Considered a near-threatened species by the IUCN, its range includes creeks in a sub-basin affected by various forms of pollution.

[1] Its taxonomy faces some mild debate, but this is not unusual regarding Astyanax as a genus; further, it can be differentiated from various similar congeners by way of several distinctive features.

[4] On the other hand, there is genetic evidence to suggest that other currently cryptic species of Astyanax may in fact be junior synonyms of A. aramburui, but research is ongoing.

[8] In terms of a common name, A. aramburui is one of various small fish species referred to as "Mojarra" in South America.

[12] The scales are mostly an iridescent silver with touches of yellow, and there is a scattering of dark color cells (chromatophores) on top of the head and body.

The sides of the head and the lateral stripe are both plain silver, ending in a black spot on the caudal peduncle.

[12] Further, males have small protrusions known as "epidermal breeding tubercles" on a notable proportion of the head and scales, which is unusual in Astyanax and can be used as a characterizing feature of the species.

[2] Its type locality is part of a relatively extensive section of river, about 50 metres (164 ft) across at its widest, with substrate consisting of mud and clay.