Artificial Propagation technique of raising Loach in Taiwan

A. the method of natural reproduction of Loach in Taiwan. After the beginning of spring, the fish pond is repaired, disinfected with quicklime and injected with new water. after the medicine of the pond water disappears, the parent fish are put into the pond at the ratio of 1:2, about 300g per square meter. When the temperature of the pool water rises to about 20 ℃, fish nests made of brown flakes, willow fibrous roots or aquatic plants should be placed in the pond. The dirt and dirt on the nest should be checked and cleaned frequently after placing the fish nest, so as not to affect the adhesion of eggs when Taiwan Loach lays eggs. Taiwan Loach likes to lay eggs in thunderstorm or when the water temperature rises suddenly. Spawning usually begins in the early morning and ends at about 10:00 in the morning. The spawning process takes 20-30 minutes. During spawning, the parent fish chased fiercely, and at the peak, the male Loach wrapped his body around the anterior abdomen of the female to complete the process of spawning and fertilization. After spawning, the nests with eggs should be taken out and hatched in another pond in time to prevent parent fish from swallowing the eggs. At the same time, new nests are added to allow non-spawning parent fish to continue to spawn. The spawning pond should prevent snakes, frogs and rats from harming parent fish.

B. the method of artificial propagation of Loach in Taiwan. The artificial reproduction of Loach in Taiwan is the same as that of domestic fish. The types and doses of oxytocin used were calculated according to each female Loach, which were as follows: 1 pituitary gland of carp, 2 pituitary glands of frogs, 100 international units of chorionic gonadotropin, or 5 μ g of analogue (LRH-A). The dose of male Loach was halved. The volume of solvent injection was 0.1ml to 0.2ml, which was injected with 1 ml syringe and No. 4 needle. The injection site is between the thoracic and ventral fins of the midline of the abdomen, and can also be injected into the dorsal muscle. Because Taiwan Loach likes to drill, it can be wrapped with warm gauze during injection (exposing the injection site). After injection, it is put into the spawning pool, and the work is the same as natural reproduction. The water temperature is 20-25 ℃. After 10-20 hours, it will be in estrus and spawn. If artificial insemination is adopted, the male and female Misgurnus anguillicaudatus who have been injected with oxytocin can be temporarily reared in a small pond or net cage respectively. When the water temperature is 18-25 ℃, after 10-15 hours, eggs flow out from the abdomen of the female Loach, and the dry method can be used for artificial insemination. The operation method and matters needing attention are the same as those of domestic fish. The egg goes to the nest immediately after artificial insemination. The method is to take a bucket of water and lay the bottom of the nest, then one person gently shakes the nest and stirs the water at the same time, and the other slowly pours the eggs into the bucket to make the eggs go to the nest evenly. After going to the nest, it is transferred to the incubator to hatch. The fertilized eggs of Misgurnus anguillicaudatus can hatch normally in the range of water temperature of 20-30 ℃, and fish fry can be hatched in about 2 days. Use small containers of still water and change water frequently (twice a day) to hatch well. It is suitable to lay 400 eggs and 600 eggs per liter of water. Concussion should be avoided during hatching. 0.1 × 10-6 malachite green solution can be used for disinfection to prevent parasitic water mildew. The newly hatched loach seedlings can not move freely, attach their heads to fish nests or other objects, and take yolk as nutrition. The hatched fry in the pond are generally kept in the original pond, with a water depth of 20cm to 30cm and a density of 500-1500 fry per square meter. when it is too dense, some of the fry should be taken out and cultured in another pond. Loach seedlings hatched for 3 days and began to feed. At this time, you should feed boiled and ground egg yolk or fish meal suspension several times a day, and the feeding amount should be limited to eating within 1 hour. Switch to water fleas, rotifers, mashed silk earthworms or silkworm pupae after 2 or 3 days. After about 10 days of cultivation. After about 1 month, when the fry grows to about 3 cm, it can be transferred to the fish pond, or it can be directly put into the rice field, pond or pit to raise adult fish. The area of fish pond should be 30-50 square meters. Before sowing, the pond should be cleaned and disinfected, and base fertilizer should be applied to cultivate bait organisms. The amount of seed is about 30 grams per square meter (800-1000). The fish species were fed with plant feed twice a day in the second half of the month, with an amount of 3% or 5% of the fish body weight. The shallow water temperature of fish ponds is high in summer, so we should pay attention to the change of water quality at any time and change new water frequently. When the fish species grow to 8cm to 10cm, they enter the stage of adult fish breeding.