Context. Galaxiids are a widespread, Southern Hemisphere radiation of mostly obligate freshwater fishes. Tasmania houses a diversity of endemic species of Galaxias and Paragalaxias. Of these, many are at risk of extinction, being landlocked, range-restricted, and subject to anthropogenic threats, placing a high conservation priority on the region. 

Aim. Our aim was to synthesize historic and published molecular datasets to provide the sound systematic framework needed to underpin future conservation and taxonomic efforts for Tasmanian galaxiids.

Methods. Novel and published nuclear (allozyme) and matrilineal (cytb) datasets were generated and integrated for every putative Tasmanian galaxiid species lacking a comparable multi-gene assessment.

Key results. The Tasmanian galaxiids are phylogenetically diverse, with molecular data generally supporting the accepted taxonomy, but with potential species-level diversity noted within an alpine radiation of the Galaxias truttaceus complex and further support for synonymy of Galaxias niger within Galaxias brevipinnis.

Conclusions. This study highlights the value of multi-locus studies in both validating species-level taxonomy and resolving taxonomic ambiguities and conservation priorities within Tasmania’s galaxiids.

Implications. Our integrated genetic analyses provide a framework to underpin more in-depth genomic approaches to assess additional cryptic diversity and conservation planning, such as genetic rescue and ex situ population security.

Allozyme electrophoresis on muscle homogenates was undertaken as described elsewhere (Richardson et al. 1986; Hammer et al. 2007). Homogenates were successfully screened for various combinations of the enzymes employed in our other studies on galaxiids (Adams et al. 2014; Morgan et al. 2016). Histochemical stain recipes plus enzyme, locus and allozyme nomenclature all follow Hammer et al. (2007).

• Adams M, Raadik TA, Burridge CP, Georges A (2014) Global biodiversity assessment and hyper-cryptic species complexes: More than one species of elephant in the room? Systematic Biology 63, 518–533.
• Hammer MP, Adams M, Unmack PJ, Walker KF (2007) A rethink on Retropinna: conservation implications of new taxa and significant genetic sub-structure in Australian smelts (Pisces : Retropinnidae). Marine and Freshwater Research 58, 327–341.
• Morgan DL, Beatty SJ, Close PG, Allen MG, Unmack PJ, Hammer MP, Adams M (2016) Resolving the taxonomy, range and ecology of biogeographically isolated and critically endangered populations of an Australian freshwater galaxiid, Galaxias truttaceus. Pacific Conservation Biology 22, 350–359.
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