JPS6137043A - Feeding of "onitenaga" shrimp in incubation period - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a method for raising prawns in the incubation stage during the cultivation process of prawns.

[Background technology 1] Onitenaga shrimp is a freshwater shrimp that is native to southeastern Anoa and lives in rivers.The shell is bluish red and has an elongated collar that is almost twice the body length, so it is also commonly called Matsuba shrimp. In recent years, it has been attracting attention as an edible shrimp that can replace kuruma shrimp and flax shrimp.

In the past, such shrimps were imported and kept as ornamental pets, but this was an extremely difficult process that involved importing shrimp that were already in the form of shrimp and feeding and raising them in an aquarium. It is simple, and it has been thought that egg storage can only be done in its natural state. However, the present inventors believe that although Onitena shrimp are originally freshwater, they live near 1oJII during the spawning season, so they require water containing a certain amount of salt, at least during the period before and after the eggs become tolerant. Focusing on this point, at least the period from the time when a female Onitena shrimp incubates eggs until the eggs become resistant, pass through floating stage larvae (shares), and become young shrimps will be under the same conditions as in a natural estuary. In addition, by raising the shrimp in diluted seawater with fresh water, it has become possible to form artificial capes in the eggs of the shrimp, which had previously been considered impossible. However, seawater is always required to make the eggs of the prawns into capes in this way, and cultivating prawns in areas where seawater is difficult to obtain requires costs such as seawater transportation costs, storage management costs, etc. The problem was that it was expensive and inconvenient.

[Object of the invention] The present invention has been made in view of the above points, and
The purpose of this is to provide a method for raising Oninana ff shrimp during the incubation period, which allows the breeding of Oninana ff shrimp in as little seawater as possible, and which enables the cultivation of Oninana ff shrimp during the incubation period, even in areas where seawater is difficult to obtain. The purpose is to

[Disclosure of the Invention] The method of the present invention comprises:
Onitena Shrimp are kept at a ratio of one male to several females, and the females with eggs are diluted with fresh water to make the seawater content 20% to 40%, and the water temperature is 23℃ to 23℃. 32
It is characterized by being reared in diluted seawater at ℃. As mentioned above, giant shrimp require seawater from the time they incubate, until the eggs become resistant, pass through floating stage larvae, and become young shrimp, but until the female incubates the eggs. can be kept in freshwater.

Originally, prawns live in freshwater, eat and grow in freshwater areas, and migrate to river mouths only during the spawning season, so it is better to keep prawns in fresh water until they incubate their eggs. It is something that can be rubbed into an environment that is close to its original ecology. The reason for rearing multiple females per male in freshwater is to increase the efficiency of egg incubation. The ratio of females to one male is preferably 5 to 8; if the ratio is higher than this, fights will occur between the females, and if it is lower, the efficiency of egg incubation will be reduced. The appropriate freshwater temperature during the incubation period is 28°C.

Females that have incubated eggs will drop their eggs if left in fresh water, so after incubating eggs, they are raised in diluted seawater diluted with fresh water to create an environment similar to a natural estuary. . According to experiments, the concentration of diluted seawater suitable for making eggs resistant is within the range of 20% to 40% seawater content, with the most favorable results being obtained at a seawater content of 30%. It is.

According to experiments conducted by the present inventor, it has been found that seawater is always required when eggs hatch into 1lllr. It was also found that even though seawater is necessary, in pure seawater, that is, 100% seawater, even if the eggs survive, the floating larvae will die before they develop into young shrimp. Further, the temperature of the diluted seawater is preferably 28°C. In the present invention, the female eggs are raised in diluted seawater after incubation, so it is possible to artificially make the eggs of the incubated female resistant, and moreover, until the female incubates the eggs. During this period, males and females were kept in freshwater, so they can be easily reared using well water or tap water, and seawater is not needed in large amounts. It is possible to easily farm giant shrimp even in difficult areas.

Hereinafter, the method of the present invention will be explained in more detail with reference to Examples.

FIGS. 1 to 5 are diagrams showing a schematic configuration of a culture apparatus using the breeding method of the present invention. The one shown in Figure 1 is a freshwater aquarium. and prepare for mating. The number of males does not necessarily have to be one; if four or more males are available, the number of females may be increased at the above-mentioned ratio accordingly. The water in this aquarium 1 is pumped up by a pump, filtered through a filter, and then returned to the aquarium 1. Also, air is constantly supplied to the water in the aquarium 1 to control the amount of oxygen in the water. I am trying not to reduce it. The temperature of the water in the water tank 1 is maintained within the range of 28°C to 30°C by a heater equipped with a temperature control device. If they are raised in this state while being fed, mating will occur and eggs will be laid within 6 to 20 hours after mating. The female shrimp protects the eggs while they are incubating until they become resistant and the larvae begin to swim. If a female with eggs is left in fresh water, she will drop the eggs, so she is taken out of a freshwater tank 1 and released into a diluted seawater tank 2 as shown in FIG. At this time, in order to easily pull out the female with eggs from tank 1, it is better that tank 1 is not too wide, and as mentioned above, it is recommended to use tank 1 with an area of about 1 tsubo. Most preferred. The diluted seawater in the water tank 2 has a seawater content of 30% by volume. Natural seawater is used as seawater. The present inventor also attempted an egg T conversion experiment using saline water or artificial seawater, but although the eggs were able to withstand conditions other than natural seawater, they died at the larval stage and even took on the shape of a shrimp. Growing up proved difficult. Water temperature in tank 2 is also 28℃
The temperature is maintained within the range of ~30°C, and air injection and water circulation filtration using a pump are performed in the same manner as in the case of water tank 1. Tank 2 for diluted seawater is gold 1!1
It is divided into 3 sections, and each female with eggs is kept in isolation. The reason why females with eggs are isolated in this way is that if females with eggs are kept close together in a small space, there is a risk that they may fight and drop the eggs. According to the inventor's experiments, the width is 6.
When the inside of a glass aquarium 2 with dimensions of about 0cm x 30c+o and water depth of about 30c+n was divided into four equal parts with three pieces of gold #i43, no eggs were dropped. The number of days it takes for the eggs to become resistant after incubation varies depending on the water temperature; the higher the water temperature, the fewer days it takes for the eggs to become resistant. According to the experiment, the water temperature was 23℃, 2
For each case of 4°C, 26'C, 28°C, 30°C, 1 and 32°C, the number of days required for eggs to become T was 25, 23, and 20 days after incubation, respectively.

1711.16th and 15th. It is better to keep the water temperature as constant as possible from the time the female incubates the eggs until the eggs become hardy, but if the temperature is unavoidable, it should be set within the range of 28℃ to 30℃. is preferred. Raising the water temperature to 32°C will further shorten the number of days required to form a cape, but this is not preferable because the energy cost required to keep the water temperature high will be high. Furthermore, raising the water temperature further than 32°C is not desirable because the water becomes cloudy and even if the eggs become resistant, they are more likely to die at the larval stage. When the water temperature is 28°C, it takes 17 days for the eggs to become resistant during incubation, so the female that has incubated the eggs two or three days before is placed in another aquarium 4 as shown in Figure 3. It is intended to be transferred to In this aquarium 4, the female, who has incubated eggs and is on the verge of becoming a cape, is kept in a cage I made of wire mesh.
They are kept in A5. The water temperature and seawater content in tank 4 are the same as in tank 2, and the point that air is injected to prevent the oxygen in the water from decreasing is the same as in tank 2, but the water is circulated by a pump. No filtration. This is because when the eggs become resistant, the larvae begin to swim, so if water is circulated and filtered using a pump, the larvae will be caught in the filter and die. When the water in the tank 4 becomes dirty, 20% to 30% of the water is replaced.

The aquarium 4 is a round aquarium made of polyethylene or concrete with a capacity of 500 to 1000 liters.The reason why a round aquarium is used in this way is that compared to a square aquarium, there are no corners, so the water can flow easily. This is because it does not easily stagnate and the water does not easily spoil. The larvae that have turned into capes from eggs are much smaller than the mesh of the breeding net 5, so they can move freely inside and outside the breeding net 5, and spread throughout the aquarium 4. In this state, the female shrimp is pulled up from the aquarium 4 along with the breeding net 5 and returned to the freshwater aquarium 1. After this, for about 40 days, air is injected and heat is kept using a heater with a bubbling device 6 etc. inserted into the aquarium 4 as shown in Figure 4, and the larvae are reared and managed until they become young shrimp. It is something that The water temperature and seawater content are the same as in Figure 3. At the early stage, within 10 days after becoming tolerant, the larvae themselves are small plankton, so it is necessary to feed plankton even smaller than the larvae.

In the inventor's experiments, brine shrimp (Artemia:
It has been found that it is preferable to provide fresh plankton by making eggs of shrimp (a type of shrimp) tolerant. Brine shrimp eggs are commercially available from, for example, "Nippon Animal Pharmaceutical Co., Ltd.". This brine shrimp is very easily acetylated, and it is said that the time required for acetylation is 24 to 48 hours when the water temperature is about 28° C. in 3% saline or pure seawater. Brine shrimp must be fed to the larvae in an acetylated state. If you feed plankton that has been kept for a long time after it has become resistant, the plankton will become unnatural during that time, and the larvae of the giant shrimp will end up being eaten. From around 10 days after the eggs have been hatched, feed the minced clams and shrimp. The larvae before forming into young shrimp are swimming relatively above the tank 4. If you continue to raise them, some larvae will take the form of young shrimp in about 28 days after becoming tolerant, and about half (strongly) will take the form of young shrimp in about 30 to 35 days after becoming tolerant. and descends to the bottom of tank 4. After about 40 days of hardening, almost all of the shrimp take the form of young shrimp. Once they grow to this state, they will not die even if reared in fresh water, so they are released into a large aquarium 7 or pond as shown in FIG. 5 and reared in fresh water. Breeding in this state is very easy. The eating habits of Onitenaga shrimp are omnivorous, and their natural sources include aquatic worms, aquatic insects, and small shellfish.
They eat anything, including crustaceans, fish and animal meat, grains, algae, and the soft leaves and stems of aquatic plants. When cultivating in the aquarium 7, etc., feed mixed feed such as trout, carp, sweetfish, sardines, egg shells, etc. Regarding water temperature, since shrimp are originally from the tropics or subtropics, they are strong against high water temperatures but weak against low water temperatures.The water temperature at which they can normally live in is within the range of 18°C to 35°C, and the preferred water temperature is 25°C. to 32°C.

They stop feeding when the water temperature drops below 20 degrees Celsius, and die when the water temperature drops below 14 degrees Celsius. Onitenaga shrimp is resistant to 4,
In 5 months, they grow into parent shrimp and lay eggs. The number of eggs laid by a single parent varies depending on the size, but the average is about 20,000 to 30,000 eggs, and if the water temperature and other living conditions are good, the number of eggs laid by each parent is 5 to 7 eggs per year.
Spawn twice.

The size of the body is 11 to 15 cm in about 6 months after storage.
They grow to a length of 30 to 40 centimeters per year, but for the domestic market it is considered appropriate to remove them from the aquarium 7 and ship them when they are about 15 centimeters long.

[Effects of the Invention] As described above, the present invention involves rearing giant shrimp at a ratio of one male to multiple females in fresh water at a water temperature of 23°C to 32°C, and breeding the females with eggs among them. , Seawater was diluted with fresh water to make the seawater content 20% to 40%, and the water temperature was 23℃ to 32℃. It is possible to artificially create a situation that closely matches the ecology of living near estuaries until the shrimp become resistant to this problem, and this makes it possible to transform the eggs of the shrimp into artificial eggs, which had previously been considered impossible. However, since the female is reared in freshwater with the male until it incubates, it can be easily reared using well water or tap water, and seawater can be used in large quantities. Since there is no need for this method, there is an advantage in that it is possible to easily cultivate prawns even in areas where seawater is difficult to obtain.

[Brief explanation of drawings]

The drawings show an aquaculture apparatus using the method of the present invention, and Fig. 1 is a schematic diagram of the aquarium used for mating and spawning of O. prawns, and Fig. 2 is a diagram showing the structure of the aquarium used for mating and spawning of O. prawns after incubation. Figure 3 is a perspective view of the tank used for the Ilrl stage of the eggs of Onitenaga shrimp, Figure 4 is a perspective view of the tank used for rearing the larvae after they have become tolerant, and Figure 5 is FIG. 2 is a perspective view of an aquarium used for raising young shrimp. 1, ,2,4. , 7 is an aquarium, 3 is a wire mesh, 5 is a breeding net, and 6 is a bubbling device. Agent Patent Attorney Ishi 1) Ai 7 Figure 1 Figure 3 Figure 2 Figure 4 District 5 Procedural amendment (method) % formula % 1. Indication of the case 1982 Patent Application No. 160040 2. Invention Name: Method of raising giant shrimp during the incubation stage 3; Relationship with the case of the person making the amendment Patent applicant address: 1-135 Mozucho Ume-cho, Sakai-shi, Osaka Postal code: 530-5; Date of amendment order: November 7, 1980 6. Subject of amendment Description 7. Contents of amendment As shown in the engraving appendix of the specification originally attached to the application (no change in content)

Claims (4)

[Claims] (1) In fresh water with a water temperature of 23°C to 32°C, prawns are raised at a ratio of 1 male to multiple females, and the females with eggs are diluted with seawater to reduce the seawater content. 2
1. A method for rearing giant shrimp during the incubation period, the method comprising rearing them in diluted seawater with a concentration of 0% to 40% and a water temperature of 23°C to 32°C. (2) The method for raising prawns in the incubation stage according to claim 1, characterized in that in fresh water, 5 to 8 females are raised for every 1 male. (3) The method for raising giant shrimp during the incubation period according to claim 1, wherein the seawater is natural seawater and the seawater content is 30%. (4) The method for raising giant shrimp during the incubation period according to claim 1, wherein the temperature of the fresh water and diluted seawater is within the range of 28°C to 30°C.