Disentangling the Genetic Relationships of Three Closely Related Bandicoot Species across Southern and Western Australia

• Main Authors: Rujiporn Thavornkanlapachai, Esther Levy, You Li, Steven J. B. Cooper, Margaret Byrne, Kym Ottewell
• Format: Article
• Language: English
• Published: MDPI AG 2021-12-01
• Series: Diversity
• Subjects: golden bandicoot; southern brown bandicoot; quenda; phylogenetic; taxonomy; evolutionarily significant unit
• Online Access: https://www.mdpi.com/1424-2818/13/1/2

The taxonomy of Australian <i>Isoodon</i> bandicoots has changed continuously over the last 20 years, with recent genetic studies indicating discordance of phylogeographic units with current taxonomic boundaries. Uncertainty over species relationships within southern and western <i>Isoodon</i>, encompassing <i>I. </i><i>obesulus</i>, <i>I. auratus</i>, and <i>I. </i><i>fusciventer</i>, has been ongoing and hampered by limited sampling in studies to date. Identification of taxonomic units remains a high priority, as all are threatened to varying extents by ongoing habitat loss and feral predation. To aid diagnosis of conservation units, we increased representative sampling of <i>I. auratus</i> and <i>I. </i><i>fusciventer</i><i> </i>from Western Australia (WA) and investigated genetic relationships of these with <i>I. </i><i>obesulus</i> from South Australia (SA) and Victoria (Vic) using microsatellite markers and mitochondrial DNA. mtDNA analysis identified three major clades concordant with <i>I. </i><i>obesulus</i> (Vic), <i>I. auratus</i>,<i> </i>and <i>I. </i><i>fusciventer</i>; however, <i>I. </i><i>obesulus</i> from SA was polyphyletic to WA taxa, complicating taxonomic inference. Microsatellite data aided identification of evolutionarily significant units consistent with existing taxonomy, with the exception of SA <i>I. </i><i>obesulus</i>. Further, analyses indicated SA and Vic <i>I. </i><i>obesulus</i> have low diversity, and these populations may require more conservation efforts than others to reduce further loss of genetic diversity.