Ephemerellidae are known as the Spiny Crawler Mayflies. They are a family of the order Ephemeroptera. There are 8 genera consisting of a total 90 species (Merritt & Cummins). They are distributed throughout North America as well as the UK. Their habitat is lotic-erosional, they are found in all sizes of flowing streams on different types of substrates where there is reduced flow. They are even found on the shores of lakes and beaches where there wave action present. They move by swimming and clinging, they are very well camouflaged. Most species have one generation per year. They are mostly collector-gatherers.