JP2817753B2 - Prevention of Heterobothrosis in Trafugu in a Sea Farm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing heterobotulism in a puffer fish in a marine aquaculture farm. More particularly, the present invention relates to a method for preventing heterobotulism, a parasitic disease of Trafugu, by eliminating heterobotulium, an ectoparasite parasitic on the gill of Trafugu.

[0002]

2. Description of the Related Art In recent years, the development of aquaculture techniques has been remarkable, and the high-grade fish, the puffer fish, belongs to the order Puffer fish, and its aquaculture has become even more active. However, with the increase in the number of cultured tail puffer fish, the number of damages caused by parasitic diseases (heterobotulism, trichodinosis, caligosis, gyrodactylosis, etc.) also increases, and this is a serious problem for farmers.

[0003] Above all, the heterobotulism of the puffer fish is a disease that is caused by heterobotulium (Heterobothrium sp.) Invading the gill operculum wall of the puffer fish. Inability to feed, weakness and death. Sodium salt bath, hydrogen peroxide bath (300 ppm, 10 minutes), and formalin bath have been attempted to control heterobotulium parasitizing the tiger puffer fish with heterobotulism. However, it has been reported that it has no control effect [1991
See “Aquaculture May” Vol. 28, No. 5, pp. 74-76 (especially, page 76, Table 4) published by Midori Shobo Co., Ltd. In addition, it seems that a method of administering a drug mixed with a diet has been attempted, but the drug efficacy did not appear because Trafugu with heterobotulism did not take a diet.

[0004] As described above, Trafugu which has developed heterobotulism is cured by a well-known drug bath method or oral administration.
It is considered that it is extremely difficult to make the eggs, and it is said that wire mesh cages to which heterobotulium eggs are unlikely to adhere are effective in preventing this disease [the above-mentioned “Aquaculture May”, Vol. 28, No. 5,
Pp. 85-88 (especially in the middle of the bottom column on page 86)]. The applicant of the present invention, as a method of controlling ectoparasitic fluke parasitic on sea-cultured fish such as yellowtail, yellowtail, and horse mackerel, accommodates the cultured fish in a swimming compartment in a reduced fish cage with a partition wall capable of blocking water flow. A method of cleaning fish bodies with hydrogen peroxide has been proposed (see JP-A-1-317346).

[0005] As a method for removing parasites generated in fish such as eel, hamachi, goldfish, and puffer fish, hydrogen peroxide is converted into porous particles such as calcium silicate in water in a culture pond where fish inhabit. It is disclosed that the supported hydrogen peroxide support is suspended in the air (see Japanese Patent Application Laid-Open No. 3-108428).

[0006]

The invention disclosed in JP-A-1-317346 is an effective method for extermination of parasites such as hadamushi, caligus, etc., which are infested on yellowtail, yellowtail, and horse mackerel. No specific solution for prevention of botulism is provided. In addition, the aforementioned “Aquaculture May” Vol. 28, No. 5, 74
Pp. 76-76 (especially p. 76, Table 4), it is not effective against heterobotulium parasitizing in the pufferfish affected with heterobotulitis, and furthermore, pages 85-88 (especially 86 (Middle of the bottom column of the page) states that "It is currently difficult to eliminate heterobotulism in Trafugu by a drug."

The invention disclosed in Japanese Patent Application Laid-Open No. 3-108428 is
It is difficult to control the concentration of hydrogen peroxide in water, and a large amount of hydrogen peroxide comes into contact with the fish, which may affect the fish. The publication does not mention the prevention of heterobotulism in Trafugu. In view of the life cycle of heterobotulium, the inventors of the present invention have studied a method for preventing heterobotulism in Trafugu.

[0008] That is, the spawning of heterobotulium is the heyday from summer to autumn, but spawns year-round. The spawned eggs are entangled with the culture net, hatch, swim, and when they reach the gills of the puffer fish, they metamorphose into parasite life. Eventually, many of them move from the gills to the gill operculum and are engulfed in the host tissue, invading the gill operculum wall, causing parasites to invade the operculum wall. Probable cause.

[0009] In general, the relationship between the type of drug, its concentration and the contact time in the drug bath method is not uniform depending on the type of drug, the type of fish and the type of parasite. The simple removal of Caligus, a parasite of the tiger, does not necessarily mean that it is possible to eliminate the girodactylus, a parasite of the same tiger puffer. Indeed, this was one of the reasons why the medicinal bath method in cultured fish was difficult.

[0010] The inventors of the present invention have proposed a method for preventing heterobotulism in Trafugu using a hydrogen peroxide bath, which has no concern for environmental pollution and has little effect on fish.
As a result of studying to prevent the attachment of the heterobotulium to the trough during the swimming period, to eliminate the heterobotulium infested on the gill, or to eliminate the heterobotulium invading the gill cover wall, It was found that it was difficult to prevent the adhesion of lium during the swimming period and to eliminate the heterobotulium that invaded the operculum wall. On the other hand, it is possible to exterminate heterobotulium by using a chemical bath method in which a specific concentration of hydrogen peroxide is contacted for a specific period of time when the heterobotulium parasitizing the tiger puffer lives on the gills As a result, it was confirmed that the concentration and the treatment time had no effect on the fish body of the puffer fish.

[0011] Furthermore, the heterobotulium once detached from the gill does not re-infest the gill, and the life cycle can be cut off by repeating the extermination of the hetero-botulium at the stage of infestation with the gill. The present inventors have found that diseases caused by the infestation of botulium can be fundamentally eliminated, and have completed the present invention.

[0012] Thus, according to the present invention, in preventing heterobotulism in a puffer fish in a seawater farm, it is confirmed that the gill of the puffer fish is infested with the heterobotulium, and the pufferfish is reduced with a partition wall. In the swimming compartment , the concentration of hydrogen peroxide is 400-2000 mg /
(1) A method for preventing heterobotulitis in a puffer fish in a seawater farm, wherein the method is performed under the condition of a treatment time of 20 to 120 minutes to eliminate heterobotulium at a stage that is parasitic on gills. You.

In the present invention, it is necessary to carry out the treatment with hydrogen peroxide at the stage where the heterobotulium is parasitic on the gills of the puffer fish, and at that time, the gills of the puffer fish are periodically inspected visually or under a microscope. When the heterobotulium is confirmed, it is necessary to carry out the test immediately after the confirmation, if desired. Hydrogen peroxide, used as a pesticide, dissolves, diffuses and dilutes in seawater very easily, thus shutting off water flow, such as plastic sheets, to maintain a concentration that ensures reliable parasite control. After covering a part of the cage with a thin cloth, the hydrogen peroxide solution is sprayed or poured at once with a pump or a bucket, for example. Although the range of reduction of the swimming section is not particularly limited, it is determined according to the size and scale of the school of fish desired to be processed, and the method described in JP-A-1-317346 is appropriately applied.

According to the studies by the inventors, hydrogen peroxide effectively acts on the eradication of heterobotulium parasitizing to the pufferfish by performing the following treatment conditions, and prevents heterobotulism in the pufferfish. And suitable properties for use in accordance with the procedure of the present invention. In other words, although the concentration of the aqueous hydrogen peroxide solution added to the fish cage is not particularly limited, it is usually 35
It is preferable to use it after arbitrarily diluting it with seawater at a concentration of not more than%. In addition, the treatment of fish with hydrogen peroxide in a fish cage maintains the concentration of seawater at 400 to 2000 mg / l and the treatment time is 20 to
The maintenance concentration and the treatment time have an interdependence between the control effect of the parasites and the degree of influence on the ecology of the fish body. Since the control effect is not sufficient and there is a danger of affecting the fish at the above-mentioned concentration and at the treatment time or more, it is preferable to carry out the treatment by appropriately combining the conditions within the above-mentioned concentration and time ranges, and a more preferable range It is particularly recommended to select a hydrogen peroxide aqueous solution concentration of 400 to 2000 mg / l and a treatment time of 30 to 120 minutes.

The relationship between the concentration of hydrogen peroxide depending on the water temperature and the bath time is as follows. That is, seawater temperature is 10-15
In the case of ℃, 400-2000mg / l is good for the medicine bath condition of about 60-120 minutes. When the seawater temperature is 15-20 ℃, it is 400-2000mg / l.
45 to 90 minutes and 400 when seawater temperature is 20 to 28 ° C
When the treatment is performed at 20002000 mg / l for about 30 to 90 minutes, the target heterobotulium can be completely eliminated.

[0016] The contact, as a method for the addition of aqueous hydrogen peroxide solution uniformly dispersed in the concentration, can be applied various known methods, practically, if it is sprayed with an aqueous hydrogen peroxide solution from the compartment upper It is preferred to do so. By such an addition process, together with the stirring effect by the swimming of the fish in the compartment,
A uniform concentration can be adjusted in a short time within the compartment. The most important thing to pay attention to besides the parasite control effect in the treatment with such a chemical agent is the abnormality of the ecology of the fish after the treatment and the presence or absence of mortality. That is, because it is processed in an unusual environment in a narrowed section with high fish shadow concentration,
In the treatment, it is necessary to shorten the time for the fish to come in contact with hydrogen peroxide at a predetermined concentration as much as possible. In this regard, hydrogen peroxide is very easily dissolved in seawater at an arbitrary concentration, and the fish school swims uniformly and uniformly. Because of rapid diffusion, it is possible to adjust the concentration of hydrogen peroxide and the treatment time without any hindrance to the growth of the fish body.

[0017]

EXAMPLES Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 From February to June 1992, the relationship between seawater temperature, hydrogen peroxide concentration, and chemical bath time was tested at a certain puffer fish farm in Mie Prefecture during different periods of seawater temperature.

20 l of seawater was placed in a panlite water tank, and hydrogen peroxide was added at a predetermined concentration. Five puffer fish, each of which is infested with heterobotulium so that it invades the gill lid wall, or five puffer fish (fish weight: 100-300 g / tail), which were infested with each other, were medicated for a predetermined time. After the chemical bath, the puffer fish was taken out and transferred to a water tank containing clear seawater, and after 24 hours, the heterobotulium parasitic on each puffer fish was measured and compared with the control group. The medicated seawater was filtered through a plankton net, and the number of heterobotulium separated from the gills was also measured and compared with the control group. In addition , 72
The effect on the fish after time was observed. Table 1 shows the results.
As shown in FIG.

[0020]

[Table 1]

Example 2 In July 1992, a test was conducted to eliminate heterobotulium parasitizing gills of a puffer fish at a certain puffer fish farm in Mie Prefecture.
Make a 2m square 1m deep water tank with vinyl sheet
Add 1.5 tons, add hydrogen peroxide to 600mg / l, add 500 heterotrothurium-infested tiger puffer fish (fish weight 300g / tail), take a medicinal bath for 60 minutes, and place it in a new culture cage. After breeding for 24 hours, five fish were picked up, the number of heterobotulium attached was counted, and the average value per fish was determined. In addition, five fish were collected before the chemical bath, and the average value of heterobotulium adhesion was similarly obtained and compared. The seawater temperature at this time was 22 ° C. The results are as shown in Table 2.

[0022]

[Table 2]

Example 3 From April to June, 1992, at a certain puffer fish farm in Mie Prefecture, as a result of observing the puffer fish, it was confirmed that heterobotulium was infested in the gill of the puffer fish. Thereafter, treatment with a chemical bath method using hydrogen peroxide was immediately performed. That is,
Hydrogen peroxide concentration 600mg / l.
A comparison was made between the torchfish that was performed twice and the torchfish that did not take a chemical bath. In both test plots, the number of tail puffer fish was about 30.
In the case of 00 fish, the number of dead fish indicates the total of the test period, and the average fish weight was randomly selected from 5 fish to obtain the average body weight. During this time, the seawater temperature was 18-22 ° C. The results are as shown in Table 3.

[0024]

[Table 3]

COMPARATIVE EXAMPLE In the same test method as in Example 1, a test was conducted using peracetic acid or formalin in place of hydrogen peroxide. Tables 4 and 5 show the results.

[0026]

[Table 4]

[0027]

[Table 5]

[0028]

According to the treatment method of the present invention, heterobotulium, which is a parasite of the puffer fish, can be efficiently removed without adversely affecting the puffer fish and without causing environmental problems.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Kunio Nishimura, Inventor Katayama Chemical Industry Laboratory Co., Ltd. 2- 10-15 Higashiawaji, Higashiyodogawa-ku, Osaka (56) Reference JP-A-1-317346 (JP, A) JP-A-5-15272 (JP, A) JP-A-3-108428 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A01K 61/00 A01K 63/04 A01N 59/00

Claims (1)

(57) [Claims] Claims: 1. In the prevention of heterobotulism in a puffer fish in a seawater farm, after confirming that a heterobotulium is parasitized on the gill of the puffer fish, the tiger puffer is placed in a swimming compartment reduced in size with a partition wall , Hydrogen peroxide concentration
400-2000 mg / l, processing time 20-120 minutes
A method for preventing heterobotulism in a puffer fish in a marine aquaculture field , comprising treating under the conditions described above to eliminate heterobotulium at a stage that is parasitic on gills.