Distinct characteristics of this frog include its eyelids, which have conical tubercles growing around the edge, a vertical ridge between the eyes, and the underdeveloped vomerine teeth.

[4] The snout of this frog is pointed, but the mouth part of the other species E. nasuta in the same genus looks sharper because of a long, fleshy proboscis.

The existence of a dextral vent tube is a common trait for the clade consisting of Edalorhina, Engystomops, and Physalaemus.

An earlier morphological and behavioral study considered Edalorhina to be most closely related to the families Lithodytes and Physalaemus as all of them construct foam nests.

[2][5] An early study conducted by Dunn in 1949 examined 52 specimens and revealed dissimilarity in vomerine teeth and dorsal skin structure.

The Perezi type has a dermal ridge between the eyes and vomerine teeth, but it lacks longitudinal warts on the back.

There are also other obvious geographical differences, such as absence of vomerine teeth and the development of a wart on the snout tip.

[4] A later study in 1990 by Duellman dug deeper into this topic by looking into dorsal skin structure and ventral color pattern.

During Pleistocene, the rivers coming down from Andes carried a greater volume of melting galcier water than today, thus isolating the frogs into different basins and causing these populations to evolve independently.

[2] Perez’s snouted frog is commonly found in the upper Amazon Basin in Ecuador and Peru.

Typical habitats are forest floors covered with leaf litter in lowland tropical rainforests.

Then, the male immediately puts its feet near the female’s cloacal region and forms a collecting basket, where fertilization occurs.

After this, the male raises its legs to water level and starts to beat the female’s foam secretion with the purpose of smoothing the surface.

[7] Male Perez’s snouted frogs can produce different types of sounds, but a typical one that can be heard from long distance is considered as an advertisement call, which consists of a series of three to five short, low whistles and two pulses per note.

Thus, in a neotropical forest with stable temperature but seasonal rainfall, the uncertainty of precipitation has a strong influence on the frog’s reproductive success.

[12] Perez’s snouted frog prefer treefall pools (holes at the roots of large fallen trees), either temporal or permanent, to lay their eggs.

[12] The three major risks for Perez’s snouted frog offspring are desiccation, insect predation, and intraspecific competition.

A mark-recapture experiment proved that adults actively select pools that benefit their offspring most based on these three factors.

Their decisions are very flexible as they vary across both temporal and spatial scales, instead of being fixed and passively triggered by seasonal changes.

This trend is reflected both by change in nest placement and tadpole density in each type of pool across time.

The reasoning behind this phenomenon is that rainfall in the transitional period is highly uncertain, so persistent pools provide more stable environment.

Many factors such as pool drying rate, depth, temperature, resource availability, and predator and tadpole density can have an effect.

When a Perez’s snouted frog is frightened, it will face away from the predator and elevate its sacral region to suddenly expose macroglands, which display hidden flash coloration resembling a pair of huge eyes belonging to a large animal.