This taxon, ranked as “least concern” (LC) on the Red List, actually comprises a complex of species that cannot be differentiated at present and are possibly polymorphic as to their color patterns.
The holotype of R. ventrimaculata originated from Sarayacu in Río Bobonaza, Pastaza Province in the Amazon lowlands of Ecuador. R. ventrimaculata sensu lato is known from large parts of the Amazon Basin and the Guayanas (southeastern parts of Colombia, eastern Ecuador, eastern Peru, Amazonian Brazil, extreme south of Guayana, and eastern half of French Guayana).
The frogs inhabit moist primary and secondary lowland rainforests that offer phytotelmata as nurseries for the larvae in bromeliads, heliconias, bamboo, or tree holes. They live both on the forest floor and in vegetation up to 2 m above the forest ground.
Depending on the locality the frogs grow up to 22 mm, with males usually somewhat smaller and thinner than females. The upper sides and flanks are varyingly shaped and marked with yellow or orange red lines and spots. The brownish, greenish or bluish limbs and ventral side have usually irregular, black to dark brown dots or a reticulated pattern.
The frog from French Guayana, known as R. ventrimaculata, is one of the most often and easily propagated small species of poison frogs in the terrarium. After a more or less brief period of acclimatization, the animals can be observed in the early morning hours or during the late afternoon, preferably right after the misting.
For breeding, the most suitable is a terrarium of the Types I or IV with some bromeliads and black film containers mounted at mid-level of the terrarium, which ought to be kept filled with water for about one third to half, since both the bromeliads and film containers are acceptable oviposition sites.
The frogs feed on white woodlice, fruit flies, aphids, springtails, the smallest of crickets, firebrats, and similar. The stomach contents of a specimen, found in Lago Agrio in Sucumbíos Province in Ecuador, showed that the frogs also feed on ants.