Upland Longjaw Galaxias

Habitat Distribution

• Endemic to New Zealand's South Island; non-migratory — the entire life cycle plays out in fresh water with no sea-run phase.
• Primarily found in mid- to high-altitude streams (above 300 m) draining to the east coast of the South Island, across Canterbury and Otago catchments.
• A separate population exists in the headwaters of the Buller River system (Maruia River) near Lewis Pass on the West Coast side.
• Favours swift, rocky streams with clean gravel and cobble substrate, but individuals typically hold in quieter margins and edge water rather than the main current.

Key Locations

• Fork Stream (Waitaki headwaters) — home to one of New Zealand's largest known populations, and the site of an active native fish protection project.
• Canterbury east-coast catchments — the core of the species' range, in mid- to high-altitude tributaries draining toward the coast.
• Maruia River / Lewis Pass area (Buller headwaters) — an isolated West Coast population, separate from the main Canterbury-Otago range.
• Rangitata River catchment — recent records have extended the known downstream range, with fish found further into the braided river system than previously documented.

Specific Spots

• Quiet margins and edge water alongside fast riffles — even in swift streams, these fish tuck into calmer pockets rather than holding in the main braid.
• Under rocks and stones during daylight; they're nocturnal, so daytime surveys find them sheltering in crevices between cobbles and boulders.
• Spring-fed tributaries and cool side channels where water temperatures stay consistently cold — these refuges are where stable populations persist.
• Riparian shade is important: stretches with intact bankside vegetation hold higher numbers, as overhead cover reduces temperature and provides terrestrial invertebrate input.