Chalceus guaporensis is a species of freshwater fish in the family Chalceidae that inhabits northern South America.

Visually, C. guaporensis is similar to other Chalceus species, with metallic scales and a vivid caudal fin (often reddish or pinkish).

[4] Chalceus guaporensis and C. epakros also both lack a fontanel (soft, membranous spot) between the parietal and frontal bones of the head.

[2] However, C. guaporensis has seven pelvic fin rays, as opposed to eight in other Chalceus species, which is the most certain method of visual identification.

[3] Despite many similarities and a close genetic relationship to C. epakros, the habitat of C. guaporensis is more restricted, and the two are not found in the same places.

[2] Chalceus guaporensis is largely a myrmecophagous insectivore, targeting ants and the aquatic larvae of moths and butterflies (Lepidoptera), though it also eats beetles, crickets, and some plant material.