Home / Fishes / Tetras, piranhas and pacus / Marbled hatchetfish
No federal permit to keepMarbled hatchetfish
Carnegiella strigata
Fishes › Tetras, piranhas and pacus (Characiformes) › Gasteropelecidae (Freshwater hatchetfish)
The marbled hatchetfish (Carnegiella strigata) is a species of freshwater ray-finned fish belonging to the family Gasteropelecidae, the freshwater hatchetfishes.
Care at a glance
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 1.4 in / 3.49 cm).
- Water: Freshwater.
- Temperature: 75–82°F (range recorded for this species).
- pH: 5–8.
- Hardness: 5–19 dGH.
- Layout: An open-water swimmer: needs long, open swimming space with few obstacles.
- Diet: A predator: feed meaty foods sized to its mouth (frozen fish, shrimp, worms); it will eat tankmates that fit in its mouth. FishBase classes it as a carnivore.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Tank: a base of at least 30 × 12 in (roughly 18 US gallons); space needed is rated “modest tank”.
- Water: soft, acidic water, 68–82 °F, pH 4–7, 1–10 dGH.
- Behaviour: temperament peaceful; a shoaling fish best kept in a group of six or more; suited to a community tank.
- Difficulty: Easy (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Should ideally be kept in a heavily-planted set-up, preferably with a dark substrate and some patches of floating vegetation around which the fish will tend to congregate since they spend almost all of their time at or towards the surface.”
- Diet: “Primarily a predator feeding on terrestrial and aquatic invertebrates and other zooplankton taken at or near the water surface in nature.”
- Tankmates: “Very peaceful but does not make an ideal community fish due to its small size and rather timid nature.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Freshwater hatchetfish
Applies to most species in this group. Habitat: These South American surface fishes inhabit forest streams, tributaries and swamps with surface vegetation, with marbled hatchetfish associated particularly with blackwater and flooded forest. [fg245-sternicla, fg245-strigata]. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Fit a very tight cover: startled hatchetfish can jump out.
- For Carnegiella strigata, provide at least 75 × 30 cm (30 × 12 inches) of surface area.
- For Gasteropelecus sternicla, the cited minimum surface area is 120 × 30 cm (48 × 12 inches).
- Provide floating plant patches and planted cover around surface swimming space.
- Use gentle to moderate current; for C. strigata, maintain soft water within the cited 1–10 dGH and pH 4.0–7.0 ranges.
Climate & lighting
| Water | 68–82.4°F |
Diet
- Gut-loaded small fruit flies offered at the surface.
- Small live or frozen Daphnia.
- Artemia nauplii for small Carnegiella.
- Frozen bloodworms and suitably sized dry foods once accepted.
Social life
- Keep at least six G. sternicla; C. strigata does best with ten or more. Choose similarly peaceful companions that do not outcompete them for food.
Health watch
- Ammonia-related illness.
- Nutritional deficiencies.
- Introduced parasitic skin or gill infections.
Understanding the animal
About this animal
About this animal
The small deep-bodied fish, in the genera Carnegiella, is from the family Gasteropelecidae which includes both Gasteropelecus and Thoracocharax. This species is found in South America, and in rivers and streams all throughout Northern South America.
Quoted from the Wikipedia article “Marbled hatchetfish” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater, in rivers and streams. Lives in groups. Feeds on crustaceans and insects. |
| Water it lives in | Freshwater, 75–82 °F (24–28 °C), pH 5–8, hardness 5–19 dH. |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
| Behavior to plan for | Breeding: open water/substratum egg scatterers. |
What this means for care
- Keep water within its wild range, 75–82 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 90°F (up to 92°F in the hottest sampled areas) |
| Cool-season lows | about 70°F (down to 65°F in the coldest sampled areas) |
| Average temperature | 78–81°F across sampled records |
| Relative humidity | 80–85% on average (driest month about 77%) |
| Rainfall | about 2388 mm a year |
Measured at 352 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | The marbled hatchetfish (Carnegiella strigata) is a species of freshwater ray-finned fish belonging to the family Gasteropelecidae, the freshwater hatchetfishes. The small deep-bodied fish, in the genera Carnegiella, is from the family Gasteropelecidae which includes both Gasteropelecus and Thoracocharax. This species is found in South America, and in rivers and streams all throughout Northern South America. — Wikipedia (community-edited) |
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Appearance and size | The marbled hatchetfish has a maximum standard length of 3.5 cm. This fish has a golden silver coloured triangular body, which has a pale stripe running from the head to the tail. It has a dark brown marbled pattern over its body. — Wikipedia (community-edited) |
| Biology | Feeds on crustaceans and insects. The females have an abdomen which is larger than those of the males. The eggs fall on the bottom or on vegetation and these hatch after 36 hours incubation at 25°C. — FishBase |
| History and naming | The marbled hatchetfish was first formally described as Gasteropelecus strigatus in 1864 by the German-born British herpetologist and ichthyologist Albert Günther, with no type locality given. In 1909, Carl H. Eigenmann classified G. strigatus in the new monospecific genus Carnegiella. He also designated it as the type species of the new genus. — Wikipedia (community-edited) |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Adult length
Maximum recorded length. Measured as standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 30 × 12 in (about 18 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Against the mainstream: exceptional evolutionary stability of ZW sex chromosomes across the fish families Triportheidae and Gasteropelecidae (Teleostei: Characiformes) Yano CF et al., Chromosome research: an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology 2021
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. 170
Sources for this sheet
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Seriously Fish: Carnegiella strigata Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Gasteropelecus sternicla Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Merck Veterinary Manual: Disorders and Diseases of Fish Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
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Silver hatchetfish
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