DOI: 10.5061/dryad.c3g8h
title: Data from: Molecular phylogeny and phylogeography of the Australian freshwater fish genus Galaxiella, with an emphasis on dwarf Galaxias (G. pusilla)

description: The freshwater fauna of Southern Australia is primarily restricted to the
 southwestern and southeastern corners of the continent, and is separated
 by a large, arid region that is inhospitable to this biota. This
 geographic phenomenon has attracted considerable interest from
 biogeographers looking to explain evolutionary diversification in this
 region. Here, we employed phylogenetic and phylogeographic approaches to
 evaluate the effect of this barrier on a group of four galaxiid fish
 species (Galaxiella) endemic to temperate Southern Australia. We also
 tested if continental shelf width has influenced connectivity among
 populations during low sea levels when rivers, now isolated, could have
 been connected. We addressed these questions by sampling each species
 across its range using multiple molecular markers (mitochondrial
 cytochrome b sequences, nuclear S7 intron sequences, and 49 allozyme
 loci). These data also allowed us to assess species boundaries, to refine
 phylogenetic affinities, and to estimate species ages. Interestingly, we
 found compelling evidence for cryptic species in G. pusilla, manifesting
 as allopatric eastern and western taxa. Our combined phylogeny and dating
 analysis point to an origin for the genus dating to the early Cenozoic,
 with three of the four species originating during the Oligocene-Miocene.
 Each Galaxiella species showed high levels of genetic divergences between
 all but the most proximate populations. Despite extensive drainage
 connections during recent low sea levels in southeastern Australia,
 populations of both species within G. pusilla maintained high levels of
 genetic structure. All populations experienced Late Pleistocene-Holocene
 population growth, possibly in response to the relaxation of arid
 conditions after the last glacial maximum. High levels of genetic
 divergence and the discovery of new cryptic species have important
 implications for the conservation of this already threatened group of
 freshwater species.
description: Cytochrome b data file
 for all Galaxiella individuals sequencedCytochrome b data for
 all individuals included in our study in nexus format. Sequence names
 match the species initials and the field codes shown in locality code
 column in our locality data table. Samples lacking a field code used the
 first four letters of the waterbody name, while samples ending in gb were
 from GenBank.galaxiella.allspp.cytb.all.ind.nexS7 data file for GalaxiellaS7 data for all individuals included in our study in nexus format. Data were aligned with MAFFT and phased in DnaSP (each allele is indicated by .a or .b at the end of the OTU code). Sequence names match the species initials and the field codes shown in locality code column in our locality data table. Samples lacking a field code used the first four letters of the waterbody name, while samples ending in gb were from GenBank.galaxiella.s7.allspp.matft.fftnsi.byphase.nexArlequin analysis file (part 1 of 2) for Galaxiella pusilla Cytb sequencesThe input file to Arlequin. Note you need the haplotype file to be in the same directory. This version of the file is grouped by population, with the structure edited for all G. pusilla populations. To examine the two lineages within G. pusilla you need to restructure the groups.pusilla.by.pop.arpArlequin analysis file (part 2 of 2) for Galaxiella pusilla Cytb sequencesThe haplotype file which is part of the input to Arlequin. Note you need the Arlequin project file to be in the same directory.pusilla.by.pop.hapDnaSP input analysis file for Galaxiella pusilla Cytb sequencesInput file for DnaSP grouped by population. This is the same file used to create the Arlequin input files.pusilla.by.pop.nexCytochrome b haplotype data file for GalaxiellaReduced cytochrome b data files containing only the haplotypes included in our study in nexus format. Sequence names match the species initials and the field codes shown in locality code column in our locality data table. Samples lacking a field code used the first four letters of the waterbody name, while samples ending in gb were from GenBank.galaxiella.spp.cytb.by.hap.nex