Unlike whitebait, which migrate to sea, some non-migratory galaxiid species live out their entire life in the stream or river in which they hatched.
Over millennia, these populations of galaxiids were isolated by geological events such as earthquakes and glacial movement. They evolved into distinct species, each with their own individual features and stories.
There are 12 species of non-migratory galaxiids and a further 13 indeterminate taxa recognised in New Zealand.
These fish are not well known, and it is difficult to tell non-migratory galaxiids species apart. Some species are only found in one or two rivers and all have a threatened or at risk conservation status.
The 12 species of non-migratory galaxiids are:
A further 13 recognised taxonomically indeterminate species of non-migratory galaxiids are:
In 2013, the current understanding of the taxonomic status of all non-migratory Galaxias taxa was determined at a DOC convened workshop. Participants at this workshop included geneticists, taxonomists, and conservation managers.
Thirteen non-migratory galaxiids are listed as taxonomically indeterminate and are awaiting formal description. However these have all been assessed for conservation status in the latest rerankings.
Otago is a biodiversity ‘hot spot’ for non-migratory galaxiids, and is home to 11 out of the 23 species. The streams and rivers that flow through Otago is the only place on Earth some of these fascinating freshwater fish can be found.
Many non-migratory galaxiids have highly fragmented populations with a number of local extinctions being confirmed in recent years, predominately in Otago and Canterbury. This is largely a result of invasive species invasion and habitat loss.
Additional threats facing our non-migratory galaxiids include:
The Department of Conservation has had some success with restoring key non-migratory galaxiid populations by removing invasive species and installing built barriers to prevent further invasion.
Here are some ideas for how you can help non-migratory galaxiids in your neighbourhood.