Eldon’s galaxias (Galaxias eldoni) or Eldon’s, as they’re known, are found in eastern areas of Otago. They live in small tributaries of the Taieri, Waipori and Tokomairiro rivers, draining from the Lammerlaw range, downstream of Lake Mahinerangi.
They make their home under banks and amongst the gravels of very small headwater streams that are typically about 200–900 m above sea level and surrounded by vegetation such as tussock, mānuka and coprosma.
Features of Eldon’s galaxias include:
- sleek, dark grey-brown, with creamy gold bars, bands or patches along their body
- typically grow to up to 150 mm in length
- difficult to spot during the day
- feed on small stream invertebrates such as mayflies and stoneflies
- spawn in spring (October to November), laying tiny 2 mm eggs during flood flows in streamside vegetation or small ‘caves’ in stream banks
- can live up to 12 years.
Over the last decade we have lost 20% of known Eldon’s populations. This can be directly linked to the spread of sports fish (trout and brook char), which eat galaxiids; and changes in land use such as stock access to streams, reduction of native vegetation, land development and forest harvesting.
These land use changes impact on the streams in which galaxiids live, increasing sedimentation, changing natural flows through water abstraction, and reducing the amount of habitat available for spawning.
This map shows the known locations of Eldon's galaxias, as at 2013.
Deep Stream in Otago: Eldon's galaxias habitat
Source: New Zealand freshwater fish database