This rather uncommon frog species, categorized as “least concern” (LC) on the Red List, can occasionally be found in the leaf litter of primary forests. The larvae were also discovered in the very narrow, lowest, water-retaining leaf axils of reed-like plants up to 3 m in height. Ranitomeya duellmani is reported to inhabit the northwestern parts of the Peruvian Departamento Loreto, in the Río Pastaza river system near the Ecuadorian border, and Napo and Orellana Province in eastern Ecuador.
Male frogs reach up to 17.7 mm and the females are hardly any larger. Ground color of the dorsal sides and flanks is black. From above the tip of the snout, two wide orange red stripes spring together and extend further to the upper insertion points of the hind legs, passing by the eyes above. A wide orange-colored median stripe begins at the level of the anterior margins of the eyes and ends at the cloaca, sometimes maintaining contact with the dorsolateral stripes. The black ground color can sometimes separate the median and dorsolateral stripes on the head but they can also be in contact, which leaves a black spot on the snout. Extending from the tip of the snout to the armpit, there is an orange supralabial stripe. An irregular black dotted pattern marks the light blue limbs, as well as the ventrolateral parts of the flanks and the ventral side. Underside of the head is orange red with large black marginal spots below the eye and tympanum. An enlogate, black spot or median streak extends to before the collar bone and is sometimes connected with the two spots below the tympanum.
The terrarium is relatively similar to the terrarium of R. reticulata. The temperatures in the natural habitat are about 22-23˚C at night and 25-27˚C during the day, which should be followed when keeping this species in a terrarium. The frogs are shy and secretive.