The main biological characteristics of Chinese black buckwheat
First, the morphological characteristics of Ukrainian body shape was cylindrical, the tail slightly flat; tip, long and flat, covered with scales, resembling a snake head, mouth large, end position, mouth crack slightly oblique and extends to the eyes, the lower jaw Slightly prominent; Upper and lower jaws, veneers, and mouth flaps are covered with fine teeth; eyes are of medium size; sacral holes are large, thick and short, and sparsely thick. There is a supraorbital capillary device over the sacral cavity, with the function of assisted breathing. The body is round scaled, larger; lateral line is relatively straight, but breaks above the starting point of the anal fins, separated by 1 scale before and after, and flannel 60 to 67; dorsal fins and anal fins are long, almost connected to the circular caudal fins. No hard thorns, round pectoral fins, short pelvic fins. The anus is located on the ventral side of the midpoint of the body; the septum is relatively slender; the stomach is cystic and has two pylorus; the intestines are short and hyperbolic, only slightly more than half the body length. The back of the body is black, the abdomen is grayish or light yellow, there are many irregular black stripes on the side of the body, two black lines on the side of the head, and the odd fins have black and white patterns. The even fins are light yellow with irregular spots. The pectoral fin base has a black spot.
Second, living habits Umbilicaria are benthic fish, hi habitat in shallow water muddy grass sediment shallow areas, preferring still water or microfluidic water environment. Its survival temperature is 1 °C ~ 36 °C, the suitable growth temperature is 13 °C ~ 30 °C, the optimum growth temperature is 25 °C ~ 28 °C. When they are below 7°C or above 33°C, they will hide in the mud of deep water and stay in a crouching state. Umbellum can live in environments where other fish do not survive, and is especially tolerant to hypoxic water bodies. Even in water-free wet places, it can survive for a long period of time. It does not die in 3 to 5 days in the summer and survives in winter. a week long. The blackbird also has excellent jumping ability. Adult fish with a tail weight of 500 grams or more can leap 1 to 1.5 meters above the water surface. Juveniles can also jump up to 0.3 to 0.5 meters. They often use this skill to escape to low water levels. Artificial breeding should pay attention to prevent escape.
Third, the dietary blackbird is a ferocious carnivorous fish, predation is an attacking predator, and very bulimia. The seedling stage mainly feeds on zooplankton, aquatic insects, small fish, and small shrimps. The prey on the adult stage is broader, including scorpions, cockroaches, flanks, red-eyed oysters, wheat ears, loach, sand ploughs, and miscellaneous fish. Shrimp and so on. It has been observed that a 500-gram blackbird can actually swallow eight 8-10 centimeter grass carp species within one and a half hours. There is a habit of self-sustaining between the Uzbek species, and can swallow the same group of individuals equal to or less than 2/3 of their body length. Therefore, in the artificial breeding, it must often be divided and sorted according to individual size, or the pooling rate will be greatly reduced. The water temperature at 22°C to 30°C is the peak period of U. rufipogon feeding. During the winter, it will stop feeding. During the spawning period, it will basically not feed.
Fourth, the growth of the growing black locust quickly, generally the breeding seedlings to the end of the year up to 8 to 18 cm in length, weight 30 to 200 grams. However, because of the regional environment and population differences, the differences in the growth of Wuyi around the country are also obvious. The largest individual is known to weigh up to 9.3 kg. V. Breeding of Scaraba mate is early sexual maturity. A winter-aged fish in South China can grow eggs with a body length of 20 cm and a body weight of 130 g or more. In the Yangtze River valley and its northern area, it has 2 winter fishes, a body length of 30 cm and a body weight of 300. Above the level of sexual maturity can be reached. The breeding season of Wuhuan is from April to September in South China, from May to August in Central China, and from May to July in North China and Northeast China. Both are breeding seasons in June. The spawning grounds are mostly distributed in the shallow shoals of aquatic weeds. Before spawning, the paired broodstock will nest in the watery grass, and the eggs will be produced in the nest. After spawning, the broodstock will have the habit of protecting eggs. Eggs are golden yellow, with oil balls, buoyant, about 2 mm in diameter. Water temperature 20 °C ~ 23 °C, the fertilized eggs can be hatched by 48 to 60 hours of fry, water temperature 25 °C ~ 27 °C, after 36 to 45 hours hatched fry. Umbilicus has a small amount of eggs, about 20,000 grains per kilogram of body weight, and its eggs are matured and produced in batches. The broodstock also had the habit of guarding young children until the larvae grew into 4-8 cm juveniles and began to stop nursing when they began to travel alone.
Seminar on Artificial Breeding Techniques in Wuyi (2)
Sichuan Provincial Fisheries Research Institute Wu Jianglin