Fine scale fish (Brachymystax Lenok) belongs to the salmoniform order, salmonidae, fine scale fish genus. Common name: mountain scale fish, river scale fish (Northeast), lugu fish, lugu flower fish, gold plate fish, flower fish (Shaanxi), plum flower fish (Gansu), small red fish (Xinjiang). English name: Lenok. It is found in the rivers of Russia, China, North Korea, and parts of Mongolia, such as the Irtysh River, the Ebi River, the Yenisei River, the Lena River, the Korema River, the Heilongjiang River, the Songhua River, the Tumen River, the Yalu River, the upper reaches of the Liao River, the Luan River and the upper reaches of the Baihe River in Hebei, and the tributaries of the Wei River and the Han Shui River in the Qinling region. It is one of the larger riverine sedentary species of cold-water fishes in China.

(A) economic value

Fine-scaled fish is one of the specialties of China's alpine region, the world is only a genus of a kind of

The meat taste fat, high fat content (3.8% to 7.7%), nutritious, and the eggs are quite valuable. It is a valuable economic fish. In recent years, due to the destruction of the natural ecological environment and the interference of man-made factors, so that the number of resources of Chinook salmon is decreasing year by year. Therefore, it is especially important to vigorously carry out the protection, proliferation and culture of the resources of the fish, and at the same time, it is also especially necessary to make full use of the rich cold water resources in the alpine region of China for the proliferation of the fish, to continuously improve the living standard of the people, and to create greater economic and social benefits.

(II) Biological Characteristics

The fish is named for its fine scales. The body is long, laterally compressed, with a slightly pointed head and blunt muzzle. Mouth small, transverse, subinferior; maxilla conspicuous, free, reaching backward below the center of the eye. The maxillae and mandibles, plow bones, palatine bones, and tongue have inwardly inclined teeth. Eyes large, scales fine, lateral line complete, adipose fins small. Pyloric blind sacs 63-91, dorsal black-brown, lateral silver-white or yellow-brown or red-brown, distributed with irregular black spots. Juveniles have several vertical dark stripes and a silvery white abdomen. Body color varies depending on the habitat. The group that inhabits mountain streams all year round has a greenish-brown back, darker sides, white abdomen, black spots on the dorsal, anal and adipose fins, and black outer edges; the pectoral and ventral fins are orange-red with black spots, and the individuals are smaller, with a length of less than 350mm, which is referred to by the fishermen as the "mountain scales". The fine-scaled fish that migrate to the big rivers in winter are large, with black and green backs, yellowish-brown sides, black spots, black bellies; black anterior corners of the dorsal fins; greenish-brown pectoral and ventral fins; slender black spots on the caudal fins and black edges; they are more brightly colored than the previous ones, and they are commonly known as the "river fine-scaled fish". During the reproductive season, adults are dark, with the anterior dorsal fin darkened and faint red spots appearing on the side of the body. In different age sizes and different habitat environments, its body color changes greatly, generally older fish are darker than younger fish.

The Chinook salmon is a cold-water fish, mostly inhabiting low water temperature and clear running water, overwintering in the deep water of tributaries or large rivers in winter, and the juveniles burrowing into rock crevices or piles of rocks to overwinter. In early spring, when the rivers thaw, they migrate upstream from the middle reaches of the rivers for spawning. In the fall, before freezing (after August), they migrate downstream from upstream streams to large rivers or streams. The age of sexual maturity is 3 to 5 years old, and the body length is about 420mm. The amount of eggs is 0.3-0.7 million, and the eggs are sedentary, with a diameter of 3-4 mm. Spawning takes place from mid-April to June, when the water temperature is 4°C to 12°C. Spawning takes place in the lower end of the river sections or whistles on gravel substrates with clear water and slow currents. At a water temperature of 5°C, fertilized eggs take about 45d to hatch. Parental fish die in large numbers after reproduction, especially in males. Littlenecks like to lurk between gravel voids and swim infrequently, usually feeding on small fish, aquatic insects, small shore-dwelling animals, and plants. It is extremely voracious, with food in its stomach accounting for about 10% of its own body weight, and is capable of preying on fish up to one-half the size of its own body length. The most appetizing time of day is morning and

evening, and the rest of the day is spent lurking in the shaded bottoms of streams and rivers. The appetite is especially strong after spawning.

The Chinook is a carnivorous fish, feeding mainly on invertebrates and small fish. Larger scale fish can also prey on frogs, insects floating on the surface of the water, and rodents that land on the shore. One of the natural enemies of the salmon is the finfish, which follows the salmon into the spawning grounds during the spawning period and feeds on the fertilized eggs of the salmon. It is active in feeding in the morning and at dusk, and can continue to feed under the ice even in winter. The individual is large, generally weighing 1kg, and the largest individual can reach 8kg.

(C) Breeding Technology

1. Cultivation of Parental Fish and Identification of Maturity

The cultivation of the parental fish has a direct impact on the development of the gonads as well as the quality of the sex cells. The following points should be grasped during the cultivation process of Chinook salmon parents: First, suitable ecological conditions. Light regulation for about 2000LX; water depth in the spawning period before the 50 ~ 60cm, to the spawning period when adjusted to about 30cm, and accompanied by water current stimulation; water temperature control at 6 ℃ ~ 8 ℃, the second is to maintain a quiet cultivation of the environment; the third is to provide high quality and quantity of sufficient artificial with the feed.

Ingredients Formula 1 Formula 2

Wild fish 50

Fish meal 20 50

Soybean meal 10 10

Fermented blood meal 5 5

Active yeast 5 5

Shrimp head meal 12

Flour 10 10

Bran 5

Inorganic salt 0.2 0.2

Vitamins 1 1

Note: Use formula 1 in summer and formula 2 in winter, with a daily baiting rate of 0.7% of the fish body.

The identification of the gonadal maturity of the fish parents can be referred to the identification method of the domestic fish or carp, namely: "a look, two touch, three squeeze, four digging, "a look" that is, look at the state of the parents of the fish abdominal contour and the genital pore, the female fish abdominal expansion, gently lifting the caudal peduncle can be seen in the outline of the ovary and accompanied by the wandering shape. The genital pore is red and swollen, which indicates that the gonads of the female fish are well developed; "two touch" touch the abdomen of the female fish with your hand, if it feels soft and elastic, then the gonads are well developed; "three squeeze" that is, gently squeeze the abdomen of the female fish with your hand, if there are egg particles or semen flowing out, then the gonads of the female fish are well developed; "four dig"; "four dig" is to look at the outline of the abdomen of the female fish and the state of the genital pore. Good; "four digging" is to use the egg digger (with a feather handle or wire made into an ear spoon) to dig up the egg particles to identify gonadal development.

2. Artificial insemination

Artificial insemination of Chinook salmon uses dry fertilization. Selected gonadal development of mature female fish quickly with

dry towel to wipe off the surface of the fish water, the left hand holding the head of the hostage eyes, the right hand gently press the fish body abdomen, so that the mature egg particles out of the pressure, with a clean basin, with the same method to take the mature semen drops of male fish in the egg particles, stirring with a feather, so that it is fully integrated, plus a little water, continue to stir, 1min rinse with water, placed in the dark place, static water absorption The eggs were then placed in a dark place, left to absorb water, and then moved to the incubator for incubation after they had absorbed water and swelled. In the process of artificial insemination, the action should be fast to avoid frostbite of the fish body due to long operation time. The basin should be clean and free of water so as not to affect the fertilization rate. Avoid squeezing too hard and injuring the fish body. Sperm and egg mixing should be even to improve the fertilization rate, and the operation process should be carried out under dark light.

3. Most of the incubation tools are special incubators, fiberglass tanks or cement pools. The incubation water should be fresh and pollution-free, dissolved oxygen should be kept above 6mg/L, the water temperature should be stable at 6℃～8℃, and the pH value should be about 7.0. The incubation process of fine scaled fish fertilized eggs is shown in Table 10-2.

Table 10-2 Development and cumulative temperature of fine scaled fish fertilized eggs (quoted from )

Cumulative temperature (degrees? day) Embryonic development

0 Fertilized egg

29.0 Late blastocyst stage

35.6 Late proto-gut stage, 1/3 of the intestinal disc surrounded by the lower part of the intestinal disc

48.0 Embryonic aperture closure

72.8 Ocular fundus emergence

100.0 Otocyst stage, dorsal cord formation

120.0 Cardiac leaping stage (69-76 beats/min)

150.0 Eye point appears, embryo wriggles faster

200.0 Broodstock rupture the membrane

Note: Cumulative temperature = number of days × average daily temperature

(4) Fry cultivation technique

Transfer the broodstock after rupture of membrane from the hatching containers to the broodstock cultivation tanks (fiberglass tanks, cement tanks, etc.) with fresh water quality.) Remove dead eggs, dead fry and broken egg membrane to reduce the oxygen consumption factor. The pond should be maintained with smooth water flow, high dissolved oxygen and stable water temperature. 10-15 days later, the fish will move from endogenous nutrition to exogenous nutrition, and will float up and open their mouths to feed.

Fine scaled fish species culture, adult fish healthy culture and disease control methods can refer to the rainbow trout aquaculture technology operation procedures.

The second one is Chironomus

The Chironomus belongs to Salmoniformes, Salmonidae, and Chironomus. Distributed in the upper and middle Heilongjiang, the upper reaches of the Nenjiang River, the Mudanjiang River, the Ussuri River, and Mirror Lake and other waters in the mountain streams.

(I) economic value

The fish is one of the specialties of China's alpine region, its meat is delicious, high nutritional value

and become a valuable economic fish in Heilongjiang Province, is the folklore of the valuable "three flowers and five Luo" (Jihua, bream, ao flower, Zhe Luo, copper Luo, Faro, Yaluo, Huluo). However, due to the serious damage to the natural ecological environment and human interference, the population has been sharply reduced, has been compiled into the "Red Book of China's Endangered Animals", and has become a rare fish.

(II) Biological Characteristics

The body is prolonged, slightly laterally compressed, and the head is flat. The mouth is terminal, with large, dentate and sharp slits. Scales are minute, with complete lateral lines. The dorsum of the body is greenish-brown, and the sides and abdomen are silvery-white. The dorsal side of the head is covered with many black spots, and during the breeding season there is a matrimonial costume present, and the abdominal ventral fins and the lower lobe of the caudal fin of the fish have an orange carmine coloration.

The fish prefers to live in clear cold water (maximum water temperature does not exceed 20 degrees Celsius), mainly distributed in some of the mountainous waters with better protection of forest vegetation. In the northern region in late April - early May after the melting of snow and ice, Zheluo fish anadromous migration to the river tributaries to feed and grow, spawning and breeding, summer more inhabited in the lower water temperature of the mountainous areas of the tributaries. In the fall and winter (northern areas in late October and early November) into the rivers and streams for overwintering.

The Tetrapod is a ferocious carnivorous fish. The age of sexual maturity of the female is 5+ and the body length is more than 400mm, while the age of maturity of the male is about 4+. Spawning occurs in early May, and the amount of eggs carried is 1.0-3.4 million, with an average of 220,000 grains. Fertilization takes 30-35 days. Eggs are 4.8-5.5mm in diameter and are submerged. It likes to spawn in gravel substrate and there is water flow, and it can spawn and reproduce many times in its life.

(3) Breeding Technology

1. Cultivation of Parental Fish and Identification of Maturity

The following technical points should be grasped in the cultivation of the parental fish of Cherokee: First, the selection of a good pond. Due to the ferocious feeding, fast swimming speed, but the best choice for the parent fish cultivation pond Temple Pond is appropriate, the area according to the field conditions, generally mastered in 300 square meters is good. Near the water source, water quality, fresh, water temperature, no pollution, the depth of the pool water to maintain in 0.5m or so. Second, stocking density of 1 tail / 2 ~ 3 square meters. Third, strengthen the feeding. Chironomus is a large carnivorous ferocious fish, thus focusing on the feeding of live animal feed, such as mixed fish. And the amount of bait is 3-5%. Fourth, frequent inspections.

2. Artificial insemination

Select the gonadal development of mature parent fish for egg collection. Due to the artificial insemination of Cherokee fish water temperature, air temperature is low, coupled with the individual parent fish is large, and therefore before to do a good job of fishing, selection, egg collection, fertilization, and other aspects of adequate preparation, articulation should be close, the action should be skilled and rapid, so as to avoid injuries to the parents of the fish, egg collection is unsuccessful. The female fish will be captured for the maturity check, when found that the sex

glands have matured and appeared to squeeze the abdomen with the phenomenon of streaming eggs, that is, select the male parent fish first sperm collection. If conditions permit, it is better to do it in two groups at the same time. After the collection of semen, the egg collection. "Fixed" good parent fish, with a dry towel to wipe the water on the fish body, along the head of the fish to the direction of the genital pore, squeeze the fish body on both sides of the abdomen, so that the mature egg particles flow out smoothly. If there are more body fluids, use a leaky basket to filter them out, add drops of mature semen collected, stir well with a feather or other dry objects, add water for rinsing 2 to 3 times after 1min, add water and leave it to fully absorb water and expand, and move it into the incubator for hatching. For the gonadal maturity check in the parent fish gonad development is not good, can be catalyzed, catalytic production. Catalytic agent can be used for the pituitary gland of rainbow eel, and catalytic agent can be used for HCG and DOM, etc. Thoracic injection is used, and the injection dose for male fish is half of that for female fish. The parent fish after egg collection and sperm extraction should be anti-inflammatory and then quickly put into the pool with fresh water quality and feed fresh bait; so that their body quality can be recovered.

(D) Fry cultivation technology

Fry cultivation can be carried out in the tank, the cultivation process to keep the water flow, and timely removal of dead eggs, egg membrane and dead fry. In 7 ℃ ~ 9 ℃ water temperature, the fertilized egg diameter 30 ~ 35 days hatch out of the young fish, 15 ~ 20 days floating open mouth feeding. Nurturing technology can refer to the technical operation of rainbow trout, you can take the running water culture, can also be mixed in the pond.