CATDOLL : CATDOLL: How to raise loach seedlings How to raise loach seedlings

1. How to raise loach seedlings How to raise loach seedlings

1. Spawning environment: The spawning pool for loach can be a small cement pool, a small pond, etc., with a water surface of 5 to 102 meters and a water depth of 40 to 50 centimeters. It is best to maintain a micro-flow of water. Put water plants, willow roots, palm skin, etc. in the spawning pool as fish nests for eggs to attach. Put 7 to 10 groups of parent loach per square meter (one group consists of one old female and two males).

2. Spawning time: When the water temperature is between 18 and 20 degrees Celsius, spawning usually occurs in the early morning on a sunny day near the leak or before 10 am. When the water temperature is between 20 and 28 degrees Celsius, spawning usually occurs after rain or at midnight. A female loach can lay 200 to 300 eggs at a time, and it takes several spawnings to lay all the eggs, with a total of 3,000 to 5,000 eggs. The fertilized eggs adhere to the fish nest, but the adhesion is poor and it is easy to fall off, so be careful when operating.

3. Spawning management: During the spawning period, fish nests should be removed and observed every morning. If there are many eggs in the nests, they should be moved to the hatching pond for hatching and put back into the nests in the afternoon. If the nests are not collected in time, the fertilized eggs will be eaten by the parent loach. The parent loach breeding pond can also be used as a spawning pond. When the water temperature rises to 18℃ and some loaches chase each other, put the fish nests in and keep the water in the pond slightly flowing, which can improve the water quality and stimulate the reproduction of parent loach.

2. How to raise loach fry

Select a site to build a pond: Build a breeding pond on a gentle slope of farmland with a good environment, sufficient water source, good water quality and convenient drainage. Stocking seedlings: Start stocking loach seedlings in mid-May every year, and choose seedlings that are vigorous, have no skin damage, are healthy and free of diseases. Daily maintenance: Change the water every three days to ensure the water quality is clean and hygienic.

How to raise loach fry 1. Select a site and build a pond

Loaches have high requirements for water quality. When breeding, they are usually built in breeding ponds on gentle slopes of farmland with good environment, sufficient water sources, excellent water quality and convenient drainage. In addition, the breeding ponds need to have a complete drainage system that can drain water separately and have normal power supply, while also ensuring that the facilities in the pond are complete.

2. Planting seedlings

In mid-May every year in Zaozhi, loach fry are released. Care is taken to select vigorous, healthy, disease-free, three to four centimeters long fry. Then the fry are sprinkled with salt water and placed in the breeding pond. Generally, 10,000 loach fry can be released per acre.

3. Daily maintenance

In order to prevent loaches from getting sick, it is necessary to regularly spray yeast, EM bacteria and other biological agents into the breeding pond. This can not only regulate the water quality, but also improve the immunity of loaches. In addition, the water should be changed every three days to ensure the water quality is clean and hygienic, and sunshade measures should be taken when the temperature is too high.

3. How to raise loach seedlings

1. Preparation before breeding

(1) Preparation of spawning ponds Spawning ponds for artificial breeding of domestic fish can be selected from rice fields, ponds, and ditches with a water depth of 15-20 cm. You can also use mesh or bamboo fences to enclose a 3-10 square meter water surface as a spawning site. It is better if you can maintain a micro-flow of water. In addition, cement pools, large plastic boxes, buckets, water tanks or other containers can be used as spawning facilities. Spawning sites must be disinfected before use. When the water depth is 20 cm, use quicklime for disinfection, applying 15-20 grams per square meter. You can also use bleaching powder for disinfection, applying 4 grams per square meter.

(2) Preparation of fish nests Fish nests should be made of soft, non-corrupt materials that can float in water, such as palm leaves, willow roots, duckweed, and polythene grass. In recent years, soft green nylon woven belts have been used to weave artificial fish nests with a width of 5 cm and a length of 80 cm. They must be disinfected before use: soak in 2% salt water for 20-40 minutes, or soak in 20ppm potassium permanganate for about 20 minutes; soak in 10ppm malachite green for 20-30 minutes, and then hang in the pool 10 cm above the water, with reed mats or straw bags for shade.

2. The reproduction method of loach There are two types of reproduction: natural reproduction and artificial reproduction.

(1) Natural reproduction can be divided into two methods: completely natural reproduction and semi-natural reproduction.

Completely natural reproduction, also known as induced breeding, is a method of using the natural resources of loaches to artificially induce their spawning groups and obtain fertilized eggs. First, during the spawning season, take advantage of the habit of loaches to lay eggs in the water grass on the shore, choose a secluded water grass area, first apply two baskets of plant ash in shallow water, and then apply 0.6-0.8 kg of pig, cattle, sheep and other animal manure per square meter in the induced breeding area. This can attract a large number of loaches to the water grass in this area to lay eggs and reproduce. However, corresponding protection measures (predator prevention, etc.) must be taken for this natural area. Artificial fish nests can also be used to collect fertilized eggs in natural waters and move them to specific containers for incubation, which can increase the hatching rate.

Semi-natural reproduction is a method of allowing mature loaches to mate and lay eggs under artificial conditions. It requires the construction of spawning ponds and hatching facilities. Before reproduction, the spawning ponds and hatching equipment must be disinfected and ready for use. The male-female ratio of parent loaches is 1:2 or 1:3 if the male loach is larger. If the male loach is only about 10 cm long, the male-female ratio can be adjusted to 1:4 to increase the number of male loaches. 7-10 groups can be placed per square meter to ensure normal reproduction. The water temperature must be stable above 18℃ before it can be carried out. Tie the fish nest to a bamboo pole and hang it in the middle or four corners of the spawning pond so that the fish nest is submerged under the water. Because loach eggs have poor viscosity, it is necessary to pay attention to checking and cleaning the dirt deposited on the fish nest to avoid affecting the adhesion effect of the fertilized eggs.

Loaches usually spawn in the morning on a sunny day and finish spawning around 10 am. When spawning is basically completed, the fish nests with eggs are immediately moved to the hatching pond or other hatching facilities for hatching, and new fish nests are replaced and added to the spawning pond to collect the eggs of the parent loaches that have not yet finished spawning. After the last batch of loaches spawn, they can be hatched in the spawning pond, but all the parent loaches in the spawning pond must be caught to prevent the parent loaches from swallowing the eggs on the fish nests and affecting the emergence rate.

(2) Artificial reproduction of old people can be divided into two methods: semi-artificial reproduction and fully artificial reproduction.

Semi-artificial breeding uses the method of artificial induction of natural reproduction. Select mature loaches, with a female-male ratio of 1:2 or 1:3. Inject induced labor drugs: carp or crucian carp pituitary gland (abbreviated as PG), 1-2 per tail; or chorionic gonadotropin (abbreviated as hCG) injected at 800-1000 international units per tail, or luteinizing hormone releasing hormone analog (abbreviated as LRH-A). Each tail is injected with 5-8 micrograms. No matter which of the above drugs is used, they must be dissolved in physiological saline, and the dose of male loaches is halved.

Because loaches are small, the amount of injection for each loach should not exceed 0.5 ml, and 0.2-0.3 ml is appropriate to avoid body swelling or liquid overflow. Use a No. 4 stainless steel needle and a 1 ml glass syringe for injection (boil and sterilize before use). In order to effectively control the depth of the needle, the needle can be shortened to 0.2-0.3 cm with a file, or a rubber tube can be put on the base of the needle so that only 0.2-0.3 cm of the needle tip is exposed to prevent the needle from being inserted too deep and stabbing the internal organs. The best injection site is the back muscle, followed by the midline of the abdomen, and between the pectoral and pelvic fins.

The loach has a lot of mucus and is very slippery. In order not to damage the loach, it should be wrapped with wet gauze for injection. Needle insertion angle: The syringe is preferably 30 degrees to the loach body. 0.1 grams of cocaine can be dissolved in 50 kilograms of water to prepare an anesthetic solution. The parent loach for induced labor is anesthetized in the anesthetic solution in just 2-3 minutes. At this time, the injection is more convenient. Put it in the spawning pool and it will wake up soon.

After artificial induction of spawning, the parent loach is returned to the spawning pond. When the water temperature is 20℃, the parent loach will start to lay eggs and fertilize after about 18 hours; when the water temperature is 25℃, it will take about 12 hours; if the water temperature is 27℃, it will only take about 9 hours to lay eggs and fertilize. The subsequent operations are the same as the semi-natural breeding method.

Completely artificial breeding is a method of artificial egg collection and fertilization based on semi-artificial breeding.