Morphological, Ecological, and Genetic Variation of the Whitefish Coregonus lavaretus sensu lato from the Upper and Middle Stream of the Lena River.

The results from morphogenetic analysis of the whitefish populations from the middle stream of the Lena River and sympatric whitefish forms/species from the Baunt lake system are presented. The data showed that the lakes were inhabited by up to eight whitefish forms/species with relatively high degree of differentiation. The Dorong, Baunt, and Bolshye Kapylyushi lakes were found to be inhabited by sympatric whitefishes, similar in the number of gill rakers, but different in the perforated lateral line scale numbers. In addition, in Lake Baunt, endemic cisco-like densely rakered whitefish was found. Analysis of the mtDNA ND1 gene variation in different forms, including the whitefish populations from the middle stream of the Lena River, showed that the whitefish haplotypes from the Baunt lake system were strongly mixed and were based on several well-defined phylogenetic lineages. The cisco-like whitefish is of more ancient origin than other species of the pidschian-like whitefishes of the genus Coregonus. [ABSTRACT FROM AUTHOR]