Method for cultivating eel
(1) The indoor water depth of water quality management is maintained at 5~8 cm, the outdoor water depth is maintained at about 10 cm, and it can reach 15~20 cm in high temperature season. Because of the shallow water level, the eel excretes a lot, and the water quality is very easy to deteriorate. Therefore, changing water more is the key to still water soilless culture. Generally, changing water once every 3-4 days in summer and once every 7 days in spring and autumn should be thorough. Production practice shows that changing water thoroughly is beneficial to pest control and does not affect the growth and development of eels.
② It takes 7~ 10 days or even longer to domesticate eels to eat compound feed (the feed is soft and wet, or twisted into strips with a meat grinder). What should I do after normal feeding? Timing, quantification, fixed point? By observing the feeding situation of eel, corresponding management measures are taken.
③ Prevention is the main way to control pests and diseases. The main pests and diseases of still water soilless culture are capillary nematodiasis, enteritis, bacterial tail rot, printing disease and red skin disease. After being domesticated and eaten successfully, drugs (such as trichlorfon and pesticides) should be mixed into the bait for killing. The prevention and treatment of other diseases is just like farming with soil.
Relatively speaking, it is easier to stay indoors in summer. Outdoor culture-shading must be considered, and measures such as deepening the water level and regulating the temperature with groundwater should be taken when the temperature is high.
⑤ Overwintering is generally carried out in soil culture ponds, which can be divided into two types: overwintering with water and overwintering without water. The overwintering depth with water is about 20 cm, but grass, branches and other things should be put to prevent the pool water from freezing. Overwintering without water means draining water before eels hibernate, keeping the mud layer moist, and covering it with insulation materials such as straw to safely overwinter. Where conditions permit, the indoor temperature should be kept above 15 degrees Celsius in winter, so that eels can still grow in winter, and commercial eels can be sold around the Spring Festival, which will bring more ideal economic benefits.
Common diseases of eel
black spot
At the early stage of the disease, light black spots appeared on the tail of the sick eel, and the hands felt strange and the eyes oozed blood. Treatment: spraying 0.5~0.75 mg/L of microbial enemy water on the whole pond; Take Huohuqing orally, 2 grams of feed per kilogram or 5 kilograms of fresh bait, mix well and feed for 2 days.
hemorrhagic disease
There are bleeding spots of different sizes on the body surface, especially in the abdomen. Hang the tail of the sick eel upside down, and the liquid similar to blood flows out of the mouth of the eel. The anus is swollen and everted. Treatment: ① Soak sick eel 15~20 minutes with 300 mg/L Yufeng iodine; ② Each kilogram of Monopterus albus was fed with 0.2g of fish blood Kangning, and 0.2g of blood Ningning was added to the severe cases, and mixed feeding was carried out for 5-7 days.
enteritis
Symptoms are manifested in three aspects: ① red and swollen anus; (2) Gill bleeding, lifting the tail of the sick eel, blood can be seen flowing out of the mouth; (2) The head is out of the water to breathe, the head is black, and erythema appears in the abdomen. Anatomy of the diseased eel shows that there is no food in the intestine, and there is congestion in the abdominal cavity 2~5 cm long before the anus. Treatment method: choose a disinfectant and spray it all over the body according to the water quality. At the same time, use fish Taikang 1 g per kilogram of eel species and feed it with mixed bait, once a day, i~gN4~5 days.
Rotten tail disease
After the onset of Monopterus albus, the tail was congested and inflamed, and the color turned white. In severe cases, the tail muscles are necrotic or ulcerated, and the tail spines are exposed. Treatment method: ① Eel species should be thoroughly disinfected. (2) Sprinkle Di Jun or Yufeng iodine in the whole pool for 3 consecutive days.
Living habits of eels
Monopterus albus is a tropical and warm temperate fish. It is a benthic fish with strong adaptability and can survive in rivers, lakes, ditches and rice fields.
During the day, I like to dig holes in humus mud or in the cracks with water on the embankment.
Little activity during the day, foraging at night. Gills are underdeveloped, but they can breathe air directly with the help of the epidermis on the inner wall of oral cavity and laryngeal cavity as an auxiliary organ for breathing; It can survive with little oxygen in water. After coming out of the water, as long as you keep your skin moist, you won't die in a few days.
Monopterus albus is an omnivorous fish, which feeds on various small animals. It is greedy and eats most vigorously in summer. Long-term consumption in cold season will not kill you.
Monopterus albus generally lives in spring, summer and autumn. I like living in ponds, rivers, mud pits and cracks on the banks of rice fields. Live in the depths of caves and hibernate in winter.
In spring, after a winter's lurking, eel consumes too much energy and needs to eat a lot, so spring is a good time to fish eel.
It's hot in summer, and Monopterus albus have come out of their holes and got into water plants, crevices and dead trees? Enjoy the cool? Fishing is also easy.
Monopterus albus begins to enter the hole in autumn, and it is not easy to take the bait.
The breeding situation of Monopterus albus is quite special. It was a female when it was young, and then it became a male after a reproduction. This phenomenon of female-male transition is called gender inversion. The breeding season is May-August, and it has the characteristics of male and female inversion in its individual development, that is, from the embryonic stage to the first sexual maturity, it is female (that is, the gonads of individuals less than 35 cm in length are all ovaries); After laying eggs, the ovary gradually becomes the testis; When the body length is 36~48 cm, it is partially inverted, and the male and female individuals are almost equal, belonging to hermaphroditism; Most of them grow to more than 53 cm for testicles. When the young fish can only grow to 20 cm, the 2-winter-old female fish will reach maturity and have a body length of at least 34 cm. The largest individual can reach 70 cm and weigh 1.5 kg. In May of 20 13, Huzhou caught an eel weighing 36kg and being1.5m long. Monopterus albus lays eggs near the cave where it lives. Before laying eggs, it will spit out foam to build a nest. The fertilized egg develops on the water surface with the help of the buoyancy of foam. Both male and female fish have the habit of protecting nests.
Eel's body is cylindrical, suitable for cave life, which is very beneficial for entering and leaving caves and reducing friction. Is it really a little? Hermit? Patience, no special attack skills, no powerful defensive weapons, the only skill is? Thirty-six plans, escape is the best policy? . It has neither pectoral fins nor ventral fins, and even the dorsal fins and anal fins have degenerated to only a little skin folds, and the scales have disappeared to the naked eye, but the whole body can secrete very oily mucus, which can slip away from your hands if you are not careful. The main functions of eel mucus are: preventing bacteria and germs from infecting the body and reducing diseases; Prevent parasitic animals and plants from winding, which is beneficial to growth; A smooth surface helps it move smoothly in the mud. Like loach, but bigger and longer than loach.
Eel embryos are female at the first sexual maturity, but they become male at the second sexual maturity. In other words, Monopterus albus is both a mother and a father in his life. This process of yin-yang transformation is biologically called sex reversal. Most fish breathe through gills, but eels are unique. Its gills degenerate, and air is directly absorbed by tiny blood vessels on the surface of the throat. Therefore, in order to make eels fresh, we must keep them moist and store them in a cool place. I like digging holes, so many holes along the river are made by eels.
ecological environment