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…

Abramites spp. are separated from other anostomids primarily on the basis of their relatively deeper bodies and presence of a prominent, post-pelvic median keel, a feature unique to the genus.

At time of writing A. eques is the only other species recognised and is native to the Río Magdalena drainage in western Colombia.

It can be distinguished by possession of 13-14 bra…

Wild fish are probably foragers feeding on algae, organic detritus, small insects, worms, crustaceans, and other zooplankton.

In the aquarium it’s easily-fed but the best condition and colours offer regular meals of small live and frozen foods such as bloodworm, Daphnia, and Artemia, alongside good quality dried flakes and granules, at least some of which should include additional plant or algal content.

Numerous ornamental forms of this species have been selectively-bred for the aquarium trade. It has also been assigned the ‘A’ number A234 under the DATZ system with possibly conspecific, related forms similarly numbered A103, A104, and A105 depending on locality.

Famed as a rapacious predator capable of rapidly stripping flesh from bone and a danger to any animal entering its native waters, P. nattereri is among the most notorious freshwater fishes in the world. As a result, displays featuring this “bloodthirsty” creature are found in most public aquaria, grisly Hollywood movies have been released, and the species has become popular in the aquarium trade. Little of this infamy is based on factual evidence, however.