Industrial cultivation of Pelteobagrus fulvidraco larvae by artificial incubation of Artemia

1. The large ridge double row planting method transplants seedlings in the order of 6 inches, 12 inches and 6 inches. Its advantages are as follows: first, the total number of holes per mu (16000 holes) is slightly less than that of monoculture rice, but the yield is increased by ventilation, light transmission and other conditions. The second is to provide more than 7 hours of light every day, increase the water temperature, plankton reproduce and grow rapidly, and create good conditions for providing natural bait organisms for Pelteobagrus fulvidraco. The third is to broaden the activity space of Pelteobagrus fulvidraco, which can kill insects in a large area, fertilize fish manure and increase rice production.

two。 Rice management Rice cultivation management is strictly operated in accordance with "NY/T5117-2002 pollution-free Food" and rice production technical regulations. First, fertilizing reasonably and timely, transplanting seedlings formally on May 18, applying urea 2.5kg/ mu and diammonium 5.0kg/ mu one day before transplanting, urea 3.0kg/ mu after 3 days of transplanting, and applying urea every 7 days. The first dosage is 4.0kg/ mu, the second is 6.0kg/ mu, and the third is 8.0kg/ mu. The second is the rational use of biotechnology and the use of photosynthetic bacteria in the process of rice cultivation. Rice seeds were soaked with 20% water volume of photosynthetic bacteria solution for 7 days; rice seedlings were sprayed with 50g/ square meters of photosynthetic bacteria (seedling bed); rice seedlings were sprayed with 5g/ square meters of photosynthetic bacteria when growing to two leaves and one core; 10g/ square meters of photosynthetic bacteria were sprayed once 2 days before transplanting, and 1000g/ mu of photosynthetic bacteria were sprayed at tillering stage, jointing stage (early July) and booting stage (mid-August).

VII. Harvest

The harvest began at the beginning of October, covering a total area of 65 hectares, with a total harvest of rice 526500kg with a value of 947700 yuan, cost of 429000 yuan and profit of 518700 yuan, while the total yield of Pelteobagrus fulvidraco 21450kg, output value of 858000 yuan, cost of 305000 yuan and profit of 553000 yuan. The comprehensive benefit of rice and fish is 1102 yuan / mu, which is 524 yuan / mu higher than that of monoculture rice.

The average cultivation specification of Pelteobagrus fulvidraco is 110g/ tail, of which: 50g/ tail ~ 74g/ tail accounts for 5% ~ 99g/ tail accounts for 25% ~ 149g/ tail accounts for 55% 150g / tail ~ 149g/ tail accounts for 55% 150g / tail and above 15%. The rice panicles planted in the ecological culture model of yellow catfish are much larger than those of monoculture rice, and the processed rice fully meets the pollution-free food standards.

VIII. Existing problems

1. The size of Pelteobagrus fulvidraco fry is too small, only 6g/ tail, which directly affects the culture yield.

two。 The phenomenon of insufficient feed feeding exists in some farming fields, and the culture specification is only 50g/ tail ~ 60g/ tail.

3. The setting of influent protection net is unreasonable, because the mesh is too large, wild miscellaneous fish enter the field to compete with Pelteobagrus fulvidraco for food, which leads to the slow growth of Pelteobagrus fulvidraco due to lack of food.

IX. Summary

1. Rice field engineering is the foundation, the larger the water body, the greater the biological capacity, the better the water environment, the more stable the yield.

two。 According to the principles of ecology and biology, the ecological culture model of yellow croaker in rice field was established and popularized to form a good ecosystem with food chain connection, rice protecting fish, fish eating insects and fish manure to increase soil fertility.

3. The use of photosynthetic bacteria in culture can not only purify water quality, reduce pollution, but also prevent diseases, produce pollution-free rice and Pelteobagrus fulvidraco, and achieve the win-win goal of rice and fish.

The key period of Pelteobagrus fulvidraco seedling cultivation is from splash to black larvae, and the selection of opening bait has always been a technical difficulty in Pelteobagrus fulvidraco seedling culture. In order to explore the technology of large-scale and industrial production of Pelteobagrus fulvidraco larvae, we used artificial hatching Artemia to cultivate Pelteobagrus fulvidraco larvae in recent years. A total of 2.64 million Pelteobagrus fulvidraco larvae were cultivated in 2 years, with an average survival rate of 61.6%.

I. preparation of nursery ponds

There are 17 indoor cement ponds, rectangular, 2m × 6m, 1.2m deep and 1.0m deep. The shower type water injection pipe is at one end, and the outlet at the other end is closed with a frame-type fish fence made of 60 mesh sieve silk. Three days before seedling release, the water was filled with water and disinfected with 1ppm concentration of strong chlorine.

2. Stocking of Pelteobagrus fulvidraco spray

The water spray of Pelteobagrus fulvidraco was bred by the local seedling breeding farm. In the first year, there were 12 batches of 192.5 spray, and in the second year, there were 15 batches of 2.36 million spray. The spray stocking density was 3500 / m2 ~ 7000 / m2.

III. Cultivation of Artemia

Artemia eggs canned, specifications for 425g/ cans. Pelteobagrus fulvidraco began to hatch Artemia 24 hours before falling into the pond. Fill plastic buckets with 100kg capacity with 2kg~3kg salt, put 212g Artemia eggs in each bucket, keep the water temperature at (26 ±1) ℃ in a constant temperature running pool, and aerate with air pump with at least 2 air stones in each bucket. According to the number of Pelteobagrus fulvidraco, Artemia was cultivated in several batches to ensure the supply of food organisms.

IV. Feeding of Artemia

Artemia usually hatch for 24 hours. After 30 hours, the body color of the newly hatched Artemia is relatively light, and the Artemia can be observed by the naked eye in the beaker sun. Pelteobagrus fulvidraco can be fed three times a day after the spray goes into the pond. The initial daily feeding amount of every 10 thousand fish is 15g~20g Artemia hatched by Artemia eggs. 30 minutes after feeding Artemia, the feeding condition of Pelteobagrus fulvidraco fry was observed. the round bulge in the abdomen of the full fry was orange-red, and the food intake increased with the growth of the fry. It is required to observe the satiety degree of Pelteobagrus fulvidraco and increase or decrease the feeding amount in time. After feeding, most fry sink to the bottom of the water or stick to the pond wall to prove that the fry is full. If there are still most fry swimming on the water and the abdomen empty after 30 minutes of feeding. It shows that if the feeding amount is insufficient, the feeding amount should be increased. After 5 days of water spray cultivation, we can properly feed the Cladocera and other zooplankton harvested from the pond to supplement the deficiency of Artemia.

V. aquaculture management

1. Control the water flow of the pond, especially when feeding Artemia, reduce the amount of water flow, prevent Artemia from flowing out of the fish pond, generally feed for 30 minutes and then return to the normal amount of water injection.

two。 Remove the Artemia eggshell in the pond water in time to prevent it from being eaten by Pelteobagrus fulvidraco fry.

3. Brush the fish-trapping grid every 2 to 3 hours to maintain water permeability.

4. It is required that the water temperature should be kept at about 25 ℃, and the dissolved oxygen and water temperature should be measured every morning and evening to make a good culture record.

5. As for disease control, 35PPm formaldehyde can be sprinkled in the whole pool every 3 days, and sterilization drugs can be sprinkled in the whole pool every 2 days.

6. Net-pulling exercise and @ # @ 136 exercise

When the body of the yellow croaker reaches 2.0cm~2.5cm, it can be sold out of the pool, and the net exercise is done once or twice one day before sale, while the feeding amount of bait organisms is reduced by 50%.

7. Test results

In the first year, 12 batches of Wuzi were produced, 1.92 million water spray were put into production, 1.03 million Wuzai were produced, and the survival rate of cultivation was 53%. The consumption of 39.1kg Artemia eggs, the average production of 10,000 Artemia eggs consumed 380g of Artemia eggs, and the biological cost of food was 58 yuan per 10,000 eggs. In the second year, 15 batches of Wuzai were cultivated, 2.366 million spray were put into production, 1.61 million Wuzai were produced, and the survival rate of cultivation was 68%. A total of 65.87kg was fed with Artemia eggs, and the production of 10,000 Artemia eggs consumed 409g of Artemia eggs, and the biological cost of food was 63 yuan per 10,000 eggs.

VIII. Analysis and discussion

1. The industrial cultivation of Pelteobagrus fulvidraco larvae by artificial incubation of Artemia in northern China can improve the survival rate of Pelteobagrus fulvidraco from spray to larvae, produce all-weather without the influence of weather, temperature and other environmental conditions, and is conducive to centralized sales and convenient users.

two。 The suitable stocking density of Pelteobagrus fulvidraco spray is 3500 / m2 ~ 5000 / m2. If the stocking density is too low and waste water, if the stocking density is too high, it is easy to cause anoxic floating head of fish fry, and the growth specifications of black fry are quite different, and the survival rate of cultivation is reduced. In the experiment, the survival rate of cultivation was only 61%. The main reason for the low survival rate was that the quality of water spray of yellow croaker was not high, the proportion of abnormal seedlings was large (10%-15%), and died due to the difficulty of ingestion of organs under the pond.

3. The cultivated Artemia should be fed within 24 ~ 36 hours, not too early or too late, which can ensure the maximum hatching rate and survival rate of Artemia, and it is also suitable for the caliber of Pelteobagrus fulvidraco. When it is fed, it can be poured into the pond together with the cultivated salt water, which can improve the water quality, prevent diseases and exterminate diseases.

4. There was no serious disease in the process of breeding Pelteobagrus fulvidraco. The oblique tube disease caused by feeding zooplankton fished from the pond can be extinguished in time by sprinkling the mixture of copper sulfate and ferrous sulfate, or the mixture of potassium permanganate, copper sulfate and ferrous sulfate is used to disinfect the zooplankton for 10 minutes before feeding, which can basically put an end to the occurrence of oblique tube disease.

5. The feed cost of cultivating Pelteobagrus fulvidraco larvae by artificially hatching Artemia is not high, which is only about 60 yuan per 10,000 fish, accounting for less than 10% of the total cost of cultivating Pelteobagrus fulvidraco. Most of the costs are determined by the costs of breeding Pelteobagrus fulvidraco, such as water spray, water and electricity, labor, etc., while the sales price of Pelteobagrus fulvidraco larvae is generally 150 / 10 000 ~ 1700 yuan / 10 000. It can be confirmed that using Artemia to cultivate Pelteobagrus fulvidraco larvae is technically feasible. The benefits are also very considerable.