KR20210113437A - Method for eliminating fish-external parasites using low-concentration hydrogen peroxide solution - Google Patents

Abstract

It provides a safer and more effective method of exterminating ectoparasites parasitic on the body surface of fish. It is a method for exterminating ectoparasites of seaweed fish with low concentration hydrogen peroxide water, characterized in that it is immersed in 30 ppm to 150 ppm hydrogen peroxide water for 15 minutes or more. Cover the side of the cage with a sheet to keep the seawater inside, and add hydrogen peroxide to the seawater in the cage in an amount such that the calculated average concentration is 30 ppm to 150 ppm, and after 15 minutes or more, the sheet It is a method of exterminating ectoparasites of marine fish by low-concentration hydrogen peroxide water, characterized in that it removes the

Description

Method for exterminating fish ectoparasites using low-concentration hydrogen peroxide solution

The present invention relates to a control agent for ectoparasites of marine fish (especially farmed fish) and a method for controlling parasites. In detail, it relates to a drug and a method for exterminating parasitism of monophytes parasitic on the body surface of fish such as skin parasites and gill parasites.

In fish farming, parasitic diseases are a very big problem because they interfere with stable production. Among parasitic diseases, monochromats belonging to the phylum Monophyllum or Calligus of the phylum Arthropoda are considered to be one of the biggest problems because they occur in many cultured fish. In monolivs, there are those commonly called skin parasites and those called gill parasites. Parasites called skin parasites are short suckers Capsaradae Neobenedenia girellae , Benedenia seriolae , etc. It is known to be parasitic on many fish species, such as tang, red snapper, jabberi, halibut, flounder, and flycatcher. On-site diagnostic methods include death accompanied by symptoms such as redness of the epidermis of the abdomen, friction of the fins, and clouding of the eyeballs, and in fish that have received a large amount of parasitism, the body surface looks cloudy due to the secretion of a large amount of mucus, etc. can be heard In addition, abnormal swimming by rubbing the body against the cage is often seen. Since the symptoms are worsened by rubbing the body with a cage, etc., and the chance of infection of the pathogen from the parasitic site increases, the damage may be expanded. When parasitism of this insect is confirmed, it is repelled by performing a fresh water bath or a high concentration hydrogen peroxide water bath for about 3 minutes while paying attention to the water temperature.

Monophytes, also called gill parasites, are parasitic flatworms of the phylum Heteraxine heterocerca , Zeuxapta japonica , and the same microcosmia parasitic on red sea bream. Bivagina tai , Microcotyle sebastis parasitic on snail rockfish Microcotyle sebastis , Microcotyle sebastisci parasitic on snailfish, Dicridophora family heterobot Heterobothrium okamotoi ), parasitic flounder, and Neoheterobothrium hirame . Examples of on-site diagnostic methods include discoloration of gills, anemia in fish, and lowering of obesity. In addition, there are cases where an abnormal swimming by rubbing the body against the cage is frequently seen. Since the chance of infection of pathogens increases from the rubbing parts of the body surface by rubbing the body with a cage, the damage may be expanded. When the parasitism of this insect is confirmed, it is repelled by performing a high concentration hydrogen peroxide water bath for about 3 minutes, paying attention to the water temperature.

In any case, since the labor required for treatment such as habitat change of fish and the stress given to the fish are large, a simpler treatment method is strongly desired.

In addition, in recent years, there have been cases in which parasitism of a huge number of Lamellodiscus spp. has been recognized in the gills of farmed red snapper, and there is concern about the effect on the host. This insect is also called a gill parasite, and it is classified in the genus Lamelodiscus of the short sucker family Diplectanidae. There is no established method for repelling this insect.

Parasites called calligus of the arthropoda crustaceans are Caligus longipedis parasitizing on horse mackerel, Pseudocaligus fugu parasitizing on porpoise, Pseudocaligus fugu, salmonid fish, mullet, and tilapia. Parasitic Caligus orientalis. The on-site diagnosis method, the effect on the parasitic fish, and the deworming method are the same as for skin parasites. However, the treatment time of fresh water bath or hydrogen peroxide water bath during deworming is about 20 minutes, which is longer than that of skin parasites.

The skin parasites that have been generated in the parasites are Benedenia Serioleae and Neobenedenia Girelae. In addition, the parasitism of Neobenedenia girellae has been reported in many marine fish other than bluefish. As for the insect repellent method in the field, a medicinal bath or fresh water bath with a hydrogen peroxide solution (Katayama Chemical Research Institute, trade name Marine Sour and Hodogaya Chemical Industry Co., Ltd., trade name Sakana Guard) is mainstream. In Japan, hydrogen peroxide is approved as an veterinary drug for benedenia serioolae of sea bass fish and vivagina dome (gill parasite) of red sea bream. The use and dose for these parasites is 3 minutes at a hydrogen peroxide concentration of 300 ppm. In the ashes culture, the damage caused by neobenedenia girellae is more severe than that of benedenia seriollae, and hydrogen peroxide is also used for anthelmintic neobenedenia girellae of the ashes. However, with this dose and method, the antiparasitic effect against Neobenedenia girellae is low, and a medicinal bath of 300 ppm for 5 minutes to 6 minutes is employed in the field. In addition, this agent is highly toxic to ash protection at high temperatures, and there are cases in which deaths are thought to be caused by lack of oxygen.

Also, recently, hydrogen peroxide has been approved as veterinary medicines for Neobenedenia girellae and Pseudocaligus pufferfish of the Pufferfish order, and the dosage and usage is 300 ppm for 20 minutes.

Patent Document 1 describes a method for exterminating ectoparasites in seawater cultured fish, in which a bath is bathed in hydrogen peroxide having a concentration of 200 to 3000 ppm for 1 to 20 minutes. Patent Document 2 describes a method of bathing for 30 to 120 minutes with hydrogen peroxide having a concentration of 10 to 100 ppm in order to exterminate gyrodactylus of freshwater fish. Patent Document 3 describes a method of bathing in hydrogen peroxide at a concentration of 400 to 2000 ppm for 20 to 120 minutes for the prevention of heterobotrium disease of purple squirrels.

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

An object of the present invention is to provide a method for controlling ectoparasites parasitic on the body surface and gills of fish that is safer and more effective.

While the inventors were studying about a medicinal bath using hydrogen peroxide, by using a low-concentration hydrogen peroxide solution of 150 ppm or less, greater damage to parasites than when using a conventional high-concentration hydrogen peroxide of 300 ppm or more can be given, and more complete control It was found that it could be done, and the present invention was completed. In addition, by combining the low-concentration hydrogen peroxide solution with the spraying method (the method of spraying chemicals directly on cages, etc.), it does not cause an oxygen shortage accident caused by bathing with a small amount of sea water, which is the conventional method, An excellent method of repelling insects that is simple and safe compared to the existing methods so far, which is said to be able to significantly reduce the extensive work of collecting and lifting, has been found.

This invention makes the summary of (1)-(5) the method of exterminating ectoparasites of marine fish.

(1) A method for exterminating ectoparasites of marine fish with low-concentration hydrogen peroxide water, characterized by immersion in hydrogen peroxide water having a concentration of 30 ppm to 150 ppm for 15 minutes or more.

(2) Cover at least the side of the net of the cage with a sheet so that the seawater inside is maintained, and add hydrogen peroxide to the seawater in the cage in such an amount that the average concentration is 30 ppm to 150 ppm by calculation, and for 15 minutes or more The method of (1), characterized in that the sheet is removed after lapse.

(3) The method according to (1) or (2), wherein the ectoparasite is a parasite belonging to the phylum Monophyllum or Arthropoda crustaceans.

(4) The method according to (1) or (2), wherein the ectoparasite is a parasite of the genus monosporidium suckers, multiform suckers, or arthropods Carapaceae caligus.

(5) The ectoparasites are from the Capsalidae family, or Diplectanidae, of the single ginger short suckers, and the Heteraxine family, Microcotyloidea. The method of (1) or (2), which is a parasite belonging to the family, the family Diclidophoridae, or the family Neoheterobothrium, or, the family Arthropod Carapaceae Caligus.

(6) External parasites are Benedenia seriolae, Benedenia epinepheli, Benedenia hoshinai, Benedenia sekii, Neobenedenia. Girellae (Neobenedenia girellae), Neobenedenia congeri (Neobenedenia congeri), Lamellodiscus, Zeuxapta japonica (Zeuxapta japonica), Bivagina tai (Bivagina tai), Heterakisine Heteraxine heterocerca, Microcotyle sebastis, Microcotyle sebastisci, Heterobothrium okamotoi, or Neoheterobothrium halibut hirame), Calligus longipedis (Caligus longipedis), Pseudocaligus fugu (Pseudocaligus fugu), Caligus orientalis (Caligus orientalis), the method of (1) or (2).

(7) The method according to any one of (1) to (6), wherein the fish is a fish belonging to the order Perciformes.

(8) The method of (7), in which the fish is a fish of a bream or a bream.

(9) The method of (1) or (2) whose immersion time is 15 minutes - 6 hours.

(10) The method of (1) or (2) whose immersion time is 15 minutes - 2 hours.

By using the control method of the present invention, ectoparasites can be controlled more reliably and without adversely affecting fish. In particular, it can effectively exterminate ectoparasites such as Benedenia Seriolae, Neobenedenia Girrellae, Zeuksafta Japonica, Vivagina Dom and Lamelodiscus, which have a great impact on the aquaculture business.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the anti-Neobenedenia girellae action|action in Example 1 of hydrogen peroxide water.
Fig. 2 is a photograph showing the anti-Neobenedenia girellae action of hydrogen peroxide solution (300 ppm·3 min treatment) in Example 1; A: control, B: immediately after return to seawater after treatment, C: after treatment and return to seawater after 3 minutes, D: after treatment and return to seawater after 15 minutes.
Fig. 3 is a photograph showing the anti-Neobenedenia girellae action of hydrogen peroxide solution (300 ppm·6 min treatment) in Example 1; A: Immediately after returning to seawater after treatment, B: After treatment and returning to seawater 30 minutes later, C: After treatment and returning to seawater after 60 minutes.
Fig. 4 is a photograph showing the anti-Neobenedenia girellae action of hydrogen peroxide solution (75 ppm 30 minutes and 60 minutes treatment) in Example 1. A: Immediately after returning to seawater after 30 minutes of treatment, B: Immediately after returning to seawater after 60 minutes of treatment, C: After treatment for 60 minutes, returning to seawater after 60 minutes, D: After 60 minutes of treatment, into seawater 10 hours after return (D-1: exfoliated object, D-2: settled object).
Fig. 5 is a diagram showing the anti-Neobenedenia girellae action of 300 ppm and 75 ppm hydrogen peroxide water in Example 2.
Fig. 6 is a photograph showing Neobenedenia girellae affected by each sphere in Example 2; A: After 60 minutes treatment with 300 ppm hydrogen peroxide, return to seawater after 30 minutes, B: Treatment with 300 ppm hydrogen peroxide for 60 minutes, return to seawater after 30 minutes, C: After 60 minutes treatment with 75 ppm hydrogen peroxide, return to seawater 30 minutes later.
Fig. 7 is a diagram showing the effect of treatment with 300 ppm and 75 ppm of hydrogen peroxide on Neobenedenia girellae re-infection of fish in Example 6;
Fig. 8 is a diagram showing the anti-Benedenia seriolae action of hydrogen peroxide water in Example 7.
9 is a photograph showing Benedenia seriolae affected by hydrogen peroxide treatment in Example 7. FIG. In the figure, arrows indicate the atrophy of the adherent plaque and the detached object. A: Immediately after treatment with 300 ppm hydrogen peroxide for 3 minutes, B: immediately after treatment with 300 ppm hydrogen peroxide for 3 minutes, returning to seawater after 2 hours, C: Immediately after treatment with 75 ppm hydrogen peroxide for 30 minutes, D: treatment with 75 ppm hydrogen peroxide for 30 minutes After 2 hours return to sea water.
10 is a photograph showing the anti-Zeuxapta japonica action of 300 ppm and 75 ppm hydrogen peroxide in Example 9; In the figure, the mark indicates the atrophy of the fixing plate. A: Immediately after treatment with 300 ppm hydrogen peroxide for 6 minutes, B: after treatment with 75 ppm hydrogen peroxide for 10 minutes.
11 is a diagram showing the anti-Zeuxapta japonica action of hydrogen peroxide at 300 ppm, 75 ppm, and 50 ppm in Example 9;

Parasites which are the object of the present invention include monolivs belonging to the phylum Monophyllae of fish (generally called skin parasites and gill parasites) and Calligus belonging to the phylum Arthropoda crustaceans. Parasites called skin parasites include those parasitic on saltwater fish such as monopods, subfamily Benedenia. As a subfamily of Benedenia , for example, Benedenia seriolae, Benedenia epinepheli , Benedenia hoshinai , Benedenia sekii , etc. Venetian denier (Benedenia) and neo Venetian denier, there may be mentioned the neo Venetian denier (Neobenedenia), such as paper relrae (Neobenedenia girellae), neo Venetian denier, Gary cone (Neobenedenia congeri). Monophytes called gill parasites are Heteraxine family Heteraxine heterocerca , Zeuxapta japonica , Microcotyredae vivagina dom ( Bivagina tai), micro Courtney Les Sheba seutiseu (Microcotyle sebastis), micro Courtney Les Sebastien skiing (Microcotyle sebastisci), Dick Lido poragwa hetero boat Solarium, ohkamotoyi (Heterobothrium okamotoi), neo-hetero boat Solarium, flounder (Neoheterobothrium hirame) etc. In addition, parasites called gill parasites are also classified as short suckers, and include Lamellodiscus spp. of the genus Lamellodiscus. Carly Cush Cush, and the like Carly Long gipe display (Caligus longipedis), pseudo Carly Goose, blowfish (Pseudocaligus fugu), Carly Goose, Oriental lease (Caligus orientalis) belonging to Cali guseugwa. In particular, it is effective for neobenedenia, benedenia, zeuksafta japonica, vivagina dome and lamellodiscus.

In the present invention, a marine fish is a marine fish species treated as a farmed fish or ornamental fish that requires extermination of parasites. Among them, industrially important ones are aquaculture fish, for example, fish species of which parasitism of fish parasites such as skin parasites and gill parasites are known, for example, purpurea of the Pufferfish family, barley of the Percidae family, tilapia of the Percidae cichlidae family, or In fish species with a possibility of parasitism of fish parasites, the agent of the present invention can be used prophylactically or therapeutically.

The fish species that are the object of the present invention include aquaculture fish of all ages that survive in seawater, aquarium fish, and commercial appreciation fish. In particular, as aquaculture fish, fish of the order Perciformes, Flounder, Pufferfish, Herringoptera, and Eeloptera, and fish of the order Brassica, Barridae, Bream, Halibut, Pufferfish, Salmon, and Eel. Specifically, grayfish, blackfish, yellowtail (maraemi), bushri, horse mackerel, line horse mackerel, red mackerel, sea bass, red snapper, stone sea bream, black sea bream, tilapia, squid, red snapper, jabberi, mackerel, brown round snapper, weapon Black squid, humpback grouper, black squid, giant flounder, flounder, halibut, yellow flounder, flounder, turbot, halibut, purple flounder, bluefish, yellow tang, horsefish, rainbow Trout, Atlantic salmon, silver salmon, red salmon, and the like are exemplified. In particular, a lot of damage from skin parasites has been reported in grayfish, yellowtail, barley, sea bass, sea bream, barramundi, tilapia, and perch.

The hydrogen peroxide solution used by this invention is not special, What is necessary is just what is normally marketed. Since a 35% solution is on sale, it is diluted to a prescribed concentration and used as a medicinal bath agent. In marine fish, conventionally, it is considered to be bathed at a concentration of 300 ppm or more, and it has been implemented as such. However, in the present invention, the medicinal bath is performed 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, and 37.5 to 75 ppm. It is preferable that the medicinal bath time is 15 minutes or more. Although it may vary depending on the species of fish, if it is a low concentration, there is no particular upper limit, since no adverse effect is seen on the fish body even if bathed for a long time. As shown in Example 5, there were symptoms such as poor feeding at 150 ppm for 6 hours, but no death was observed 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 in terms of work efficiency, it is 15 to 120 minutes, preferably 15 to 90 minutes, more preferably 30 to 60 minutes. Therefore, at 30-150 ppm, 15 minutes - 6 hours are preferable, and 15 minutes - 2 hours are more preferable. Or, at 30-100 ppm, 15 minutes - 6 hours are preferable, and 15 minutes - 2 hours are more preferable.

For example, 37.5 to 75 ppm of parasites of multiposterior suckers other than short suckers and vivaginas are most preferable, and 75 to 100 ppm is preferable in vivaginas.

Take this medicinal bath as soon as you suspect a parasitic infection. The medicinal bath should be performed once. After that, when a parasite infection is suspected during breeding, it may be carried out immediately once. In this specification, ppm represents the amount of hydrogen peroxide in water by weight/capacity.

The reason why the parasiticidal effect of the medicinal bath performed at a low concentration of the present invention is high compared with the conventional medicinal bath performed at a high concentration can be explained as follows from the results of the Examples.

When Neobenedenia girellae is treated at a water temperature of 25°C with a hydrogen peroxide concentration of 300 ppm for 6 minutes, the body is clearly atrophied, but the suckers (adherent plaques) used to settle in the host are not atrophied or deformed. Therefore, this insect stays adsorbed to the wall surface of the petri dish, and the insect is gradually recovered after treatment (Example 1). It is thought that the same thing is occurring also in the host body surface, and it becomes the cause of the parasiticidal effect unstable. In fact, under the conditions of a hydrogen peroxide concentration of 300 ppm·6 minutes, when the amber bait infected with Neobenedenia girellae was bathed, the parasiticidal rate was 59.1%, and there was a limit to the parasiticidal effect (Example 3).

On the other hand, it was found that when Neobenedenia girellae was treated at a low concentration of 75 ppm or 50 ppm for 30 to 60 minutes, the degree of atrophy of the body was weak, but the suckers were also atrophied and deformed and peeled off from the wall surface of the petri dish. Moreover, the atrophy of Neobenedenia girellae after treatment also continued (Example 1).

Even when Neobenedenia girellae was treated at a high concentration of hydrogen peroxide (300 ppm) for 60 minutes, the atrophy and deformation of the suckers (adherent plaques) was only 30%. Therefore, it became clear that the action of atrophying and deforming the sucker of Neobenedenia girellae was higher at a low concentration of 75 ppm or 50 ppm than at a high concentration (Example 2).

At a water temperature of 25 DEG C, under the conditions of a hydrogen peroxide concentration of 75 ppm·30 minutes, the amber fern infected with Neobenedenia girellae was bathed. The insect repellent rate was 94.3%. Moreover, the insect repellent rate at the time of a 50 ppm*30 minute process was 86.6 %. Therefore, it is important for the insect repellent of Neobenedenia girellae to atrophy and deform the adherent plaque, thereby making it clear that a high insecticidal effect can be stably obtained (Example 3). Moreover, in Example 4, it confirmed that the high parasiticidal effect was acquired also under the conditions for 30 minutes or 60 minutes at 37.5 ppm of hydrogen peroxide density|concentrations. If it is low concentration, since the adherent plaque of Neobenedenia girellae is atrophied and deformed and peels off from the host, there is no factor in which this insect is recovered after treatment, and a stable antiparasitic effect can be expected.

The medicinal bath with a hydrogen peroxide agent at the aquaculture site is performed by preparing a 300 ppm solution of hydrogen peroxide concentration on a pool-shaped sheet of about 200 t, and accommodating the fish there. If the amber bath is bathed with a hydrogen peroxide concentration of 150 ppm or more, the fish swims vigorously up and down for 1 to 3 minutes, perhaps due to the stimulation (Example 5). At high temperatures in the summer, fatal accidents thought to be caused by lack of oxygen occurred in some cases, and the violent swimming observed in this test was considered to be one of the causes. On the other hand, when the grayfish was immersed in a hydrogen peroxide concentration of 75 ppm for 6 hours, there was no adverse effect on swimming or swimming behavior the next day (Example 5). From these results, it became clear that when the hydrogen peroxide concentration was less than 150 ppm, particularly 75 ppm or less, it was possible to bathe without adversely affecting the ashes. In addition, it was also clear that the medicinal bath treatment at a high concentration damaged the body surface of the grayfish and made it easier to re-infect the neobenedenia girellae, and that the treatment at a low concentration did not damage the body surface (Example 6).

As for the medicinal bathing method in salmon farming in Norway, the skirt method in which the side of the rim is surrounded by a sheet is adopted. In this method, since there is no need to move the fish to a narrow bath, it is possible to secure dissolved oxygen in the breeding environment. In addition, it is also possible to maintain dissolved oxygen in the environmental water by means of oxygen or air ventilation. By combining this method with the present invention, a relatively long medicinal bath of 30 to 60 minutes is possible.

For the injection of the drug, a dedicated container material in which many holes are formed in the tubular tube is devised, and the drug can be simultaneously sprayed from the surface layer to the bottom layer of the cage. In addition, the chemical is diffused by the swimming of the fish, and it can be made uniform.

Specifically, the side of the net of the cage is covered with a sheet so that the seawater inside is maintained, and an amount of hydrogen peroxide solution with an average concentration of 30 ppm to 150 ppm calculated by calculation is added to the seawater in the cage, for 15 minutes As described above, the medicinal bath of the present invention can be performed by removing the sheet after elapse of preferably 15 minutes to 6 hours, or 15 minutes to 2 hours, more preferably 30 to 60 minutes. By this method, it is possible to bathe the fish without stress.

It was confirmed that the same results were obtained not only with Neobenedenia girellae but also Benedenia Serioleae (Examples 7, 11, and 12). Moreover, it became clear that it exhibits a clear parasiticidal effect also with respect to lamellodiscus by an in vivo test (Example 8). Benedenia Serioleae is classified into the genus Benedenia of the single ginger short sucker, Neobenedenia girellae in the genus Neobenedenia, and Lamelodiscus in the genus Lamelodiscus. Since the low-concentration hydrogen peroxide water bath exhibited a high parasiticidal effect in common to these parasites, it was thought to have an effect on the parasites of the monosperedal sucker.

In addition to this, deformation and persistence of parasites at the time of low-concentration treatment were also observed in adherent plaques arranged with the valva of Zeucsaphtha japonica (Example 9). As a result of investigation in an in vivo test, it became clear that a clear parasiticidal effect was also exhibited against this insect (Examples 11 and 12). In addition, a clear insecticidal effect was exhibited also against vivagina dome (Example 10). Zeuksaphta japonica is classified as the genus Zeucsaphta of the single ginger sucker, and Vivagina dom is classified as the genus Vivagina. Since the low-concentration hydrogen peroxide water bath exhibited a high anthelmintic effect in common to these parasites, it was thought to have an effect also on the parasites of the monophyletic sucker family.

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

Example 1

<In vitro anthelmintic effect of low-concentration hydrogen peroxide treatment on Neobenedenia girellae-1>

Test method: About 100 g of 4 yellowtails were housed in one 100 liter tank, and 2000 neobenedenia girella hatching larvae were put into the tank and attacked. The fish were sampled on the 14th day after the attack, and the adults parasitic on the body surface were recovered with tweezers and used for testing. In addition, the water temperature during the breeding period was 25±0.5°C. Filtered seawater subjected to UV sterilization was used as seawater, and the supply amount was 1.2 liters/minute. As the feed, a commercially available EP feed was used, feed was fed once a day, and the feed amount was 2% of the fish body weight.

10 adults were accommodated in each of 7 petri dishes for 90 mm tissue culture containing 20 ml of seawater and settled. After fixation, it was washed 3 times with seawater. The seawater was removed with a decanter, and the remaining seawater was wiped off with Kimwipes. 20 ml of each test solution was added thereto, and it culture|cultivated under the room temperature of 25 degreeC. After the treatment, it was washed 4 times with seawater, 20 ml of seawater was added, and cultured for 10 hours. Immediately after treatment and return to seawater, every 30 minutes after return to seawater for 2 hours, and 10 hours after treatment, atrophied individuals and adults detached from the walls of the chalet were counted and recorded. In addition, in order to grasp the size of Neobenedenia girellae used in the test, the body length of 30 individuals was measured.

Test spheres: Table 1 shows the test spheres.

Results and considerations

The body length of this insect provided for the test was 4.17±0.25 mm.

Hydrogen peroxide solution is a parasitic anthelmintic for Vivagina dome parasitic on the gills of Benedenia Seriolanae or red sea bream that parasitizes on the body surface of yellow sea bream.

In Neobenedenia girellae of test group 1, all individuals showed moderate atrophy immediately after treatment and return to seawater (Fig. 1, Fig. 2B), and the degree of atrophy increased until about 10 minutes after transfer to seawater, , 3 out of 10 had severe atrophy ( FIG. 2C ). However, the atrophied individuals gradually recovered (FIG. 2D), and all individuals recovered from atrophy at 30 minutes after returning to seawater (FIG. 1).

In the Neobenedenia girellae of test group 2, all individuals had severe atrophy immediately after treatment and return to seawater (FIG. 3A). Even after 30 minutes of returning to seawater after treatment, all the individuals were atrophied (FIG. 1), but the atrophy was restored to a moderate level (FIG. 3B). 60 minutes after returning to seawater, 90% of individuals had recovered from atrophy (FIG. 1, FIG. 3C).

In the test group 1 and the test group 2, the adherent plaques (large suckers) of Neobenedenia girellae did not shrink at both the treatment time of 3 minutes and 6 minutes (FIG. 2B & C, FIG. 3A). In view of the above, the treatment with a hydrogen peroxide concentration of 300 ppm·3 minutes and double the treatment time of 6 minutes, which are the conditions for deworming of Benedenia, is a relatively short time until the atrophied main insect recovers. It was thought that this insect was removed from the body surface by a physical action such as rubbing and exerting an insect repellent effect. It is considered that there is a limit to the insect repellent effect from the recovery of the individual not subjected to the physical action.

In test group 3 and test group 5, all subjects were atrophied to a moderate level immediately after returning to seawater after 30 minutes of treatment (FIG. 1, FIG. 4A). Both treatment groups exhibited a tendency for atrophy to become significant after transfer to seawater after treatment. This trend is the same as the treatment for 3 minutes at 300 ppm. Although more than half of the atrophied worms recovered after 30 minutes, one worm that was atrophied even after returning to seawater for 1 hour and 30 minutes was observed (FIG. 1). All of them had atrophied sticking groups, and they were unable to settle in the chalet.

In test group 4 and test group 6, the atrophy was moderate immediately after the treatment, and a large difference from test group 3 and test group 5 was not recognized. In both treatment groups, after treatment and transfer to seawater, there was a tendency for atrophy to progress. In particular, in the test group 4, it returned to seawater and the individual peeled from a petri dish gradually increased in 60 minutes, and the peeling rate after 60 minutes reached 100%. Even after 120 minutes of treatment in both test groups, more than half of the individuals were atrophied. As the point of atrophy, an adherent plaque was prominent (FIGS. 4B & C). Moreover, in the test group 4, 7 individuals which had not recovered|restored even after 10 hours were observed, and the individual which did not settle in the petri dish was 4 of them. The atrophy of the adherent plaque was continued, and atrophy was observed not only in the individual not settled in the chalet, but also in the settled individual (FIG. 4D).

These results indicate that Neobenedenia girellae can be repelled by treatment for 30 to 60 minutes even at low concentrations of 75 ppm and 50 ppm. In particular, in terms of atrophy of the adherent plaque of Neobenedenia girellae, it was considered to stably exhibit a high parasiticidal effect compared with the treatment for a short time at a high concentration conventionally performed in a cage.

Moreover, in the test group 7, the atrophy|shrink of Neobenedenia girellae or peeling from a petri dish was not observed during the test period.

Example 2

<In vitro anthelmintic effect of low-concentration hydrogen peroxide treatment on Neobenedenia girellae-2>

Test method: The test was carried out in the same manner as in Example 1. Neobenedenia girellae provided a test with what was parasitic on the defense on the 12th day after attacking, and housed and settled 10 adults each in 3 chalets. At 30 minutes of treatment, immediately after returning to seawater after 60 minutes of treatment was completed, atrophied individuals and adults detached from the wall of the chalet were counted and recorded 30 minutes after returning to seawater.

Test spheres: Table 2 shows the test spheres.

Results and considerations

The body length of this insect provided in the test was 3.86±0.29 mm.

Neobenedenia of test group 1 atrophied in 2 to 3 minutes after starting the treatment, and atrophy became remarkable after 6 minutes. However, at the time of 30 minutes of treatment, immediately after treatment for 60 minutes, after treatment was completed and returned to seawater 30 minutes after being returned to seawater, all individuals of Neobenedenia girella were atrophied, but this insect that had been peeled off from the wall of the chalet was It was recorded as 3 subjects (Fig. 5). Thirty minutes after the treatment was completed and returned to seawater, although the bodies of all the individuals were in a state affected to the extent that they were cloudy and immobile, no shrinkage or deformation was observed in the adherent plates of 7 individuals, and they were settled in the chalet. (Fig. 5, Fig. 6A & B). Two out of the seven individuals were barely peeled off the wall of the petri dish after 1 hour of incubation after treatment. These two individuals were judged to have died because the remarkable atrophy had become mild, and their bodies were obviously cloudy.

The number of individuals peeled off from the petri dish in Test Group 2 was 9 individuals in 30 minutes immediately after the treatment for 60 minutes and after the treatment was completed and returned to seawater ( FIG. 5 ). In the exfoliated worm, not only the body was atrophied, but the fixation plaque was clearly atrophied and deformed (FIG. 6C), and the test result of Example 1 was reproduced.

From the above results, it was found that the action of atrophying and deforming the sucker of Neobenedenia girellae was clearly higher at a low concentration of 75 ppm or 50 ppm than at a high concentration, which is a normal dose. These results show that the low-concentration treatment with a hydrogen peroxide concentration of 75 ppm or 50 ppm removes the atrophied Neobenedenia girella from the body surface by fish contact or rubbing the body against a cage or obstacle. In addition to the normal physical action of dropping off, Neobenedenia girellae has the action of atrophying and deforming the adherent plaque for settling in the host, thereby exfoliating it from the host body. It was considered that it stably exhibits a high insect repellent effect compared with a treatment.

Moreover, in test group 3, the shrinkage of neobenedenia girellae or peeling from a petri dish was not observed during the test period.

Example 3

<Antiparasitic effect of low-concentration hydrogen peroxide treatment on Neobenedenia girellae in vivo-1>

Test method: 48 fishtail fish, having an average fish weight of about 130 g, were bred in a 500-liter water tank for about 7 days, and acclimatized to a water temperature of 25°C. The feed supply in the meantime gave a commercial feed, and made the feed supply rate 2% of fish body weight. Water was injected at 8.3 liters/minute. After acclimatization, about 4500 neobenedenia girella hatching larvae were put into a 500 liter tank, and the insect was attacked by allowing the water to stagnate for 1 hour. Seven days after the attack of the hatching larvae, the fish were transferred to 7 200 liter tanks to set the test plots (Table 3). The remaining 4 rice were continued to be bred in a 500-liter water tank for measuring the length of Neobenedenia girellae when treated with hydrogen peroxide, and during the medicinal bath treatment, this insect was recovered and the length of 30 individuals was measured. The injection of water during the breeding period was 6.7 liters/minute. 9 days after the attack, each ward was treated with a medicinal bath in a 200-liter square tank, and after treatment, the fish were transferred back to a 200-liter breeding tank and reared until the next day. All fish were sampled, fish weight was measured, and the parasitic Neobenedenia girellae were counted. Evaluation of the parasiticidal effect was performed by comparing the neobenedenia girella parasitic water of each ward.

Test spheres: Table 3 shows the test spheres.

Results and considerations

The length of Neobenedenia girellae at the time of drug treatment was 3.01±0.43 mm, and it was an adult.

Table 3 shows the parasiticidal effect on the parasitic worms in the grayfish.

The neobenedenia girellae parasiticide rate of test group 1 (dose and use at the time of parasitization of Benedenia seriolae in a hydrogen peroxide solution) was 33.5%. Moreover, the insect repellent rate of the test group 2 which made the immersion time double for 6 minutes was 59.1 %. From the test results of Example 1, the treatment with a hydrogen peroxide concentration of 300 ppm · 6 minutes intensely atrophys the body of Neobenedenia girellae, but does not cause atrophy or deformation of the adherent plaque (large sucker) of this insect, atrophy or It has been found that the atrophied and detached main insect recovers in about 1 hour or the like. From the results of this test, the parasiticidal effect under these conditions is exhibited by physical actions such as contact between fish and rubbing the body against a cage in a relatively short period of time until the atrophied main insect is recovered. It became clear that there was a limit to the insect repellent effect just by atrophying the body.

The parasiticidal rate of test group 3 was 94.3%, and the parasiticidal rate of test group 4 was 99.2%, indicating a high parasiticidal effect. Moreover, the parasiticide rate of test group 5 was 86.6 %, and the parasiticide rate of test group 6 was 97.5 %, and it was similarly high parasiticidal effect. In Examples 1 and 2, these low-concentration treatments atrophy not only the body of Neobenedenia girellae but also the adherent plaque. It became clear from Examples 1 and 2 and this test result that it is important for the insect repellent of Neobenedenia girellae to atrophy and deform|transform an adherent plaque, thereby obtaining a high insecticidal effect stably.

Example 4

<The antiparasitic effect of low-concentration hydrogen peroxide treatment on Neobenedenia girellae in vivo-2>

Test method: The test was made into 30 degreeC of water temperature, and operation was implemented similarly to Example 3. 42 flounder, having an average body weight of about 130 g, were bred in a 500 liter water tank for about 7 days, and acclimatized to a water temperature of 30°C. Neobenedenia girella hatching larvae used for the attack were about 5,500 individuals. Three days after the attack of the hatching larvae, the fish were transferred to six 200 liter tanks to set the test plots (Table 4). After 7 days of the attack, each ward was treated with a medicinal bath, and the parasiticidal effect was evaluated 8 days after the attack.

Test spheres: Table 4 shows the test spheres.

Results and considerations

The length of Neobenedenia girellae at the time of drug treatment was 3.01±0.18 mm, and it was an adult.

Table 4 shows the parasiticidal effect on the parasites parasitized in the grayfish. The results of Example 3 were reproduced. And it became clear that the high parasiticidal effect was exhibited by processing for 30 minutes - 60 minutes also in the low density|concentration of 37.5 ppm of hydrogen peroxide density|concentrations.

Example 5

<Effect of hydrogen peroxide solution on gray protection-1>

Test method: 6 fish were housed in 6 tanks of 200 liters each with an average fish weight of about 208 g. The fish were domesticated at 25 °C for 7 days. The feed supply in the meantime gave a commercial feed, and made the feed supply rate 2% of fish body weight. Water was injected at 6.7 liters/minute.

After diluting a specified amount of hydrogen peroxide with seawater in advance, the breeding water was allowed to stagnate without flowing, and it was put into each water tank. After that, observation was performed for a maximum of 6 hours. After 6 hours of treatment, it was again made into flowing water.

Test spheres: The test spheres are shown in Table 5.

Results and considerations

The observation results are shown in Table 6. In the treatment group with a hydrogen peroxide concentration of 300 ppm or more, the fish swam violently up and down 1 to 3 minutes after the start of the immersion treatment. After that, although the swimming abnormality subsided, the state in which opening and closing of the opening and gill lids were repeated was observed 15 minutes after the start of immersion. Before death, the fish repeated flash swimming, lateral swing, and gentle swimming, and died accompanied by patterns on the body surface. In the 300 ppm treatment group, the surviving remnants of 2 undoed subs were gentle. Although the occurrence of dead fish was not recognized in the 150 ppm treatment group, abnormal swimming and opening during the treatment, and abnormality in the feeding behavior on the next day after the treatment were confirmed. Therefore, it was found that the concentration of 300 ppm, which is the usual dose at the time of anthelmintic treatment of Benedenia seriolae in perciform fish, was toxic to fish in a short time. On the other hand, in the 75 ppm treatment group, which is 1/4 of the normal dose, no abnormality was observed during immersion, and no abnormality was observed either after completion of immersion or at the time of feeding the next day. Therefore, it has been found that a concentration of less than 150 ppm, particularly a concentration of 75 ppm or less, can reliably perform a long-term medicinal bath treatment without adversely affecting the fish. And this concentration or a low concentration process, such as 50 ppm, atrophy|shrinks and deform|transforms the adherent plaque of neobenedenia girellae, and is a condition which exhibits a high insect repellent effect stably.

Aquaculture sites WHEREIN: In the case of high temperature in summer, the death accident which is thought to be the cause of oxygen starvation in the hydrogen peroxide water bath may generate|occur|produce. It is generally known that this medicinal bath affects the gills of fish as the water temperature is high. In this test, violent swimming behavior was observed from 1 minute to 3 minutes from the start of the treatment at 150 ppm or more spheres. Therefore, the cause of death was not only the effect of hydrogen peroxide on the gills, but also this vigorous swimming, which was thought to be a factor causing oxygen deficiency.

Example 6

<Effect of hydrogen peroxide solution on ashes-2>

Test method: 33 grayfish of an average fish weight of about 195 g were labeled with an electronic tag to identify individuals, and were allowed to acclimatize by breeding in a 500 liter water tank for 7 days. Breeding conditions such as water supply, feed amount, and water temperature were in accordance with Example 3. After acclimatization, the fish were transferred to 3 groups of 200 liter tanks so that there were 11 fish in each tank, and the fish were accommodated in each tank and the tag number of the fish was recorded. The test group was set as the 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 housed in one 500 liter tank, and about 7,200 neobenedenia girella hatched larvae were put in, and the water was allowed to stagnate for 1 hour. All fish were sampled 6 days after the attack, and the parasitic Neobenedenia girellae were counted. The evaluation of the safety after the treatment was performed by comparing the Neobenedenia girella parasitic waters of each district.

Results and considerations

The observation results are shown in FIG. 7 . Parasitic water in the hydrogen peroxide concentration 300 ppm·3 min group was significantly higher than that in the untreated control group. On the other hand, the parasitic water in the 75 ppm·30 min sphere was the same value as the control. From the above results, it was thought that a high-concentration hydrogen peroxide bath, such as a normal dose, caused some obstacles such as exfoliation of mucus on the body surface of the fish even after a short treatment for several minutes, and it was thought that the parasite was easily re-infected. 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 such an extent that the parasite was easily re-infected. Therefore, it became clear that the safety|security with respect to the fish of this invention is higher than the conventional method not only during a process but also after a process.

Example 7

<The parasiticidal effect of low-concentration hydrogen peroxide treatment on Benedenia Seriole in vitro>

Test method: About 150 g of 4 yellowtail fish were accommodated in one 100 liter tank, and 1300 hatched Benedenia Seriollae larvae were put into the tank and attacked. The fish were sampled on the 19th day after attack, and adults parasitic on the body surface were recovered with tweezers and used for testing. In addition, the water temperature during the breeding period was 20.5±0.5°C. The breeding and in vitro test of yambo were carried out in the same manner as in Example 1. In addition, the count of atrophied individuals and adults detached from the wall of the petri dish was performed for 2 hours every 30 minutes after returning to seawater immediately after being treated and returned to seawater, and recorded.

Test spheres: The test spheres are shown in Table 7.

Results and considerations

The body length of this insect provided for the test was 5.30±0.31 mm.

In the Benedenia Seriole of Test Group 1, immediately after the treatment, all individuals were severely atrophied (FIG. 9A), and 3 out of 10 individuals were peeled off from the chalet wall surface (FIG. 8). After treatment, it was returned to seawater, and after 30 minutes, an additional 4 individuals were peeled off from the chalet wall. The adherent plaque of the detached individual was atrophied and deformed (FIG. 9B). However, in the 90 minutes following treatment and return to seawater, 3 individuals recovered from atrophy. In the test of Neobenedenia girellae of Example 1, exfoliated worms were not observed under these conditions, and all individuals recovered from atrophy within 30 minutes after returning to seawater after treatment. These results show that Benedenia Seriole is more susceptible to the influence than NeoBenedenia girellae because of its higher sensitivity to hydrogen peroxide.

In test group 2, peeling of 5 individuals was observed immediately after the treatment, and further 4 individuals were peeled off during 90 minutes after returning to seawater after treatment. In this district, 1 individual recovered from atrophy. In both test groups, an individual recovering from atrophy is observed, so there is a limit to the anthelmintic effect, and it is considered that the anthelmintic result is not stable.

In the test group 3, all the individuals contracted and peeled from the petri dish wall 13 minutes after the start of the treatment. Also in Test Group 4, 10 out of 10 individuals were atrophied at 13 minutes from the start of the treatment, 9 individuals were peeled off, and the remaining 1 individual was also peeled off within 30 minutes. In both cases, no shrinkage or recovery from peeling was observed in 10 peeling individuals in observation 2 hours after returning to seawater after treatment. In addition, the adherent plaque of the detached individual was atrophied and deformed (FIGS. 9C & D).

In test group 4, after treatment, it was returned to seawater, and the body became cloudy and the movement stopped after about 30 minutes, so the insect was considered to have died.

In view of the above, the treatment of 75 ppm·30 minutes causes atrophy and deformation of the adherent plaques of Benedenia Seriollae, and does not recover even about 2 hours after the treatment, so 300 ppm·3 minutes or 300 ppm·6 It became clear that the insect repellent effect was exhibited stably rather than a powder treatment.

In addition, in the untreated control group, shrinkage of Benedenia Seriollae or peeling from the petri dish was not observed during the test period.

Example 8

<Antiparasitic effect of low-concentration hydrogen peroxide treatment on lamellodiscus in vivo>

Test method: 50 red sea bream cultured in an outdoor cage were provided for the test. The average fish weight of this group was about 74 g. The red sea bream was moved from the cage to a 1 t tank on land, and 10 red sea bream were accommodated in 5 30 ℓ tanks containing 15 ℓ of seawater. A small air pump was used to ventilate to prevent oxygen starvation. A predetermined amount of a hydrogen peroxide solution was dissolved in 50 ml of seawater, put in a container containing fish, and stirred, and the fish was immersed for a predetermined time. After the treatment, the container was tilted to receive the fish in a bag-shaped net, and from the top, about 3 L of seawater was poured and washed. The fish were returned to a container containing 18 L of seawater and bred for 1 hour while being aerated. After that, the fish were sampled and the lamellodiscus parasitic on the gills was counted. Evaluation of the parasiticidal effect was performed by comparing the parasitic number of Lamelodiscus of each sphere. The water temperature of the seawater used in the test was 22.0°C.

Test spheres: Table 8 shows the test spheres.

Results and considerations

The lamellodiscus anthelmintic rate of the 300 ppm*3 minute treatment group was 0%. In the dose and usage at the time of vivagina dome anthelmintic, no anthelmintic effect was exhibited. In addition, even in the 300 ppm·15-minute treatment group, the parasitic water of this insect was the same as that of the control group, and no parasiticidal effect was exhibited. The red sea bream of 300 ppm·15 division was turned over under the influence of this treatment immediately before the end of the treatment, and it was considered that further treatment was impossible. On the other hand, in the 75 ppm·30 min treatment group and the 100 ppm·30 min treatment group, a clear parasiticidal effect was recognized (Table 8), and abnormalities such as swimming of fish were not observed.

These results indicate that the low-concentration and long-time treatment has an effect on the degree of drop-off from the grasping phase of the lamellodiscus than the high-concentration and short-time treatment. For this insect, the effectiveness of long-term treatment with a low concentration of hydrogen peroxide was confirmed.

Benedenia Seriolae, Neobenedenia girellae, and Lamelodiscus are classified as short-ginger short suckers. Since the low-concentration hydrogen peroxide water bath exhibited a high parasiticidal effect in common to these parasites, it was thought to have an effect on the parasites of the monosperedal sucker.

Example 9

<In vitro anthelmintic effect of low-concentration hydrogen peroxide treatment on Zeuxapta japonica>

Test method: The gills of about 1.4 kg of aquaculture ashes were obtained, and Zeuksafta yaponica parasitic on the gill plates was collected in a state parasitic on the gill plates. The in vitro test was carried out in the same manner as in Example 1, using 5 individuals of each clade. Observations were made in the middle of treatment, immediately after treatment and return to seawater, and every 10 minutes after return to seawater for 30 minutes to count and record atrophic individuals.

Test spheres: Table 9 shows the test spheres.

Results and considerations

At 300 ppm·3 min and 6 min, the atrophy of the body was mild even immediately after treatment ( FIG. 10A ), and recovered from atrophy within about 10 minutes after treatment ( FIG. 11 ). On the other hand, the main insects in the 75 ppm·60 min treatment group clearly atrophied at 6 to 10 minutes of treatment ( FIG. 10B ). In addition, in the group treated with 75 ppm·60 minutes, all the insects were atrophied even at 30 minutes after treatment, and even in the group treated with 50 ppm·60 minutes, only one individual recovered at 30 minutes after treatment. The atrophy of this insect in the low-concentration treatment group was observed not only on the body but also on the adherent plaques in which the valva were arranged (FIG. 10B).

Long-term treatment at a low concentration causes atrophy of Zeucsaphtha japonica for a long time, and the atrophy is severe and also affects the adherent plaques arranged with valva, so it has a more anthelmintic effect than 300 ppm·3 min or 300 ppm·6 min treatment. It turned out to be stable.

Moreover, in the untreated control group, atrophy of Zeuxapta japonica was not observed during the test period.

Example 10

<Antiparasitic effect of low-concentration hydrogen peroxide treatment on vivagina dome in vivo>

Test method: 50 red sea bream cultured in an outdoor cage were provided for the test. The average fish weight of this group was about 61 g. Red sea bream was moved from the cage to a 1 t tank on land, and 10 red sea bream were accommodated in 5 30 ℓ tanks containing 15 ℓ of seawater. A small air pump was used to ventilate to prevent oxygen starvation. A predetermined amount of hydrogen peroxide solution was dissolved in 50 ml of seawater, put in a container containing fish and stirred, and the fish was immersed for a predetermined time. After the treatment, the container was tilted to receive the fish in a bag-shaped net, and from the top, about 3 L of seawater was poured and washed. The fish were returned to a container containing 18 L of seawater and bred for 1 hour while being aerated. After that, the fish were sampled and the vivaginas dome parasitic on the gills were counted. Evaluation of the parasiticidal effect was performed by comparing the parasitic number of vivagina dome of each ward. On the other hand, the water temperature of the seawater used in the test was 23.2 °C.

Test spheres: The test spheres are shown in Table 10.

Results and considerations

The vivagina dome insect repellent rate of the 300 ppm*3 minute treatment group (dose and use at the time of the vivagina dome repelling agent of a hydrogen peroxide solution) was 64 %. In this sphere, the fish immediately after the start swam vigorously as if bouncing off the water surface. From this behavior, it was considered that the high-concentration treatment gave toxicity and irritation|stimulation with respect to red sea bream. The parasiticidal ratio of the 100 ppm·30 minute treatment group was 89%, and in the group treated with the same concentration for 60 minutes, it was 100%. In addition, the parasiticidal rate of the 75 ppm*60-minute treatment group was 99 %. There was no change in the swimming of the fish in these low concentration treatment groups from the start of the treatment to the end, and no abnormalities were observed in the fish.

From these results, it was found that treatment with a low concentration of hydrogen peroxide for a long time exhibited a high anthelmintic effect against the gill parasite, vivagina.

Example 11

<The parasiticidal effect of low-concentration hydrogen peroxide treatment on Benedenia seriolae, Neobenedenia girellae and Zeucsafta japonica in vivo>

Test method: About 430 g of 400 gray sardines that had been cultured in an open-air cage were used for the test. 15 t of seawater was added to the sheet for medicinal bath, and a hydrogen peroxide solution was added and stirred so that the hydrogen peroxide concentration became 75 ppm. 390 fish were accommodated and immersed for 30 minutes. After treatment, the fish were transferred to cages. Sampling was performed by lifting each 10 rice before the process and on the next day after the process. Benedenia Seriole and Neobenedenia girellae parasitic on the body surface and Zeuksafta japonica parasitic on the gills were counted. Evaluation of the anthelmintic effect was performed by comparing the number of parasites in each ward. Moreover, the water temperature of the seawater at the time of a process was 28.5 degreeC.

Results and considerations

The results are shown in Table 11. Parasitism of Benedenia seriolae, Neobenedenia girellae, and Zeuxapta japonica was not observed in the fish after treatment, and the parasiticidal rate was 100% for all parasites.

Therefore, the effectiveness of the present invention was demonstrated even under such large-scale conditions.

Example 12

<Effectiveness test of low-concentration hydrogen peroxide treatment by the skirt method of ashes>

Test method: Around a 11.5 m×11.5 m×10 m edge that accommodates about 2 kg of ashes, a sheet of 48 m in length and 10 m in width is wound, and chucks installed at both ends of the sheet are filled into a cylindrical shape. and surrounded the perimeter. An amount of hydrogen peroxide solution having an average concentration of 35 ppm was added to the seawater in the sheet for 5 minutes, and the sheet around the cage was removed after 60 minutes had elapsed. Sampling was performed by lifting each 10 rice before the process and on the next day after the process. Benedenia seriolae and Neobenedenia girellae parasitic on the body surface (n = 10) were counted, and Zeuksafta japonica parasitic on the gills (n = 5) was counted. Evaluation of the anthelmintic effect was performed by comparing the number of parasites in each ward. Moreover, the water temperature of the seawater at the time of a process was 26 degreeC.

Results and considerations

The concentration of the hydrogen peroxide solution was gradually diluted with 35 ppm at the start time, 15 ppm after 30 minutes, and 3 ppm after 60 minutes. The number of skin parasites (Neobenedenia and Benedenia) was 110±48.3 individuals/before treatment and 28.9±24.3 individuals/bee after treatment. The number of parasites of Zeuxapta was 110.8±49.0 individuals/mild before treatment and 54.0±41.6 individuals/mildew after treatment. Therefore, the effectiveness of the low-concentration hydrogen peroxide treatment was verified even in the skirt method under the condition that this agent was gradually diluted.

Industrial Applicability

By the method of the present invention, it is possible to more safely and efficiently exterminate ectoparasites parasitic on fish using hydrogen peroxide water currently used in aquaculture sites.

Claims (1)

All inventions described herein.

Images