What's In a Name?
Lake trout: named for the habitat in which it is found

Salvelinus (sal-veh-lynn´-us) taken from a word meaning "little salmon"
namaycush (nam´-ay-cush) a Native American name, translated as "tyrant of the lakes"

How Big Do They Get?
How Long Do They Live?
In Lake Superior, lake trout reach 114.3cm (45 in) or more and can weigh over 18.2 kg (40 lbs). They are usually smaller in inland lakes, and even in Lake Superior you are most likely to catch lakers in the range of 450-650 mm (18-26 in) and about 1.4-2 kg (3-4.5 lbs). Minnesota's state record for lake trout is a whopping 19.7-kg (43 lbs 5 oz). It was caught from Lake Superior in Cook County. Lake trout commonly reach the ages of 12-16, but they can live for 25 years.

What Eats Them?
Young lake trout are eaten by a variety of piscivorous (fish-eating) fishes. Adults have very few predators because they live in deep waters. Their major predator, besides humans, is the sea lamprey, which has contributed greatly to the decline of lake trout populations in the Great Lakes.

How Do They Reproduce?
Lake trout spawn in the fall, mostly in October though early November, when water temperature falls below 10° C (50° F). They spawn over boulder beds where water currents keep the rocks clear of silt. Lake trout do not dig nests, but the early arriving males clear away algae, slime, and any other debris by fanning the rocks with their fins and scraping them with their bodies. Males are not territorial and they do not fight over females. Spawning takes place over the rock as males press along side of females. Sometimes two males and one female are involved. Sometimes several males and females form a spawning group. Each fish will repeat the spawning act many times over a period of days or weeks. The fertilized eggs sink to the rock bottom and fall into the protective crevices. Here the current of the passing water keeps the eggs oxygenated and silt free. A single female may lay 2,000-20,000 eggs depending on her size. The embryos develop for 4 to 5 months and hatch into alevins (free swimming embryos) then in February and March. The alevins live in the rock crevices for another few weeks while they finish their fin development. Then they disperse into the lake.

Conservation and Management
Lake trout used to be a very important commercial fish in the Great Lakes. A combination of predation by the sea lamprey, declines in the cisco populations (their main food), and overfishing caused their populations to go way down. Today they are recovering in Lake Superior, but they probably will never return to their previous numbers. The lake now has exotic competitors, like coho and chinook salmon, as well as exotic forage fish like smelt and alewives. The ecosystem is a very different one from what it was when the lake trout was king.

"Cool Fact": For many years the Canadian and American governments have been working to control the sea lampreys in the Great Lakes. They do this by using poisons that selectively kill larval sea lampreys.