This frog species, ranked as “least concern” (LC) on the Red List, lives in premontane mountain slopes instead of hot lowland rainforests. It inhabits primary forests, especially in places affected by windfalls, and margins between primary forests and the fields of small-scale farmers. Some populations were discovered in leaf litter on the ground, mossy boulders and in bromeliads on trees to the height of 8 m.
Ranitomeya fantastica was found in Cordillera Oriental and Cordillera Azul to the north and south of Río Huallaga passage in the east of Departamento San Martín in Peru, and southeast to the region of the Cerro Azul in Departamento Loreto, Peru, at about 300-700 m a.s.l. and sometimes even at 200-900 m a.s.l..
Ranitomeya fantstika is the bigest species in the group of Ranitomeya ventrimaculata because males grow up to 18 and females up to 23 mm in length. The sizes of adult frogs vary between different populations, but not as much as the color pattern.
While the ground color is always black, the light pattern can be brilliant copper red, as well as orange or yellowish orange, sometimes with some whitish gray added. The usually light color of the head can be copper red, extending to the armpits. An isolated black spot of various shapes and sizes often remains on the head and is occasionally complemented by a black streak, beginning behind the eye. The black may additionally exhibit a whitish gray or orange reticulated pattern of fine lines. While the back can sometimes be uniformly black, a light band often crosses the body where it may meet with a median stripe, forming a cross-like shape. Sometimes a very coarse, whitish gray pattern can be seen on the limbs. Light, straight, broad streaks often mark the frog’s upper sides, while the lighter lower surfaces are usually copper red, orange or yellow under the head, often somewhat paler on the chest, belly and limbs (orange, yellow, whitish gray, partly with a bluish tint), upon which there are more or less irregular, large, black spots. These spots may also be arranged in a pair on the throat, with one below each eye.
Aside from the differences in the color patterns, another distinctive feature of this species is its stiff-legged, robotic-like, jerky gait. The larvae were found in water-filled tree holes and aracean plants, more rarely in bromeliads. A tree-dwelling variety is also said to reproduce in bromelads, at heights 1-8 m above the ground. The leaf axils are normally occupied by one larva only, with some exceptions.
The frogs feed on springtails, aphids, fruit flies, firebrats and the tiniest of crickets. In the stomach of a specimen from Chazuta, Peru, there were 81 ants of at least ten different species.
For breeding, the most appropriate is a spacious terrarium of the Type I. Most varieties inhabit the higher stories of the vegetation, therefore a higher terrarium ought to be used with bromeliads tied to high branches and other suitable spots in order to create a usable “top story”. Always slightly moist black film containers, used as spawning sites, should be mounted at various levels in a horizontal or slightly oblique way and pointing to the rear.
