JP4154326B2 - Parasiticides for cultured fish - Google Patents

Description

実施例２
１００Ｌのポリ容器に５０Ｌの海水を入れ、表２に示すピルビン酸メチル、ピルビン酸プロピル、ピルビン酸ブチルの各濃度の薬浴液を調整した。ハダムシ約１０匹が寄生している養殖トラフグ（体長約１０ｃｍ）を１０尾づつ投入し３０分間浸漬した。処理後のハダムシの脱落数とトラフグに寄生している数を調べてハダムシの除去率を調査した。又、養殖漁場において、表２に示す薬浴剤５０００Ｌを調整し、トラフグ３０００尾を投入した。３０分間浸漬処理を行いトラフグの状態を調査した。
結果は、表２に示す。

実施例３
魚体重約５０ｇのトラフグを各々２００尾収容する漁場試験区５つを用意し、試験開始時に無作為２０尾を取り上げ平均魚体重を測定した。この試験区の内４つにおいては、表３に示す薬浴剤（ピルビン酸エステル濃度５０ｐｐｍ、液量５００Ｌ）を用い２週間に１回の周期で、３０分間の浸漬処理を、半年間実施した。他の１つの試験区においては、半年間薬浴剤による処理を行わなかった。半年後、トラフグの生存率と無作為２０尾の平均体重・成長率を調査した。
結果は、表３に示す。

ピルビン酸メチル、ピルビン酸プロピル、ピルビン酸ブチルから選んだ１種以上を２０００ｐｐｍ以下用いた場合、養殖魚にストレスを与えず、寄生虫除去が出来て生存率が高い上に、成長率も高いことが分る。
産業上の利用可能性
ピルビン酸メチル、ピルビン酸プロピル、ピルビン酸ブチルから選んだ１種以上を有効成分とする駆除剤は、養殖魚の寄生虫駆除に用いることができる。TECHNICAL FIELD The present invention relates to a parasite-controlling agent that parasitizes farmed fish.
Background technology Cultured fish troutfish, yellowtail, sea bream, flounder, yellowtail, thailand, horse mackerel, scorpionfish, tuna, hagi, eel, salmon, trout, trout, ayu, carp, swordfish, goldfish, crucian carp, crab, catfish, tilapia, peherei, If parasites parasitize suppon, etc., the growth is inhibited, the appetite is weakened, and they are weakened and die, or the commercial value is reduced.
The parasites are mainly beetles and aphids. The damselfly adsorbs on the skin of the fish and eats the fish epithelial cells and pigment vesicles. Aphids parasitize the fish leaves and have a direct etiological effect of anemia, which can cause the fish to turn gray and become anorexic, weakened, and sometimes fatal.
As measures for combating these parasites, methods of fresh water bath, concentrated salt water bath, and medicine bath have been reported. This is a method of picking up fish once and storing it in still water.
The fresh water bath is not workable because it is difficult to supply and transport a large amount of fresh water. The concentrated salt bath method is not adopted because of the high risk of dehydration of fish and the large amount of salt required. Therefore, conventionally, a chemical bath method using formalin has been adopted. However, the method using formalin has a problem that the toxicity of formalin is strong although the effect of controlling the parasite is high.
Formalin is used every 10 days at a concentration of 1000-2000 ppm. This means that about 1000 kg per capita is used annually, and a large amount of poorly degradable formalin is dumped in the seawater, so it has a great impact on marine seafood in nearby fishing grounds. Recently, there has also been an accident where a large amount of formalin accumulates in cultivated pearl oysters and kills in large numbers. Currently, the use of formalin is prohibited in the aquaculture industry.
Formalin is a very dangerous compound for humans that stimulates mucous membranes such as the respiratory tract and can lead to death in the presence of 0.5 mg in 1 L of air. Accordingly, there is an urgent need to develop a bath salt that is safe for the human body, has good degradability in seawater, and does not accumulate residually.
An object of the present invention is to provide a parasite-controlling agent for cultured fish that is safe and highly effective in degradability in water and does not accumulate in living organisms, and that can improve the survival rate and growth rate of cultured fish. There is to do.
DISCLOSURE OF THE INVENTION As a result of diligent research to solve the above-mentioned problems, the present inventor has eradicated parasites by immersing cultured fish with a treatment solution containing ethyl pyruvate, which is rapidly degradable, as an active ingredient. I have already found what I can do. However, it has been found that when a chemical bath is used in an aquaculture fishery using ethyl pyruvate, trough puffers often swell and bite due to stress.
In general, a chemical bath in an aquaculture fishery is processed by adding a large amount of 1000 to 3000 fish in an overcrowded state in a 5 to 10 ton aquarium in consideration of workability and cost, and adding chemicals. Therefore, the stress on the fish during the medicine bath is excessive. Therefore, normally, when cultivating trough puffer, etc., bacteria often enter the wound and become ill. Therefore, even if the teeth are bitten regularly and bitten, they are prevented from being damaged as much as possible.
Therefore, as a result of research on a bath salt that does not give stress even during bathing, swims well, and does not chew, one or more selected from methyl pyruvate, propyl pyruvate, and butyl pyruvate as active ingredients The present inventors have found that a pesticide that can safely control parasites without giving stress to cultured fish.
That is, this invention consists of following (1)-(2).
(1) A parasite-controlling agent for cultured fish containing one or more selected from methyl pyruvate, propyl pyruvate, and butyl pyruvate as active ingredients.
(2) The method for controlling parasites using the insecticide for cultured fish according to (1) above, wherein the concentration during treatment is 50 to 1000 ppm.
By using the antiparasitic agent of the present invention, it is possible to safely perform a medicine bath without applying stress to the cultured fish during the medicine bath.
BEST MODE FOR CARRYING OUT THE INVENTIONThe pesticide of the present invention can be used for both marine fish and freshwater fish.For example, marine fish trough puffer fish, yellowtail, flounder, yellowtail, Thailand, horse mackerel, scorpion fish, tuna, hagi, etc. It can be used for freshwater fish eels, salmon, trout, yamame trout, ayu, carp, nishikigoi, goldfish, funa, loach, catfish, tilapia, peherei, suppon, etc.
Examples of the parasite to be controlled according to the present invention include the following.
Parasites of the yellowtail, Benedenia seriole, Heteraxine heterocerca, Caligus spinosoleti, Bivalina, Bivalina・ Longxanlum pagrosomi, Tainoe (Rhexelanella verrucosa), etc., Kurodai parasites Cryptocarion irritans, Anoprodiscus spall (Anoprodiscus sp. macrotrachelus, etc., Ideidae parasites, Benedenia hoshinai, etc., flounder parasites, Ichthyobodo sp. ), Gyroductylus, Heterobothrium tetrodonis, Kudoa percardialis, Buloceroides mcmurrich, sep unagai), scorpion parasite, Microcotyle sebastisci, parasitoid, neobenedeniella congeri, eel parasite, Pleistophorumumium,・ Multipleiis (Ichthyophthirius multifiliis), Pseudodactyrogyrus bini, Diplostomum sp., Angilicora globiscept Indium-Takehiro (Microsporidium takedai), Mikusoborusu (Myxobolus sp. ), Ichthyobodo necator, Chilodonella piscicola, Trichodina sp., Chrydonia sp. Lepeofthairus salmonis, Salmincola spp., Argulus corregoni, Rocinela maculata, Margarite margarite , Ayu of parasite Gurugea-plecos Grossi (Glugea plecoglossi), Girodakuchirusu-Yaponikusu (Gyrodactylus japonicus), Girodakuchirusu-Tominagai (Gyrodactylus tominagai), Girodakuchirusu-plecos Grossi (Gyrodactylus plecoglossi), shoe dwell Agassi Luz Zakkonisu (Pseudergasilus zacconis), carp -Parasites of Nishikigoi, Thelohanellus kitauei, Myxobolus sp. Nakai, Chilodonella piscicola, Trichodina, Trichodina Sutensasu (Dactylogyrus extensus), Dakuchirogirusu-Minutsusu (Dactylogyrus minutus), Girodakuchirusu-Kerurenshisu (Gyrodactylus kherulensis), Girodakuchirusu-Supurosutone (Gyrodactylus sprostonae), Philo Metro Lee Death Shipurini (Philometroides cyprini), goldfish Fna of parasite Hofererusu-Karashiii ( Hoferellus carassiii, Ichtyophthius multifiliis, Clinostomum complanatum, Lernea cyprinasea (Lerna) ea cyprinacea, Argurus japonicus, loach parasite Clinostoum complanatum, American catfish parasite Ichthiphithulitis piste It is.
Pyruvate has poor water solubility, but methyl pyruvate has good solubility in water, so methyl pyruvate is most preferable among the three types. On the other hand, since propylpyruvate and butylpyruvate are strong in the disinfecting effect, it is possible to obtain a preparation having high effect and good solubility by mixing methylpyruvate and propylpyruvate and / or butylpyruvate. .
As for the density | concentration at the time of the chemical bath of the pyruvic acid ester of the disinfectant of this invention, 50-1000 ppm is preferable. This is because if it is less than 50 ppm, the effect becomes insufficient, and if it exceeds 1000 ppm, a phenomenon occurs in which cultured fish bite.
The treatment time may be 10 minutes or longer.
Antiparasitic agents of this invention will become rapidly hydrolyzed pyruvic acid with an alcohol in water, eventually no phytotoxicity to farmed fish occurs be performed no matter how long the process for changes in carbon dioxide and water . It is also a very safe substance for the environment.
When the parasite control agent of the present invention is used repeatedly over a long period of time, the survival rate and growth rate of cultured fish can be improved.
Among pyruvic acid esters, ethyl pyruvate is not directly toxic to fish, but it can be killed by bacterial infection from the bite created by biting fish in a medicine bath. There is. In contrast, methyl pyruvate, propyl pyruvate, and butyl pyruvate, which are the active ingredients of the parasitic insecticide of the present invention, can safely control parasites without biting even in trough pugs during drug bathing, etc. Since the state was maintained, a high survival rate and growth rate were obtained.
As can be seen from the survival rate of Examples described later, methyl pyruvate is most preferable from the viewpoint of safety to fish among the three types of pyruvate esters which are the active ingredients of the present invention.
EXAMPLES Next, the present invention will be described in detail with reference to examples and comparative examples.
Example 1
50 L of seawater was put into a 100 L plastic container, and the chemical bath solutions having respective concentrations of methyl pyruvate and ethyl pyruvate shown in Table 1 were prepared. Ten cultured trough puffers (about 10 cm long) infested with about 10 damselfly were added and immersed for 30 minutes. The removal rate of damselfish was examined by examining the number of damselfish shedding after treatment and the number parasitizing the trough pufferfish. Also, in the aquaculture ground, 5000 L of bath powder shown in Table 1 was prepared and 3000 trough fish were introduced. An immersion treatment was performed for 30 minutes to investigate the state of the trough puffer. The results are shown in Table 1.

Example 2
50 L of seawater was put into a 100 L plastic container, and chemical bath solutions having respective concentrations of methyl pyruvate, propyl pyruvate and butyl pyruvate shown in Table 2 were prepared. Ten cultured trough puffers (about 10 cm long) infested with about 10 damselfly were added and immersed for 30 minutes. The removal rate of damselfish was examined by examining the number of damselfly dropped after treatment and the number parasitizing on the trough. Moreover, in the aquaculture ground, 5000L of bath powders shown in Table 2 were prepared, and 3000 trough fish were introduced. An immersion treatment was performed for 30 minutes to investigate the state of the trough puffer.
The results are shown in Table 2.

Example 3
Five fishing ground test zones each accommodating 200 trough fishes weighing approximately 50 g were prepared, and 20 fish were randomly picked at the start of the test, and the average fish weight was measured. In four of these test sections, the immersion treatment for 30 minutes was carried out for half a year using a bath agent shown in Table 3 (pyruvate concentration 50 ppm, liquid volume 500 L) at a cycle of once every two weeks. . In another test group, no treatment with a bath salt was performed for half a year. Half a year later, the survival rate of trough puffer and the average body weight / growth rate of 20 random animals were investigated.
The results are shown in Table 3.

When one or more selected from methyl pyruvate, propyl pyruvate, and butyl pyruvate is used at 2000 ppm or less, the cultured fish will not be stressed, the parasites can be removed, the survival rate is high, and the growth rate is also high. I understand.
Industrial Applicability A pesticide containing one or more selected from methyl pyruvate, propyl pyruvate, and butyl pyruvate as an active ingredient can be used for parasite control of farmed fish.

Claims (2)

A parasite-controlling agent for cultured fish containing one or more selected from methyl pyruvate, propyl pyruvate, and butyl pyruvate as active ingredients. The parasite control method using the parasite control agent for cultured fish according to claim 1, wherein the concentration during treatment is 50 to 1000 ppm.