Allozyme variation and taxonomic status of Calomys hummelincki (Rodentia, Sigmodontinae)

The level of genetic polymorphism was analyzed in a population sample of Ca lomys hummelincki from Venezuela. Enzymes and proteins studied by means of gel electrophoresis give information on 30 loci. The proportion of polymorp hic loci was 40 %, and mean expected heterozygosity (H-e) was 12.7 %. These values are higher than those reported for most species of rodents in the n orthern hemisphere, but are comparable to those observed in other Sigmodont inae species from Argentina. Nei's genetic distance (D-N) with the species C. laucha, C. venustus, and C. musculinus ranged from 0.289 to 0.494. D-N v alues between populations of different Sigmodontinae species are below 0.09 . A distance Wagner tree based on modified Rogers' distances shows that C. hummelincki is more closely related to C. venustus than to C. laucha. Our d ata support the proposal that C. hummelincki and C. laucha are fully distin ct species.