Carnegiella strigata

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The Carnegiella strigata, also known as the Marbled Hatchetfish, is a small Amazonian characiform instantly recognized by its deep, laterally compressed body adapted to life near the surface. Its brownish-silver pattern resembles marble, while its extended pectoral fins strengthen its distinctive outline. Peaceful and shoaling, it should be kept in a group and appreciates aquariums with floating plants, gentle lighting and a secure cover. This wild-collected species remains an excellent example of South American surface-fish diversity, but it requires stable water and special attention to its jumping ability.

General species description

The Carnegiella strigata belongs to the freshwater hatchetfishes, a group specialized for occupying the water surface. Its short, strongly laterally compressed body is greatly widened toward the front, giving it a shape reminiscent of a hatchet blade. It lives in schools and usually stays just beneath the surface, where it takes small prey drifting or falling onto the water. Its temperament is calm, although it is quick and easily startled by sudden movements. In an aquarium, it should be kept in a group and provided with a mature environment offering shaded areas. Because it is wild collected, gradual acclimation and varied feeding are especially important. With a rarity level of 2, it is moderately available through the specialty trade rather than being constantly offered.

Geographic origin and biotope

The Carnegiella strigata is native to tropical South America, especially the Amazon and Orinoco basins; Colombia is part of its range. It inhabits small forest tributaries, quiet areas and seasonally flooded habitats associated with riparian forests. The water may be stained by tannins released from leaves and decomposing wood, with low mineral content and light filtered by surrounding vegetation. The surface is often cluttered with roots, branches and floating plants, providing both food and shelter. To recreate this setting, use gentle circulation, floating plants and an open surface area for swimming. Water temperatures of 24 to 28 °C and slightly acidic to neutral pH are generally suitable.

Precise location and local name

In Colombia, the Carnegiella strigata is associated with forested waterways in the Amazonian and Orinoco regions, particularly quiet areas and vegetated margins. It mainly occupies the upper layer, close to covered banks, submerged branches and floating vegetation. Vernacular names vary between countries and communities; names include pez hacha marmolado in Spanish and peixe-borboleta in Portuguese. The English name Marbled Hatchetfish refers to its marbled pattern and hatchet-like body shape. In an aquarium, a perfectly fitted cover is essential, since even a small opening may allow this fish to jump out.

Appearance and physical characteristics

The Carnegiella strigata generally reaches about 4.5 cm as an adult. Its silver to golden-brown body is very deep, laterally compressed and marked with irregular lines forming a marbled pattern. The dorsal profile is relatively straight, while the underside is deeply arched. The pectoral fins are long and held outward, contributing to its characteristic silhouette and rapid movements near the surface. The caudal fin is forked, and the mouth is directed upward, a clear adaptation to surface feeding. Mature females may appear slightly fuller than males, especially when carrying eggs, but sexual differences remain subtle. Gentle lighting brings out its silver reflections and marbled pattern.

General feeding

In nature, the Carnegiella strigata mainly consumes small prey living near the surface or falling onto the water, including terrestrial insects, larvae, small crustaceans and other tiny organisms. In aquariums, it accepts fine floating dry foods, but its diet should regularly include frozen or live foods such as daphnia, mosquito larvae and small planktonic foods. Food should remain available at the surface because its upturned mouth and surface-dwelling habits make it less effective on the bottom. Small portions offered several times a day encourage better feeding. Oversized foods and items that sink quickly should be avoided. A varied diet supports condition, coloration and natural behavior, while a calm surface makes surface feeding easier.

Essential data

• Name of original river: Amazon and Orinoco basins
• Local name used: Pez hacha marmolado; peixe-borboleta
• Origin of the scientific name: The genus Carnegiella honors Carnegie; strigata refers to a striped or marked pattern
• Etymology of the full name: Carnegiella is a generic name formed in honor of Carnegie; strigata is Latin for striped or marked with lines
• Common/vernacular names: Marbled Hatchetfish; marble hatchetfish; pez hacha marmolado; peixe-borboleta
• Family: Gasteropelecidae
• Subfamily: Gasteropelecinæ
• Name pronunciation: kar-NEE-jee-EL-ah stri-GAH-tah
• Discovery: Albert Karl Ludwig Gotthilf Günther, 1864
• Maximum adult size: About 4.5 cm
• Water temperature and pH: 24 to 28 °C; pH 5.5 to 7.0
• Appearance of the watercourse and surrounding vegetation: Slow or quiet water, often tannin-stained, bordered by forest, roots, branches and floating vegetation
• Typical tankmates: Peaceful small Amazonian tetras, Nannostomus beckfordi, Hemigrammus bleheri, Otocinclus macrospilus, Corydoras sterbai and small peaceful dwarf cichlids
• Temperament and behavior: Peaceful, shoaling, active and mainly surface-oriented; an excellent jumper
• Water depth: Upper water layer, generally close to the surface
• Sexual dimorphism: Mature females may be rounder; differences are subtle
• Bottom structure and flow: Leaf litter, wood and fine sediments; low to moderate flow in occupied areas

In your aquarium

To succeed with the Carnegiella strigata, provide a mature, securely covered aquarium with enough length for group swimming. A clear surface area, floating plants, subdued lighting and moderate circulation better reproduce its natural environment. Maintain warm, stable, slightly acidic to neutral water, then feed small, varied foods that remain afloat. Avoid boisterous or predatory tankmates and acclimate wild-collected specimens carefully. Success depends mainly on three elements: an appropriate group, a secure cover and consistent water quality.