Paths of introduction: Assessing global colonization history of the most
successful amphibian invader
Abstract
International socioeconomic relationships form the background that
underlies the history of invasive species. Species with economic value,
such as the North American bullfrog (Lithobates catesbeianus), are more
likely to become internationally distributed and to be subsequently
introduced to non-native areas and, consequently, become more difficult
to control. Using population genetics methods, we investigated the
invasion pathways, the connectivity among clusters in different
countries and the native population of origin of globally introduced
bullfrog populations. Throughout the analysis of seven microsatellite
nuclear loci, one fragment of the mitochondrial cytochrome b locus, and
historical information, four main lineages were identified and analyzed
along with previous findings. This species’ capability to colonize
several countries from few starting lineages highlights the necessity to
control new propagule pressure to ensure successful management programs,
as high inbreeding and bottleneck effect seem not to diminish the
invasive success of this species. There is a consensus between markers
that most areas of South America belong to the same genetic population
while populations in Asia have a more complex history of introduction.