Little has been published regarding the feeding habits or behavior of A. argentatus, but it is known to have the northernmost distribution of any member of the genus Astyanax.

There is debate regarding its status as a species, as it was considered a synonym of the Mexican tetra (A. mexicanus) for 20 years, but it has recently come back into favor as its own distinct entity.

It also has visual similarities to various other members of the genus; its silver scales, single humeral spot, and yellowish or reddish fins are not uncommon features therein.

[5] In its 2017 redescription, A. argentatus was designated a member of subgenus Astyanax, based on a complete predorsal series of scales.

[6] Sources such as the World Register of Marine Species[9] and OBIS[10] still consider the two synonymous, while others cite A. argentatus as valid on its own, such as FishBase,[11] the IUCN,[1] and the Harvard Museum of Comparative Zoology.

Though the meaning of the scientific name of A. argentatus is understood, the precise reason for such nomenclature was not made clear in the original text.

[16] On the anal-fin rays of mature males, there are small fleshy protrusions or spines sometimes referred to as nuptial tubercles.

[6] The Nueces River is in a region of low rainfall, but it is fed by various springs and aquifers, which means that it is largely composed of clear and cool water.

Despite a fragmented population, it is often one of the most frequent species when it is present at surveyed sites, and appears to be adaptable enough for high survivability.

[1] Though the species itself is healthy, some of the habitats of A. argentatus are at minor risk due to human recreational use; for instance, small-scale pollution from nearby hiking trails and campgrounds affects the Nueces River.