Respiration of Mayflies

Mayflies are insects that spend the vast majority of their lives in a larval stage as "nymphs." Some types of mayflies spend as long as two years in their nymph form before molting into adult form, laying eggs and quickly dying. Some varieties of adult mayflies live less than an hour and no variety lives longer than a day. How the mayfly breathes will depend on whether it is a nymph or an adult.

Lifecycle of a Mayfly

A mayfly spends most of its time as a nymph living in water. While in water, it feeds and grows until conditions are right for its transformation into an adult. Once it changes to its adult form, the entire purpose of an adult mayfly is to mate and lay eggs. Although mayfly nymphs feed, adult mayflies do not live long enough to require food, and thus do not feed.

Nymph Breathing

Mayfly nymphs live underwater. Although they do not have lungs, they still need to breathe. They breathe by extracting oxygen from the water using specially adapted breathing filaments that are sometimes called gills. These breathing filaments wave back and forth through the water. As they move the water, they extract oxygen.

Adult Breathing

Adult mayflies breathe in the same fashion as other insects. They do not have lungs. Adult mayflies extract oxygen from the air via special openings in their sides called spiracles. These spiracles are always in pairs, with one on each side of the body. The number of pairs will vary from insect to insect. These spiracles lead to air ducts that vent air to different parts of the mayfly's body.

Nymphs Out of Water

Because the breathing apparatus of nymphs depends on water passing over the filaments, nymphs cannot survive outside of water. When removed from an aquatic environment, the filaments are unable to separate oxygen from the air and the nymph will die.

Adults In Water

As opposed to the nymphs, adult mayflies are optimized to extract oxygen from air. If an adult mayfly falls in water, its spiracles are not suited for extracting oxygen from the water. Water will clog the small openings in the adult's side and the mayfly will drown.