Comparative phylogeography of five sympatric Hypseleotris species (Teleostei: Eleotridae) in south‐eastern Australia reveals a complex pattern of drainage basin exchanges with little congruence across species

Abstract

Aim To determine biogeographical patterns in five closely related species in the fish genus Hypseleotris, and to investigate the relative roles of drainage divide crossings and movement during lowered sea levels between drainage basins and biogeographical provinces based on the phylogeographical patterns within the group. The high degree of overlap in the distributions and ecology of these species makes them ideal candidates for comparative phylogeographical study.Location Eastern, central and south-eastern Australia.Methods A total of 179 Hypseleotris individuals were sequenced from 45 localities for the complete mitochondrial cytochrome b gene and the first 30 base pairs of the threonine transfer RNA for a total of 1170 bp. Phylogenetic relationships were hypothesized using parsimony and Bayesian analyses.

Microsatellite markers and mtDNA data indicate two distinct groups in dwarf galaxias, Galaxiella pusilla (Mack) (Pisces: Galaxiidae), a threatened freshwater fish from south-eastern Australia

“…Wong et al 2004;Thacker et al 2007;Burridge et al 2008;Schultz et al 2008). It is possible that the geographic split of G. pusilla into two broad east and west lineages relates to an ancient network of freshwater systems that facilitated gene flow across its range during a period of substantially lowered sea level (e.g.…”

Comparative population genetics of Basilichthys microlepidotus (Atheriniformes: Atherinopsidae) and Trichomycterus areolatus (Siluriformes: Trichomycteridae) in north central Chile

“…Considering that there is no clear geological evidence of secondary contact between river basins after their formation, and the area was not affected by the last glaciations (Clapperton 1994), this difference in haplotype composition might be explained by the different ecological features of the species. These different ecological attributes and habitat requirements determine how and when fish may have moved among basins during lower sea levels (Thacker et al 2007;Burridge et al 2008) or taken advantage of coastal routes (see discussion below).…”

Accurate systematic frameworks are vital to advance ecological and evolutionary studies, with an example from Australian freshwater fish (Hypseleotris)

“…Further, the clade of the remaining Australian species, which causes the western carp gudgeon to become the "basal" lineage, is only very weakly supported (lowest possible support of decay index=1). Another more recent topology of carp gudgeons (Thacker et al 2007) does not recover western carp gudgeon as sister to the other species, and is itself only based on a single mitochondrial gene (cytochrome b).…”

“…They suggest that possible morphological differences between them may also represent the same process of specialisation that they had inferred for the empire/firetail species "pair", due to developmental plasticity. Leaving aside; 1) the probability that these western carp gudgeon "forms" represent different biological species (Thacker et al 2007); 2) that any morphological differences between inland and coastal populations are still very unclear; and 3) that many short coastal rivers of eastern Australia are not particularly stable (Kennard et al 2010); this pattern sounds very like standard allopatric divergence and speciation.…”