Genetic structure of Rhodeus sinensis reflects historical imprints of East Asian paleo-drainages

Abstract

ABSTRACTA complete reconstruction of the history regarding the distribution of a species requires a separate analysis of the events before and after colonizing the current distribution. In a freshwater species, the historical pattern of linkages between water systems, as an event before colonization, can be determined by examining the phylogenetic relationship between the populations from different drainages. Given the insular nature of freshwater systems, on the other hand, intra-population genetic diversity is largely related to the effective sizes of the first colonizing populations and the habitat capacities. This study analyzed the genetic diversity and structure of Rhodeus sinensis, a freshwater acheilognathid inhabiting the southern and western parts of the Korean Peninsula using two mitochondrial and twenty microsatellite loci. Korean R. sinensis appears to have originated from mainland China along the paleo-Yellow river across the vast continental shelf of the Yellow Sea and first colonized the west coast of the Korean Peninsula, based on phylogenetic data obtained from mitochondrial loci. These west coast populations have remained relatively small, and populations that migrated south appear to have thrived in the southwestern part of the peninsula, where the populations thereby displayed relatively high genetic diversity. Southern populations appear to have been formed by the movement of relatively small numbers following geological fluctuations, which likely have left traces of genetic drift throughout history, as also reflected in our results. The population of this species on the southeast coast of the peninsula appears to have been established by anthropogenic translocation.

Keywords

• Rhodeus sinensis
• Acheilognathidae
• Korean Peninsula
• mitochondrial DNA
• microsatellites