The smallest and most delicate of the nominal hatchetfishes. The rounded keel is shallower than related species, giving this fish a distinctive elongate profile.

The family Gasteropelecidae is separated from other Characiformes by the following combination of characters: front…

Unfortunately diagnostic characters cannot be provided since we have been unable to obtain the type description to date, and little else has been written about this species.

There is also confusion regarding whether C. lamberti, the unidentified ‘C009’, and similar-looking fish collected close to Iquitos are conspecific or not. We include all together here until these issues are resolved.

Despite being a wholly unsuitable aquarium subject, C. idella is often traded as such, with an albino form having been developed specifically for the ornamental market.

Individuals which have outgrown their aquarium or pond should never be released into natural waters, either, since this species has proven capable of causing serious environmental damage under a wide range of climatic conditions.

Widely-distributed throughout the Amazon, Orinoco, Essequibo, and Tocantins river systems in Brazil, Peru, Bolivia, Ecuador, Colombia, Venezuela, and Guyana.

Type locality is ‘Rio Cupai [= Rio Cupari], Rio Tapajós basin, Amazon River drainage, Pará State, Brazil’.

An obligate predator feeding on other fishes in nature, but quality dried foods are normally accepted in captivity.

It should also be offered meaty fare such as strips of white fish, live earthworms, shrimp, etc., for optimum health.

H. eschwartzae is told apart from other laterally-striped Hyphessobrycon species from the Madre de Dios watershed by the following characters: 4 simple anal-fin rays (vs. 3 in other species listed); 13-15 dentary teeth (vs. 5-11); 6 teeth in the internal premaxillary ro…

This species is relatively rare in the aquarium hobby but is occasionally traded as ‘red-tailed flag tetra’.

It lends its name to the H. aghula group of closely-related species within the genus as proposed by Géry (1977, see below) of which members share the following characters which set them apart from other characids: lower half of the body dark, especially above the anal-fin; usually possessing a laterally-elongate humeral spot, more-or-less united wit…

This unidentified species was originally traded under the C-numbers C115 and C116 but these two are now thought to represent the same species, while fish collected from Manú National Park and sold as C. sp. ‘Manu 1 long nose’, C. sp. ‘Manu 4’, C. sp. ‘Manu 7’, and C. sp. ‘Manu 8’ may represent this species as well.

It’s highly variable in terms of colour patter…