Mayflies: Ephemeroptera

Physical characteristics: Adults are 0.6 to 0.9 inches (15.2 to 22.9 millimeters) in length. Their bodies and wings are yellowish. The larvae have large heads and almost circular gills covering the abdomen. The gills vary in color from pale yellow or pink to violet.

Geographic range: This species lives in southern Argentina and Chile.

Habitat: They live in cold, fast-flowing creeks and streams as well as the borders of lakes with well-oxygenated water.

Chiloporter eatoni live in cold, fast-flowing creeks and streams as well as the borders of lakes with well-oxygenated water. (Illustration by Patricia Ferrer. Reproduced by permission.)

Diet: The larvae are active predators and eat the larvae of other aquatic insects.

Behavior and reproduction: The larvae crawl on the bottom and are fast swimmers. They use their gills to propel themselves through the water. When they are not feeding, they hide under rocks and other debris. The behavior of adults, including reproduction, is unknown.

Chiloporter eatoni and people: They do not affect people or their activities directly.

Conservation status: The World Conservation Union (IUCN) does not officially list this species, but their populations may be threatened by the introduction of insect-eating trout. ∎