These mayflies are of small to medium size, measuring between 6 and 14 mm. Key characteristics include antennae that are less than twice the width of the head, maxillae with pectinate spines, and gills consisting of a single oval-shaped plate with a sclerotized band. Gills are typically present on abdominal segments 1-7, and long setae are found on the caudal filaments, occurring on both sides of the terminal filament and only on the inner side of the cerci. While these mayflies may resemble brush-legged (Isonychiidae) or small minnow (Baetidae) mayflies at first glance, they can be distinguished by the presence of pectinate spines on the maxillae and the absence of rows of long hairs on the fore legs. Ameletid larvae exhibit strong swimming abilities, enabling them to navigate robust currents. Certain species can endure temporary stream conditions by entering a dormant egg stage during periods of dryness.