The ancient aviator of the New Zealand riverbank. Folding smoky dark wings in a steep tent-like shape over a robust heavy body, the alderfly represents a lineage that has remained largely unchanged for millions of years. As adults, they are short-lived and non-feeding, focusing entirely on finding a mate and returning eggs to the water's edge. The larvae are the underwater tigers of the benthos, living buried in silt and mud of slow-moving streams. These benthic hunters are formidable predators, equipped with powerful forward-facing jaws used to ambush other small invertebrates. To survive in the low-oxygen environment of the streambed, they possess delicate feathery gills arranged in pairs along their abdomen, allowing them to extract oxygen directly from the water. This life cycle is a definitive sign of living water. Alderflies require stable, unpolluted sediment and a complex food web to reach maturity. They represent the connection between land and water, illustrating how the health of our terrestrial forests is linked to the predatory life hidden beneath the surface of the mud. While currently not threatened, alderflies are sensitive indicators of sedimentation and loss of riparian vegetation. To encounter an alderfly resting on a riverside fern is to witness a survivor that has mastered the art of freshwater continuity.