Chum Salmon Farming Techniques and Key Points of Feeding Management
[Local names] Ma-ha-yu, Ma-ha-yu, salmon, Ma-gao-yu.
[Morphological characteristics] The body is generally about 60 cm long. The body is elongated and laterally compressed, gradually rising behind the head. The head is large and laterally compressed. The mouth is large. The tip of the snout protrudes and curves slightly, resembling a bird's beak; during the breeding season the protrusion is most pronounced in males, curving toward each other like pincers so that the upper and lower jaws do not meet. The eyes are small. The gill openings are large. The scales are small and fine. The lateral line is distinct. Behind the dorsal fin there is a very small adipose fin, opposite the anal fin. The caudal fin is slightly forked. Body color varies considerably; when first entering fresh water from the sea, the back and sides are yellow-green, gradually turning blue-black, the belly is silvery white, and there are 10-12 orange-red nuptial color markings on each side.
[Origin and season] It migrates into the water systems of China's Heilongjiang and Tumen rivers, and is more abundant in the Ussuri River; September to October is the peak production season.
[Economic value] The chum salmon is a valuable large commercial fish. It is large and plump, with delicious flesh; it can be eaten fresh, or cured, smoked, or processed into canned goods, all of which have a distinctive flavor. The salted roe, known as the famous "red caviar," is highly nutritious and enjoys a high reputation on the international market.
The chum salmon is an export variety; its English name is Chumsalmon, and the destination country is: Japan.
Export ports: Liaoning, Heilongjiang.
Every year when the autumn wind begins to blow, the Ussuri River in China is packed with chum salmon. The Hezhen people living on both banks then cheer and shout, "Da-yi-ma-ha," meaning that the fish that come and go on schedule have arrived. This is the origin of the name "Da-ma-ha-yu" (chum salmon). There are many kinds of chum salmon, distributed throughout the world.
The ancestors of the chum salmon originally lived in rivers in cold regions, but food was scarce there. In order to find food and reproduce their species, they had to swim downstream, all the way to the ocean to feed and grow. The ocean has abundant food, and they lived there freely and at ease. However, the long years did not make them fully adapt to ocean life; as their bodies grew and matured, their homesickness grew stronger and stronger, and no matter how far they were from their birthplace, they had to return home to raise their young, because young chum salmon cannot survive without the nourishment of their homeland.
The chum salmon's journey home is long and full of hardships, and along the way they must pass waterfalls several meters high and many other obstacles. But no matter how great the difficulties, they never turn back and press bravely onward. They have extremely keen olfactory organs, and the scent of their homeland draws them to swim all the way back; they must swim several thousand li to reach the spawning grounds. When they first set out, their bodies are plump, their coloration handsome, and their energy abundant. They swim very fast, able to travel 40 km per day and night upstream. After days and nights of long trekking and countless hardships, they finally return to their long-parted homeland. Yet by then the chum salmon are already exhausted, their whole bodies dull and lusterless, so thin that their backs protrude like camel humps, their lower jaws turned inward into a hook shape, and their large, long teeth exposed, giving them a ferocious appearance. Even so, they are still actively preparing for their own wedding. At first they frolic and play in the clear streams, then gather in pairs and groups in small stone pits, where the female first lays her eggs and the male sprinkles milt over them; this is the most glorious moment in the chum salmon's life. Once spawning is complete, the chum salmon are utterly exhausted, having completed the journey of life in the sweet waters of their homeland, and they slowly die. At this time the river is filled with thousands upon thousands of chum salmon carcasses, and their offspring begin to hatch and grow right here.
The eggs of the chum salmon are much larger than those of ordinary fish, with a diameter of 7 mm, and contain rich nutrients to supply the development of the young fish. Their embryonic development period is very long, requiring 3-4 months before the young fish can hatch from the egg membrane. Newly hatched young fish are about 2 cm long and still carry residual yolk beneath their bellies to provide nutrition for their continued development. Only when they have grown to about 4 cm do they leave the hatching nest one after another and go to nearby waters to forage for small animals; sometimes the carcasses of their parents also become their food. The time when young chum salmon hatch is early spring, when the weather is still very cold and other fish have not yet revived, so the environment is safe for them. After they grow to 6 cm, they must leave their homeland and set out downstream with the rushing current toward the sea.
Fish like the chum salmon that are born in fresh water, then grow up in the ocean, and as adults migrate upstream back to their homeland to reproduce their offspring are called anadromous migratory fish.