Scientific name: Salvelinus namaycush
Other names; mackinaw, lake char, touladi, togue, and grey trout.
(Namaycush in Native American means “Lake Tyrane”).
Weight and measures: This species is native from Canada, where it is often called "touladi" or gray trout. It can reach 1.20 m in length and weigh over 30 kg. The world record angled specimen was 29.5 kg, caught in Great Bear Lake in 1991, northwest Canada. However, the heaviest fish was caught with a net in 1961, on Lake Athabasca in Saskatchewan, and weighed 43.6 kg.
The average weight is between 1 kg and 4 kg, even though, as it is a species that can live up to 20 years, it is common to find specimens of 1.1 mt long and 10 kg weight. In lake Argentino, Argentina, there is evidence of remarkable developed Lake trouts.
Distribution: They are native of the northern parts of North America, mainly Canada but also Alaska and, to some extent, the northeastern United States including The Great Lakes. Lake trout have been introduced into many other parts of North America, causing impact on other species and its predators (bears and eagles) as well.
In Argentina, the species was introduced in many lakes and rivers of Patagonia, but only developed in Lake Argentino and Lake Buermeister, in Perito Moreno National Park.
For several reasons, since 1930 Lake Trout has spread far from its natural region. In Chile, USA, Philippines and Singapore it was introduced for sport fishing. In 1940 its presence was detected in some lakes in Germany, also in Portugal (on Mira River) from where it spread down to Spain.
Habitat and life cycle: Lake trout is a gregarious fish that lives in small shoals of few individuals when young, and become lonely when adult. During ice melting season, this trout are often found near the surface. As surface waters warm in summer it retreats to the bottom, where water is colder and well oxygenated, living at depths between 18 m and 53 m. This is a very distrustful fish which rarely can be seen near the surface, except at night when they come up to hunt. Lake Trout do not migrate, it chooses to feed and breed in the lake.
As regards reproduction, this species prefers lentic environments (lagoons and lakes) in deep areas. Unlike other trouts, it reproduces after 6 or 7 years of life. Within the court period males are not territorial neither aggressive, though females are more numerous.
Spawning season happens during late fall and the eggs hatch 4 to 5 months later. Usually, lake trout reuses the same spawning grounds each year. Eggs are laid at night on a long rocky substrate, not in spawning beds.
Lake trout can cross with Salvelinus fontinalis (brook trout) giving birth to “Splakes”, very voracious fish.
Appearance: Lake trout is usually thin with a disproportionately large head, reason why locals call them "big head".
As a Salvelinus it has a thin pointed head, an exaggerated open mouth and the maxillary bone exceeds the edge of the eye. It has a moderately elongated body shape, which makes it a fast predator, and well developed teeth in the jaw, tongue and palate.
Its skin coloring varies according to environment factors and their physiological state; however, they are often covered with light spots on a darker background of green or grayish brown. In larger lakes they tend to be silver. They have two dorsal fins, one thicker, reddish orange fins with white borders, and a forked tail. Their bellies are white and during the spawning season fins turn pale orange.
Diet: It is a cannibal predator that feeds primarily on other fish, but also on crustaceans, mollusks, insects and even small mammals. It inhabits deep and cold waters where often travels miles in search of preys.