Spotfin Hatchetfish Care Guide
Thoracocharax stellatus is the largest common freshwater hatchetfish, a wide-ranging South American surface insectivore marked by a dark spot on its dorsal fin.
Compiled by Aquairi from published sources · Published · Updated
Overview
Thoracocharax stellatus is a freshwater hatchetfish of the family Gasteropelecidae and one of the largest commonly seen hatchetfishes. A prominent dark spot on the dorsal fin distinguishes it from the related Thoracocharax securis. It is a pelagic surface fish found in open water of larger rivers, usually where riparian vegetation is abundant.
Taxonomy
- Family: Gasteropelecidae
- Genus: Thoracocharax
- Scientific name: Thoracocharax stellatus (Kner, 1858)
Habitat
The species is widely distributed across tropical and subtropical South America, including the Amazon, Orinoco, Paraná, Paraguay and Tocantins-Araguaia river basins. It occurs in open surface waters of larger rivers, typically near overhanging bankside vegetation from which it gleans insects.
Tank requirements
- Minimum tank volume: 150 L
- Temperature: 22-28 °C (72-82 °F)
- pH: 6.0-7.5
- GH: 4-15 °dGH
- School size: 6 or more individuals
- Lifespan: 4-6 years
- A secure, tightly fitting lid is essential — it is a powerful jumper
Diet
Wikipedia reports the species as almost entirely insectivorous, with terrestrial insects such as ants, beetles and mayflies making up the great majority of stomach contents; it feeds by leaping from the water to take insects from riparian vegetation, mainly at sunrise and sunset. In the aquarium it should be offered floating and surface foods, including small live and frozen insects such as fruit flies, alongside dried preparations.
Compatibility
Thoracocharax stellatus is a peaceful, top-dwelling schooling fish that should be kept in groups of at least six. It mixes well with calm mid- and lower-water species such as larger tetras and discus. Aggressive or fin-nipping tankmates should be avoided.
Conservation status
IUCN Red List: Least Concern (assessed 2020). The species supports minor commercial fisheries and is traded as an aquarium fish.
Spotfin Hatchetfish Breeding Guide
Overview
Thoracocharax stellatus is the largest of the commonly traded hatchetfishes, distributed widely across South America through the Orinoco, Amazon and Parana river systems. Seriously Fish records a size of 60-70 mm SL. It is a surface-dwelling, primarily insectivorous species; like all freshwater hatchetfish it is a powerful jumper, so a tightly sealed cover is essential (Wikipedia).
Sexing
Seriously Fish notes that females are noticeably rounder-bodied than males when full of eggs. No further reliable sexing method is described.
Conditioning
In nature the diet is almost entirely insects, with one study cited by Seriously Fish reporting that 99.6% of the diet consists of insects, 87.6% of which were terrestrial. In the aquarium offer frozen and live foods such as bloodworm, Daphnia and fruit flies at the surface. Documented parameters are 20-28 C, pH 5.0-7.5 and hardness 18-215 ppm (Seriously Fish). Keep groups of at least half a dozen.
Common Challenges
With no documented spawning and a strongly insectivorous, surface-oriented, nervous nature, controlled breeding has not been achieved and no protocol can be cited.