''Thoracocharax stellatus'', the silver hatchetfish, spotfin silver hatchetfish, spotted hatchetfish or platinum hatchetfish, is a widespread hatchetfish found throughout South America including Venezuela, Colombia, Ecuador, Brazil, Peru, Bolivia, Paraguay, and Argentina in the Amazon, Orinoco, Paraguay and Tocantins-Araguaia basins. This species is one of the largest of the hatchetfishes. It is usually found in areas with abundant riparian vegetation.

Description

A typical hatchetfish, ''Thoracocharax stellatus'' is superficially similar to ''

Thoracocharax securis ''Thoracocharax securis'', the giant hatchetfish, is a hatchetfish found in the Amazon River Basin. Adults will grow up to 6.8 cm in the wild and 9 cm in the aquarium. It is a rarely seen species in the aquarium hobby. It is known to g ...

'', but has a prominent dark spot in the dorsal-fin. In the wild, adults vary in length between 21–55mm, but in captivity, can grow up to between 60–70mm,maximum length is 80mm.

Taxonomy

The genus ''Thoracocharax'' is monophyletic and is sister to ''

Carnegiella ''Carnegiella'' is a genus of freshwater hatchetfishes found in the Amazon and Orinoco basins in South America. This genus contains some popular aquarium fishes. Species There are currently four recognized species in this genus: * ''Carnegiell ...

'' and ''

Gasteropelecus ''Gasteropelecus'' is a genus of freshwater hatchetfishes found in Central and South America. This genus includes some popular aquarium fishes. There are currently three described species in this genus. Species * '' Gasteropelecus levis'' ( C. ...

. Thoracocharax stellatus'' has four distinct lineages suggesting the this species may represents a species complex. The four lineages are found in the following rivers: * Orinoco River (most basal): Venezuela and Colombia *

Paraguay River The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in ...

: Paraguay *

Araguaia River The Araguaia River ( pt, Rio Araguaia , Karajá: ♂ ''Berohokỹ'' eɾohoˈkə̃ ♀ ''Bèrakuhukỹ'' ɛɾakuhuˈkə̃ is one of the major rivers of Brazil though it is almost equal in volume at its confluence with the Tocantins. It has a total ...

: Brazil *

Amazonas River The Amazon River (, ; es, Río Amazonas, pt, Rio Amazonas) in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world in comparison to the Nile. The headwaters of t ...

: Brazil The genus name, ''Thoracocharax'', is derived from the Greek θώραξ (thṓraks), meaning breastplate or cuirass coupled with the word ''Charax'', type genus of the Order Characiformes, which comes from the Ancient Greek χάραξ (chárax), meaning a

palisade A palisade, sometimes called a stakewall or a paling, is typically a fence or defensive wall made from iron or wooden stakes, or tree trunks, and used as a defensive structure or enclosure. Palisades can form a stockade. Etymology ''Palisade' ...

of pointed sticks, in reference to the densely packed sharp teeth of the fish. The species epithet, ''stellatus'', is Latin for starry or studded with stars, a reference to the fish's platinum-coloured shiny appearance.

Diet

In the wild, feeding occurs at sunrise and sunset, and analysis of the stomach contents of 88 specimens indicates that this species is mostly insectivorous (99.6% of stomach contents were insects) and consisted mostly of ants,

beetles Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

, and

mayflies Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the orde ...

. ''Thoracocharax stellatus'' appears to be a specialist on terrestrial insects and feeds by leaping out of the water and taking insects from riparian vegetation.

Aquarium care

Because of this fish's propensity to jump several meters out of water for feeding, a cover or lid may be necessary or floating plants over the water's surface. An Amazon biotope-style tank is preferred (e.g. driftwood branches, sand substrate, leaf litter). Breeding is difficult, but possible in single-species tanks.

References

. {{Taxonbar, from=Q1073918 Thoracocharax Fish of South America Taxa named by Rudolf Kner Fish described in 1858