When raising Monopterus albus artificially, animal feed should be the ma
When raising Monopterus albus artificially, animal feed should be the main feed, supplemented by plant feed, and compound feed with high protein content should be provided. Animal feed includes earthworms, pupae, maggots, snails, mussels, etc. Plant feed includes wheat flour, corn flour, bran, chaff and bean dregs. Note: Although plant feed can promote intestinal peristalsis of Monopterus albus and increase food intake, it can hardly digest plant protein and cellulose, so plant feed should not be too much.
1. What food does Monopterus albus eat by artificial feeding?
1. When feeding Monopterus albus artificially, it is necessary to provide it with compound feed with high protein content, usually the protein content should be between 35-45%, and it is also required to be palatable. The feed formula of Monopterus albus is: fish meal 28%, bean cake powder 10%, earthworm (dry) 20%, cooked soybean powder 30%, blood powder 2.5%, corn gluten 1.5%, monocalcium phosphate 3% and adhesive 5%.
2. Monopterus albus is a fish with animal feed, which requires fresh feed and does not eat rotten animal feed. Therefore, when raising Monopterus albus, animal feed should be given priority to, supplemented by plant feed. Animal feed mainly includes earthworm, silkworm chrysalis, fly maggot, snail, mussel, small fish and shrimp, and plant feed includes wheat flour, corn flour, bran, chaff and bean dregs.
3. Monopterus albus is usually forced to eat plant feed. It can effectively digest animal protein, starch and fat, but it can hardly digest plant protein and cellulose. However, a proper amount of plant feed rich in cellulose can promote intestinal peristalsis and improve the feeding intensity. Therefore, when feeding Monopterus albus, suitable plant feed can be provided selectively.
Second, artificial propagation technology of Monopterus albus
1, artificial insemination
(1) injection of oxytocin
① First, put the eels injected with oxytocin into an aquarium or cage for temporary cultivation. Note: the water in the tank should not be too deep, and the depth should be 20-30cm. Change the water 1 time every day, and the water temperature should be below 25℃.
② When the injection time has exceeded 50 hours, check the ovulation of eels once every 3 hours. After catching an eel, touch its abdomen with your hand and slide from front to back. If you feel that the egg has started to free or excrete, it means that the eel has started to ovulate and can be artificially inseminated immediately.
③ Usually, the ovulation time of the same batch of eels injected with oxytocin is different, so the check of ovulation can be extended to about 80 hours after oxytocin injection.
(2) Insemination
(1) First, take out the spawning eel, put a dry towel under the eel body with one hand and hold the front part, and squeeze the belly of the spawning eel with the other hand from front to back, and squeeze the eggs into the sterilized artificial insemination container. Note: Some species of eels have blocked reproductive pores. You can cut a 0.5- 1.0cm incision at the genital foramen with small scissors, then squeeze out the egg for 3-5 times continuously, or you can take out the whole ovary, which can reduce the blood volume.
(2) Immediately after the eggs are squeezed into the container, the male eel is killed, the testis is taken out, and the 1 small piece inside is put under a microscope for less than 400 times. If the sperm activity is normal, you can cut the testicles with scissors, put them into the extruded eggs and stir them with feathers, then add 200ml of stone man solution or 0.5-0.7% normal saline, let them stand for 5 minutes, and then add water to wash away the testicle fragments and blood stains.
③ The male-female ratio of artificial insemination depends on the quantity, which is generally (3-5): 1.
④ The formula of the stone man solution: sodium chloride 0.78g ++ sodium bicarbonate 0.0021g+potassium chloride 0.02g ++ calcium chloride 0.021g+distilled water 100ml.
2. Artificial incubation
(1) The specific gravity of fertilized eggs is larger than that of water, and they are not sticky. In the process of natural reproduction, fertilized eggs will attach to the foam-producing ovaries spit out by Monopterus albus and float on the water to hatch. In artificial incubation, it is necessary to choose a suitable incubator to prevent fertilized eggs from accumulating at the bottom of the water and dying of lack of oxygen.
(2) Incubators need to be selected according to the number of eggs and local conditions. If the number of eggs is small, you can choose incubators such as glass jars, porcelain jars, aquariums and small cages. Note: the water should not be too deep, generally controlled at around 10cm.
(3) When incubating in still water, water should be changed frequently, and batch production should be carried out by using incubators such as incubation barrels, incubation rings and incubation tanks.
(4) It is suggested that the running water method be used for artificial incubation. Running water method can increase the flow of dissolved oxygen in water, make water enter from the bottom of the incubator, and then overflow from the top, so that fertilized eggs can keep rolling and not sink to the bottom, and avoid hypoxia death.
3. Incubation management
(1) water quality management
① Incubation water is generally filtered by sand or wire mesh to filter out harmful organisms or large plankton.
② Because of the low success rate of artificial insemination of Monopterus albus, it is difficult to tell whether it has been fertilized successfully, and unfertilized eggs are easy to disintegrate during incubation, which leads to the deterioration of water quality. Therefore, it is necessary to replace the sewage or keep the fluidity of the water in time during the incubation process to ensure that the water quality of the incubation is in good condition.
(2) Water temperature management
① The water temperature is 25-30℃, which is suitable for the incubation of Monopterus albus. When the water temperature is kept at 25-28℃, the fertilized eggs can hatch into larvae of Monopterus albus within 5-7 days, and all of them hatch after 65,438+00 days.
② Note: During incubation, the water temperature should be kept relatively stable. When the water temperature rises or falls sharply (3-5℃ away from the appropriate temperature), it will lead to abnormal embryo development and even death, and the success rate of hatching will decrease.