Colostethus ruthveni

"Colostethus" ruthveni is a species of frog with unresolved relationships within its family Dendrobatidae; it is found only in the mountains of northeastern Magdalena Department in northern Colombia. The specific name ruthveni honors Alexander Grant Ruthven, an American herpetologist.

This frog is endemic to the lower slopes of the north-western portion of the Sierra Nevada de Santa Marta. Its natural habitats are tropical dry forests and cloud forests where it occurs near streams at altitudes above 450 m and up to 2100 m AMSL, and is threatened by habitat loss. Males of this species on average have a snout-vent length of 18.9–20.1 millimetres (0.74–0.79 in) whereas females average about 19.8–24.1 millimetres (0.78–0.95 in).