Order: Ephemeroptera

Nine families within Australia, comprising around 119 species. Most species have two pairs of membranous wings, forewings larger than hindwings (when present), but still only of moderate length. Adults have non-functioning mouthparts (mandibulate in nymphs), large eyes and 3 ocelli, moderately short antennae and three (rarely two) long, filamentous cerci. Nymphs are aquatic and look much like wingless adults.