First assessment of genetic diversity, population structure and historical population dynamics of Myocastor coypus (Rodentia: Echimyidae) in the centre of its native range

Myocastor coypus is a rodent native to South America that is strongly linked to river systems. Past studies on the coypu in its native distribution range were aimed mainly at its ecology and parasitology and genetic studies are very limited. Here, we used sequences of the mitochondrial D-loop control region to study the genetic diversity, population genetic structure and some aspects of historical population dynamics of coypu at the centre of its native range. Our results showed moderate to high levels of genetic diversity and an absence of genetic structure in the study area. Bayesian analysis of population structure (BAPS) showed the existence of two haplogroups distributed in most sampling sites. These results suggest that movement of coypu is independent of the structure of current known river networks and its dispersal patterns are related to flooding events and the presence of lagoons connecting river basins. The demographic expansion patterns in these populations and those of other South American mammals during the Late Pleistocene support the hypothesis that demographic changes in wild populations are related to fluctuations in climate and ecology. The mitochondrial data obtained in this study constitute the first record of these types of sequences in the native range of M. coypus.