (large suction cups) did not atrophy at both treatment times of 3 minutes and 6 minutes (Figs. 2B & C, Fig. 3A). From the above, in the Benedenia anthelmintic conditions, the hydrogen peroxide concentration of 300 ppm for 3 minutes and the treatment time of 6 minutes doubled, the fish contacted each other within a relatively short time until the atrophied main insect recovered. It is considered that the insects have an anthelmintic effect by dropping from the body surface by a physical action such as rubbing their bodies against the cage net. It is considered that the anthelmintic effect is limited, because the individual that has not been physically affected recovers.
In the test plots 3 and 5, immediately after returning to seawater after treatment for 30 minutes, all the individuals were atrophied to a moderate level (Fig. 1, Fig. 4A). Both treatments tended to become more atrophy after being transferred to seawater after treatment. This tendency is similar to the treatment area at 300 ppm for 3 minutes. More than half of the atrophied worms recovered after 30 minutes, but one atrophied worm was observed 1 hour and 30 minutes after returning to seawater (Fig. 1). In both cases, the fixing plate was atrophied and could not be fixed on the petri dish.
Immediately after the treatment, the test sections 4 and 6 had moderate atrophy, and no significant difference was observed between the test sections 3 and 5. In both treatment plots, atrophy tended to progress after the treatment was transferred to seawater. Particularly in Test Zone 4, the number of individuals that peeled from the petri dish gradually increased in 60 minutes after returning to seawater, and the peeling rate after 60 minutes reached 100%. Even after 120 minutes from treatment in both test plots, more than half of the individuals were atrophied. The fixation disc was prominent as the atrophy site (Figs. 4B & C). Further, in test section 4, 7 worms that were not recovered even after 10 hours were observed, and 4 of them were not settled in the petri dish. Atrophy of the fixation discs continued, and atrophy was observed not only in the non-established petri dishes but also in the established ones (Fig. 4D).
These results show that even at low concentrations of 75 ppm and 50 ppm, it is possible to exterminate Neobenedenia gillerea by treating for 30 to 60 minutes. In particular, it is considered that the fixing disc of Neo-Benedenia gillere is atrophied, so that it can stably exert a high anthelmintic effect as compared with the high-concentration and short-time treatment conventionally performed in cages.
In test section 7, no atrophy of Neobenediania gillere or detachment from petri dish was observed during the test period.

<In vitro anthelmintic effect of treatment with low-concentration hydrogen peroxide solution against Neobenediania gillere-2>
Test method: The test was performed in the same manner as in Example 1. Neo-Benedenia gillere attacked and tested the parasite in yellowtail on the 12th day, and contained 10 adults each in 3 petri dishes and allowed them to settle. Immediately after the treatment for 60 minutes was completed and returned to seawater after 30 minutes of treatment, 30 minutes after the treatment was returned to seawater, the number of atrophied individuals and adults detached from the wall of the petri dish were counted and recorded.
Test section: The test section is shown in Table 2.

Results and discussion The body length of the worms used in the test was 3.86±0.29 mm.
Neo-Benedenia of the test section 1 atrophied 2 to 3 minutes after the treatment was started, and the atrophy became remarkable after 6 minutes. However, 30 minutes after the treatment, immediately after the treatment for 60 minutes, and after observation for 30 minutes after the treatment was completed and returned to seawater, all the neobenedenian gilleres were atrophied but were detached from the wall of the petri dish. The number was as small as 3 individuals (Fig. 5). Thirty minutes after the treatment was completed and returned to seawater, no atrophy or deformation was observed in the sticking plate of 7 individuals, despite the fact that the bodies of all individuals were cloudy and affected so that they did not move. Was established in (Figs. 5 and 6A & B). Two of the 7 individuals finally peeled off from the wall of the petri dish 1 hour after the culture. These two individuals were judged to have died because their marked atrophy was mild and their bodies were clearly clouded.
The number of exfoliated individuals from the petri dish of test section 2 was 9 immediately after the treatment for 60 minutes and 30 minutes after the treatment was completed and returned to seawater (Fig. 5). In the detached insect, not only the body was atrophied but also the fixation disc was atrophied and deformed (FIG. 6C), and the test results of Example 1 were reproduced.
From the above results, it was revealed that the low concentration of 75 ppm or 50 ppm had a clear effect of atrophying and deforming the sucker of Neobenedenia gillere at a low concentration of 75 ppm or 50 ppm, compared with the high concentration of the usual dose. These results show that treatment with a low concentration of hydrogen peroxide of 75 ppm or 50 ppm showed that the atrophic parasites caused by the fish contacting the atrophied Neobenedenia gillere, or rubbing their bodies against cage nets or obstacles. In addition to the physical action of the usual dose to drop it from the surface, it also has the effect of atrophiing and deforming the fixation plate for Neobenedenia gillere to settle in the host and peeling it from the surface of the host body, which has been conventionally performed in cages. It was considered that a high anthelmintic effect could be stably exhibited as compared with the treatment at a high concentration for a short time.
In Test Group 3, no atrophy of Neobenedenia gillere or detachment from the petri dish was observed during the test period.

<In-vivo anthelmintic effect of treatment with low-concentration hydrogen peroxide solution against Neo-Venedenia gilleri-1>
Test method: 48 amberjacks with an average fish weight of about 130 g were bred in a 500-liter water tank for about 7 days and acclimated to a water temperature of 25°C. During the feeding, commercial feed was given, and the feeding rate was 2% of the fish weight. Water injection was 8.3 liters/minute. After acclimatization, about 4500 Neovenedian gillere hatching larvae were placed in a 500-liter aquarium, and the insects were attacked by stopping the water for 1 hour. Seven days after the attack of hatching larvae, the fish were transferred to seven 200-liter aquariums and the test plots were set (Table 3). The remaining 4 fish were continuously bred in a 500-liter water tank for measuring the length of Neobenediania gillere during hydrogen peroxide treatment, and during treatment with the medicinal bath, the worms were collected and the body lengths of 30 individuals were measured. Water injection was 6.7 liters/minute during the breeding period. Nine days after the attack, the chemical bath treatment of each ward was performed in a 200-liter square aquarium, and after the treatment, the fish was transferred again to the 200-liter rearing aquarium and bred until the next day. All the fish were sampled, the fish weight was measured, and the parasitic Neobenedenia gillere was counted. The evaluation of the anthelmintic effect was carried out by comparing the numbers of parasites of Neovenedia gillerii in the respective plots.
Test plots: Table 3 shows the test plots.

Results and discussion The body length of Neovenedia gillere at the time of drug treatment was 3.01±0.43 mm, and it was an adult.
Table 3 shows the anthelmintic effect against the main insect parasitizing Amberjack.
The test area 1 (dosage/use of hydrogen peroxide solution for Benedenia/seriole deworming) had a neobenedenia gilleri repellent rate of 33.5%. In addition, the anthelmintic rate of test section 2 in which the immersion time was doubled to 6 minutes was 59.1%. From the test results of Example 1, treatment with hydrogen peroxide concentration of 300 ppm for 6 minutes causes the body of Neobenediania gillere to atrophy severely, but does not cause atrophy/deformation of the sticking disc (large sucker) of this insect. Alternatively, it has been found that the atrophied and detached main insect recovers in about 1 hour. From the results of this test, the anthelmintic effect under these conditions is that the fish contact each other in a relatively short time until the atrophied main worm recovers, and the physical action such as rubbing the body on the cage net It has been clarified that it is exerted and that the anthelmintic effect is limited only by atrophy of the insect body.
The anthelmintic rate of test section 3 was 94.3%, and the anthelmintic rate of test section 4 was 99.2%, showing a high anthelmintic effect. Furthermore, the anthelmintic rate of test section 5 was 86.6%, and the anthelmintic rate of test section 6 was 97.5%, which was a high anthelmintic effect. In Examples 1 and 2, these low-concentration treatments atrophied not only the body of Neobenedenia gillere but also the fixation discs. From the results of Examples 1 and 2 and this test, it was revealed that it is important for Neobenedenia gillere's anthelmintic to atrophy and deform the fixation disc, and thereby a high anthelmintic effect can be stably obtained.

<Anthelmintic effect of treatment with low-concentration hydrogen peroxide solution against Neovenedia gillere in vivo-2>
Test method: The test was performed at a water temperature of 30° C., and the operation was performed in the same manner as in Example 3. 42 amberjacks with an average fish weight of about 130 g were bred in a 500-liter water tank for about 7 days and acclimated to a water temperature of 30°C. The number of hatching larvae of Neo-Venedenia gillere used for the attack was about 5,500. Three days after the attack of hatching larvae, the fish were transferred to six 200-liter aquariums and the test plots were set (Table 4). Seven days after the challenge, each group was treated with a chemical bath, and eight days after the challenge, the anthelmintic effect was evaluated.
Test section: The test section is shown in Table 4.

Results and Discussion The body length of Neovenedia gillere at the time of drug treatment was 3.01±0.18 mm, and it was an adult.
Table 4 shows the anthelmintic effect against the main insect parasitizing Amberjack. The results of Example 3 were reproduced. Furthermore, it was found that a high anthelmintic effect can be exhibited by treating for 30 to 60 minutes even at a low hydrogen peroxide concentration of 37.5 ppm.

<Effect of hydrogen peroxide on amberjack-1>
Test method: Six amberjacks having an average fish weight of about 208 g were accommodated in six 200-liter aquariums each. The fish was acclimated for 7 days at 25°C. During the feeding, commercial feed was given, and the feeding rate was 2% of the fish weight. Water injection was 6.7 liters/minute.
A predetermined amount of hydrogen peroxide water was previously diluted with seawater, and then the breeding water was stopped and put into each water tank. After that, observation was performed for up to 6 hours. After the treatment for 6 hours, it was flushed again.
Test section: The test section is shown in Table 5.

Results and Discussion Table 6 shows the observation results. In the treatment area with a hydrogen peroxide concentration of 300 ppm or more, the fish vigorously swim up and down 1 to 3 minutes after the start of the immersion treatment. After that, although swimming abnormalities subsided, it was observed repeatedly that the opening and gill lid were opened and closed approximately 15 minutes after the start of immersion. Before death, the fish repeated mad swimming, rollover, and slow swimming, and died with spots on the body surface. The feeding behavior of the two surviving fish in the 300 ppm treatment group was also slow. In the 150 ppm treatment area, no dead fish were observed, but abnormal swimming or opening during treatment and abnormal feeding behavior were confirmed the day after treatment. Therefore, it was clarified that 300 ppm concentration, which is the usual dose for Venedenia seriole extermination of Perciformes, causes toxicity to fish in a short time. On the other hand, in the 75 ppm treatment group, which was 1/4 times the normal dose, no abnormalities were observed during immersion, and no abnormalities were observed after the completion of immersion or during feeding on the next day. Therefore, it was proved that a concentration of less than 150 ppm, particularly 75 ppm or less, can reliably treat the chemical bath for a long time without adversely affecting the fish. Furthermore, the treatment at this concentration or at a low concentration such as 50 ppm is a condition for atrophying and deforming the fixing disc of Neobenediania gillere and stably exerting a high anthelmintic effect.
At the aquaculture site, there may be a fatal accident due to lack of oxygen in the hydrogen peroxide solution chemical bath at high water temperature in summer. It is generally known that the higher the water temperature, the higher the temperature of this drug is to the gills of fish. In this test, intense swimming behavior was observed 1 to 3 minutes after the start of treatment in the area of 150 ppm or more. Therefore, it is considered that the cause of the fatal accident is not only the effect of hydrogen peroxide on the gills, but also this vigorous swimming, which causes oxygen deficiency.

<Influence of hydrogen peroxide on amberjack-2>
Test method: 33 amberjacks with an average fish weight of about 195 g were labeled with an electronic tag to identify individuals, and were acclimated by breeding in a 500-liter aquarium for 7 days. Rearing conditions such as water supply, feed amount, and water temperature were in accordance with Example 3. After acclimatization, the fish were transferred to three 200-liter water tanks so that each fish tank had 11 fish, and the fish were stored in each water tank and the tag number of the fish was recorded. The test group was a group treated with a hydrogen peroxide concentration of 300 ppm for 3 minutes, a group treated with a hydrogen peroxide concentration of 75 ppm for 30 minutes, and an untreated control group. After the treatment, all the fish were again stored in one 500-liter aquarium, and about 7200 Neovenedenia gillerei hatching larvae were added to the fish to stop the water for 1 hour. Six days after the attack, all fish were sampled and the number of parasitic Neobenedenia gillere was counted. The post-treatment safety evaluation was carried out by comparing the number of Neobenediania gilleris parasites in each ward.

Results and Discussion Observation results are shown in FIG. 7. The number of parasites in the hydrogen peroxide concentration of 300 ppm and 3 minutes was significantly higher than that in the untreated control. On the other hand, the number of parasites in the 75 ppm/30-minute group was similar to that in the control group. From the above results, a high-concentration hydrogen peroxide drug bath such as a regular dose causes some damage such as exfoliation of mucus on the body surface of fish even after a short treatment for several minutes, and parasites are re-infected. It was thought to be in an easy state. On the other hand, it was found that the treatment at a low concentration for a long time did not damage the body surface of the fish to the extent that parasites were easily reinfected. Therefore, it was revealed that the safety of the present invention for fish is higher than that of the conventional method not only during the treatment but also after the treatment.

<In vitro anthelmintic effect of low-concentration hydrogen peroxide solution treatment on Benedenia ceriole>
Test method: About 150 g of four yellowtails were stored in one 100-liter water tank, and 1300 Benedenia seriole hatching larvae were placed in the water tank and attacked. On the 19th day after the attack, the fish were sampled, and the adult parasites on the body surface were collected with tweezers and used for the test. The water temperature during the breeding period was 20.5 ± 0.5°C. Breeding and in vitro tests were performed in the same manner as in Example 1. In addition, the numbers of the atrophied individuals and the adults detached from the wall surface of the petri dish were counted and recorded every 30 minutes for 2 hours immediately after the treatment and returning to seawater.
Test section: The test section is shown in Table 7.

Results and discussion The body length of the worms used in the test was 5.30 ± 0.31 mm.
Immediately after the treatment, all the individuals of Benedenia ceriole in the test section 1 were severely atrophied (Fig. 9A), and 3 out of 10 individuals were detached from the wall of the petri dish (Fig. 8). Thirty minutes after returning to seawater after treatment, four more individuals had peeled from the wall of the petri dish. The fixation disc of the exfoliated individual was atrophied and deformed (Fig. 9B). However, in 90 minutes after treatment and returning to seawater, 3 individuals recovered from atrophy. In the test of Neobenedenia gillere of Example 1, no detached insect was observed under these conditions, and all the individuals recovered from atrophy within 30 minutes after returning to seawater after the treatment. These results indicate that Benedenia ceriole is more sensitive and more susceptible to aqueous hydrogen peroxide than Neobenedenia gillere.
In test section 2, peeling of 5 individuals was observed immediately after the treatment, and further 4 individuals were peeled off within 90 minutes after returning to seawater after the treatment. In this area, 1 individual recovered from atrophy. It was considered that the anthelmintic effect is limited and the anthelmintic results are not stable because some individuals recover from atrophy in both test plots.
In test section 3, all the individual shrunk at 13 minutes after the treatment and peeled off from the wall surface of the petri dish. Also in the test section 4, 10 minutes out of 10 individuals atrophied 13 minutes after the treatment started, 9 individuals exfoliated, and the remaining 1 individual exfoliated within 30 minutes. In both plots, atrophy and recovery from exfoliation were not observed in 10 exfoliated individuals after 2 hours of observation after returning to seawater after treatment. Furthermore, the sticking discs of the exfoliated individuals were atrophied and deformed (Fig. 9C & D).
In test plot 4, the body was clouded and the movement stopped about 30 minutes after returning to seawater after the treatment, so it was considered that the worm died.
From the above, treatment of 75 ppm for 30 minutes causes atrophy and deformation of the fixed disc of Benedenia and Ceriole, and does not recover even within about 2 hours after treatment, so it is more effective than 300 ppm for 3 minutes or 300 ppm for 6 minutes. It has been found that it can stably exert.
In the untreated control group, neither atrophy of Benedenia seriole nor detachment from the petri dish was observed during the test period.

<Anthelmintic effect of low-concentration hydrogen peroxide treatment on in vivo lamelogiscus>
Test method: 50 red sea breams cultivated in field cages were tested. The average fish weight of this group was about 74 g. The red sea bream was transferred from the cage to a 1t water tank on land, and 10 red sea breams were stored in 5 30L water tanks containing 15L seawater. Aeration was performed with a small air pump to prevent oxygen deficiency. A predetermined amount of hydrogen peroxide solution in each section was dissolved in 50 mL of seawater, and the solution was placed in a container containing fish and stirred to dip the fish for a predetermined time. After the treatment, the container was tilted to receive the fish with a bag-shaped net, and about 3 L of seawater was poured and washed from above. The fish were returned to a container containing 18 L of seawater and bred for 1 hour while aerating, and then the fish were sampled to count the lamelogiscus parasitic on the gills. The anthelmintic effect was evaluated by comparing the number of parasites of Lamelogiscus in each plot. The water temperature of the seawater used in the test was 22.0°C.
Test section: The test section is shown in Table 8.

Results and discussion
The rate of lamellosicus extermination in the treatment area of 300 ppm for 3 minutes was 0%. The anthelmintic effect was not exhibited with the dose and usage of Vivagina and Thailand. Furthermore, the number of parasites of the parasite was similar to that of the control group even in the 300 ppm/15-minute treatment group, and showed no anthelmintic effect. The red sea bream of 300 ppm in 15 minutes was overturned due to the influence of this treatment just before the end of treatment, and it was thought that further treatment could not be performed. On the other hand, a clear anthelmintic effect was observed in the 75 ppm/30 min treatment group and the 100 ppm/30 min treatment group (Table 8), and no abnormalities were observed in swimming of the fish.
These results show that low-concentration/long-time treatment has a greater effect than the high-concentration/short-time treatment on the grasping device of lamellidiacus. It was confirmed that the long-term treatment of the present insects with a low concentration of hydrogen peroxide was effective.
Benedenia ceriole, Neobenedonia girelle and Lamelogiscus are classified as monosomatic post-suckers. Since the low-concentration hydrogen peroxide solution baths exhibited a high anthelmintic effect in common with these parasites, it was considered to have an effect on the parasites of the monophyletic single post sucker.

<In vitro anthelmintic effect of low-concentration hydrogen peroxide treatment on Zeuxapta japonica>
Test method: About 1.4 kg of five gills of cultured amberjack were taken out, and Zexapta japonica parasitizing the gills valve was collected while parasitizing the gills valve. The in vitro test was carried out in the same manner as in Example 1, using 5 individuals of each ward. The observation was performed in the middle of the treatment, immediately after the treatment and returning to seawater, and every 10 minutes for 30 minutes after returning to seawater, and the atrophic individuals were counted and recorded.
Test plots: The test plots are shown in Table 9.

Results and discussion
The body atrophy of 300 ppm, 3 minutes, and 6 minutes of the insects was mild even immediately after the treatment (Fig. 10A), and the atrophy was recovered within about 10 minutes after the treatment (Fig. 11). On the other hand, the worms treated with 75 ppm for 60 minutes were obviously atrophied in 6 to 10 minutes of treatment (Fig. 10B). Furthermore, all the worms in the 75 ppm/60-minute treatment group atrophied even 30 minutes after the treatment, and even in the 50 ppm/60-minute treatment group, only 1 individual recovered within 30 minutes after the treatment. The atrophy of the worms in the low-concentration treatment group was observed not only in the body but also in the fixation disc where the graspers were arranged (Fig. 10B).
Treatment with low concentration for a long time causes Zeuxapta japonica to atrophy for a long time, and the atrophy is severe and extends to the sticking board where the grasping device is arranged, so it is better than 300 ppm・3 minutes or 300 ppm・6 minutes treatment. It was found that the anthelmintic effect was stably exhibited.
In the untreated control group, no atrophy of Zeuxapta japonica was observed during the test period.

<Anthelmintic effect of low-concentration hydrogen peroxide solution treatment on Vivagina and Thailand in vivo>
Test method: 50 red sea breams cultivated in field cages were tested. The average fish weight of this group was about 61 g. The red sea bream was transferred from the cage to a 1t water tank on land, and 10 red sea breams were stored in 5 30L water tanks containing 15L seawater. Aeration was performed with a small air pump to prevent oxygen deficiency. A predetermined amount of hydrogen peroxide solution in each section was dissolved in 50 mL of seawater, and the solution was placed in a container containing fish and stirred to dip the fish for a predetermined time. After the treatment, the container was tilted to receive the fish with a bag-shaped net, and about 3 L of seawater was poured and washed from above. The fish were returned to a container containing 18 L of seawater and bred for 1 hour with aeration, and then the fish were sampled to count the vivagina tie infesting the gills. The anthelmintic effect was evaluated by comparing the number of parasites in Vivagina and Thailand in each ward. The temperature of seawater used in the test was 23.2°C.
Test plots: The test plots are shown in Table 10.

Results and discussion
The Vivagina-Thai deworming rate in the 300ppm/3-minute treatment group (the dose and usage of the hydrogen peroxide solution for Vivagina-Thai deworming) was 64%. In the main ward, the fish just after the start swim violently like jumping on the water surface. From this behavior, it was considered that high-concentration treatment caused toxicity and irritation to red sea bream. The insect repellent rate in the 100 ppm/30-minute treatment group was 89%, and that in the 60-minute treatment group was 100%. Further, the anthelmintic rate in the 75 ppm/60-minute treatment group was 99%. Swimming of the fish in these low-concentration treatment areas did not change from the beginning to the end of the treatment, and no abnormalities were observed in the fish.
From these results, it was found that long-term treatment with a low concentration of a hydrogen peroxide agent exerts a high anthelmintic effect on the aphid Vivagina tie without causing obvious toxicity or irritation to red sea bream. ..

a: The number of parasites is shown as the average ± SD.
b: Significantly different from the number of parasites in the control plot (P<0.01).

<Anthelmintic effect of low-concentration aqueous hydrogen peroxide treatment on Benedenia ceriole, Neobenedenia gillere and Zeuxapta japonica in vivo>
Test method: About 400 amberjack of about 430 g that had been cultivated in an outdoor cage were used for the test. 15 t of seawater was put in the chemical bath sheet, and a hydrogen peroxide solution was added and stirred so that the hydrogen peroxide concentration became 75 ppm. 390 fish were housed and soaked for 30 minutes. After treatment, the fish were transferred to cages. Sampling was done by picking 10 fish each before and the day after treatment. Benedenia seriole and neo-benedenia gillere, which are parasitic on the body surface, and Zeuxapta japonica, which is parasitic on the gills, were counted. The anthelmintic effect was evaluated by comparing the number of parasites in each plot. The water temperature of the seawater during the treatment was 28.5°C.

Results and discussion Table 11 shows the results. No parasitism of Benedenia ceriole, Neobenedenia gillere or Zeuxapta japonica was observed in the treated fish, and the anthelmintic rate was 100% for all the parasites.
Therefore, the effectiveness of the present invention was proved even under such a large-scale condition.

<Effectiveness test of low-concentration hydrogen peroxide solution treatment by amberjack skirt method>
Test method: A 11.5 mx 11.5 mx 10 m cage containing about 2 kg of amberjack, a 48 m long and 10 m wide sheet is wrapped around the cage, and the chucks attached to both ends of the sheet are closed to form a cylinder. Then I surrounded the cage. An amount of concentrated hydrogen peroxide solution having an average concentration of 35 ppm was added to the seawater in the sheet in 5 minutes, and after 60 minutes, the sheet around the cage was removed. Sampling was done by picking 10 fish each before and the day after treatment. Benedenia seriole and neo-benedenia gillere (n=10), which are parasitic on the body surface, and Zeuxapta japonica (n=5), which are parasitic on the gills, were counted. The anthelmintic effect was evaluated by comparing the number of parasites in each plot. The temperature of seawater during treatment was 26°C.

Results and Discussion The hydrogen peroxide concentration was 35 ppm at the start, 15 ppm after 30 minutes, and 3 ppm after 60 minutes, and the concentration was gradually diluted. The number of parasitic beetles (Neo Benedenia and Benedenia) was 110±48.3 individuals/tail before the treatment and 28.9±24.3 individuals/tail after the treatment. The number of parasites of zekusapta was 110.8±49.0 individuals/tail before the treatment and 54.0±41.6 individuals/tail after the treatment. Therefore, the effectiveness of low-concentration hydrogen peroxide solution treatment was verified even in the skirt method under conditions in which this agent was gradually diluted.

By the method of the present invention, ectoparasites that parasitize fishes can be exterminated more safely and efficiently using the hydrogen peroxide solution currently used in aquaculture.

Claims (8)

A marine fish sucker with a low-concentration hydrogen peroxide solution, which is characterized by immersing marine fish in a hydrogen peroxide solution having a concentration of 30 ppm to 150 ppm for 15 minutes or more to atrophy or deform the sucker or sticker of ectoparasites. Alternatively, a method for exterminating ectoparasites having a sticking disc. Cover at least the side surface of the cage net with a sheet to keep the seawater inside, and add hydrogen peroxide solution to the seawater in the cage to calculate the average concentration of 30 ppm to 150 ppm, and keep it for 15 minutes or more. The method of claim 1 wherein the sheet is removed after the passage. The method according to claim 1 or 2, wherein the immersion time is 15 minutes to 2 hours. The method of claim 3, wherein the soaking time is 15-60 minutes. The method according to claim 1, wherein the marine fish is a marine fish belonging to the order Perciformes. The method according to claim 5, wherein the marine fish is a yellowtail or Thai fish. The method according to any one of claims 1 to 6, wherein the ectoparasite is an ectoparasite belonging to the genus Capsula or Diplectinidae of the phylum Monophylla .. Ectoparasites are Benedenia ceriole, Benedenia epinepheri, Benedenia Hoshinai, Benedenia Sekii, Neobenedenia gillere, Neobenedenia congheri, Lamelogiscus, Zeuxapta japonica or Vivagina tai, Heteraxine heterocerchiaceta, micrococcilece, micrococcus 8. The method of claim 7, which is Sebastiski.