Bryconops vibex reaches a maximum of roughly 6.8 cm (2.8 inches) in standard length (excluding the tail fin).

[4] Its scales are silver to silver-green in life, which is not uncommon in the genus, and it bears a single humeral spot by each pectoral fin.

[7] Its body is shallower than that of B. cyrtogaster (though still robust),[8] and small factors like a thicker caudal peduncle and a higher number of scales beneath the lateral line differentiate it from sister species B.

However, an in-depth study in 2011 determined by way of phylogeny that Bryconops, along with the genera Iguanodectes and Piabucus, should occupy their own family, Iguanodectidae.

[14][15] Bryconops vibex has been evaluated by the IUCN as a near-threatened species; the main danger comes from settlement of nearby farmland.