DOI: 10.5061/dryad.g81c8
title: Data from: Genetic reconstruction of a bullfrog invasion to elucidate vectors of introduction and secondary spread

description: Reconstructing historical colonization pathways of an invasive species is
 critical for uncovering factors that determine invasion success and for
 designing management strategies. The American bullfrog (Lithobates
 catesbeianus) is endemic to eastern North America, but now has a global
 distribution and is considered to be one of the worst invaders in the
 world. In Montana, several introduced populations have been reported, but
 little is known of their sources and vectors of introduction and secondary
 spread. We evaluated the genetic composition of introduced populations at
 local (Yellowstone River floodplain) and regional (Montana and Wyoming)
 scales in contrast to native range populations. Our objectives were to (1)
 estimate the number of introductions, (2) identify probable native
 sources, (3) evaluate genetic variation relative to sources, and (4)
 characterize properties of local- and regional-scale spread. We sequenced
 937 bp of the mitochondrial cytochrome b locus in 395 tadpoles collected
 along 100 km of the Yellowstone River, from three additional sites in MT
 and a proximate site in WY. Pairwise ΦST revealed high divergence among
 nonnative populations, suggesting at least four independent introductions
 into MT from diverse sources. Three cyt b haplotypes were identical to
 native haplotypes distributed across the Midwest and Great Lakes regions,
 and AMOVA confirmed the western native region as a likely source. While
 haplotype (Hd = 0.69) and nucleotide diversity (π = 0.005) were low in
 introduced bullfrogs, the levels of diversity did not differ significantly
 from source populations. In the Yellowstone, two identified haplotypes
 implied few introduction vectors and a significant relationship between
 genetic and river distance was found. Evidence for multiple invasions and
 lack of subsequent regional spread emphasizes the importance of enforcing
 legislation prohibiting bullfrog importation and the need for continuing
 public education to prevent transport of bullfrogs in MT. More broadly,
 this study demonstrates how genetic approaches can reveal key properties
 of a biological invasion to inform management strategies.
description: KX344485
 Sequence data
 for the American Bullfrog (Lithobates catesbeianus) mitochondrial
 cytochrome b haplotype, MT1 KX344486
 Sequence data
 for the American Bullfrog (Lithobates catesbeianus) mitochondrial
 cytochrome b haplotype, MT2 KX344487
 Sequence data
 for the American Bullfrog (Lithobates catesbeianus) mitochondrial
 cytochrome b haplotype, MT3 KX344488
 Sequence data
 for the American Bullfrog (Lithobates catesbeianus) mitochondrial
 cytochrome b haplotype, MT4 KX344489
 Sequence data
 for the American Bullfrog (Lithobates catesbeianus) mitochondrial
 cytochrome b haplotype, MT5 KX344490
 Sequence data
 for the American Bullfrog (Lithobates catesbeianus) mitochondrial
 cytochrome b haplotype, MT6 KX344491
 Sequence data
 for the American Bullfrog (Lithobates catesbeianus) mitochondrial
 cytochrome b haplotype, MT7 KX344492
 Sequence data
 for the American Bullfrog (Lithobates catesbeianus) mitochondrial
 cytochrome b haplotype, WY8 Bullfrog cytb haplotype
 data This file contains data
 on cytochrome b (cyt b) haplotypes of invasive American Bullfrogs
 (Lithobates catesbeianus) sampled at sites in Montana and Wyoming, with
 associated metadata (collection year, population/river, state, latitude,
 longitude, and sample size). It also contains bullfrog native range data
 extracted from the text of Austin et al. 2004, including haplotype
 composition, region, and location (description, town, state, latitude,
 longitude) of each sampling site. Two data files compiling native range
 and introduced haplotype data are prodvided, which were used to create
 haplotype distribution maps (Figures 3 and S1 of Kamath et al.
 2016). Bullfrog cytb haplotype
 metadata.xlsx Bullfrog diversity and
 differentiation input files This folder contains the
 Arlequin v3.5 input files used to estimate diversity within and
 differentiation between introduced American Bullfrog (<em>Lithobates
 catesbeianus</em>) populations in Montana and Wyoming. AMOVA input
 files used to evaluate differentiation between the introduced and native
 range are also provided. Results from these analyses are shown in Tables
 1-3. Arlequin Input
 Files.zip Yellowstone River
 Bullfrogs: Isolation by distance This folder contains the
 R code and data input files used to examine the relationship between
 genetic distance and geographic river distance in invasive American
 Bullfrog (Lithobates catesbeianus) populations along the Yellowstone
 River. Description of the individual files can be found below.
 Yellowstone_HapDistribution.zip