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Atlantic Salmon are slender spindle fish often somewhat laterally compressed, usually with smallish fins and a well forked tail and are well adapted to a free swimming life in mid-water. They have quite small rounded scales. Their mouth is armed with single rows of sharp curved teeth. And the digestive canal is simple with a single loop at the stomach and a short intestine that runs directly back to the anus. Like other Pacific salmons, they undergo a huge physical transformation as breeding approaches. This transformation is particularly spectacular in the male, which starts as a sleek, silvery, trout-like fish before going upriver. They then develop large, hooked jaws, a humped back, and bright red and green coloration.

How do they behave?

In reproduction, the eggs are laid in gravel nests in freshwater streams. The hatchlings, or alevin, remain in the nest until they absorb all the nutrients in their yolk sac, then emerge as feeding, free-swimming fry. The fry leave the stream and live as parr in rivers or small lakes before turning silvery and entering the sea as smolt. After a period of life in saltwater, the adult undergoes dramatic changes in shape and coloration and returns to the stream in which it hatched to spawn and die, beginning the cycle again.

What else should you know about them?

Many salmonids are of great importance as food fishes – important for aboriginal, commercial, and recreational fisheries, and also in aquaculture. They are highly prized as food and angling fishes, and are also of great interest to biologists because of their amazing migratory habits.