Distribution Patterns of Tubifex tubifex (Oligochaeta, Tubificinae) Genetic Lineages in Relation to Environmental Factors in the Vychegda River Basin

The results of DNA barcoding of Tubifex tubifex from various freshwater bodies within the Vychegda River basin (Komi Republic, Russia) are presented. The molecular genetic analysis of 32 specimens collected from 14 sites based on nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (cox1) gene revealed six distinct lineages (A, B, C, D, E, and J), exhibiting interlineage divergence exceeding 17–24%. A significant correlation was found between the genetic diversity of the species and habitat characteristics, including hydrological and hydrochemical parameters of water and sediments. The ecological differentiation confirms the presence of heterogeneous adaptive traits within T. tubifex and highlights the importance of considering the population genetic structure in ecological assessments of freshwater ecosystems.