Baiyun Mountain Lamp Fish, scientific name Tang Fish, also known as Baiyun Golden Fish, Golden Silk Fish, White Cloud Mountain Fish, Red Tail Fish, belongs to the order Cyprinidae, Carp family, (Fish Dan) subfamily, Tang fish genus. The body side has a longitudinal stripe of gold and black gold in the middle, a black spot on the tail handle, and a bright red color in the center of the tail fin, which is a mild-tempered social fish. The 1988 Red Book of Chinese Animals identified the animal as a national second-level protected animal with an endangered status of extinct (wild).
It was originally reported to be found only in The Baiyun Mountains of Guangzhou and the mountains and streams near Guangzhou, and was later found in Qingyuan, Huadu, Shenzhen and Hong Kong in Guangdong.
Tang fish have bright color and beautiful posture, and have high ornamental value. At present, tangyu has gradually become a good material for scientific research work such as molecular biology, transgenic research, and drug toxicity testing.
Tang fish is small in body and slightly flattened. The dorsal back is slightly raised, highest at the beginning of the dorsal fin, and slightly curved. The abdomen is round and unobtrusive. The head is medium large and rounded. The snout is short, wide and round. The mouth is small, the end is positioned, the mouth is slanted, the lower collar is slightly protruding, and the apex is rounded and blunt. The lips are thin and have no tentacles. The eyes are large, slightly above the anterior side of the head. The end of the maxilla reaches below the anterior edge of the nostrils. The gill rakers are short and conical. The hypopharyngeal teeth are slender and hook-shaped at the ends. Scales and other large. The lateral lines are not significant. The anus is close to the beginning of the fin. The dorsal fin is short, has no hard spines, is very backward, and the distance from its starting point to the snout end is greater than the distance to the base of the caudal fin. The pectoral fin is short and the end does not reach the ventral fin. The ventral fin ends up to the anus. The fin is opposite to the dorsal fin, and its starting point to the base of the ventral fin is closer to the base of the caudal fin, and the caudal fin is forked.
Tang fish live in bright colors, the back of the body brown or bluish brown, metallic luster body side has three color stripes, from top to bottom are golden or red yellow, bronze green, indigo blue, mainly golden or red yellow band, so it is called "white cloud goldfish". There is a black spot at the base of the tail fin, and later there is a gorgeous red spot in the center of the tail fin, so it is also commonly known as "red tail fish". There are many small red spots at the base of the dorsal and caudal fins, the dorsal and fins are yellowish-green, and black appears at the edge of the fins in different living environments. There are many small black spots on each scale on the body. Male individuals are more colorful than female individuals. The abdomen is bright white.
The most obvious feature of sexually mature females and males is the redness of the snout, the male is darker and more colorful than the female, the body is slender, the fins are red, the dorsal fin and fin are larger than the females; the females are obviously fatter than the males, the color is dull, and the abdomen is slightly white. Fertilized eggs are sticky and can be laid multiple times a year.
From the field site observation, it is found that tang fish like to move on the upper water surface, especially around aquatic grass. Often gathered in small groups, as few as 3-5 tails, as many as 20-30 tails, the group has no fixed members, often have random additions and withdrawals. In shallow and clear streams prefer to counter-current top water. Activities are frequent in the morning, afternoon and dusk on sunny days. Tang fish are quite docile and bold, and tapping the water surface in large ponds often attracts them to gather and swim near the sound source.
Tang fish is a broad-temperate fish, in the water temperature range of 5.0-33.0 °C can grow, the water temperature is lower than 14 °C when the activity slows down, 7 °C often sinks to the bottom of the water or hides in the aquatic grass, at this time lifting the water hyacinth in the pond can often find individuals hiding in the root bushes, and often gather in groups. From the end of January to February of each year, the lowest temperature in guangzhou, tang fish can overwinter naturally, and no frostbite deaths have been reported.
Tang fish are omnivorous animals, feeding mainly on the larvae and branches of the water copepods, and also eat planktonic or benthic algae, especially the larger or filamentous species of benthic diatoms and green algae. The feeding intensity of tang fish has a certain relationship with the biological richness of bait and the change of water temperature, in the summer and autumn, the food of bait is more abundant, the water temperature is higher, the feeding of tang fish is more vigorous, the food in winter and spring is relatively less, the water temperature is lower, the feeding intensity is lower, and the feeding intensity is less affected by reproductive activities.
Breeding and breeding
Broodstock rearing
Broodstock are suitable for cultivation in aquariums of 100 cm × 50 cm × 45 cm, using small air pumps for oxygenation, water temperature control in the range of 24 ~ 26 ° C, to watch ornamental fish artificial compound feed and harvest insects arvedic larval feeding, bait 4 times a day, the bait rate is 3% to 5%. Suction sewage every two days, change the water twice a month, the first time the water is 1/2, and the second time is a full water change. The temperature difference should not exceed 2 ° C when changing water, and the new water should be aerated for half an hour before it can be used. Before the birth, the broodstock of Tang fish are intensively cultivated, the water temperature is controlled at about 24 °C, the artificial compound feed and harvest insects with a protein content of more than 41% are fed, the amount of bait should be increased to 4% to 6% of the body weight of the broodstock, and the sun lamp is used to enhance the light during the day, and the water is changed every two days, and the water exchange is 1/3.
Broodstock pairing and reproduction
Select a 30cm × 20cm × 18cm aquarium as the breeding tank, stock a disinfected water lotus, maintain a water temperature similar to the intensive cultivation tank (about 24 °C), and maintain a pH value between 6.5 and 7.0. Generally in the evening, choose the female fish with enlarged abdomen and lighter body color and the male fish with strong body and bright colors for pairing, it is recommended to put only one female fish per tank, and 1 to 2 male fish. This facilitates paired observation of tang fish and collection of fertilized eggs. By around 8:00 a.m. the next morning, the chase behavior can occur, and then the eggs can be laid, and the egg-laying climax can last for 2 to 3 hours. During the tail crossing, the male fish is close to the female from the side, and the tail is tightly wrapped around the female from the bottom up, and the fertilization and spawning process is completed in an instant. Tang fish spawn is a multi-batch type, tang fish lay 12 to 20 eggs at a time per tail, with an interval of 3 to 8 minutes to cross the tail, and each female fish lays up to 400 to 600 eggs.
Hatching of fertilized eggs
The mating female prefers to lay her eggs in the corner of the tank. Because tang fish have the habit of eating eggs, in order to prevent the eggs they produce from being eaten, the eggs they produce should be collected in a petri dish in time to hatch, and the broodstock that have laid eggs can also be fished out for temporary rearing alone, and the eggs hatch in the breeding tank. In addition, there is an option of hanging a small eye cage in the breeding tank, and then placing multiple pairs of broodstock into the cage for breeding, and the fertilized eggs produced fall outside the cage to hatch. The optimal incubation water temperature of the fertilized eggs is 25 ~ 27 ° C, maintaining an inflated state, and the dissolved oxygen is above 5mg/L. The next day, the unfertilized dead eggs should be sucked out in time to prevent polluting the water quality, and the fertilized eggs can hatch out of the membrane after 72 hours.
Rearing of juvenile fish
Hatched baby fish can be temporarily raised in a 1000 mL beaker, keeping the water temperature at 26 to 28 °C. After 3d opening, the cruise mode is gradually established, keeping micro-inflated, feeding shrimp with micro-sac bait BP powder and harvest worm chymomy slurry every 2h, and waiting for the position of the fish intestines to have a slight color. Bait should be thrown in small quantities and times, change the water once a day, and pay attention to maintaining the stability of water temperature and pH. After 20 to 22 days of cultivation, the baby fish can directly feed the in vivo of the macrophyllum macrophyllum larvae, transfer it to a glass tank of 30 cm × 20 cm × 18 cm, and after 30 days transfer to 60 cm × 36 cm × 45 cm glass tank feeding, at this time its feeding ability is the strongest, the amount of bait should be increased, with artificial compound feed and harvest nymph larva mixed feeding, when its body grows to 2 cm, it is appropriate to maintain density feeding, it is generally recommended to cultivate 500 to 600 per cubic water body.
Rearing of adult fish
During this period, the bait feeding should be strengthened, the amount of bait should be increased to 4% to 5% of the body weight, the water temperature should be controlled at about 25 ° C, the sewage should be sucked once every two days, the water should be changed 1/2 every week, the water should be changed once a month, the water should be kept fully replaced, and the temperature difference should not exceed 2 ° C when changing the water. Before entering the adult stage, juveniles grow very rapidly. Some tang fish over 80 days old, individuals with early sexual maturity can reproduce and can only lay a small number of eggs. After 100 days of age, the male and female characteristics of tang fish gradually become obvious, the abdomen of the female fish begins to become larger, and the male's body color becomes bright. After the adults have reached the age of 4-5 months, they have the strongest reproductive ability and can be used as broodstock in pairs again.