The main breeding techniques of stingray
2 Selection and cultivation of broodstock Selection of stingray broodstock to grasp the "three elements": First, require more than 2 years of age; Second, female bred body weight of more than 60g, male and female body weight of 100g or more; Third, normal body color, both sides markings Bright, disease-free and injury-free. The selected broodstock was soaked in 3% salt solution for 10 minutes and put into a broodstock for cultivation. The broodstock can be fed with minced fish, oysters, and snails on the second day of the next day. The amount of broiler feeding is 2% to 3% of the broiler's body weight. In mid-April, flushing starts every 4 to 5 days for 2 to 3 hours. In early May, the gonads of yellow sturgeons tend to mature, and lightly press the abdomen of males. There is a thick milky white semen out of the reproductive hole, and the water immediately disperses. The abdomen of the female fish is obviously enlarged, soft and elastic, and artificial ovulation can be performed at this time.
3 artificial oxytocin and artificial insemination
3.1 artificial oxytocin artificial reproduction using an aphrodisiac hormone: carp pituitary (PG) + chorionic gonadotropin (HCG) + luteinizing hormone-releasing hormone analogue (LRH? A2) + domoxone (DOM), injection dose of PG5mg / Kg, HCG 800 IU/kg, LRH A A 25 μg/kg, DOM 50 mg/kg, females were injected 2 times, 1/10 of the total dose of the 1st injection, remaining dose of the 2nd injection. The males were injected once and injected with the females at the second injection. The dose was halved. The difference between the two injections was 8-12 hours. After the second shot, the broodstock was inserted into the spawning pool at a ratio of 1:1 male to female. , And in the spawning pond, hang a fish nest made of palm pieces or willow roots. The spawning pool keeps the flushing water to stimulate the broodstock. The water temperature is 20～24°C and the effect time is about 13～15h. When the broodstock produce complete eggs, The fish nest can be transferred to the hatchery hatch.
3.2 Artificial insemination When close to the effect time, when the broodstock is found to be estrus, the operator brings the yarn gloves to check the female broodstock and gently presses the abdomen. If the oocysts flow out smoothly, artificial insemination can be performed. Dry insemination is generally used. The method of operation is as follows: one person catches the female head upwards, the tail downwards, squeezes the granules into a clean basin, another person catches the male fish and squeezes the semen into the basin, and quickly stirs it evenly with a feather, and takes off. Stick artificial hatching.
4 artificial hatching first dehydration of fertilized eggs with yellow mud water, the specific method is: according to 200,000 to 300,000 fertilized eggs with yellow mud 4 ~ 5kg (yellow mud: water = 1:5), the yellow mud into the basin Inside, the yellow mud slurry is constantly stirred by hand, and the artificially fertilized eggs are gently poured into the yellow mud slurry. After approximately 5 to 6 minutes, the dehulled eggs are hatched in the hatching tank or the hatching ring. 1? The water body can be put into 400,000-600,000 eggs, the hatching pool wall should be kept smooth, the water quality is fresh, and the water flow rate can ensure that the fertilized egg can be uniformly turned. The dissolved oxygen requirement in the water is more than 5mg/L, and it is often Scrub filter screens, after 4 to 5 days of incubation can be stripped to form about 4mm larvae.
With PSA principles, ETR medical PSA Oxygen Generator can produce 93%±3% purity oxygen gas directly from compressed air. Compared with traditional Bulk liquid oxygen and cylinders oxygen, ETR on-site PSA oxygen generator can reduce cost down to 50 percentages. They can produce oxygen by your will, overcoming the limits of distance, location and transportation.
Compressed air is purified through the air dryer and filters to a certain level for main generator to work with. Air buffer is incorporated for smooth supply of compressed air thus to reduce fluctuation of compressed air source. The generator produces oxygen with PSA (pressure swing adsorption) technology, which is a time proven oxygen generation method. Oxygen of desired purity at 93%±3% is delivered to oxygen buffer tank for smooth supply of product gas. Oxygen in buffer tank is maintained at 4bar pressure.
Oxygen Generator
Oxygen Generator,Psa Oxygen Generator,Medical Oxygen Generator,Hospital Oxygen Generator
Hunan Eter Electronic Medical Project Stock Co., Ltd. , http://www.centralgas.be