Naiads of the mayfly Potamanthus myops were collected six times over a one year period from the Huron River to obtain some information on their natural history. Contrary to other Ephemeroidea, myops was never collected below the substrate surface, but was usually found on the underside of stones. The immature mayflies were measured and their length plotted for each collection period. The results support the hypothesis that the majority of myops requires two years to mature.
Bartholomae, Philip G. and Meier, Peter G.
"Notes on the Life History of Potamanthus Myops in Southeastern Michigan (Ephemeroptera: Potamanthidae),"
The Great Lakes Entomologist, vol 10
Available at: https://scholar.valpo.edu/tgle/vol10/iss4/10