Because of the small body of water, high stocking density, high temperature, and rapid water pollution, industrialized rearing crickets lack the conditions of self-defense and protection in the natural environment, and are prone to disease and other injuries, resulting in losses. Through experiments, we have found that culturing plankton in Dianchi Lake can control the water quality and form an aquaculture environment where cocoon and plankton coexist and benefit each other. Not only does cockroach grow fast and has a high survival rate, but also it can significantly reduce costs and increase production and obtain stable economic benefits. . The results of the study are reported below:
First, experimental materials and methods (a) experimental pool and feeding management
1. Experimental conditions The experimental point is two industrialized breeding ponds at the Aquatic Technology Promotion Station in Changsha (25m2/port). The size, shape, structure, experimental conditions and management methods of the two pools are the same. They are smooth cement structures. The bottom of the pool and the walls are all insulated. During the experiment, the boilers supply heat, and the water temperature is maintained at 30°C (±0.8°C) for a long time; 31°C (±0.5°C). The deepest pool water is 0.8M, and 2/3 of the pool floor is covered with 10CM thick sand. Water is pumped from the pond into the preheating pool and then warmed into the dike pond. Drainage is naturally discharged at the bottom of the pool. The greenhouse is completely closed. Every day, exhaust fans are vented outdoors using air exhaust fans and inflated with water pumps. Because there is no natural light, two 250w far-infrared lamps are used for lighting such as feeding and sewage disposal.
2. Restocking and Management Two pool points experiment pool (No. 2 pool) and control pond (No. 1 pond) were placed on the same day at about 5 grams on November 7, 1996, including 604 No. 2 ponds and 712 No. 1 ponds. The No. 2 pool adopts phytoplankton which takes cryptophyte as the main body to control the water quality of the Dianchi Lake. Generally, it does not change the water, but only inflates. In the rearing period, depending on the situation of the sewage, 7 to 10 days, a small amount of water is discharged from the bottom valve, but each time the displacement is Do not exceed 1/4 of the total amount of pool water, strictly control the PH value and water temperature of the pool water, and try to maintain stable environmental conditions for the growth of cryptophytes in the pool water. L No. 1 pool is under normal factory aquaculture management. At least two cuts of water are taken at the end of each week and the water is often cleaned. The other two ponds had the same management of other feeding quails. They were fed twice a day, and they were fed with domestically prepared larvae and fed with vitamin supplements and disease-prevention drugs on a regular basis. Every day, a person manually checks gas, water temperature, and other observation data, and removes bait and residual bait, and finds that there are abnormalities and timely treatment to ensure the normal growth of hernia.
(II) Observation methods
1. Plankton qualitative and quantitative observations from January 1996 to the end of May 1997 were taken at regular intervals from the 1st and 2nd pool water samples respectively to detect the type, amount, and change of plankton, specific detection and conversion methods according to "Terrestrial Fisheries Natural Resources Survey Trial Practice". In order to obtain data on the day-night changes of plankton in a fully-sealed greenhouse, a 48-hour continuous pool bottom and surface sampling test was conducted in January.
2. The determination of the water chemistry index was used to measure the transparency, dissolved oxygen, oxygen consumption of organic matter, and ammonia nitrogen content of the pool water samples at the same time as the plankton sampling and detection. The collection and testing methods were all tested on the spot according to the “Freshwater Aquaculture Chemistry†method. 3. The number of bacterial cultures in Dianchi Lake was measured on the stability of the water quality of L-1 and L2 pools and the growth of Cockroach were stable (at least one week without application and replacement of water). The constant temperature incubator at °C measured the number of bacteria and mold in 24 hours and 48 hours. And compared with outdoor ponds.
Second, the experimental results
(1) The growth rate and yield of earthworms were randomly sampled at the I and No. 2 pools every 15 days from the young fisherman's lower pool and weighed (Table 1:1 pond and No. 2 pool pond weight gain test table). On May 5th, 1997, an expert from Changsha Science and Technology Commission organized the acceptance of the No. 1 and No. 2 pools. After six months of cultivation, the Ganchi test results showed that there were 572 ponds out of No. 2 pool with a net weight of 123.3 kg. Weight 212g, the output per square meter 4.85kg; No. 1 pond 672, net weight 93.8kg, average weight 1398 per square meter, yield 3.75k8 per square meter. No. 2 she was 29.3% higher than the output of the No. 1 pond, individual growth 52% faster. Net income of 250 yuan per square meter, significant economic benefits.
(B) Plankton observations Although the waters in the No. 1 and No. 2 ponds are the same pond water source, the water temperature and the air temperature are completely the same. From the observations of regular sampling and continuous sampling observations, there are still differences in plankton changes between No. 2 and No. 1 ponds. 2 The phytoplankton species in the pool water are dominated by Cryptophyta. In the stable water pools in January and February, the predominance of Cryptophyta is more obvious and stable, while the No. 1 pond water has more phytoplankton species, and there is no dominant population formation. The main species are green algae, which is more consistent with the phytoplankton species in the outdoor pond water during the same period (Table 2: Comparison of species and amounts of phytoplankton in No. 2 and No. 2 pools).
(III) Results of chemical test on water The results of the chemical tests on pools l and 2 indicate that although pool 2 consumed 38.7% more feed than pond l, pool water was grayish-black for a long time and rarely changed water, but number 2 The pool water is obviously better than the l-pool (Table 3:1 and 2 pool water-soluble oxygen, ammonia nitrogen content, monthly average oxygen consumption of organic matter). The total dissolved oxygen was 9.7% higher than that of No. 1 pond, while the organic oxygen demand and ammonia nitrogen content were 10.6% and 12.99% lower respectively.
First, experimental materials and methods (a) experimental pool and feeding management
1. Experimental conditions The experimental point is two industrialized breeding ponds at the Aquatic Technology Promotion Station in Changsha (25m2/port). The size, shape, structure, experimental conditions and management methods of the two pools are the same. They are smooth cement structures. The bottom of the pool and the walls are all insulated. During the experiment, the boilers supply heat, and the water temperature is maintained at 30°C (±0.8°C) for a long time; 31°C (±0.5°C). The deepest pool water is 0.8M, and 2/3 of the pool floor is covered with 10CM thick sand. Water is pumped from the pond into the preheating pool and then warmed into the dike pond. Drainage is naturally discharged at the bottom of the pool. The greenhouse is completely closed. Every day, exhaust fans are vented outdoors using air exhaust fans and inflated with water pumps. Because there is no natural light, two 250w far-infrared lamps are used for lighting such as feeding and sewage disposal.
2. Restocking and Management Two pool points experiment pool (No. 2 pool) and control pond (No. 1 pond) were placed on the same day at about 5 grams on November 7, 1996, including 604 No. 2 ponds and 712 No. 1 ponds. The No. 2 pool adopts phytoplankton which takes cryptophyte as the main body to control the water quality of the Dianchi Lake. Generally, it does not change the water, but only inflates. In the rearing period, depending on the situation of the sewage, 7 to 10 days, a small amount of water is discharged from the bottom valve, but each time the displacement is Do not exceed 1/4 of the total amount of pool water, strictly control the PH value and water temperature of the pool water, and try to maintain stable environmental conditions for the growth of cryptophytes in the pool water. L No. 1 pool is under normal factory aquaculture management. At least two cuts of water are taken at the end of each week and the water is often cleaned. The other two ponds had the same management of other feeding quails. They were fed twice a day, and they were fed with domestically prepared larvae and fed with vitamin supplements and disease-prevention drugs on a regular basis. Every day, a person manually checks gas, water temperature, and other observation data, and removes bait and residual bait, and finds that there are abnormalities and timely treatment to ensure the normal growth of hernia.
(II) Observation methods
1. Plankton qualitative and quantitative observations from January 1996 to the end of May 1997 were taken at regular intervals from the 1st and 2nd pool water samples respectively to detect the type, amount, and change of plankton, specific detection and conversion methods according to "Terrestrial Fisheries Natural Resources Survey Trial Practice". In order to obtain data on the day-night changes of plankton in a fully-sealed greenhouse, a 48-hour continuous pool bottom and surface sampling test was conducted in January.
2. The determination of the water chemistry index was used to measure the transparency, dissolved oxygen, oxygen consumption of organic matter, and ammonia nitrogen content of the pool water samples at the same time as the plankton sampling and detection. The collection and testing methods were all tested on the spot according to the “Freshwater Aquaculture Chemistry†method. 3. The number of bacterial cultures in Dianchi Lake was measured on the stability of the water quality of L-1 and L2 pools and the growth of Cockroach were stable (at least one week without application and replacement of water). The constant temperature incubator at °C measured the number of bacteria and mold in 24 hours and 48 hours. And compared with outdoor ponds.
Second, the experimental results
(1) The growth rate and yield of earthworms were randomly sampled at the I and No. 2 pools every 15 days from the young fisherman's lower pool and weighed (Table 1:1 pond and No. 2 pool pond weight gain test table). On May 5th, 1997, an expert from Changsha Science and Technology Commission organized the acceptance of the No. 1 and No. 2 pools. After six months of cultivation, the Ganchi test results showed that there were 572 ponds out of No. 2 pool with a net weight of 123.3 kg. Weight 212g, the output per square meter 4.85kg; No. 1 pond 672, net weight 93.8kg, average weight 1398 per square meter, yield 3.75k8 per square meter. No. 2 she was 29.3% higher than the output of the No. 1 pond, individual growth 52% faster. Net income of 250 yuan per square meter, significant economic benefits.
(B) Plankton observations Although the waters in the No. 1 and No. 2 ponds are the same pond water source, the water temperature and the air temperature are completely the same. From the observations of regular sampling and continuous sampling observations, there are still differences in plankton changes between No. 2 and No. 1 ponds. 2 The phytoplankton species in the pool water are dominated by Cryptophyta. In the stable water pools in January and February, the predominance of Cryptophyta is more obvious and stable, while the No. 1 pond water has more phytoplankton species, and there is no dominant population formation. The main species are green algae, which is more consistent with the phytoplankton species in the outdoor pond water during the same period (Table 2: Comparison of species and amounts of phytoplankton in No. 2 and No. 2 pools).
(III) Results of chemical test on water The results of the chemical tests on pools l and 2 indicate that although pool 2 consumed 38.7% more feed than pond l, pool water was grayish-black for a long time and rarely changed water, but number 2 The pool water is obviously better than the l-pool (Table 3:1 and 2 pool water-soluble oxygen, ammonia nitrogen content, monthly average oxygen consumption of organic matter). The total dissolved oxygen was 9.7% higher than that of No. 1 pond, while the organic oxygen demand and ammonia nitrogen content were 10.6% and 12.99% lower respectively.