Chalceus epakros is a species of freshwater fish in the family Chalceidae, found in northern South America.

[1] Chalceus epakros is incredibly visually similar to C. guaporensis, including a thin lateral stripe, a pointed snout, and the occasional indistinct humeral patch.

[4] C. epakros and C. guaporensis are also alike in that they lack a fontanel (soft, membranous spot) on the head, while the other three species have one between the frontal and parietal bone.

[7][8] In the year 2004, Brazilian biologists Mônica Toledo-Piza and Angela M. Zanata performed a re-examination of the genus Chalceus, resulting in the nomination of not only C. epakros but its congeners C. guaporensis and C.

[1] Upon study in 2005, C. epakros and C. guaporensis were determined to form a clade, accounting for their visual similarities, while C. spilogyros, C. erythrurus, and C. macrolepidotus share another.

In one study (Torrente-Vilara et al.), very few examined specimens had food material in their stomachs, making diet-mapping difficult.