ephemerids

Ephemerids are a type of aquatic insect belonging to the order Ephemeroptera. They are commonly known as mayflies, shadflies, or fishflies. A defining characteristic of ephemerids is their remarkably short adult lifespan, often lasting only a day or two, though some species can live for up to a week. This brief adult stage is primarily dedicated to reproduction. The majority of an ephemerid's life is spent as an aquatic nymph, a period that can last for several months to a few years, depending on the species and environmental conditions.

Ephemerid nymphs are herbivores or detritivores and play a significant role in freshwater ecosystems by consuming algae and decomposing organic matter. They breathe through gills located along their abdomen. Once mature, the nymphs undergo a final molt into a winged subimago, which is a transitional stage. This subimago then molts one last time to become the winged adult. Adult ephemerids lack functional mouthparts and digestive systems, as they do not feed. Their sole purpose is to emerge, mate, and lay eggs. The synchronized emergence of large numbers of mayflies is a well-known phenomenon in many aquatic environments. Ephemerids are sensitive to water pollution, making them valuable bioindicators of water quality.