Salvelinus

Salvelinus is a genus of salmonid fish often called char or charr; some species are called "trout". Salvelinus is a member of the subfamily Salmoninae within the family Salmonidae. The genus has a northern circumpolar distribution, and most of its members are typically cold-water fish that primarily inhabit fresh waters. Many species also migrate to the sea. Most char may be identified by light-cream, pink, or red spots over a darker body. Scales tend to be small, with 115–200 along the lateral line. The pectoral, pelvic, anal, and the lower aspect of caudal fins are trimmed in snow white or cream leading edges. Many members of this genus are popular sport fish, and a few, such as lake trout (S. namaycush) and arctic char (S. alpinus) are objects of commercial fisheries and/or aquaculture. Occasionally such fish escape and become invasive species. Deepwater char are small species of char living below 80 m in the deep areas of certain lakes. They are highly sensitive to changes in the quality of the water and one species, Salvelinus neocomensis, was driven to extinction in the twentieth century. The origin of the name "char" or "charr" is unknown, but was perhaps from Celtic, such as the Irish word ceara meaning "fiery red" (found in some Celtic personal names), likely for the bright red belly of the Arctic char; or perhaps borrowed from Middle Low German schar meaning "flounder, dab"; or from Proto-Germanic *skardaz or *skeraną meaning "to cut or shear", possibly referring to its sherd-like shape. There are currently three subgenera in the genus Salvelinus: Baione, Cristovomer, and Salvelinus sensu stricto. Baione, the most basal clade in the genus, contains the brook trout (S. fontinalis), and the presumably extinct silver trout (S. agassizii). Cristovomer contains only the lake trout (S. namaycush). All other species are in the subgenus Salvelinus. If the long-finned char (Salvethymus svetovidovi) is considered a member of the genus Salvelinus, it would be classified in the subgenus Salvethymus, adding a fourth subgenus.