ephemerid

An ephemerid is a mayfly, an insect of the order Ephemeroptera. These insects are characterized by their short adult lifespans, which can last from a few hours to a few days. The name "ephemerid" itself comes from the Greek word "ephemeros," meaning "short-lived."

The life cycle of an ephemerid involves three stages: egg, nymph, and adult. The nymph stage is aquatic and can last for several months, even up to two years, depending on the species and environmental conditions. During this time, the nymphs molt multiple times as they grow.

Once the nymphs are fully developed, they emerge from the water as subimagos, a winged stage that is not yet sexually mature. This subimago stage is also short-lived, typically lasting only a day or two. The subimago then molts one final time to become the adult imago, the winged, sexually mature form.

Adult ephemerids do not feed; their primary purpose is reproduction. They emerge from the water, mate, and the females lay eggs, often by dipping their abdomens into the water. After reproduction, the adults die. Their brief adult existence is a remarkable adaptation for aquatic insects, allowing them to reproduce quickly and avoid predation in their terrestrial adult form. Ephemerids are considered an important part of freshwater ecosystems, serving as a food source for fish and other aquatic animals.