Blackwing Hatchetfish Care Guide
Carnegiella marthae is a tiny, surface-dwelling South American hatchetfish that needs a tightly fitting lid and a group of its own kind.
Compiled by Aquairi from published sources · Published · Updated
Overview
Carnegiella marthae, the blackwing or black-winged hatchetfish, is a tiny South American characiform described by George S. Myers in 1927. It is a surface-dwelling species with a deeply keeled, hatchet-shaped belly and wing-like pectoral fins, marked by a fine dark line along the body.
Taxonomy
- Family: Gasteropelecidae
- Genus: Carnegiella
- Scientific name: Carnegiella marthae
Habitat
The species occurs in the upper Orinoco drainage in Venezuela and the rio Negro and rio Madeira drainages in Amazonian Brazil. It lives in blackwater environments, including igapó and igarapé habitats characterised by thick, often overhanging riparian vegetation and calm streams and pools.
Tank requirements
- Minimum tank volume: 60 L (about 16 gal)
- Temperature: 22-28 °C (72-82 °F)
- pH: 5.5-7.0
- GH: 1-10 °dGH
- School size: at least 6, ideally 10 or more
- Lifespan: 3-5 years
Surface dimensions of about 60 x 30 cm or larger are recommended, with gentle to moderate flow. A tightly fitting cover is essential, because the fish may jump when startled, especially in darkness.
Diet
Carnegiella marthae is a micropredator that feeds at the water surface, taking small invertebrates and insects. In the aquarium it accepts suitably small dried foods but should be offered regular small live and frozen items such as Artemia nauplii, Daphnia, Moina and grindal worm.
Compatibility
The species is very peaceful but is timid and, owing to its small size, is not an ideal general community fish. It is gregarious and should be kept in as large a group as possible, ideally ten or more, which makes the fish bolder and reduces nervousness. Suitable companions are similarly sized peaceful characids and smaller callichthyid or loricariid catfishes; it also works as a dither fish for dwarf cichlids such as Apistogramma.
Breeding
Breeding of Carnegiella marthae is essentially unrecorded in aquaria, so reliable spawning details are not available.
Blackwing Hatchetfish Breeding Guide
Overview
Carnegiella marthae is a tiny freshwater hatchetfish from the upper Orinoco drainage in Venezuela and the rio Negro drainage in Amazonian Brazil. The largest officially recorded specimen measured 28.1 mm (Seriously Fish). It is a surface-dwelling micropredator. Members of the family Gasteropelecidae have powerful pectoral-fin muscles that let them leave the water surface, so a tightly sealed cover is essential (Wikipedia).
Sexing
Seriously Fish notes that some specimens grow larger and become rounder-bodied than others, presumably representing adult females, but reliable sexing methods are not described.
Conditioning
The species feeds on small invertebrates and zooplankton at the surface; in the aquarium it should receive regular small live and frozen foods such as Artemia nauplii, Daphnia, Moina and grindal worm. Documented parameters are 20-28 C, pH 4.0-7.0 and hardness 18-179 ppm (Seriously Fish). It is gregarious and best kept in groups of ten or more, which is the recommended husbandry baseline for any breeding attempt.
Common Challenges
The lack of reliable sexing, the absence of any documented spawning trigger, and the fish's small size and timidity make breeding extremely difficult, and no success has been reported.