Found in a number of habitat-types, though rarely in smaller tributaries, generally preferring deeper, flowing channels through which it travels for considerable distances at certain times of year. Like other large, migratory pimelodids these movements are typically associated with nutrient-rich, white water drainages rather than nutrient-poor black waters.

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).

Endemic to the Río Meta, a major tributary of the Río Orinoco in eastern Colombia and western Venezuela. It is known from several tributaries within the upper basin including the ríos Humea, Ocoa, Guatiquía (including its two branches the ríos Negrito and Guayuriba), Manacacias, and Metica (the name given to the upper Río Meta above its confluence with the Río Humea). It appears to be absent from the lower Meta and has not been recorded in Venezuela.

The genus Apistogramma is among the most speciose of South American cichlid genera with around 70 species valid at present but many more awaiting description. In addition many species exist in two or more geographical colour forms which may or may not turn out to be distinct in the future. Hobbyists tend to label these with collection data if available in order to avoid mixing them and the potential of hybridisation.

Member species have also been organised into a series of species lineages, complexes and groups by authors in order to better separate them.