Name: Flatheaded Mayflies (Family Heptageniidae)

Order: Ephemeroptera - Mayflies

Natural History: If you have turned over more than a couple of rocks in Potomac streams, you have probably seen quite a few flatheaded mayflies.  Heptageniids are very common in this region, and their flattened body plan makes them well adapted for living under rocks.  Poor swimmers, they spend much of their time gazing on algae and detritus.

Pollution tolerance: Moderate (4 out of 10)

Location: Skaggs Run, Hardy County

When collected: January 2005