JPS6137042A - Hatching of "onitenaga" shrimp - 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 is directed to artificially growing eggs of A. prawn during the shrimp cultivation process. This article concerns a method for storing eggs of giant shrimp.

1 Background technology 1 The Onitenaga shrimp, which is native to Southeast Asia, is a freshwater shrimp that lives in rivers.The carapace is bluish-red, and it has elongated pincers that are nearly twice the length of its body, so it is also called the Matsuba shrimp, and in recent years it has become popular. , is 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 done by simply importing shrimp that were already in the form of shrimp and feeding them in an aquarium. It is extremely pure 1L, and it has been thought that -T conversion of eggs can only be done in their natural state. However, in order to cultivate large quantities of shrimp for food, it is necessary to be able to artificially eave the eggs, and the establishment of this method has been strongly desired.

[Object of the invention 1 The present invention has been made in view of the above points,
The purpose is to provide a method for artificially quaternizing the eggs of the giant shrimp.

[Disclosure of the Invention] The method of the present invention involves diluting seawater with fresh water so that the seawater content is 20% to 40% by volume, and the water temperature is 23°C to 32°C.
This method is characterized by raising giant shrimp to incubate eggs in diluted seawater. The giant shrimp is originally a freshwater species, but since it lives near the river Roi during the spawning season, it requires water containing a certain amount of salt, at least during the period before and after the eggs become snoring. In the present invention, taking this point into consideration, at least the period from the time when a female Onitenaga shrimp incubates the fish, until the egg develops into four, and passes through the floating stage larva (share) and becomes a young shrimp, is natural. The shrimp were raised in diluted seawater, which was prepared by diluting seawater with fresh water, so that the conditions were the same as those near the mouth of the river. According to experiments conducted by the present inventors, it was found that seawater is absolutely necessary for eggs to develop into four, and that if a female with eggs left in freshwater is left alone, the female will drop the eggs. , Il:
Even though seawater is necessary, it has been found that in pure seawater 1, that is, 100% seawater, even if the eggs become snoring, they will die during the floating stage before they become young shrimp.

According to experiments, the concentration of diluted seawater suitable for converting eggs into egg T is within the range of 20% to 40% seawater content, and the most favorable results were obtained at a seawater content of 30%. It is.

FIG. 1 to FIG. 5 are diagrams showing a schematic configuration of an aquaculture apparatus for carrying out the egg storage method of the present invention.

The one shown in Figure 1 is a freshwater aquarium, and in tank 1, which is about the size of a tsubo, parents are released in a ratio of 5 to 8 shrimp to 1 male to create a burem. , 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, filtered through a filter, and then returned to the aquarium 1, and the water in the aquarium 1 is constantly supplied with air to keep it submerged. The amount of oxygen is kept from decreasing. The temperature of the water in the water tank 1 is maintained within the range of 28°C to 30°C by a heater outside the 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 hatch and the larvae swim out. If a female with eggs is left in fresh water, she will drop the eggs, so she is removed from the fresh water tank 1 and released into a diluted seawater tank 2 as shown in Figure 2. 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. As seawater,
Natural seawater is used. The present inventor also attempted egg fertilization experiments using saline water or artificial seawater, but although the egg fertilization itself was carried out in water other than natural seawater, the eggs died at the larval stage, and the eggs did not change to the shape of shrimp. Growing up proved difficult. The water temperature in the water tank 2 is also maintained within the range of 28°C to 30°C, and air injection and water circulation filtration by a pump are performed in the same manner as in the water tank 1.

The aquarium 2 for diluted seawater is partitioned with a wire mesh 3, and the females with eggs are kept isolated one by one. 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, they may fight and drop the eggs. According to the inventor's experiments, when a glass aquarium 2 with a size of about 60 cm x 30 cm and a water depth of about 30 cm was divided into four equal parts with three pieces of wire mesh 3, most eggs were dropped. Nothing like that happened.

The number of days it takes for the eggs to turn four after incubation varies depending on the water temperature; the higher the water temperature, the fewer days it takes for the eggs to turn four. According to experiments, the water temperature was 23℃, 24℃,
For the cases of 26°C, 28°(:'), 30°C, and 32°C, the number of days required for egg T development is 25, 23, and 20 days after incubation, respectively.

They were on the 17th, 16th, and 15th. It is best to keep the water temperature as constant as possible from the time the female incubates the eggs until the eggs hatch, but if it is unavoidable that the temperature changes, set it within the range of 28℃ to 30℃. It is preferable to do so. 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. Water temperature 3
If the temperature is raised even higher than 2°C, the water will become cloudy and the water will become cloudy.
This is undesirable because the larvae that have turned into larvae often die.

If the water temperature is 28℃, will the egg be I? ?
Since it takes 17 days for the eggs to hatch, the female that has incubated the eggs 2 to 3 days before that time is transferred to another aquarium 4 as shown in Figure 3. In this aquarium 4, the female, which has incubated eggs and has reached the state of pre-quaternity, is kept in a breeding net 5 made of wire mesh. 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 turn four, 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. 2 when the water in tank 4 is dirty
The water is exchanged in increments of 0% to 30%. Water tank 4 is
It 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 does not stagnate. This is because water is not perishable. The larvae that have hatched from eggs are much smaller than the mesh of the rearing net 5, so they can move freely inside and outside the rearing net 5 and spread throughout the aquarium 4. In this state, the female shrimp is pulled up from the four aquariums together with the breeding net 5 and returned to the freshwater aquarium 1.

After that, for about 40 days, as shown in Figure 4, with a bubbling device M6 etc. inserted into the aquarium 4, air is injected and heat is kept using a heater, and the larvae are reared and managed until they become young shrimp. It is something that Water temperature and seawater content are the third
This is the same as the case shown in the figure.

In the early stage, within 10 days after becoming a cape, the larvae themselves are small plankton, so it is necessary to feed plankton even smaller than the larvae. In the inventor's experiments, it was found that it is preferable to quaternize brine shrimp (Artemia: a type of shrimp) eggs to provide plankton in a fresh state. Brine shrimp eggs are commercially available from, for example, "Nippon Animal Pharmaceutical Co., Ltd.". This brine shrimp is very easy to transform into 48% water at a temperature of about 28°C in 3% saline or pure seawater.
℃, the time required for quaternization is said to be 24 to 48 hours. Brine shrimp must be fed to the larvae in a 4-staged, unopened state. If you feed plankton that has been stored for a long time after it has turned four, the plankton will grow in size during that time, and the larvae of the giant shrimp will be eaten. From about 10 days after the cape is grown, mince the meat of 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 turning four, and about half (strongly) will take the form of young shrimp about 30 to 35 days after turning four. and descends to the bottom of tank 4. Approximately 40 days after they turn four, almost all of them take on the shape of Shii shrimp. Once it grows to this state, it will not die even if kept in fresh water.
The fish are stocked in a large aquarium 7 or pond as shown in FIG. 5, and reared in fresh water. It is very easy to keep them in this condition. The eating habits of the giant shrimp are omnivorous, and in the wild they eat anything, including aquatic worms, aquatic insects, small shellfish, crustaceans, fish and animal meat, grains, algae, and soft leaves and stems of aquatic plants. . When cultivating in the aquarium 7, etc., feed mixed feed such as trout, carp, and sweetfish, as well as grains such as sardines and eggs. 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.

After 4 to 5 months, the Onitenaga shrimp grows into parent shrimp and lays eggs. The number of eggs laid by a single parent varies depending on the size, but the average number of eggs is about 20,000 to 30,000, and if the water temperature and other living conditions are good, they will spawn 5 to 7 times a year. After becoming a cape, the fish grow to a length of 11 to 15 cm in about six months, and 30 to 40 cm in two years, but for the domestic market, it is best to remove them from tank 7 and ship them when they are about 15 cm. I think that the.

[Effects of the Invention] As described above, the present invention incubates eggs in diluted seawater with a seawater content of 20% to 40% by volume by diluting seawater with fresh water and a water temperature of 23°C to 32°C. Since we have started to raise prawns that grow in their natural habitat, we have been able to create conditions that closely match their natural habitat conditions, in which the prawns live near river mouths after incubation until the eggs hatch into capes. This has succeeded in converting the eggs of the giant shrimp to four, which was thought to be impossible, and will greatly contribute to the cultivation of the shrimp.

[Brief explanation of drawings]

The drawings show an aquaculture device using the method of the present invention. Figure 1 is a schematic diagram of the aquarium used for mating and spawning of giant shrimp, and Figure 2 is a schematic diagram of the aquarium used during the period after egg incubation until the time when shrimp are about to turn into capes. Figure 3 is a perspective view of an aquarium used for raising shrimp eggs, Figure 4 is a perspective view of an aquarium used for rearing larvae after they turn four, Figure 5 is a perspective view of a tank used for rearing young shrimp. FIG. 1.2 and 4.7 are water tanks, 3 is a wire mesh, 5 is a breeding net, and 6 is a bubbling device. Agent Patent Attorney Ishi 1) Ai No. 7 5 @ Procedural Amendment (formality) 1. Indication of the case Patent Application No. 160039 of 1982 2. Name of the invention A method for detailing shrimp eggs 3. Person making the amendment Relationship to the incident Patent applicant address 1-135 Mozubaimachi, Sakai City, Osaka Prefecture Name
Noboru Izumi 4, agent postal code 530 5, date of amendment order November 7, 1980 6, subject of amendment Particulars 7, contents of amendment As per the engraving appendix of the specification originally attached to the application (contents (no change)

Claims (4)

[Claims] (1) Dilute seawater with fresh water to make the seawater content 20% by volume.
% to 40% and a water temperature of 23° C. to 32° C. A method for hatching eggs of A. prawns, which is characterized by raising the prawns to incubate eggs in diluted seawater with a water temperature of 23° C. to 32° C. (2) The method for hatching eggs of giant shrimp according to claim 1, wherein the seawater is natural seawater. (3) The method for hatching eggs of giant shrimp according to claim 2, wherein the content of natural seawater is 30%. (4) The method for hatching eggs of giant shrimp according to claim 1, wherein the water temperature is within the range of 28°C to 30°C.