Population genetics of the capybara, Hydrochoerus hydrochaeris, in the Chaco-pampean region

Abstract

Hydrochoerus hydrochaeris is an herbivorous rodent that inhabits most wetlands of South America. It is a well-known species, but studies about their population genetics are scarce. The aim of this study was to analyze the genetic diversity, population genetic structure and historical population dynamics of the species in the Chaco-pampean region, using mitochondrial DNA control region sequences and a non-invasive sampling design. Our results showed the existence of four haplogroups in the study area. Haplogroup I is composed by individuals from most of the study area, while the remaining include individuals from some sites in Paraguay (haplogroups III and IV) or Argentina (haplogroup II). The genetic diversity was low in haplogroups I, III and IV. Our results suggest that the Paraná and Paraguay rivers would be acting as a migration corridor for the species. Historical population dynamics analyses and haplotype network showed past population expansions and secondary contact between haplogroups I–II and I–IV, which could be related to past climatic events such as the Iberá Wetlands formation. These results must be taken as working hypotheses for future studies about the population genetics of capybara and related species inhabiting the region.