WO2015172573A1

WO2015172573A1 - Initial feed for early-stage larvas of eels and culturing method therefor

Info

Publication number: WO2015172573A1
Application number: PCT/CN2015/000076
Authority: WO
Inventors: 何卫星
Original assignee: 何卫星
Priority date: 2014-05-12
Filing date: 2015-02-03
Publication date: 2015-11-19
Also published as: CN104012759A; CN104012759B

Abstract

Disclosed are an initial feed for early-stage larvas of eels and a culturing method using the feed. The feed comprises marine organisms having an autolysis characteristic such as jellyfishes.

Description

Open bait for early larvae and breeding method thereof

Technical field

The invention belongs to the field of fish seedling cultivation, and particularly relates to an open bait for early larvae and a method for cultivating the same.

Background technique

The scientific name of squid is 鳗鲡, its nutritional value is very high, so it is called soft gold in the water. The growth process of earthworms is extremely peculiar. First, it lays eggs in seawater and then grows into fresh water. At present, the Japanese carp cultured in China, Japan and South Korea all rely on the capture of wild seedlings, and the seedling resources are declining year by year due to overfishing. Moreover, due to the problems of cultivating technology, the yield of wild seedlings caught is low, which also causes further waste of resources. The study of artificial reproduction of squid has always been a problem in the international aquatic biology community, so it is called the Goldbach conjecture in biology. .

The Aquaculture Department of Japan is the main ingredient in the shark yolk freeze-dried powder, and the krill or other fresh fish and shrimp extract is added to make a paste-like feed for the cultivation of the hatched young fish (the early larvae), which has been successfully obtained. Willow scorpion, and eventually obtained a small amount of squid adult (white peony, also known as glass enamel).

However, this artificial cultivation of Japanese cockroaches still has the following disadvantages: 1. The survival rate of seedlings from hatching of fertilized eggs to early larvae is only 0 to 5%. 2. The incubation period from hatching early larva to glass seedlings takes about half a year. 3. The cost of the first generation of fully hatched glass seedlings is 1 million yen per foot (about 75,000 yuan); the cost of the second generation of glass seedlings also needs several thousand yen (a few hundred yuan). The success of the second generation of full artificial hatching is only in the laboratory stage, and it takes about 10 years to achieve scale production. In the short term, the success of artificial breeding has no real impact on the domestic and international squid industry.

Among them, the main problem of artificial breeding is the early hatching of the early larvae (ie, from the fertilized eggs by 3-5 The choice of the open bait for the early hatching of the larvae in the day is not suitable for the early larvae because the digestive system of the early larvae is not yet complete and the digestive capacity is weak.

Summary of the invention

In order to solve the above problems, the present invention provides a method for cultivating an easily absorbed nutrient such as a jellyfish by using jellyfish as a material, utilizing the autolytic property of jellyfish, inducing autolysis of jellyfish, and releasing self-dissolving of jellyfish, thereby solving the early larvae (generally The larvae that are hatched from fertilized eggs for 3-5 days to 1-19 days after filming do not have the ability to digest and fail to feed early larvae.

The technical proposal of the present invention is to provide an open bait for an early larvae, the bait comprising marine organisms having autolysis characteristics, preferably the jellyfish is selected as the main component of the open bait, and the jellyfish autolysate and extract can also be used. Wait as the main ingredient to feed the early larvae.

At the same time, the present invention also provides a method for cultivating early larvae by using the above-mentioned open bait, which is: (1) selecting a living wild or artificially cultured jellyfish to remove the toxic tentacles of the jellyfish; and (2) loading the jellyfish into the plastic. In the bag or the fresh-keeping bag, the jellyfish will die due to lack of oxygen, and the autolysis will occur within a few hours (1 to 5 hours) after the jellyfish dies; (3) When the jellyfish is in a semi-dissolved state, the early larvae (yolk) are fed. The sac has not disappeared in the pool of early larvae. Pay attention to changing the water to maintain the water quality: If the feeding time is too early, you can remove the jellyfish tissue that has not been autolyzed and feed it again after changing the water until the early larvae start to feed the jellyfish in the autolysis state.

At the same time, the early larvae can be domesticated, and after the above steps, the fresh jellyfish (including the jellyfish whole or tissue blocks) or the living jellyfish or jellyfish living tissue can be fed. Since the juveniles have sharp teeth, they can directly feed on the living jellyfish tissue after domestication. Because living tissue is not easy to rot, feeding management is more convenient.

Advantages of the invention:

Technical level: The material fed by the present invention has self-dissolving properties relative to the method of feeding the hatched juvenile fish with shark yolk. The early development of the digestive system of the larvae is extremely imperfect, and the ability to digest protein and other nutrients is very weak. The jellyfish can be autolyzed and have low requirements on the digestive system, adapting to the physiological characteristics of the early larvae. At the same time, the jellyfish texture is soft and easy for early larvae to feed.

Application level: Because the jellyfish is easy to obtain and the cost is low, the cost of cultivating juvenile fish is much lower than that of shark yolk, which has operability and practical value.

The method of the invention can also continue to be used for the cultivation of canker-like larvae of alfalfa.

Advantages: 1. After autolysis, the jellyfish release peptides, nucleotides, polysaccharides and other "flavoring substances", which can induce the early larvae to feed and enhance the feeding effect. After the late adaptation, the early larvae and willow-like larvae can be slowly domesticated to receive fresh jellyfish.

2. The physiological characteristics of early hatching larvae are different from those of common fish seedlings. Because the digestive organs of the early larvae are basically not developed, the digestive enzymes are extremely inactive and cannot digest complex nutrients such as proteins and fats. After the jellyfish is autolyzed, macromolecules such as proteins, fats, nucleic acids, and mucopolysaccharides are hydrolyzed into small molecules by their own digestive enzymes, and the seedlings can be absorbed without digestion. The living jellyfish will be self-dissolved in the digestive cavity of the juvenile fish by the seedlings of the alfalfa, and they can be well absorbed and utilized.

Because the water content of jellyfish is high and toxic, the nutrient content is much lower than that of conventional open bait such as fish meal, brine shrimp and rotifer, and the general organism does not feed. Therefore, there is no precedent for jellyfish as the open bait for fish in the prior art. The material used for fish breeding is the first of its kind. Early larvae and willow mites have no digestive organs such as liver and pancreas. The intestines are a straight pipe with little digestive capacity. The cultivation of the larvae is a world problem in the cultivation of fish seedlings. However, the invention has obtained the characteristics of jellyfish autolysis through long-term experiments. It is suitable for the conclusion of early larvae and willow mites, greatly reducing the cultivation cost and increasing the survival rate of seedlings, and solving this world problem.

detailed description

The following embodiments are merely illustrative of the invention, and the scope of the invention is not limited to the following examples. The objects of the present invention can be achieved by those of ordinary skill in the art in light of the present disclosure.

Artificially cultured or wild live jellyfish, early larvae (the larvae that have been hatched by fertilized eggs for 3 to 5 days, and the yolk sacs are near disappearing).

Tools: gloves, scissors, plastic bags or storage bags, other materials needed to cultivate seedlings (oxygen pumps, artificial sea water, sinks for seedlings, etc.).

Cultivation method: (1) remove the venomous thorns of the jellyfish. Jellyfish have thorns, grow on the edge of the umbrella-shaped head, and will lick the larvae, so they should be removed. Wear gloves and cut all the thorns with scissors. To ensure that the cuts are clean, you can also cut off a part of the jellyfish cover.

(2) Inducing autolysis of jellyfish. Jellyfish will self-dissolve after death, so it is only necessary to kill the jellyfish to induce autolysis. The jellyfish is sealed in a plastic bag or a plastic wrap bag, causing the jellyfish to suffocate and die. After a few hours (1 to 5 hours), the jellyfish is autolyzed. Pay attention to the autolysis process. When autolysis is found, you can take out the seedlings. If it is taken too late, it will lead to excessive autolysis and turn into a pool of water. It is easy to use and it is easy to pollute the water.

(3) Feeding early larvae. The initially autolyzed jellyfish is placed in the early larval pond. Be careful to keep the water clean and change the water frequently. In order to ensure that the early larvae open their mouths smoothly, they should be fed before the early larvae yolk sac disappeared in the pool. If the feeding time is too early, you can remove the jellyfish group that is not autolyzed. After weaving and changing the water (the jellyfish that have been autolyzed can no longer be taken out, only water can be changed), feed again. Until the juveniles begin to feed on the jellyfish in the autolyzed state.

(4) Domestication. After the juveniles adapt to the jellyfish as bait, they can feed the fresh jellyfish (including the jellyfish whole or the tissue block), or further feed the living jellyfish or the living jellyfish tissue (the living jellyfish will not be cut after the cut) Death, able to maintain vitality). Feeding live jellyfish or living jellyfish tissue is convenient and low cost. Juvenile fish can be fed as needed. After feeding, jellyfish will self-dissolve in the digestive tract of juvenile fish and will not pollute the water body.

(5) Cultivation of willow mites. After 10 to 35 days of feeding, the early larvae grow up and become lanceolata (ie, willow). The method of cultivating the willow-like larvae is the same as that of the early larvae.

(6) Cultivate glass bottles. After 3 to 12 months of feeding, when the length of the willow mites is 3 to 10 cm, the seawater concentration will be gradually lowered, and the willow mites will metamorphose into glass sputum. The glass crucible can be fed according to the regular feeding method.

For the raw materials used in the above examples, the bait of the present invention may also have the following alternative forms: 1. pulverized jellyfish or jellyfish autolysate 80% to 90% by weight and potato starch 10% to 20%; or pulverized jellyfish Or jellyfish autolysate 90% ~ 98% and seaweed gum 2% ~ 10%, the production of frozen gelatinous solids, this method can reduce the water pollution of jellyfish autolysis, reduce the amount of water replacement.

2. The pulverized jellyfish or jellyfish autolysate is 50% to 80%, the fermented soybean meal or MSG residue is 10% to 30%, and the potato starch is 10% to 20%. The paste-like feed pellet produced by this method has a good attracting effect. Not easily soluble in water.

3. The pulverized jellyfish or jellyfish autolysate is 60%-80%, the fermented soybean meal or MSG residue is 15%-30%, and the seaweed gum is 2%-10%. The jelly-like feed pellet produced by this method has good attracting effect. Not easily soluble in water.

Claims

An open bait for early larvae characterized in that the bait comprises marine organisms having autolysis properties.
The open bait of an early larvae of the larvae according to claim 1, wherein the marine organism having autolysis characteristics is jellyfish.
The open bait of an early larvae according to claim 1 or 2, characterized in that the main component of the bait is a jellyfish autolysate or an jellyfish extract.
The invention relates to a method for cultivating early larvae, which is characterized in that the method comprises cultivating an early larvae as a main component of a bait with autolysis characteristics.
The method for cultivating an early larvae of the larvae according to claim 4, wherein the marine organism having autolysis characteristics is jellyfish.
The method for cultivating an early larvae according to claim 4 or 5, characterized in that the main component of the bait is a jellyfish autolysate or an jellyfish extract.
The method for cultivating an early larvae of the larvae according to any one of claims 4-6, wherein the method comprises the following steps:

(1) removing the venomous thorns of the jellyfish;

(2) Inducing self-dissolving of jellyfish: the jellyfish obtained in step (1) is suffocated and died, and after a few hours (1 to 5 hours), the jellyfish is autolyzed;

(3) Feeding the early larvae: The preliminary autolyzed jellyfish obtained in the step (2) are placed in the pool of the early larvae.
The method for cultivating an early larvae of the larvae according to claim 7, wherein the method further comprises the steps of:

(4) Domestication: After step (3), the early larvae can adapt to the jellyfish as a bait, and can feed the fresh jellyfish (including the jellyfish whole or the tissue block), or further feed the living jellyfish or living body with the barbed wire removed. Jellyfish tissue.
The method for cultivating an early larvae according to claim 7, characterized in that in step (3), the preliminary autolyzed jellyfish obtained in step (2) are placed in a pool of early larvae of the yolk sac that have not disappeared; Early in time, the jellyfish tissue that is not autolyzed can be removed and fed again after changing the water until the early larvae begin to feed the jellyfish in the autolyzed state.
A method for cultivating an early larvae of the larvae according to any one of claims 4 to 10, characterized in that the method can also be used for cultivating scorpion larvae.