Arctic Char

The Arctic char or Arctic charr (Salvelinus alpinus) is a cold-water fish in the family Salmonidae, native to alpine lakes and arctic and subarctic coastal waters. Its distribution is Circumpolar North. It spawns in fresh water and populations can be lacustrine, riverine, or anadromous, where they return from the ocean to their fresh water birth rivers to spawn. No other freshwater fish is found as far north; it is, for instance, the only fish species in Lake Hazen on Ellesmere Island in the Canadian Arctic. It is one of the rarest fish species in Britain and Ireland, found mainly in deep, cold, glacial lakes, and is at risk from acidification. In other parts of its range, such as the Nordic countries, it is much more common, and is fished extensively.

The Arctic char is closely related to both salmon and lake trout, and has many characteristics of both. The fish is highly variable in colour, depending on the time of year and the environmental conditions of the lake where it lives. The appearance of Arctic char differs between populations. The dorsal side of the Arctic char is dark in its colour while the ventral varies from red, yellow, and white.

Arctic char has a distinct size dimorphism, dwarf and giant. Dwarf Arctic char weigh between 0.2 and 2.3 kg (7 oz and 5 lb 1 oz) and average a length of 8 cm (3 in), while giant Arctic char weigh between 2.3 and 4.5 kg (5 lb 1 oz and 9 lb 15 oz) and average 40 cm (16 in) in length. Individual fish can weigh 9 kg (20 lb) or more with record-sized fish having been taken by anglers in Northern Canada.

Arctic char is notable for exhibiting numerous, seemingly distinct morphological variants or 'morphs' throughout the range of the species.  Consequently, Arctic char have been referred to as the 'most variable vertebrate on Earth'. These morphs are often sympatric within lakes or rivers. Morphs often vary significantly in size, shape, and colour.  Morphs often demonstrate differences in migratory behaviour, being resident or anadromous fish, and in feeding behaviour and niche placement.  Morphs often interbreed, but they can also be reproductively isolated and represent genetically distinct populations.

Arctic char can be anadromous, landlocked, or semi-anadromous. Arctic chars found north of 65°N latitude are generally anadromous. Anadromous Arctic chars spend their juvenile years in fresh water, and once mature, migrate annually to the marine environment.  The first migration of Arctic char has been found to occur between four and 13 years of age.  When in the marine environment, Arctic chars inhabit coastal and intertidal areas.  They migrate back to frozen lakes at the end of summer. Generally, Arctic char inhabits shallow waters, rarely swimming deeper than 3 m (10 ft).  An exception to this applies to landlocked Arctic chars, which often swim much deeper in the summer in order to occupy colder waters. 

Arctic char exhibits a Circumpolar North distribution. There is no other species of fish found at a higher latitude.  Arctic char is native to Arctic and subarctic coasts and lakes of high elevations. In general, it has been observed in the Canadian Arctic, Greenland, Iceland, Scandinavia, Siberia, and Alaska. Anadromous Arctic chars migrate to the sea annually in mid-June to mid-July. After about two months, they return to fresh water to reproduce and overwinter.

The diet of Arctic char varies with season and location. During late spring and summer, Arctic char feeds on insects found on the water's surface, salmon eggs, snails and other smaller crustaceans found on the lake bottom, and smaller fish up to a third of its size. During the autumn and winter months, it feeds on zooplankton and freshwater shrimps that are suspended in the lake, and also occasionally on smaller fish. The marine diet of Arctic char consists mostly of a small crustacean species  and krill.  Lake-dwelling Arctic chars feed mostly on insects and other organisms that live in deeper waters. Some giant Arctic chars have been recorded as cannibals of their young as well as dwarf Arctic chars.

Spawning occurs over rocky shoals in lakes with heavy wave action and in slower gravel-bottom pools in rivers. As with most salmonids, vast differences in colouration and body shape occur between sexually mature males and females.

Everything You Want to Know About Arctic Char (Salvelinus alpinus) - by Orvis

Arctic Char - by fishpartner.com