MITOCHONDRIAL GENETIC DIFFERENTIATION AND PHYLOGENETIC RELATIONSHIPS OF THREE Eptesicus (Histiotus) SPECIES IN A CONTACT ZONE IN PATAGONIA

Eptesicus (Histiotus) magellanicus is a relatively rare and poorly known Patagonian endemic. This species is currently recognized as a valid, butuntil recently some authors treated it as a subspecies of E. (H.) montanus. In fact, nomolecular data exist to support the distinctiveness of the former. In Patagonia, the distribution of these two speciesoverlap marginally; they are also sympatric with a third Histiotus species,E. (H.) macrotus. In this study, we present for the _rsttime molecular data that corroborate morphological evidence of the separationbetween E. (H.) magellanicus from other Eptesicus (Histiotus)species, in special the ones with which it shares its distribution. Wesequenced a nuclear intron (THY) and thecytochrome b (Cyt b) gene from specimens of E. (H.) magellanicus, E. (H.) montanus, and E. (H.) macrotus, collected in theChubut Province (Argentina), and from an undescribed Eptesicus (Histiotus)species from Peru. We included these sequences in a phylogenetic analysistogether with previously published sequences of four typical Eptesicus species. The THY intron showed very little variation, while the Cyt b phylogeny recovered three highly supported Histiotus clades. A highly supported clade comprising all specimens of E. (H.) magellanicus was the _rst to split o_ Histiotus,suggesting that the Andean region was important during the early diversi_cationof the genus. Unexpectedly, the clade containing the specimens of E. (H.) macrotus and E. (H.) montanus showed no internal resolution, eitherquestioning their mutualidentity as a separate species, or suggesting the occurrence of localhybridization and introgression.