### Identification Often hailed as the "King of Fish," the Atlantic Salmon is a streamlined, silver-sided torpedo built for speed. In the ocean, they sport a gleaming metallic-blue back and white belly, peppered with small, X-shaped black spots primarily above the lateral line. When they enter freshwater to spawn, their silver "chrome" fades to a dark bronze or reddish-brown.
To distinguish them from the similar Brown Trout (*Salmo trutta*), look at the mouth and tail: the salmon’s upper jaw (maxilla) rarely extends past the rear of the eye, and its tail is slightly forked with a narrow "wrist" (caudal peduncle) that allows you to pick the fish up by the tail—a feat nearly impossible with a thick-wristed trout.
### Habitat & Range These anadromous athletes bridge two worlds. They are native to the cool, temperate waters of the North Atlantic, ranging from the Connecticut River to the Arctic Circle in North America, and from Portugal to Russia in Europe. They require pristine, oxygen-rich gravel-bottomed rivers for spawning, while their adult lives are spent in the vast, nutrient-dense "pastures" of the open ocean.
### Behaviour The Atlantic Salmon is defined by its obsessive homing instinct. After years at sea, they navigate thousands of miles to return to the exact stream where they were hatched. An observer at a waterfall might witness their namesake behavior—*salio* is Latin for "to leap"—as they jump up to 12 feet to clear obstacles. During the autumn spawn, males undergo a dramatic transformation, developing a "kype" (a hooked lower jaw) used for sparring with rivals over nesting sites, known as redds.
### Diet In the ocean, they are opportunistic predators, gorging on capelin, herring, and crustaceans like krill, which provide the pigments that turn their flesh pink. Remarkably, once they enter freshwater to spawn, they cease feeding entirely, living off stored body fat for months while they focus solely on reproduction.
### Fascinating Fact Atlantic Salmon possess a "chemical GPS" so sensitive they can detect the unique scent of their home river’s minerals and vegetation at a concentration equivalent to one drop of water in an Olympic-sized swimming pool.