[1] The main diagnostic characteristic of the genus is the presence of an external covering over the areolae.

[2] The genus was circumscribed by Wim Vyverman and Pierre Compère in 1991, with Nupela giluwensis assigned as the type, and at that time, only species.

[3] Nupela was originally described from high elevation ponds in Papua New Guinea.

Since then, Nupela has been found in waters with a neutral pH and low conductivity throughout Europe, South America, North America, Asia and Africa.

[1] Five newly described species from Yunnan China were added to the genus in 2022.