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

Fish mixing in the blender of hybridisation: patterns in rainbowfishes in southeastern Australia (#126)

Karl Moy 1 , Peter Unmack 1
  1. Institute for Applied Ecology, University of Canberra, Canberra, Australian CapitalTerritory, Australia

Rainbowfishes represent the most diverse family of fishes in Australia and New Guinea (Sahul) with 113 described species. Rainbowfishes numerically dominate fish communities and they are found in virtually every river system in the warmer parts of Sahul. As a result, closely related species occurring in adjacent rivers are likely to regularly contact each other over evolutionary time scales. Multiple outcomes are possible when closely related species come together. For example, they can mix with the loss of both pure parental species, form a stable hybrid zone with one or both parental species persisting upstream/downstream of the hybrid zone, one may go extinct, or they can co-occur and without mixing.  Here we explore the biogeography and distribution patterns in south eastern Australian Rainbowfishes.


The patterns are complex due to multiple mixing zones between species such as Desert Rainbowfish (Melanotaenia splendida tatei) and Murray Rainbowfish (M. fluviatilis), Duboulayi’s Rainbowfish (M. duboulayi) and Murray Rainbowfish as well as Duboulayi’s Rainbowfish and Eastern Rainbowfish (M. s. splendida). We have now clarified where each of these hybrid zones are located. This information leads us to speculate that Eastern Rainbowfish are slowly expanding their distribution south and gradually replacing Duboulayi’s Rainbowfish over biogeographic time scales (100,000–500,000 years).