Oral Presentation Australian Society for Limnology Congress 2013

Distribution of the Oriental Weatherloach (Misgurnus anguillicaudatus) in the South Australian region of the Murray-Darling Basin: From specimens collected by Natural Resources SA Murray-Darling Basin, 2010-2013. (#56)

Irene K Wegener 1 , Lara Suitor 1
  1. Natural Resources SA Murray-Darling Basin, Department of Environment, Water and Natural Resources, Berri, South Australia

The Oriental Weatherloach (Misgurnus anguillicaudatus), a fish species native to East Asia, was first recorded as a wild breeding population in the Yarra River (Victoria) in 1984. Since then, it has dispersed into other systems including the Murray–Darling Basin. The Oriental Weatherloach is considered to be a successful invader due to its high reproductive potential, flexible diet, longevity and tolerance to a broad range of environmental conditions. Additionally, it shows remarkable environmental adaptability and therefore has the potential to inhabit a range of habitat and environments present across South Australia.

In February 2011, the Oriental Weatherloach was recorded for the first time in South Australia on the Chowilla Floodplain. Following its initial capture, the species has now been recorded at 12 wetland locations across the South Australian region of the Murray–Darling Basin between 2011 and 2013. Oriental Weatherloach caught during sampling between 2010 and 2013 exhibited distinct length modes, with the range and mean fish size increasing between 2011 (mean = 108mm) and 2012 (mean = 137mm). Fish were caught at sites with varying substrates and physical habitat. Environmental variables such as surface water electrical conductivity, pH, turbidity, dissolved oxygen and temperature did not appear to influence presence or absence of the Oriental Weatherloach at particular sites. The species distribution range has increased downstream since its initial capture, however it is still being caught in low numbers. Ongoing surveying will assist with determining the range expansion of the species through the South Australian region of the Murray–Darling Basin.