Fish fry culture

The hatched fry are slender and tender, with a body length of only 3~ 4 mm. If cultured in a pond, the survival rate is extremely low, or even all of them die. In order to improve the survival rate, fry are generally cultivated in an incubator with flowing water. The hatching tank with water capacity of 350~ 400 kg can hold 500 fry just five days after hatching, and the water flow speed is lower than that during hatching. Fry are highly selective about food. Megalobrama amblycephala or other fry just emerging from the film are generally used as open bait for feeding (whether the first fry can be eaten is the key to successful breeding). At the beginning of feeding, only 1 ~ 2 fry were swallowed every day, and then gradually increased to 5~ 6 fry every day. After feeding for 5~ 7 days, the fry can grow to the size of "watermelon seeds" and melanin appears on the body surface. 1.4-day-old Xenopus laevis fry can eat 1.5 ~ 20 fry every day. When raised in the incubator, it was found that the larvae of Aquilaria sinensis would devour each other without other fry to eat. Therefore, it is necessary to feed enough palatable "bait fish" during this period.

Fish breeding

Pond conditions The pond for raising mandarin fish requires sandy bottom, less silt, an area of 2-3 mu, a water depth of more than 1.5m, convenient drainage and irrigation, light water quality, no turbidity, no sewage inflow and a few submerged aquatic plants. Newly opened ponds depend on the soil quality, and acidic ponds and muddy ponds are not suitable for raising mandarin fish. Culture mandarin fish

Australian Chinese fish

2. Pond preparation and feed fish cultivation:

(1) Clean the pond with quicklime on April 5th, pile grass fertilizer around April 10 in the four corners of the pond (if the bottom fertilizer is good, no fertilization is needed), and add 0.8 ~ 1.0m of fresh water to cultivate water quality and cultivate natural bait for feed fish.

(2) Feed fish is generally crucian carp fry. Around April 15, the fish nest (floating handle) containing crucian carp eggs is put into the pond for hatching, and the fry density is generally controlled at about 500,000 per mu. Fish eggs can be released in 2 ~ 3 batches, with one day interval between each batch, such as 1-3-5. In this way, it can be taken into account that all the Siniperca chuatsi fry with irregular specifications have palatable bait.

⑶ Make the specifications of feed fish by controlling the feed quantity. Generally, the standard for stocking Siniperca chuatsi fry is about 2 cm, and the standard for feeding fish can be controlled at about 1.2 cm.

3. Stocking and cultivation of Siniperca chuatsi fry;

(1) Add 10 cm of water the day before the Siniperca chuatsi fry is released (1/3 can be replaced if the water quality is strong).

⑵ The stocking density of Siniperca chuatsi fry is about 4000/mu.

⑶ Check the density of feed fish in the pond and replenish palatable feed fish in time.

(4) Pay attention to the water quality changes and weather conditions, and change the water in time if the water quality is poor.

(5) Disease control: Trichinella spiralis, rotifers and other ciliates are dominant, and the incidence of giant salamander is low. See adult fish culture for prevention and control methods.

Adult fish culture

Fish pond conditions

The pond for adult mandarin fish culture requires sandy bottom, less silt (about 1.5cm), an area of 3-8 mu, a water depth of more than 1.5m, convenient drainage and irrigation, good water quality, no sewage inflow and few submerged plants. A shallow ditch with a depth of 30 ~ 40 cm should be dug around the pond to facilitate mandarin fish fishing.

pond culture

(1) Clean the pond with quicklime for disinfection 10 ~ 12 days before feeding the fish.

(2) Cultivation of natural bait: 7 days before feeding fry (bream, silver carp, crucian carp, etc.). ), add water to 60 cm, put decomposed fertilizer about 150 kg per mu of water surface (no base fertilizer is needed), and cultivate zooplankton such as rotifers and cladocera.

(3) feed fish cultivation:

① Species and stocking density of feed fish: generally, feed fish are silver carp, crucian carp and shad. The stocking amount per mu is about 300,000.

(2) The day before feeding the feed fry, add 10 cm clear water to make the water fresh and rich in natural bait. It is not necessary to feed the fry immediately after they are put in, but it is necessary to observe the density, physique, growth rate and the number of red worms in the water every day. When the number of red worms decreases and the fry feed around the pond, they should immediately "water the beach" with thick slurry, check the situation of each feeding point several times a day and eat feed in the early stage.

Australian Chinese fish

It is necessary to control the specifications of feed fish in the later stage. Generally, 8 ~ 10 cm mandarin fish species should be stocked, and the size of feed fish should be controlled at about 3 ~ 4 cm.

③ Some old loaches can also be put into feed fish culture, and the cultivated small loaches can be used as high-quality bait for mandarin fish.

④ The ratio of mandarin fish culture area to feed fish pond area is generally 1: 3 ~ 4. Mandarin fish farm

Fish stocking

(1) Before stocking mandarin fish, drain half of the pond water, then inject fresh water to make the pond water slightly thin, and then gradually increase the water depth to more than1.5m. ..

⑵ Stocking density: about 800 heads per mu.

Feeding and management

(1) Feed feeding:

① Feed fish can be shad, silver carp, crucian carp and grass carp.

② Feeding techniques:

A, regularly (every 3-5 days is 1 period).

B, judging the number of feed fish in the pond:

When there are enough feed fish in the pond, mandarin fish will chase the bait fish at the bottom of the water, so there are only some small splashes on the surface of the pond. Listen carefully, fish will make a small underwater sound when chasing feed fish, and the interval is long. If there is not enough feed fish in the pond, mandarin fish will catch up with the food.

Australian Chinese fish

The fish is expected to reach the upper water, so the splash is big and the sound is frequent and loud. If you see mandarin fish chasing feed fish in groups by the pond, it means that the feed fish in the pond are basically eaten up.

C, palatability of feed fish:

Generally speaking, the size of feed fish with good palatability is about 65438 0/3 of the length of mandarin fish. If the size of feed fish is uneven, it is necessary to screen out the large feed fish with a fishing net.

(2) Water quality management:

(1) The water quality of the fish pond keeps the standard of "fat, live and cool" all the year round, and the transparency of the pond water keeps about 30cm. Fresh water should be replenished frequently, especially during the high temperature period from June to September, once every 5 ~ 7 days, and each time 15 ~ 20cm. If the drug is used many times, it is necessary to change the water to prevent drug damage.

② When the weather is abnormal, water should be replenished immediately to keep the water level in the fish pond relatively stable and provide good environmental conditions for the growth of Siniperca chuatsi. If the pool water is turbid, you can water it with 1 kg alum or 5 ~ 7.5 kg quicklime per mu, and then sprinkle the pool water.

(3) Install an aerator to prevent mandarin fish from floating head due to lack of oxygen. Generally, it will be opened at noon in sunny or partly cloudy weather, and it will be opened from midnight to early morning in case of sultry weather.

(4) Prepare some hydrogen peroxide (above 30%) or hydrogen peroxide, which can be used for rescue when mandarin fish float. How to use hydrogen peroxide: use molecular oxygen per mu.