Twenty-three species of galaxiids have been discovered in New Zealand, and before non-native species like trout were introduced they were the dominant freshwater fish family.
Like all non-migratory galaxias, bignose live in freshwater their whole lives and mostly feed at night on invertebrates. They are found in small spring and wetland-fed tributaries and like good cover along the stream edges. Bignose are unique to the upper Waitaki River system.
Bignose are a golden colour, with darker mottled markings. They may have a big nose but they are a small fish that usually don’t grow any longer than 80mm. Their biggest threat is introduced fish like trout – not only do they eat galaxias, but they also compete with the native fish for food.
When native fish are threatened they will often move to more marginal habitat to find refuge rather than compete and be eaten. This is evident in areas of Fork Stream where trout are abundant. Where they have not been driven to local extinction, once trout are removed bignose become bolder and expand back into their niche.
Photos : Wikimedia Commons credit Simon Howard, Simon Elkington and Dr Robert McDowall
