The term “charr” (or “char”) is used to describe five members of the genus Salvelinus. They are members of the Salmonidae family, which also includes trout, salmon, whitefish, and grayling, all of which are endemic to the temperate and cool regions of the Northern Hemisphere but have been introduced widely outside their native range.

The charr group includes only one species that is actually called a “charr” in the English language, the arctic charr (Salvelinus alpinus), which is also referred to in some scientific texts as the S. alpinus complex, because in modern times it has come to represent many fish that were previously thought to be separate species or subspecies.

The arctic charr’s four cousins include two of the most prominent species that are referred to as “trout,” the lake trout (S. namaycush) and the brook trout (S. fontinalis), and two less widely known species, the Dolly Varden (S. malma) and the bull trout (S. confluentus).

Charr and other members of the Salmonidae family are primitive fish; their fossil remains date to more than 100 million years ago. Evidence indicates that many of the more advanced or specialized families of modern-day bony fish have ancestral stocks closely resembling these primitive fish.

The most clearly evident primitive feature of the group is the lack of spines in the fins. Most of the soft rays in the fins are branched. The pelvic fins are situated far back on the body—in the “hip” region, where the legs of amphibians articulate with the body. This position differs from the location of the pelvic fins in many other species, including largemouth bass, for example, whose pelvic fins are so far forward, they are almost directly beneath the pectoral fins. Other indications of its primitive nature are an adipose fin and a crude type of air bladder.

Charr, as a group, are among the most distinguished looking and prettiest fish that appear in freshwater. Some are especially colorful, particularly in spawning mode. All have distinctive body markings, although there are great variations, depending on their environments. The lake trout found deep in one of the Great Lakes, for example, is rather bland compared to the lake trout caught in more sterile waters of the far north.

Most members of the Salmonidae family are in some way associated with cold, often rushing waters and high oxygen demands. Some, including two of the charr, are also tied to the sea, spending a portion of their lives there. All members of the family spawn in freshwater, and most require cold running water. Members of some of the sea-running species, including at least arctic charr, have become accidentally or deliberately landlocked, living and reproducing successfully entirely in freshwater, without ever taking a journey to saltwater.

Some charr species, especially arctic charr and lake trout, are of great historical, cultural, and food significance to native peoples of the Arctic or the near-Arctic and to settlers, and they have had—and, to some degree, still have both subsistence and commercial value. All native charr have rich red flesh and are excellent eating, primarily when fresh or smoked.

Some populations of the various charr have declined dramatically, and most are not what they were decades ago, in terms of overall size, as well as in the number of large individuals. In addition, some landlocked forms with limited distribution (blueback trout, Quebec red, and Sunapee trout) have become extinct, their loss in some cases hastened by stocking of nonnative salmonids.

The subject of the proper spelling of this group—charr or char—has generated spirited debate in the scientific community. The original and historical spelling is reportedly Celtic (from ceara, meaning “blood red”), and became “charre” in seventeenth-century England, then “charr.” The general public, especially the popular media, today predominantly uses “char.” Many Canadian ichthyologists, who arguably have a greater claim to the group because of the abundance of these species and studies of them, use “charr.”