Living under a rock

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Brodie Foster

It’s been alone for two million years, during which time it lost the ability to fly, and its habitat has shrunk to just a few hundred metres of stream with a view of Dunedin Airport—but the Maungatua stonefly is finally enjoying a moment in the spotlight.

Its discovery was an accident: Jon Waters, a professor of zoology at the University of Otago, was out in the Maungatua Range looking for an entirely different species of stonefly. But this species was different, and Waters knew it. It’s flightless, chunky, and short, less than two centimetres long. PhD student Brodie Foster, who led its taxonomic description, called it a “relict”.

Juvenile stoneflies, called nymphs, live under stones in rapids. At first, researchers found only nymphs of the Maungatua stonefly, so they reared a male to adulthood to study. DNA analysis confirmed it as a new species, named Zelandoperla maungatuaensis. Landcare Research considers nymphs from the Zelandoperla genus to be indicators of good water quality—they’re among the first species to disappear from an unhealthy stream.

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