Cool-water
Guides
Siphlonuridae
primitive minnow mayfly
Siphlonuridae, commonly called primitive minnow mayflies, is a family of mayflies (Ephemeroptera) characterized by morphological traits considered ancestral within the order. Members are adapted to cool waters and occur across temperate regions of the Northern Hemisphere. The family includes approximately six extant genera: Ameletoides, Edmundsius, Parameletus, Siphlonisca, Siphlonurus, and the former genus Metretopus (now sometimes placed in Siphlonuridae). Nymphs inhabit diverse freshwater habitats including temporary ponds, streams, and floodplains, with habitat preferences often shifting during ontogeny.