Kaluga (sturgeon) scientific name for the sturgeon, is a kind of sturgeon, mainly produced in the waters of the Heilongjiang River, the hometown of the Heilongjiang River, the body is huge, the general weight of 50 to 100 kilograms, the big ones up to 1,000 kilograms, for large carnivorous fish. Known for its long life, large body, much food, strong strength, known as ? Living fossil? Giant panda in the water? The king of freshwater fish is known as. It only exists in the border river between China and Russia, the Heilongjiang River. In 1998, the United Nations Washington Convention recognized the sturgeon as an endangered species.

The sturgeon is about 2 meters long, and the largest can be up to 5 meters long. The head is slightly triangular with a long, sharp muzzle. The surface of the head is covered with most of the bone plate. The lower part of the mouth is wide and slightly curved; there are two pairs of kissing whiskers in front of the mouth, the inner whiskers are slightly in front, and the outer whiskers are more back. Eyes small, closer to end of muzzle. Right and left gill membranes extended ventrally, fused to each other, all with 5 rows of longitudinal rhombic bony plates, bony plates with sharp, slightly curved spines. The dorsal plates are 1 row, larger, 10-16 pieces, located in the middle of the back, connecting directly to the caudal fin from the back of the head. There are 2 rows of dorsal and 2 rows of ventral plates, 32-46 dorsal plates; 8-12 ventral plates; and 1 or 2 less obvious plates after the base of the ventral fin. Other parts of body smooth and scale-free. Dorsal fins 43 to 57, located posteriorly; anal fins 26 to 36; their beginning is below the posterior part of the dorsal fin. Caudal fin crooked, upper lobe long and pointed. Body surface blackish-blue, sides yellow, ventral surface grayish-white; dorsal bony plates yellow, lateral bony plates yellowish-brown.

Habitat:

Koi lives in large rivers, mostly at the confluence of two rivers, at the entrance of tributaries, and at the eddies of rapids. Prey on other fish. Distributed in the northeast, Heilongjiang is particularly common. The sturgeon is a fish that lives in the middle and lower levels of the river. Perennial habitat in freshwater, not for long-distance migration. Like to live in the big river sandwich layer, river forks and other slow current or rapid eddy at the gravel and gravelly water bottom. Do not like grouping, often scattered activities. Sew large rivers swim unusually active when the water rises, commonly with the phenomenon of tumbling and leaping. When the water recedes, it is less active. Winter in the depths of the river overwintering, early spring began to migrate to the spawning ground.

The juvenile sturgeon feeds on benthic invertebrates and aquatic insect larvae; it switches to fish after one year of age. The sturgeon's diet is quite large, and its period of fattening coincides with the anadromous movement of salmon, which often scurries into schools of fish to prey on the salmon. Some people have dissected a 250-kilogram sturgeon, surprised to see that its stomach food is as much as 15 kilograms. Reproductive period to stop taking food.

The sturgeon is a regional migratory fish, inhabiting the river, long-term in the Heilongjiang Fuyuan County, the territory of the river for the larger water migratory activities (less in the Ussuri River), like in the bottom of the gravel section of the river for bait, and in the winter set in the river in the deeper water overwintering.

Growth and reproduction:

It takes more than 16 years for the fish to reach sexual maturity and start reproducing at a length of 1.6-2 meters. Females spawn from May to July, at a water temperature of 15-17°C. Spawning takes place in sandy river sections with smooth currents and water depths of 2-3 meters, with the eggs adhering to the gravel. The number of eggs laid is amazing, about 600,000 to 4 million. The amount of eggs carried varies according to the size of the fish, generally from 400,000 to 3 million, and the weight of the ovaries is mostly about 17-38 kilograms, with those of large individuals weighing up to 75 kilograms. Mature eggs are grayish-black in color, and each grain is about the size of a pea.

Juvenile fish in the spring river thawing into shallow waters to solicit bait, adult fish in the spring in May?June began to spawn swimming, in the river water temperature of 16 ℃?18 ℃ into the spawning ground, began to spawn

Chinese sturgeon Heilongjiang sturgeon artificial propagation technology in the late 50's that has been successful. Qindeli Shi's sturgeon breeding and releasing experimental station, completed in 1988, in 1989, artificial breeding was successful, and in Heilongjiang Qindeli farms in a small amount of the river section of the release. Heilongjiang Province has built five sturgeon release station, two salmon release station, a beach head Yarrow fish release station, two aquatic wildlife rescue center, Shi's sturgeon and dachshund sturgeon original seed farms, that is, Qindeli Shi sturgeon aquaculture and release test station, Fuyuan County salmon, sturgeon and koelu release station, Dongning County, salmon, beach head Yarrow fish release station, Heilongjiang Province, Lobei sturgeon and koelu release base, Heilongjiang Province Aquatic Wildlife Rescue Center, Harbin City Aquatic Wildlife Rescue Center, Provincial Specialty Fish Research Institute sturgeon pilot base, Dachshund sturgeon original seed farm and Tongjiang City, Jinjiekou sturgeon release station.