The Origin and Dispersal of Chars of the Genus Salvelinus (Salmonidae, Salmoniformes)

A new approach to addressing the issue of origin and dispersal of Salvelinus chars is proposed. It is based on the analysis of the ecology and biology of multiplication of species and forms during the climatic and geological evolution of Earth. As a result, a conclusion is drawn that the ancestor of chars was formed from one of the coldest-water populations of the phyletic lineage Parasalmo clarki–Salmo trutta that inhabited an isolated eastern part of the Arctic in the early Pliocene. With further cooling of the climate in the East Arctic, the chars gradually adopted to the colder habitat conditions, and the stages of this adaptation were subsequently fixed during isolations of the ancestral forms outside the region. The most ancient of the char species, Salvelinus leucomaenis, evolved approximately 4 Ma ago. Most other species of this genus were formed in the late Pliocene during the first glaciation of the Northern Hemisphere. Cristivomer namaycush is considered as belonging to the subfamily Huchoninae, while the phylogenetic branch of S. svetovidovi was formed independently from Salvelinus chars in the Pacific Ocean. The evolution of salmonids since the late Miocene proceeded toward adaptation to progressive climate cooling; therefore, Salvelinus chars, as well as C. namaycush, acquired a convergent similarity as the coldest-water representatives of the phyletic lineages Salmoninae and Huchoninae.