1, species classification
Rainbow trout: Rainbow trout is an important freshwater aquaculture species, which belongs to the animal kingdom, Chordata, Actinidia, Salmoniformes, Salmonidae and Pacific Salmon in biological classification. It is named after the adult fish has a rainbow-like brown-red longitudinal stripe along the lateral line.
Salmon: Salmon is a transliteration of Salmon. In a narrow sense, salmon refers to Atlantic salmon. In a broad sense, salmon also includes red salmon (red salmon), silver salmon (silver salmon), dog salmon (salmon) and king salmon (large-scale salmon).
2. Morphological characteristics
Rainbow trout: The trout body is spindle-shaped, slightly flat on the side, with a large mouth, blunt snout and small and round scales. There is a reddish brown longitudinal band like a rainbow on the side, with a short dorsal fin base, a small fat fin behind the dorsal fin, a medium pectoral fin, a small ventral fin, a blue-green, yellow-green or brown back and head top, silvery white, white or grayish white on the side and abdomen, and irregular distribution all over the body.
Salmon: The body of salmon is spindle-shaped, slightly flat on the side, with a head length slightly equal to the body height, a large mouth opening, a beak-shaped upper jaw extending to the back edge of the eye, teeth on the upper jaw, lower jaw and vomer, a short dorsal fin base, a fat fin behind the dorsal fin, a medium pectoral fin and a small ventral fin. All fins except the fat fin have black edges, and the fish body has blue and red spots in fresh water.
3. Habitat environment
Rainbow trout: Rainbow trout likes to live in fresh water with clean water quality, low water temperature, rich dissolved oxygen and abundant flow. The optimum survival water temperature is16 ~18℃, and the critical feeding water temperature is 7 ~ 24℃. When the water temperature is lower than 7℃ or higher than 24℃, it gradually stops feeding.
Salmon: There are two types of salmon: land-sealed type and migratory type, in which the land-sealed type lives in a lake completely isolated or almost completely isolated from the sea, while the migratory type lays eggs in the freshwater rivers that lead to the sea, and the eggs hatch into young fish and then return to the sea for fattening.
4. Feeding habits
Rainbow trout: Rainbow trout is a carnivorous fish, in which zooplankton, aquatic insects, etc. are mainly eaten in the fry stage, while fish, crustaceans, benthos, aquatic insects, etc. are mainly eaten in the juvenile and adult stages, and a small amount of plants, branches and leaves, seeds, etc. are also swallowed.
Salmon: Salmon is a carnivorous fish, in which benthos, aquatic insects, etc. are the main food in the fry stage, and small fish such as anchovy and herring are the main food in the juvenile and adult stages. Migratory salmon will not eat after entering fresh water during the breeding period.
5. Species difference
Salmon: It is a kind of marine fish of Salmonidae, Salmonidae, which usually lives in the Atlantic Ocean and the Pacific Ocean, and also has a small amount of output in Japan.
Rainbow trout: it is a species of rainbow trout belonging to Pacific salmon of Salmoniformes, Salmoninae, belonging to a kind of freshwater fish, and usually lives in North America, the west coast of the Pacific Ocean, Heilongjiang and other places.