Overview
Two subfamilies are recognised: Eustheniinae, confined to Chile and south-eastern Australia, and Stenoperlinae, occurring in Chile, New Zealand and eastern Australia. The large and colourful adults of Australian Eustheniidae occur in spring, summer or autumn along the banks of streams or lakes. They mostly rest in rock crevices or amongst foliage; several species are unable to fly. Adults have abundant cross-veins and remnants of lateral abdominal gills. Larvae run actively when disturbed and can swim with an undulating action.