Carnegiella marthae – Black‑wing Hatchetfish

The Black‑wing Hatchetfish (Carnegiella marthae) is a striking, surface‑dwelling hatchetfish from South America — known for its laterally compressed, hatchet‑shaped body and “wing‑like” pectoral fins. Its unique morphology and flashing markings make it an attractive and dynamic addition to a community or species‑specific aquarium.

Detailed Description & Features:

• Scientific Name: Carnegiella marthae

• Common Name: Black‑wing Hatchetfish, Blackwing Hatchetfish

• Origin / Habitat: Native to the calm, black-water streams and pools of the upper Orinoco and Negro River basins in South America (Venezuela, Brazil)

• Adult Size: Up to ~3.5 cm total length in captivity.

• Behavior & Temperament: Peaceful, social, schooling fish that thrives in groups. Prefers to stay near the surface and is adapted to catch insects — they often glide or “fly” just above the water surface using their wing‑like fins.

• Tank Size & Setup: Minimum tank with a surface area around 60 cm long recommended. Gentle filtration and well‑matured tank, with dim lighting, dark substrate or decor, plenty of driftwood/leaf litter, plants (especially floating or with overhangs) to mimic their natural black‑water habitat.

• Water Conditions: Soft, acidic to neutral water — pH roughly 4.5–7.0, with low hardness. Temperature around 23–27 °C.

• Diet: Omnivorous but with strong carnivorous/insectivorous tendencies. In the wild they feed on insects at the surface and small crustaceans. In the aquarium, they readily accept surface foods: live/frozen or freeze‑dried insects, mosquito larvae, daphnia, brine shrimp; also high‑quality floating flakes/pellets for surface‑feeders.

• Schooling & Tankmates: Should be kept in groups of at least 6 — preferably more — to feel secure and display natural schooling behavior. Best tankmates: small, peaceful, non‑aggressive fish that occupy mid or bottom zones (small tetras, pencilfish, Corydoras, dwarf cichlids, small plecos, etc.) rather than other top‑dwelling or fin‑nippers.

• Behavioral Notes: Because they live near the surface and have “flying” pectoral fins, they are excellent jumpers — a tightly fitted lid on the aquarium is essential to prevent escapes.

Additional Notes:
The Black‑wing Hatchetfish brings a unique visual and behavioral element to freshwater aquariums. Its silvery body highlighted by distinctive black patches and stripes (often a golden stripe from gill to tail base), plus the elegant “hatchet” silhouette, make them stand out — especially when kept in a dim, well‑planted black‑water style tank with floating plants and subdued lighting. This species is best suited for intermediate aquarists who can maintain stable soft/acidic water and provide gentle conditions.

Meta Description: Discover Carnegiella marthae (Black‑wing Hatchetfish) — peaceful, surface‑dwelling South American fish. Care guidelines, tank setup, feeding, and group requirements from Aquatropics.

Focus Keywords: Carnegiella marthae, Black‑wing Hatchetfish, freshwater hatchetfish, surface‑dwelling fish, South American aquarium fish, tropical hatchetfish, peaceful schooling fish