Virtual Poster Presentation - 3 minute narrated video presentation AFSS Conference 2020

Complex carp gudgeons, the joys of hemiclonal unisexual species complexes (#128)

Peter Unmack 1 , Mark Adams 2 , Michael Hammer 3
  1. University of Canberra, Canberra, ACT, Australia
  2. Evolutionary Biology Unit, South Australian Museum, Adelaide, SA, USA
  3. Curator of Fishes, Museum & Art Gallery of the Northern Territory, Darwin, NT, Australia

Carp gudgeons in eastern Australia have evolved a complex and quirky system of hemiclonal unisexual reproduction. The system came about through hybridisation and good luck, with the species needing to be just different enough to not make “normal” hybrids, but not so different that the hybrids were unviable. We have conducted extensive genetic investigation across the range of the complex and have resolved the number of species present and the various hemiclonal combinations.  In some parts of the Murray-Darling Basin up to three sexual species co-occur with three hemiclonal forms, all being captured in the same location. Some of the hemiclonal types have highly skewed sex ratios. We’ve also identified a number of enigmas that currently cannot be explained.  These include cases where we have female sexual genotypes, but only hemiclonal males (i.e., no sexual males present). One site which had only hemiclonal types present, and a couple cases where a sexual genotype appears to have been recreated, but this seems extremely rare and unusual. The presentation will provide an overview of the group and highlights of their enigmatic existence!