[1][3] The specific name riparius refers to the creek-side habitat from which many specimens in the type series were collected.

[3] It is known as gwnm in the Kalam language of Papua New Guinea, a name that is also applied to Xenorhina rostrata.

Preserved specimens are dorsally purplish brown, with an irregular pattern of dark markings.

[2] Cophixalus riparius is found in montane rainforests among boulders and grass near streams at elevations of 1,900–2,800 m (6,200–9,200 ft) above sea level.

[1] This species is common and adaptable, probably able to withstand a degree of habitat degradation.