What can genetics tell us about the history of a human-mediated introduction of the golden-striped salamander south of its native range?

The golden-striped salamander is a streamside species endemic to the northwestern corner of Iberian Peninsula. In first half twentieth century, an undisclosed number individuals this were reportedly captured in Buçaco, Central Portugal, and deliberately introduced Sintra Mountains, 170 km south its native distribution range. discovery breeding population during 2015 prompted work: we used neutral genetic markers, mitochondrial DNA cytochrome b (cytb), seven microsatellite loci elucidate on relict/human-introduced nature population, identify potential source infer severity founder effect. Our results support human-mediated introduction. First, sequencing analysis cytb showed presence unique haplotype (h31) Sintra, which was detected only Buçaco two additional populations located close Mondego river. Second, that more closely related between Douro rivers (Central Portugal), instead geographically closest (southernmost), as would be expected if relict isolated interglacial refuge. Third, presents both reduced levels variability effective size when compared populations, particularly those Portugal. Consistent with funded by small (inferred herein ca. 10–11 salamanders), forms coherent unit significantly differentiated from extant C. lusitanica populations. Although our data provide supporting evidence for likely documented literature, overall, cannot unequivocally exclude other river Sintra.