C. aurofrenatus is currently understood to occur throughout much of the Río Paraguay-Paraná system in Paraguay, and has also been recorded in Argentina and Bolivia.

It was described from Paraguay with type locality given as ‘Aguada near Arroyo Trementina’. The latter is stated to be a tributary of the ‘Rio Aquido Canigi’.

T. stellatus is superficially similar to its only congener T. securis, but can immediately be identified by the presence (vs. absence) of a prominent dark spot in the dorsal-fin. It is sometimes traded as ‘platinum hatchetfish’.

The genus Thoracocharax was originally erected by Fowler in 1906 as a subgenus of Gasteropelecus, but was elevated to generic status by Weitzman (1960).

This species is normally referred to as A. paraguayensis, but that name has been considered a synonym of A. nattereri since 2003.

Confusion remains however, as the type locality for the latter is ‘Villa Bella’, now known as Parintins, a settlement on the main Amazon river channel between Manaus and Santarém and many kilometres away from the majority of confirmed localities.

This species is very common in the aquarium trade and is also referred to as ‘jewel’, ‘red minor’, ‘blood’, or ‘callistus’ tetra.

A number of selectively-bred ornamental strains have been developed, including ‘metallic’, ‘long-finned’, ‘balloon’ and ‘fairy-fin’.

Characiformes is among the most diverse orders of freshwa…

Despite the ubiquity of its name in aquarium literature, confusion surrounds its true identity. Given it’s the only member of the genus occurring on the island, fish from Trinidad do presumably represent C. aeneus (see our image), but the classification of those from other localities appears far from certain.

Today the species is accepted to occur throughout much of South America, and indeed similarly-patterned fish do occur across a large portion of the continent. Some of these, such as the gree…