Morphological, ecological and mtDNA sequence variation in coregonid fish from the Baunt Lake system (the Vitim River basin)
Bochkarev, Nickolay A.; Zuykova, Elena I.; Abramov, Sergey A.; Katokhin, Alexey V.; Matveev, Arkady A.; Samusenok, Vitaly P.; Baldina, Svetlana N.; Gordon, Natalia Y.; Politov, Dmitry V.
We performed morphological, ecological and genetic analyses of taxonomically complex sympatric whitefish forms inhabiting the Baunt Lake system in the Vitim River basin, Transbaikalia. It was shown that the whitefish forms in this system clearly differed based on morphological traits, growth rate and diet. The most significant differences were based on the number of gill rakers, while the number of lateral line scales was similar. These whitefish had distinct diets, namely euryphagous and planktivorous diets. We developed a phylogeny of mtDNA haplotypes among the whitefish species and populations from the Baunt Lake system and the headwater regions of the Ob and Yenisei River basins. A morphologically homogeneous cisco-like whitefish sample revealed two distinct mitochondrial lineages. A strong genetic divergence between the first mitochondrial lineage of cisco-like whitefish and all of the studied whitefish forms was revealed. We analyzed alternative hypotheses regarding the origin of cisco-like whitefish and the densely rakered whitefish form from the Baunt Lake system.