摘要 : In the Subarctic and Arctic, the fauna of hydrothermal systems is considered to be an allochtho-nous, migration-mediated system comprised of the representatives of different taxa, which are characterized by a set of preadaptations... 展开 In the Subarctic and Arctic, the fauna of hydrothermal systems is considered to be an allochtho-nous, migration-mediated system comprised of the representatives of different taxa, which are characterized by a set of preadaptations to life in hot springs. These adaptations evolved before species had colonized this thermal anomalous environment. Hot springs characterizing by a constant temperature and hydrochemical regime appear to be the favorable sites compared to the usual local environment. The short-term existence of thermal springs on the geological time scale and their evolutionary evanescence serve as preconditions for the low fauna endemism that make up the taxa on the intraspecific and species levels. The taxonomical status of many of theseforms has not yet been defined with certainty, since populations of new species and intraspecific taxonomic categories of mollusks that inhabit thermal pools may evolve similar morphological, physiological, and biochemical features independently; i.e., they may exhibit convergent similarity. 收起