Diversidad genética y abundancia relativa de Didelphis marsupialis y Didelphis virginiana en Chiapas, México Genetic diversity and relative abundance of Didelphis marsupialis and Didelphis virginiana in Chiapas, Mexico

In wide distribution species, as D. marsupialis and D. virginiana, large population sizes, high diversity and little genetic differentiation are predicted. In this study, the relative abundance of D. marsupialis and D. virginiana by capturing organisms in the Highlands and the Central Depression regions, in Chiapas, was estimated. Also the diversity and structure genetic from 7 microsatellite loci were estimated. The relative abundance was low (between 0.008-0.06 individuals traps nights) and the highest incidence of opossums was observed in the Central Depression. The sex ratio was significantly adjusted to the relation 1:1 in both species. The greater genetic diversity was recorded in the Central Depression in D. virginiana (He= 0.58), with high levels of inbreeding. Genetic differentiation moderate was observed between species (Frt= 0.13) and minimum among populations of each species (Fsr= 0.01). Although the values of genetic diversity were moderate, D. marsupialis and D. virginiana have low abundances with high levels of inbreeding, which may have negative consequences in the future on the genetic variability of these species in the studied populations.