CATDOLL : CATDOLL: Can yellow croaker be cultivated artificially?

1. Can yellow croaker be artificially cultivated?

1. Yellow croaker can be artificially cultivated. After years of research, yellow croaker began mass breeding in 1990. Commercial fish farming has been continuously expanded since 1992, and the output has increased year by year. The breeding provinces started in Fujian and radiated to Zhejiang, Guangdong, Hainan and other provinces.

2. Yellow croaker is quite precious, so we must be very careful and careful when choosing fish species, so as to improve the survival rate of yellow croaker farming and reduce the loss of denier. We usually choose fish species with uniform size, strong and lively, complete scales, shiny skin, no internal and external injuries and no diseases for stocking, so as to facilitate unified management of fish populations.

3. Feeding management mode: Having a correct management mode will bring more help. In the process of feeding yellow croaker, you must choose the right food, which is the essence of feeding. Yellow croaker can eat anything, and there are many choices for feed. When choosing feed, we should consider its normal body needs and then choose a suitable feed. It will bring it better growth nutrition.

4. The daily management of yellow croaker has become the most difficult task in the industry. You need to know some normal management knowledge, especially for ponds, which need to be observed three times a day. You need to check the normal growth status of the yellow croaker every time. If there is an adverse growth environment, timely remediation should be carried out.

2. The environment is very important for fish farming. What are the environmental requirements for yellow croaker farming?

If you want to artificially breed large yellow croaker, you must first understand the basic characteristics of large yellow croaker, including its growth habits, feeding habits, growth characteristics, etc., and establish a fish farm suitable for the growth and development of large yellow croaker. The following will introduce the growth characteristics of large yellow croaker and the design and planning of hungry skin fish farms. The basic characteristics of large yellow croaker. The body of large yellow croaker is long and laterally flat. The head is flat, large and blunt, and the mucosal cavity is well developed. There are two nostrils on each side, the front nostril is small and round, and the back nostril is large and oblong. The mouth is large, front, and has an oblique crack. The mandible is slightly protruding, with a tuberculous protrusion at the suture, and the rear end of the maxilla is far beyond the rear edge of the eye. The teeth are small and sharp.

The two teeth behind the tubercle-like protrusions of the maxillary suture are larger and pointed inward. The gills are open. The edges of the front lamellar bones are finely serrated. There are pseudogills, long and slender gills. The head and the front of the body are covered with round scales, and the back of the body is covered with pectinate scales. The dorsal and ventral margins are wide arcs, and the caudal peduncle is slender. The back and one side are yellowish brown, the lower part and the ventral surface are golden, the pectoral and pelvic fins are yellow, and the lips are orange-red. Large yellow croaker is a warm water migratory fish, and the adaptability range of water temperature is 8~32℃, and the optimal growth temperature is 18~28℃. When the water temperature drops from high temperature to 17℃, the food intake begins to decrease. When the water temperature continues to drop to 15℃, the food intake is only 50%~55% of the normal amount. When the water temperature drops to 11.5℃, the feeding activity is slow. At noon or afternoon on a sunny day, the water surface is used for feeding activities, and the food intake is only 10%~12% of the normal amount.

A pond should also be selected for breeding large yellow croaker. The pond must be close to a water source and have convenient water access. It is best to change the water every day. The size of the pond depends on the scale of the farm. The depth of the pond should be between 2 and 3 meters, the transparency of the water should be above 100 meters, and the temperature should be between 8 and 28 degrees. The dissolved oxygen of the water quality should be above 5 milliliters per liter. The pond water should be alkaline, which is more suitable for the growth of large yellow croaker. Be sure to clean the pond before stocking the fry.

How to disinfect: To disinfect the pond and kill harmful bacteria and microorganisms in the pond, first pour 10 to 20 cm of water, then sprinkle quicklime, so that each acre of land will immediately have 100 to 150 kg more water. The water can be drained within a week and replaced with a new water source. It must be temporarily raised for two days to ensure that the yellow croaker can better adapt to the environment and avoid losses caused by death after stocking.

The water source must be wide, the water must be clean, and it must be disinfected regularly. The water temperature must be appropriate, and the fish pond must be provided with sufficient oxygen.

The water temperature should be maintained at 25 to 35 degrees. Attention should be paid to the breeding density and the depth and width of the venue. During the breeding process, water stains should be replaced in time. High-quality aluminum seedlings should be selected. During the breeding process, drainage must be done well and oxygen in the water must be guaranteed.

The water must be disinfected and sterilized, the water quality must be clean, the water temperature must be moderate, and clean food must be fed. To raise yellow flower fish, there must be plenty of water, and the water must be changed frequently.

The water temperature should be appropriate, the water quality should be clean, the water should be deep, there should be nutrients in the water, and the weather temperature should not be too cold.

3. What kind of feed is good for fish farming?

In recent years, research on the nutritional requirements of marine fish has made rapid progress. Although compound feeds have been rapidly applied in the cultivation of harrier fish, fish farming still relies exclusively on biological baits, and the use of compound feeds as supplements is still rare. However, from the perspective of health management of farmed fish and pollution prevention of fish farms, compound feeds have gradually attracted attention. Here, Mr. Takeda focuses on the development of compound feeds for fish and introduces some recent research on practical feeds for marine fish.

1Overview of commercially available feed

The shapes and usage categories of the compound feeds for marine fish currently on the market are listed in Table 10.1.

The feed is mixed with the usual biological feed and pelletized, that is, the "Oregon wet granulation" is used to extodder or ex-

pander is made into porous pellets (floating bait). It is fed after being soaked and puffed in an emulsion of water and oil. The main ingredients of fish powder are fish meal and wheat flour, with a small amount of meat and bone meal, soybean oil meal, corn bran meal, edible yeast, etc. When making porous pellets, a large amount of starch and a small amount of wheat bran powder are mixed in addition to fish meal. The main ingredients of high-protein kite pellets and powders are fish meal, vegetable oil meal, and wheat flour, some of which are also mixed with a large amount of krill powder. Low-protein fish feed, in addition to these main ingredients, also mixes rice bran oil meal, etc.

2Fish feed

(1) Mixed wet granules

The Japan Federation of Fisheries Cooperatives has been in existence for three years since Showa 64, and has been awarded the titles of Mie Prefecture and Kochi Prefecture.

With the cooperation of the fisheries test stations in Kagawa and Ehime prefectures, the company conducted a research on the development of its own pollution prevention technology by wet granulation with fish as the subject. In this test, the oregon wet granules made of various feed composition powders and biological baits are mixed, that is, the mixed wet granules (MP). An example of its composition is listed in Table 10.2. In the test area in Kagawa prefecture, about 4,000 fish were raised in 8 m angle nets. From July to December, the results of the feeding showed that there was no difference between the MP area and the live bait (sand eel) area, and both showed excellent growth. There was no significant difference in the survival rate, feed efficiency, protein efficiency, protein accumulation rate, body composition, blood traits, vitamin content of imitation fish liver, etc. between the two feed areas. In the test area in Mie prefecture, the results of feeding with MP containing 27-40% soybean meal powder were not worse than those in the biological bait area.

On the other hand, MP has a higher feeding rate than biological feeds, and the amount of organic matter dissolved in water is also less, so the environmental pollution load from suspended and dissolved nitrogen and phosphorus, suspended lipids, etc. is much less than that of biological feeds. In this way, the self-pollution of this feed is reduced, which is very effective in prevention. If low-cost powder feed can be developed in the future, it will be quickly put into practical use.

3. Single type wet granules

Mr. Takeda and others have been working with Kochi Prefecture since 1947 to develop practical and nutritious fish feed.

The Fisheries Research Institute has worked together to conduct a fish feeding experiment using a single wet pellet feed, that is, a wet pellet feed made of water and oil without using biological bait. Among the most experimental feeds so far, representative feeds of each year have been selected, and their composition is shown in Table 10.3. The prescriptions of the added vitamin mixture and main mineral mixture are listed in Table 10.4 and Table 10.5 respectively. The mixture of whole fish meal of coastal fish meal and processing residue of cod in the ratio of 85:15 (produced in Kushiro) used in this experiment, the basic composition of the feed and the prescription of vitamin and mineral mixture were designed with reference to the results of past basic research.

150 to 170 fish with an average weight of 72 to 225 grams were raised in 2.5 m angle nets and kept for 10 weeks from late July to early August. The growth of the compound feed group in 1955 and 1957 was about the same as or slightly better than that of the biological feed group. The reason why the growth of the compound feed group in 1958 was lower than that of the biological feed group was that the daily feeding rate was about 1.9% lower, so the feed conversion rate of the compound feed group was lower than that of the biological feed group, which had less heat energy intake than the biological feed group (Table 10.6). Therefore, in the experiment in 1959, when the same feed as the F1 feed in 1958 was used, the dry matter feed amount and metabolic heat energy amount were the same as those of the biological feed group. Although the growth of the group with the same dry matter amount was significantly lower than that of the biological feed group, the growth of the group with the same energy amount was about the same as that of the biological feed group.

F: single type wet pellet; R: frozen sand eel (with commercially available nutrients added); W: Northern Ocean fish meal (63%); WB: Northern Ocean fish meal (32%) + coastal fish meal (31%); B: coastal fish meal (64%); Vitamin and chocolate mixture: refer to Table 10.4; Mineral mixture: refer to Table 10.5.

The breeding results of compound feed area and biological feed area in each year are listed in Table 10.6. It can be seen from this table that when half or all of the northern fish meal is replaced by coastal fish meal, and the prescription of vitamin and mineral mixture is changed from MH to TH 4 and from Y to T 4 to simplify, the feed efficiency of compound feed area is almost not lower, and the accumulation rate of protein and heat energy is also higher than that of biological feed area. In addition, the values ​​of its survival rate and blood trait are lower than those of biological feed area in 1955 and 1957, but in 1958, they are roughly equal to the values ​​of biological feed area. The above results show that the compound feed (F-1) in 1958, which uses coastal fish meal as the main raw material and adds vitamin mixture of TH 4 prescription and mineral mixture of T 4 prescription, is a fish feed with high nutritional value, which is better or not worse than biological feed (sand eel) with added nutrients.

Therefore, first of all, in order to understand the reason why coastal fish meal is an excellent protein source for fish feed, the content of various nutrients was analyzed. It is known that the essential amino acid balance of this fish meal is roughly the same as that of northern fish meal and the whole body of sand eel, and its highly unsaturated fatty acid content is about 38% higher. The minerals such as Fe, Zn, Mn, Cu, vitamins, niacin, pantothenic acid, B12, C and other vitamins are also high. Secondly, in order to confirm that the vitamin mixture of TH 4 formula is an appropriate nutrition for fish, the content of various water-soluble vitamins in the F 1 feed of 58 years added with TH 4 vitamin mixture and the liver of fish fed with this feed for 10 weeks were analyzed. The various contents in the feed showed a significant increase in the vitamin requirements of any group of fish, and the various contents in the liver were roughly equal to or higher than the contents at the beginning of feeding and the contents in the liver of the biological feed area after 10 weeks. It can be seen from this that this vitamin mixture can be proved to be very suitable as a vitamin mixture for fish feed made from coastal fish meal as the main raw material.

In addition to the facts mentioned above, the results of a series of experiments conducted so far have also made the following points clear. That is, (1) The best feed oil for fish is bonito oil, which contains a high content of ω3 highly unsaturated fatty acids. (2) The most suitable feed iron supplement is a complex amino acid iron composed of primary ferrous sulfate and secondary ferrous citrate, which is not easy to cause hemosiderosis. (3) When a small amount of krill pigment oil with astaxanthin diester as the main component is added to the feed, tunaxanthin on the fish surface will rapidly settle, and the body color will be significantly improved after 2 to 3 weeks. (4) Although the fat content of the compound feed area 1 muscle is lower than that of the biological feed area, it has a moderately firm texture. (5) When a small amount of a mixture of proline, alanine, and sodium 5-fiber nucleic acid is added to the feed, fish are more active in eating food in a lower salt environment. (6) When the compound feed is mainly made of coastal fish meal, the fish have a high appetite even if the above-mentioned feeding promoting substances are not added. When proteolytic enzymes are added to this feed, the fish will actively feed even at low water temperatures. (7) When a part of the wheat bran powder in the feed raw materials is replaced by cheaper corn bran powder and wheat flour, the fish breeding performance will not be reduced. From the above series of test results, the fish raised with a single wet pellet feed without biological bait has excellent growth and feed efficiency comparable to that of fish raised with biological bait, and their health and meat quality are also good. It can be said that the future of the practical application of complete compound feed is bright.

Porous feed

Masuda and Takamatsu have shown through field experiments that porous feed is effective in growing fish.

The results showed good weight gain efficiency. In the experiments in Kagoshima Bay and Owase Bay, the porous feed alone area showed the same good growth and feed efficiency as the biological feed or mixed wet pellet area. In the experiment in Mie Prefecture, the porous feed and biological feed combined area showed high survival rate and feed efficiency.

Porous feeds that are easy to store and simple to prepare are expected to become more popular as practical fish feeds that save labor. However, they are criticized for requiring a large amount of starch to maintain their porous form and for destroying some of the vitamins during extrusion and puffing during production.

How to choose fish feed for ornamental fish, what should you pay attention to?

Go to the market and buy them. They are all available at the flower and bird market.

The more expensive the better