Ameletidae
Comb-mouthed Minnow Mayflies
Ameletus was previously included among genera of the Siphlonuridae, but is now the only genus in the family Ameletidae. There are 34 known species in North America, most from west of the Rocky Mountains. Larvae are fusiform or streamlined in body shape, making them strong swimmers and clingers. They are collector-gatherers or scraper-grazers, feeding on fine detritus and diatoms. They tend to be found in cold, fast-flowing mountain streams, especially along edges, undercut banks, and in root masses. The family can often be confused with Isonychiidae or Baetidae, but can be distinguished by its maxillae, each with a row of golden pectinate spines.