Platinum Hatchetfish (Thoracocharax stellatus)

Thoracocharax stellatus is native to the Amazon, Paraguay, and lower Orinoco River systems across Brazil, Bolivia, Argentina, and surrounding South American countries. It is the largest commonly kept hatchetfish, reaching 9 cm in length compared to the 4–5 cm of Carnegiella species — making it suitable for larger community setups that would be too boisterous for smaller hatchetfish.

The body is the deeply keeled, laterally compressed 'hatchet' shape characteristic of all gasteropelecid hatchetfish — an adaptation for surface dwelling and surface skimming. The overall body coloration is brilliant platinum-silver with a slight bluish sheen, giving rise to the common name. A dark spot may be visible at the base of the pectoral fin in some specimens.

Like all hatchetfish, T. stellatus uses its enormously developed pectoral fin musculature (creating the 'hatchet' body profile) to power rapid surface-skimming bursts to escape predators. This ability means a tight-fitting lid with no gaps is absolutely essential.

In the aquarium, Platinum Hatchetfish hover just below the surface film in loose groups, rarely descending deeper. They are surface feeders that must be provided with floating or surface-delivered food.

Platinum Hatchetfish prefer soft, slightly acidic water: pH 5.5–7.5, hardness 2–15 dGH, and temperatures 22–28°C. They adapt to a range of conditions better than smaller Carnegiella species but still require clean water and stable parameters.

A minimum 120-liter aquarium with dense floating plant coverage (Salvinia, Water Lettuce, Frogbit) and open surface swimming lanes suits a group of 6–8 well. A weighted, completely secure lid is mandatory — they jump distances of 30+ cm. Good surface agitation provides oxygen and simulates natural stream conditions.

Feed floating or surface-delivered foods: floating pellets, floating flake, freeze-dried bloodworms, live or frozen daphnia, and small insects (fruit flies). They will not readily descend to feed at lower depths. Feed 2–3 times daily near or at the surface.

Platinum Hatchetfish are entirely peaceful. Compatible with medium tetras, corydoras, peaceful mid-water and bottom-dwelling species. Their size makes them suitable for community aquariums that would be too boisterous for smaller hatchetfish species.

Keep in groups of 6+. Water changes of 25–30% weekly maintain water quality. Drip acclimatize carefully when introducing new specimens.