CATDOLL : CATDOLL: Where does the golden fish come from?

1. Where does the golden fish come from?

Golden trout is a variant of rainbow trout. It is called golden trout because of its golden color. Like rainbow trout, it is a cold-water fish. It is native to the Pacific coast of North America. Currently, golden trout farming has spread across five continents, making it one of the most widely farmed fish in the world.

2. Question: How to breed goldfish

How to breed goldfish:

1. Distinguishing between male and female: During the breeding period, female fish are larger, with enlarged posterior abdomen and unusually active. Several small white protrusions appear on the first fin ray of the pectoral fin and the gill cover of male fish. These small protrusions are named "star chasing". "Star chasing" is the second characteristic of male fish, but after the breeding period, star chasing disappears in male fish, while female fish do not have this characteristic. The shape of male fish's pectoral fin is slightly longer, while that of female fish is slightly rounder. The tail stalk of male fish is slightly thicker, while that of female fish is slightly thinner. You can also hold the goldfish in your hand with the belly facing down, and use your index finger to touch the belly ridge of the abdomen from the anal fin. If it feels hard, it is a male fish, and if it feels soft, it is a female fish. In addition, the excretory opening of male fish is small and elongated, in the shape of a date, with pointed ends, slightly enlarged in the middle, and slightly turned inward or level with the body surface, while the excretory reproductive opening of female fish is pear-shaped and slightly protruding outward, with one side of the pear stalk in front and the other side opposite to the pear stalk in the back. By combining the above methods, it is not difficult to distinguish between males and females.

2. Artificial breeding methods: There are two methods: in-water fertilization and out-of-water fertilization.

In-water fertilization is when the male fish starts to chase the female fish violently and the female fish has a few eggs, they should be fished out and put into a new container filled with 1/3-1/2 water. Then, select male and female broodstock of appropriate age with both hands, make their genital openings face each other, first press the abdomen of the male fish gently with the thumb, wait for milky white semen to flow out, and then squeeze out the eggs of the female fish in the same way, so that both semen and eggs enter the water body for rapid fertilization. At this time, the eggs change from transparent to beige fertilized eggs. The characteristics of in-water fertilization are that fertilization does not leave the water, the damage to the broodstock is less than that of out-of-water fertilization, the fertilized eggs are highly viscous, can quickly attach to the artificial fish nest, are not easy to change, are easy to operate, and have a high fertilization rate.

The out-of-water fertilization method requires first selecting excellent broodstock with obvious chasing phenomena, then taking out the male fish, gently squeezing the male fish's abdomen, sucking out the semen with a straw, and placing it in a dry container. At the same time, quickly squeeze the female fish's abdomen. After the eggs are injected into the container containing semen along the abdomen, use a clean feather to gently mix them so that the semen and eggs are evenly mixed. Then inject an appropriate amount of clean water to quickly fertilize the eggs. After a few minutes, replace the original water, and most of the eggs will become fertilized eggs.

The water temperature during breeding should be 19-21℃. After 100 hours, fry with swinging tails will appear in the eggs.

3. Growth of fry: After 1 week or 10 days, fry have the ability to escape from human capture. The water used for breeding should be clean and not too deep. The density should be controlled. When feeding, the bait should be provided on time and in a guaranteed quantity and quality. Egg yolk water is suitable. When the fry reaches 1 cm, small water fleas can be fed. The water quality needs to be clean. When changing the water, the temperature difference should be minimized. When the fry grows to 2 cm, red worms or water earthworms can be fed. When the fry grows to 4-6 cm, granular feed can be fed.

4. During the growth period of fry, it is necessary to screen the fry. The screening of fry can be divided into five times: when the fish body grows to 1 cm, screening should be carried out, and the fry with a single tail should be eliminated at this time; when the body is 2 cm long, the tail fin is basically formed, and those without four tails can be eliminated; keep the varieties with well-developed fins, complete dorsal fins, and the varieties without dorsal fins, the back of the body must be smooth and free of thorns. If there are defects or irregular body shapes, they will be eliminated; when the body is 4-6 cm long, the characteristics of the variety are clearly discernible. At this time, screening is mainly based on morphology. For example, for the high head system, it is better to choose a square and wide head with flat lips; when the body is 6-8 cm long, the color change activity is nearing the end, and some are still in progress. Among them, the color change of five-color, blue, purple, black fish and crane's crown red has ended. At this time, attention should be paid to the selection of color, and those with early color change and bright colors should be kept.

3. Do pike eat shrimp fry?

Barracudas do not eat shrimp fry. They feed on organic matter in the mud at the bottom of the water. Under artificial breeding conditions, they also like to eat rice bran, soybean cake powder, peanut cake powder, dried water fleas, and artificial compound baits.

pike

Barracuda, also translated as golden barracuda or barracuda, commonly known as sea wolf (Barracuda) or sparrow brocade, is a ray-finned fish of the family Golden Barracuda. ​​The body is elongated, with a small tip at the front and a slightly flattened back. The head is short and wide, and the back is flat. The eyes are small, and the fat eyelids are not well developed, only distributed on the edge of the eyes. There are two nostrils on each side, the front nostril is small and round; the back nostril is large and oval. The mouth is small and lower in front. There is a notch in the center of the upper jaw that matches the protrusion in the center of the lower jaw. The teeth in the upper jaw are thin and weak, and the lower jaw has no teeth. The tongue is small and round, and the front end is not free, with fine hair-like teeth. The gill opening is large. The gill rakers are dense and long. The head is round scales. There are two dorsal fins. The starting point of the anal fin is located in front and below the second dorsal fin. The pelvic fins are close to each other. The tail fin is shallowly forked. The back of the body is blue-gray, and the abdomen is white. There are several blue-gray vertical stripes on the upper side of the body, as well as many oblique horizontal stripes, the bottom is white, and each fin is light gray.

Living habits

Under artificial breeding conditions, they also like to eat rice bran, soybean cake powder, peanut cake powder, dried water fleas, and artificial compound baits. The feeding intensity of pike varies between day and night, seasons, and individuals. In the daily cycle, they feed both during the day and at night, but the feeding intensity is usually greater around dawn and sunset than at night.

During the growth cycle, the 20-40 cm long pike feeds heavily; before the reproductive period, the feeding intensity is relatively high, and the esophagus and stomach are always full of food. During the reproductive period and spawning period, they rarely or even do not eat.

Migratory barracuda is a nearshore semimigratory fish. It does not migrate long distances, but can migrate over short distances and within a small area depending on the season, water temperature and its own development. Mullet often lives in shallow seas or estuaries at a depth of 1-16m. When the weather turns cold, it swims to the deep sea to hibernate.

However, some of them also overwinter in deeper bays and shallow seas. Mullet lays eggs in deeper seas, and the hatched fry drifts to the nearshore estuaries with the tide, staying at the intersection of salt and fresh water to feed and grow. Pike generally grows near the coast, and regularly forms large groups to lay eggs in harbors and estuaries every year. Between June and July, a large number of young fish born that year appear along the coast of the Yellow Sea and Bohai Sea, and enter the estuaries of rivers. When it is cold, they swim to deeper sea areas to overwinter.

In April every year, pike spawn in various estuaries and only make short migrations. In December, they hibernate in the deep sea. In the spring of the following year, they grow and fatten in the near-shore estuaries, forming a fishing season. Pike is rich in nutrients, tender and delicious, with a high protein content. It is a delicacy in high-end banquets, especially the spring pike. The head of the cooked pike is the most fragrant, so there is a saying among the people that "you can lose the car and the cow, but not the pike head." Pike can be caught all year round except during the closed fishing season.

Farming technology

Breeding facilities and supporting facilities

The factory-scale breeding plant is a reinforced concrete structure with colored steel tiles on the roof. A breeding pond is built in the house. The breeding pond is a circular concrete structure with an inner diameter of 4.5 m and a height of 1.5 m. The bottom of the pond is in the shape of a pot bottom. A drain is set in the middle. The drain is equipped with an anti-escape net with a stainless steel mesh. The drain uses a 75mm PVC pipe to connect the water level control pipe outside the pool. The depth of the pool water is controlled to 0.4~0.6 m by the height of the water level control pipe. The breeding pond is equipped with independent inlet, outlet and oxygenation facilities. During the breeding period, a 2.2 kW Roots blower is used to increase oxygen through pipes and air stones. Ten air stones are placed in each breeding pond. The water used for breeding is aerated underground deep well water. The water quality meets the requirements of "Water Quality for Pollution-free Food Freshwater Breeding (NY5051-2001)". The water temperature at the inlet of the breeding pond is 14~18 ℃ all year round. In addition, it is equipped with a 10kW diesel generator, a 2.2kW Roots blower and a deep well pump as backup.

Stocking and management

1. Disinfection of the breeding pond. Before stocking the seedlings, the breeding pond should be disinfected in advance. You can use 20-25 mg/L bleaching powder or 100-200 mg/L potassium permanganate to soak for 24 hours. If it is a new cement pond, use 50 mg/L superphosphate to remove the alkali 30 days in advance.

2. Stocking of seedlings. The stocking time is generally from March to October each year, and the stocking size is 10~16 cm. The stocking time in 2011 is June 10, the size of the fish is about 14 cm, the stocking density is 70 fish/m2, and 1120 fish are stocked in each breeding pond, with a total of 11,208 seedlings. The stocked fish are required to be of uniform size, free of injuries and diseases, strong in activity, and normal in feeding. Before stocking, the fish are soaked in 3% salt water for 5 minutes for body surface disinfection.

Feed and feeding

After stocking, feed begins on the third day. Feeding is carried out according to the "four fixed" principles of fixed time, fixed location, fixed quantity and fixed quality. Feed 6 times a day in the early stage of breeding, and gradually reduce to 2 times a day. According to the growth specifications of sturgeons, use sturgeon complete pellet feed with a protein content of 40%~42%. The particle size of the feed is flexibly controlled according to the weight of the fish and the principle of "small is better than large". The amount of feed is adjusted according to the weight of the fish and the water temperature. It is best to eat the amount of feed each time within 20 minutes after feeding.