Culture technology of baby fish

Baby fish, commonly known as giant salamander, is a national second-class key protected wild animals. Chinese giant salamander except * *, Xizang, Inner Mongolia. Except for Heilongjiang, Jilin, Liaoning and Taiwan, it is distributed in other provinces and autonomous regions, mainly in the mountains and rivers of the Yangtze River, the Yellow River and the tributaries of the middle and upper reaches of the Pearl River, especially in Sichuan, Hubei, Hunan, Guizhou, Shaanxi and other provinces. Giant salamander likes yin and is afraid of light, and its growth rate is slow. it takes 5 to 6 years for it to mature in wild conditions, weighs more than 500 grams, and at least 3 years to meet commercial specifications under artificial conditions. Moreover, it is difficult for giant salamander to breed artificially. Therefore, aquaculture is not common and is limited to a few farms in Jiangsu, Hubei, Guangdong and other places. However, in recent years, the culture of baby fish has received extensive attention, and it is a potential species of famous, special and excellent culture.

Structure of aquaculture pond

According to the unique ecological habits of baby fish, the living habits and ecological environment suitable for the growth and development of baby fish should be considered in the design of culture ponds. There are two kinds of baby fish culture areas, one is open-air culture pond, the other is civil air defense engineering and basement culture pond. Its structure is brick, cement, stone and concrete. The specific structural requirements are:

1. Pool wall structure: the requirement for the wall of baby fish culture pond is: ① to cut off water so that it does not leak. ② is safe and firm, can withstand the pressure of the pool wall for four weeks and the pressure in the pool water, and the pool wall does not sink. ③ should have escape prevention facilities. ④ is cheap. Doll fish culture pond walls are generally made of square stones, bricks or concrete, cement seams, and the pool walls should be smooth or pasted with cement paste. The top of the pool wall should stick out 10 centimeters into him to prevent the baby fish from escaping.

2. Pool bottom structure: the doll pond bottom is generally compacted with stones, with a thickness of 20cm to 30cm, then filled with small stone slag, and finally paved with concrete. In order to facilitate drainage, the bottom of the pool is tilted from all around to the center, with an inclination of about 2%, and then from the center to the outlet at one corner, with an inclination of about 1% to 1.5%.

3. Water inlet: the position of the water inlet is based on the intake channel and opposite to the outlet is located at the corner of the pool. The water inlet should be higher than the pool wall, preferably 60 cm higher than the surface of the ground, and extend 20 cm into the pool. The water inlet material can be made of cement pipe or concrete, cast iron pipe and plastic pipe, no matter what material is used in the water inlet. Control facilities and filters must be installed. The control facility adopts a straight-through globe valve, and the size of the pipe diameter can be determined according to the amount of water needed at the mouth of all kinds of doll fish pond and the inlet pressure. The larval pool can be 100lu 300mm and the adult pool 300mm 500mm. The intake filter material should be made of stainless steel, and the same item should be determined according to the size of the doll fish pond.

The construction of breeding grounds

Baby fish adult culture pond is an important environmental condition of baby fish culture and a key period in the stage of commercial culture of baby fish. In the adult stage, the resistance and adaptability of dollfish increased, while absconding and the law of the jungle also reached a peak. Therefore, adults are required according to their physiological characteristics at this stage. More than 5 are built so that they can be cultured separately according to individual size.

According to the actual situation in various places, the adult pool can be built indoors or in civil air defense projects, or outside. The area of the pool can reach 100 to 2000 square meters. The artificial Radian or cave area accounts for 2 × 3 of the adult pool area, and the Radian or cave size depends on the size of the adult tree. Outdoor pool construction, in addition to indoor adult requirements and facilities, shading facilities must be installed. Shade can be installed in all places according to the actual situation, requiring shade at the top and all around the pool.

Adult culture

Successful experience and technology have been obtained in adult culture in China, and the main culture methods are outdoor culture, basement, civil air defense engineering culture and industrial temperature control culture that we have developed. To sum up, it is mainly divided into still water culture and running water culture.

Natural baby fish is based on bait in the natural environment, so it grows slowly and generally needs 5 years old to reach adult. Artificial breeding of baby fish is to create a good ecological environment and provide nutritious feed. Generally speaking, it takes only 2 to 3 years of age to reach the adult stage.

Baby fish has great economic development value because of its high nutritional value and medicinal value. Therefore, the breeding technology of baby fish will be the focus of competition in China's aquatic industry for a period of time in the future, and baby fish will also be the key species to be developed in the future.

Adult stocking

1. Preparation before stocking

The main purpose of the maintenance and disinfection of ① adult pool is to check the inlet and outlet pipes. Check whether the barrier net is damaged, check the filter pool, filter device and temperature control machine for failure, and carry out maintenance, check the adult pool to see if it is damaged, repair it in time, then disinfect the adult pool and release it after the medicine disappears.

② adult disinfection adult disinfection mainly prevents water mold and bacterial diseases, and the disinfection methods and drugs are the same as those of larvae. When stocking, the water temperature of the adult culture pond should be the same as that of the larva pond.

Before ③ stocking, the number and specifications of adults should be checked so that they can be reared in ponds according to the size, size and size of adults. In this way, adults of the same size are basically the same in feeding ability and intensity, and the growth rate is basically the same, which can avoid mutual cannibalism caused by mixed culture.

2. Stocking density

The adult stocking density of baby fish should be determined according to the culture mode, technical level and culture conditions of different places.

Feed and feeding

Feed and feeding are the central links of the whole baby fish culture technology. The advantages and disadvantages of feeding and management work on the growth and development of adults. The occurrence of baby fish disease, the stability of water quality and the yield of adult survival rate are all closely related.

1. Ecological and physiological habits of adults

The adults of ① living habits inhabit the dark springs of the Yinhe River in the natural environment, and the farmed ones live in artificial caves.

The adult diets of ② are carnivorous animals, which can be divided into two categories: fresh and frozen animals (but excessive fat content is not suitable) and artificial compound feed.

The suitable range of ③ water temperature for adult growth and gonadal development is 16-25 ℃, and the best range is 18-23 ℃.

The oxygen consumption of ④ is 20.28 mg / kg ha in daytime and 21.69 mg / kg ha in nighttime.

The suitable PH of ⑤ PH for adults is 6.5-7.5.

The ⑥ light adult is a backlight movement-photophobia, requiring a light intensity of 100 lux to 500 lux.

2. Feed and feeding methods

① feed species baby fish is carnivorous animals, its natural feed resources are very rich, mainly fish, shrimp, frog, shellfish, Loach, chicken and duck embryos, mutton, beef, rabbit meat, earthworms, etc., artificial formula feed can choose eel formula feed, we have developed a baby fish artificial formula feed. The feed coefficient of adults fed with natural diet is 3.5-6.3. The feed coefficient of adults fed with artificial formula feed was 2.8 ~ 3.6. Each place can decide the kind of bait according to the local feed resources.

② feeding in order to improve the breeding efficiency of baby fish and reduce the feed cost, before feeding, it is necessary to understand the digestion, absorption and utilization of nutrients in feed by adults in order to determine the reasonable feeding. Rational feeding includes nutrition, growth, metabolism, physiology, ecological environment and other factors, such as feeding amount, feeding times, feeding methods and feeding principles.

Feeding time and times: under the condition of suitable temperature, the baby fish were digested and absorbed vigorously, usually once every 2-3 days, and once every 5-7 days if the humidity was less than 10 ℃. Baby fish lie dormant during the day and eat at night, so the feeding time is 8: 10 p.m. every day in summer and 6-8 p.m. In winter.

Feeding amount: there are many factors that affect the feeding of baby fish, such as water temperature, dissolved oxygen, water quality, disease, feed variety, feed quality and so on. The feed requirement of baby fish can be calculated according to the number of adults in the pond and the daily feeding rate.

Atom W × E

A: daily feed consumption

W: baby fish weight

E: feeding rate.

Water temperature is an important factor affecting the feeding of baby fish, because baby fish is a variable temperature animal, with the level of water temperature, the physiological metabolism of the body changes. In the range of suitable temperature, the feeding and growth of baby fish are positively correlated with the increase of water temperature. Generally, the food intake is more than 12 ℃, and the food intake is the largest and the growth is the fastest at 18-23 ℃. When the water temperature rises above 26 ℃, the food intake decreases, and when it is over 28 ℃, it enters "summer dormancy". Under the condition of suitable temperature and the same feed quality, dissolved oxygen and water quality play an important role. Therefore, the feeding amount of adults should be determined by combining various factors. after 10 years of research results, we have obtained a feeding standard under different water temperature conditions, which can be used for adult culture.

Feeding method: the reasonable feeding method should be determined according to the biological and ecological habits of baby fish. In order to improve the feed utilization rate and reduce the feed cost, we must adhere to the four-fixed feeding method, that is, timing, positioning, quality and quantity.

① timing: according to the biological habits of baby fish feeding characteristics at night on time, but also according to the season, water temperature, water quality conditions appropriate advance or delay. The general feeding time is 10 pm in summer and 8 pm in winter.

② positioning: the development of positioning feeding habits of baby fish can promote the concentrated feeding of baby fish. Group feeding can not only improve the appetite and food intake of baby fish, but also reduce the dispersion of feed and improve feed efficiency.

③ quality: if the feed is artificial compound feed, it should be kept in a place of low temperature, dryness and no moisture, and the addition of feed additives for adults is also different due to different breeding purposes. In order to improve the utilization rate of protein in formula feed, oil should be added in feed preparation, such as fish oil, vegetable oil and so on. The amount of oil added varies with the water temperature. Generally, fish oil and corn oil are added 5% and 5% respectively when the water temperature is 18-23 ℃. When the water temperature is nbsp14~l.7 ℃, the oil addition amount is 5%-6%. When the water temperature is below 12 ℃, no oil can be added. Natural bait is required to be fresh and clean, and spoiled bait must not be fed. Loach, maggot worms, crucian carp, chicken and duck embryos are the ideal feed for natural bait.

④ quantity: appropriate amount of feed is given according to different factors such as feeding, digestion, individual growth, body size, water temperature, water quality and so on.

Culture management

The main results are as follows: 1. The management of adult pond: after raising adults for a period of time, the individual grows and the density increases relatively, and baby fish disease also occurs. Therefore, daily management is very important. The daily management of adult pool can be summed up as follows: first diligence, second morning, third look, and four precautions.

Yiqin: is to patrol the pool frequently. Patrol the pool three times a day, observe the situation after feeding in the morning, pay attention to the change of water temperature at noon, and observe the adult feeding condition in the evening.

Second morning: that is, early stocking and early feeding. Pay attention to whether you are feeding when the water temperature rises after the Spring Festival. if you do not eat, you should use heating to make adults eat as soon as possible.

The third look is to look at food intake, to see if there is a rush to eat or whether there is vomiting, and to see the water quality. The main way to look at food intake is to see whether adults are concentrated or scattered in the food market. To see if there is a rush to eat or whether there is a phenomenon of vomiting, in order to adjust the amount of feed. Water quality is mainly determined by whether the water quality is fresh and transparent, so that measures can be taken to improve the water quality.

Four defenses: heat prevention, disease prevention, escape prevention and waterproof change.

① heat prevention is one of the important tasks in adult pool management in summer. Due to the high water temperature in summer, adults are easy to die, so it is necessary to take heat prevention and cooling, which is beneficial to the growth of baby fish. Outdoor heat prevention is mainly to set up shade to make the light intensity low. The change of water is carried out late at night, which is beneficial for adults to "spend the summer".

The purpose of ② disease prevention is to prevent baby fish disease. It is necessary to pay attention to the feeding activities of baby fish at any time. If adults are found to be wandering alone, check and study the disease condition, adopt isolation and prevention measures, and treat them in time.

③ escape prevention is to prevent adults from escaping, to often check the water entrance and exit, to strengthen management, to prevent flight.

The waterproof change of ④ is to prevent the water quality from deteriorating.

The adult pond should not only do a good job of feeding management, but also carry out water quality management, adult disease prevention and control work.

2. Water quality management: the adult pond requires fresh water, less zooplankton and enemy biomass, and a transparency of 50-60 cm. The water quality of the adult pond will directly affect the feeding of baby fish and the occurrence of baby fish disease. The water quality is good, the adult feeding ability is strong, the physique is strong, the disease is less.

① change water: the self-purification ability of adult pool water is poor, so the pool water should be changed frequently. Generally speaking, the daily change of water volume is 2 pounds per day. When the summer temperature and water quality deteriorate, the pool water should be drained and fresh water should be injected.

② is a good cleaner to keep the ground water: the residual bait, dirt and dead baby fish floating on the surface should be removed in time in the daily management. Keep the pool water clean to prevent water quality from being polluted by the decay of such substances.

③ pays attention to the changes of plankton and enemy organisms in the pond water: the mass reproduction of plankton is one of the main factors leading to the change of water quality and adult diseases in the adult pond. once it is found that there is a large amount of plankton in the pond water, it should be treated in time and disinfected.

3. Disease prevention and treatment: the occurrence of baby fish disease will directly affect the adult feeding, survival rate and yield. The prevention and treatment of baby fish disease should adhere to the principle of prevention and treatment. The following work should be done well in the prevention and treatment of baby fish disease.

For ① adult water, it is best to use tap water or underground well water to reduce bacteria and pollution sources. In farms that make use of natural water sources such as reservoirs, mountain stream springs and Yin river water, the influent water must be filtered to prevent harmful organisms from entering the adult pond.

Fish and shrimp with pathogens are not mixed in ② adult ponds.

The newly introduced baby fish from ③ were sterilized before they were put into the pond for breeding.

④ disinfects the pool water regularly and feeds the bait into medicine bath to prevent the occurrence of disease.

Adult separate culture

As adults are cultured for a period of time, due to differences in feeding, digestion and absorption, the difference in individual size is obvious, and this difference will become more and more serious. Because of the large size of adult feeding intensity. The food intake is large, its growth is fast, while the small size adults have poor grazing ability, less food intake, and the growth is becoming slower and slower. Therefore, the baby fish in the same adult pond have individual large, medium and small differentiation. in order to avoid the law of the jungle, adult grading and pond feeding must be carried out.

1. Preparation before separation

① doll fish ponds and tools: prepare separate doll fish ponds and tools before separate cultivation. Doll fish ponds should first disinfect and cultivate water quality. For its method, see the stocking section. Adult separate culture tools include plastic buckets and plastic pots.

② fasting: stop eating for 5-7 days before adult separation, which can prevent damage during fishing.

2. Fishing: drain the water from the prepared separate adult pond, then pick up the adults of different specifications and ready for separate culture, put them in the plastic basin prepared in advance, and finally put them into their new adult land.

3. Several problems of separate cultivation of adults

① dollfish are photophobia, so separate breeding should be carried out on cloudy and rainy days. In cloudy and rainy days, the temperature is low and the air humidity is high, so adults are not easy to be injured during capture. The summer temperature is high, the light intensity is strong, the separate cultivation should choose to carry on in the late night, must not start the capture and separate cultivation operation under the direct sunlight.

The water temperature of ② separate culture doll fish pond should be basically the same, if the difference of water temperature between the two ponds is large, it is easy to cause adult vomiting and disease. Therefore, the separate culture of adult pond water requires that the water temperature is similar, so that baby fish will not refuse to eat.